import { useEffect, useMemo, useState } from "react"
import { Link } from "react-router-dom"
import {
  ChevronDown,
  ChevronRight,
  ClipboardList,
  HelpCircle,
  Image as ImageIcon,
  Languages,
  Lightbulb,
  Link2,
  Loader2,
  Mic,
  Plus,
  Search,
  Trash2,
  Video,
} from "lucide-react"
import { Card, CardContent, CardHeader, CardTitle } from "../../components/ui/card"
import { Button } from "../../components/ui/button"
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
} from "../../components/ui/dialog"
import { SpinnerIcon } from "../../components/ui/spinner-icon"
import {
  addQuestionToSet,
  createPractice,
  createQuestion,
  createCourse,
  createCourseCategory,
  createHumanLanguageLesson,
  deletePractice,
  deleteQuestion,
  deleteSubCourse,
  getHumanLanguageHierarchy,
  getQuestionById,
  getPracticeQuestions,
  getPracticeQuestionsByPractice,
  updatePractice,
  updateQuestion,
} from "../../api/courses.api"
import { Badge } from "../../components/ui/badge"
import type {
  CreateQuestionRequest,
  HumanLanguageCourseTree,
  HumanLanguageSubCategoryTree,
  LearningPathPractice,
  LearningPathVideo,
  QuestionDetail,
  QuestionSetQuestion,
} from "../../types/course.types"
import { cn } from "../../lib/utils"
import { toast } from "sonner"

const CEFR_LEVELS = ["A1", "A2", "A3", "B1", "B2", "B3", "C1", "C2", "C3"] as const
type SubModulePanelTab = "lessons" | "practices"

type SubModuleCardSelection = { lessonId: number | null; practiceId: number | null }

type PracticeQuestionsFetchState =
  | { status: "idle" }
  | { status: "loading"; startedAt: number }
  | { status: "ok"; questions: QuestionSetQuestion[]; totalCount: number }
  | { status: "error"; message: string }

type PracticeDialogState =
  | { open: false }
  | {
      open: true
      mode: "create" | "edit"
      subModuleId: number
      practiceId?: number
    }

type QuestionDialogState =
  | { open: false }
  | {
      open: true
      mode: "create" | "edit"
      practiceId: number
      questionId?: number
    }

function formatDurationSeconds(total: number): string {
  const s = Math.max(0, Math.floor(total))
  const m = Math.floor(s / 60)
  const r = s % 60
  return `${m}:${r.toString().padStart(2, "0")}`
}

function practiceStatusStyle(status: string): string {
  const u = status.toUpperCase()
  if (u === "PUBLISHED") return "bg-green-50 text-green-700 ring-1 ring-inset ring-green-200"
  if (u === "DRAFT") return "bg-grayScale-50 text-grayScale-600 ring-1 ring-inset ring-grayScale-200"
  if (u === "ARCHIVED") return "bg-amber-50 text-amber-700 ring-1 ring-inset ring-amber-200"
  return "bg-grayScale-50 text-grayScale-600 ring-1 ring-inset ring-grayScale-200"
}

function questionTypeBadgeClass(questionType: string): string {
  const t = questionType.toUpperCase().replace(/\s+/g, "_")
  if (t === "MCQ" || t.includes("MULTIPLE")) {
    return "border-transparent bg-violet-50 text-violet-800 ring-1 ring-inset ring-violet-200"
  }
  if (t === "TRUE_FALSE" || t.includes("TRUE")) {
    return "border-transparent bg-sky-50 text-sky-800 ring-1 ring-inset ring-sky-200"
  }
  if (t === "SHORT" || t === "SHORT_ANSWER") {
    return "border-transparent bg-emerald-50 text-emerald-800 ring-1 ring-inset ring-emerald-200"
  }
  if (t === "AUDIO") {
    return "border-transparent bg-orange-50 text-orange-800 ring-1 ring-inset ring-orange-200"
  }
  return "border-transparent bg-grayScale-100 text-grayScale-700 ring-1 ring-inset ring-grayScale-200"
}

function formatQuestionTypeLabel(raw: string): string {
  return String(raw ?? "—")
    .replace(/_/g, " ")
    .trim()
    .toLowerCase()
    .replace(/\b\w/g, (c) => c.toUpperCase())
}

const URL_REGEX = /(https?:\/\/[^\s<>"')\]]+)/gi

function extractUrls(text: string): string[] {
  const out = text.match(URL_REGEX) ?? []
  return [...new Set(out)]
}

function normalizeUrl(raw: string): string {
  return raw.trim().replace(/[),.;!?]+$/, "")
}

function getVimeoEmbedUrl(url: string): string | null {
  const m = url.match(/vimeo\.com\/(?:video\/)?(\d+)/i)
  return m?.[1] ? `https://player.vimeo.com/video/${m[1]}` : null
}

function detectMediaType(url: string, hint?: "audio" | "video" | "image"): "audio" | "video" | "image" | "unknown" {
  if (hint) return hint
  const vimeo = getVimeoEmbedUrl(url)
  if (vimeo) return "video"
  const clean = url.split("?")[0].toLowerCase()
  if (/\.(png|jpe?g|gif|webp|svg|avif|bmp)$/.test(clean)) return "image"
  if (/\.(mp4|webm|ogg|mov|m4v)$/.test(clean)) return "video"
  if (/\.(mp3|wav|m4a|aac|ogg|webm)$/.test(clean)) return "audio"
  return "unknown"
}

function withTimeout<T>(promise: Promise<T>, ms: number): Promise<T> {
  return new Promise((resolve, reject) => {
    const timer = setTimeout(() => reject(new Error("Request timed out")), ms)
    promise
      .then((value) => {
        clearTimeout(timer)
        resolve(value)
      })
      .catch((err) => {
        clearTimeout(timer)
        reject(err)
      })
  })
}
type CefrLevel = (typeof CEFR_LEVELS)[number]

type PendingRemove = {
  ids: number[]
  key: string
  successMessage: string
  title: string
  description: string
}

export function HumanLanguagePage() {
  const [loading, setLoading] = useState(false)
  const [categoryId, setCategoryId] = useState<number | null>(null)
  const [subCategories, setSubCategories] = useState<HumanLanguageSubCategoryTree[]>([])
  const [selectedSubCategoryId, setSelectedSubCategoryId] = useState<number | "ALL">("ALL")
  const [selectedCourseId, setSelectedCourseId] = useState<number | "ALL">("ALL")
  const [selectedLevel, setSelectedLevel] = useState<CefrLevel | "ALL">("ALL")
  const [collapsedLevels, setCollapsedLevels] = useState<string[]>([])
  const [creatingKey, setCreatingKey] = useState<string | null>(null)
  const [quickSubCategoryName, setQuickSubCategoryName] = useState("")
  const [quickCourseName, setQuickCourseName] = useState("")
  const [quickSearch, setQuickSearch] = useState("")
  const [quickCreating, setQuickCreating] = useState(false)
  const [deletingKey, setDeletingKey] = useState<string | null>(null)
  /** Course IDs whose path body is collapsed (headers stay visible). */
  const [collapsedPathIds, setCollapsedPathIds] = useState<number[]>([])
  const [pendingRemove, setPendingRemove] = useState<PendingRemove | null>(null)
  /** Per sub-module panel tab (lessons vs practices). */
  const [subModulePanelTab, setSubModulePanelTab] = useState<Record<string, SubModulePanelTab>>({})
  /** Selected lesson / practice card per sub-module (for inline detail panel). */
  const [subModuleCardSelection, setSubModuleCardSelection] = useState<Record<string, SubModuleCardSelection>>({})
  const [practiceQuestionsState, setPracticeQuestionsState] = useState<Record<number, PracticeQuestionsFetchState>>({})
  const [practiceDialog, setPracticeDialog] = useState<PracticeDialogState>({ open: false })
  const [questionDialog, setQuestionDialog] = useState<QuestionDialogState>({ open: false })
  const [practiceForm, setPracticeForm] = useState({ title: "", description: "", persona: "" })
  const [questionForm, setQuestionForm] = useState({
    questionText: "",
    questionType: "MCQ" as "MCQ" | "TRUE_FALSE" | "SHORT",
    difficulty: "EASY",
    points: 1,
    tips: "",
    explanation: "",
    imageUrl: "",
    voicePrompt: "",
    sampleAnswerVoicePrompt: "",
    audioCorrectAnswerText: "",
    optionA: "",
    optionB: "",
    optionC: "",
    optionD: "",
    correctOption: "A" as "A" | "B" | "C" | "D",
    shortAnswer: "",
  })
  const [questionDetailById, setQuestionDetailById] = useState<Record<number, QuestionDetail>>({})
  const [practiceTargetDelete, setPracticeTargetDelete] = useState<{ id: number; title: string } | null>(null)
  const [questionTargetDelete, setQuestionTargetDelete] = useState<{ id: number; practiceId: number; text: string } | null>(null)
  const [savingPractice, setSavingPractice] = useState(false)
  const [savingQuestion, setSavingQuestion] = useState(false)
  const [deletingPractice, setDeletingPractice] = useState(false)
  const [deletingQuestion, setDeletingQuestion] = useState(false)
  /** While fetching full question detail before opening the edit dialog (avoids empty form flash). */
  const [loadingQuestionEditId, setLoadingQuestionEditId] = useState<number | null>(null)
  /** Show inline field errors only after an explicit save attempt (avoids noisy empty-state on open). */
  const [practiceSubmitAttempted, setPracticeSubmitAttempted] = useState(false)
  const [questionSubmitAttempted, setQuestionSubmitAttempted] = useState(false)
  const [practiceFormTouched, setPracticeFormTouched] = useState(false)
  const [questionFormTouched, setQuestionFormTouched] = useState(false)

  const renderMediaPreview = (
    urlRaw: string,
    hint?: "audio" | "video" | "image",
    className = "mt-2",
    label?: string,
  ) => {
    const url = normalizeUrl(urlRaw)
    if (!url) return null
    const mediaType = detectMediaType(url, hint)
    const vimeoEmbed = getVimeoEmbedUrl(url)
    const showPlayer =
      mediaType === "image" || mediaType === "video" || mediaType === "audio"
    return (
      <div
        className={cn(
          "rounded-lg border border-grayScale-100 bg-white p-3 shadow-sm",
          !showPlayer && "border-dashed bg-grayScale-50/50",
          className,
        )}
      >
        {label ? (
          <p className="mb-2 flex items-center gap-1.5 text-[10px] font-semibold uppercase tracking-wider text-grayScale-500">
            {hint === "image" ? (
              <ImageIcon className="h-3 w-3" aria-hidden />
            ) : hint === "audio" ? (
              <Mic className="h-3 w-3" aria-hidden />
            ) : hint === "video" ? (
              <Video className="h-3 w-3" aria-hidden />
            ) : (
              <Link2 className="h-3 w-3" aria-hidden />
            )}
            {label}
          </p>
        ) : null}
        {mediaType === "image" ? (
          <img
            src={url}
            alt=""
            className="max-h-52 w-full rounded-md border border-grayScale-200/90 bg-grayScale-50 object-contain"
          />
        ) : mediaType === "video" ? (
          vimeoEmbed ? (
            <iframe
              src={vimeoEmbed}
              title="Vimeo preview"
              className="aspect-video h-auto min-h-[200px] w-full rounded-md border border-grayScale-200/90 bg-black/5"
              allow="autoplay; fullscreen; picture-in-picture"
              allowFullScreen
            />
          ) : (
            <video
              controls
              className="max-h-60 w-full rounded-md border border-grayScale-200/90 bg-black/5"
              src={url}
            />
          )
        ) : mediaType === "audio" ? (
          <audio controls className="h-9 w-full" src={url} />
        ) : (
          <p className="text-xs text-grayScale-500">Preview not available for this URL type.</p>
        )}
        <a
          href={url}
          target="_blank"
          rel="noopener noreferrer"
          className="mt-2 inline-flex items-center gap-1 text-xs font-medium text-brand-600 hover:text-brand-700 hover:underline"
        >
          <Link2 className="h-3 w-3 shrink-0" aria-hidden />
          Open link
        </a>
      </div>
    )
  }

  const loadHierarchy = async () => {
    setLoading(true)
    try {
      const res = await getHumanLanguageHierarchy()
      const data = res.data?.data
      setCategoryId(data?.category_id ?? null)
      setSubCategories(data?.sub_categories ?? [])
    } finally {
      setLoading(false)
    }
  }

  useEffect(() => {
    const run = async () => {
      setLoading(true)
      try {
        await loadHierarchy()
      } finally {
        setLoading(false)
      }
    }
    run().catch(() => undefined)
  }, [])

  const filteredSubCategories = useMemo(
    () =>
      selectedSubCategoryId === "ALL"
        ? subCategories
        : subCategories.filter((s) => s.sub_category_id === selectedSubCategoryId),
    [subCategories, selectedSubCategoryId],
  )

  const availableCourses = useMemo(() => {
    return filteredSubCategories.flatMap((s) => s.courses)
  }, [filteredSubCategories])

  const selectedCourses = useMemo(
    () =>
      selectedCourseId === "ALL"
        ? availableCourses
        : availableCourses.filter((c) => c.course_id === selectedCourseId),
    [availableCourses, selectedCourseId],
  )

  /** A1 always; A2–C3 only after that level has at least one module (incremental UI). */
  const visibleCefrLevels = useMemo(() => {
    if (availableCourses.length === 0) return [] as CefrLevel[]
    const out: CefrLevel[] = []
    for (const level of CEFR_LEVELS) {
      if (level === "A1") {
        out.push(level)
        continue
      }
      const hasContent = selectedCourses.some((c) => {
        const node = c.levels.find((item) => item.level.toUpperCase() === level)
        return node !== undefined && (node.modules?.length ?? 0) > 0
      })
      if (hasContent) out.push(level)
    }
    return out
  }, [availableCourses.length, selectedCourses])

  useEffect(() => {
    if (selectedLevel === "ALL") return
    if (!visibleCefrLevels.includes(selectedLevel)) {
      setSelectedLevel("ALL")
    }
  }, [selectedLevel, visibleCefrLevels])

  const toggleLevel = (levelKey: string) => {
    setCollapsedLevels((prev) => (prev.includes(levelKey) ? prev.filter((l) => l !== levelKey) : [...prev, levelKey]))
  }

  const togglePathCollapsed = (courseId: number) => {
    setCollapsedPathIds((prev) =>
      prev.includes(courseId) ? prev.filter((id) => id !== courseId) : [...prev, courseId],
    )
  }

  const levelsWithContentForCourse = (course: HumanLanguageCourseTree) =>
    course.levels.filter((l) => (l.modules?.length ?? 0) > 0).map((l) => l.level.toUpperCase())

  const parseModuleNumber = (title: string): number | null => {
    const match = title.match(/module-(\d+)/i)
    if (!match) return null
    const value = Number(match[1])
    return Number.isFinite(value) ? value : null
  }

  const parseSubModuleNumber = (title: string): { module: number; sub: number } | null => {
    const match = title.match(/(?:sub-)?module-(\d+)\.(\d+)/i)
    if (!match) return null
    const module = Number(match[1])
    const sub = Number(match[2])
    if (!Number.isFinite(module) || !Number.isFinite(sub)) return null
    return { module, sub }
  }

  const handleCreateModule = async (courseId: number, level: string, modules: { title: string }[]) => {
    const key = `module-${courseId}-${level}`
    setCreatingKey(key)
    try {
      const maxExisting = modules
        .map((m) => parseModuleNumber(m.title))
        .filter((v): v is number => v !== null)
        .reduce((acc, n) => Math.max(acc, n), 0)
      const next = maxExisting + 1
      const title = `Module-${next}`
      await createHumanLanguageLesson({
        course_id: courseId,
        cefr_level: level,
        title,
        description: `${level} ${title}`,
      })
      toast.success(`${title} created`)
      await loadHierarchy()
    } catch (error) {
      console.error("Failed to create module:", error)
      toast.error("Failed to create module")
    } finally {
      setCreatingKey(null)
    }
  }

  const handleCreateSubModule = async (
    courseId: number,
    level: string,
    moduleTitle: string,
    existingSubModules: { title: string }[],
  ) => {
    const moduleNo = parseModuleNumber(moduleTitle)
    if (!moduleNo) {
      toast.error("Cannot derive module number from title")
      return
    }
    const key = `submodule-${courseId}-${level}-${moduleNo}`
    setCreatingKey(key)
    try {
      const maxExisting = existingSubModules
        .map((s) => parseSubModuleNumber(s.title))
        .filter((v): v is { module: number; sub: number } => v !== null && v.module === moduleNo)
        .reduce((acc, item) => Math.max(acc, item.sub), 0)
      const next = maxExisting + 1
      const title = `Module-${moduleNo}.${next}`
      await createHumanLanguageLesson({
        course_id: courseId,
        cefr_level: level,
        title,
        description: `${level} ${title}`,
      })
      toast.success(`Sub-module ${moduleNo}.${next} created`)
      await loadHierarchy()
    } catch (error) {
      console.error("Failed to create sub-module:", error)
      toast.error("Failed to create sub-module")
    } finally {
      setCreatingKey(null)
    }
  }

  const requestRemove = (payload: PendingRemove) => {
    if (payload.ids.length === 0) return
    setPendingRemove(payload)
  }

  const executePendingRemove = async () => {
    if (!pendingRemove) return
    const { ids, key, successMessage } = pendingRemove
    setPendingRemove(null)
    setDeletingKey(key)
    try {
      for (const id of ids) {
        await deleteSubCourse(id)
      }
      toast.success(successMessage)
      await loadHierarchy()
    } catch (error) {
      console.error("Failed to delete item(s):", error)
      toast.error("Failed to delete item(s)")
    } finally {
      setDeletingKey(null)
    }
  }

  const handleCreateNextLevelForCourse = async (courseId: number) => {
    const course = availableCourses.find((c) => c.course_id === courseId)
    if (!course) {
      toast.error("Course not found")
      return
    }
    const existing = new Set(levelsWithContentForCourse(course))
    const next = CEFR_LEVELS.find((level) => !existing.has(level))
    if (!next) {
      toast.error("All CEFR levels (A1–C3) already have content for this path")
      return
    }
    const key = `next-level-${courseId}-${next}`
    setCreatingKey(key)
    try {
      await createHumanLanguageLesson({
        course_id: courseId,
        cefr_level: next,
        title: "Module-1",
        description: `${next} Module-1`,
      })
      toast.success(`${next} created with Module-1`)
      await loadHierarchy()
    } catch (error) {
      console.error("Failed to create next level:", error)
      toast.error("Failed to create next level")
    } finally {
      setCreatingKey(null)
    }
  }

  const handleQuickCreatePath = async () => {
    if (!quickSubCategoryName.trim() || !quickCourseName.trim()) {
      toast.error("Subcategory and course names are required")
      return
    }
    setQuickCreating(true)
    try {
      let effectiveCategoryId = categoryId
      if (!effectiveCategoryId) {
        const createdCategory = await createCourseCategory({ name: "Human Language" })
        effectiveCategoryId = createdCategory.data?.data?.id ?? null
        setCategoryId(effectiveCategoryId)
      }
      if (!effectiveCategoryId) {
        throw new Error("Missing human language category id")
      }
      const title = `${quickSubCategoryName.trim()} - ${quickCourseName.trim()}`
      await createCourse({
        category_id: effectiveCategoryId,
        title,
        description: `${quickSubCategoryName.trim()} / ${quickCourseName.trim()}`,
      })
      toast.success("Subcategory/course path created")
      setQuickSubCategoryName("")
      setQuickCourseName("")
      await loadHierarchy()
    } catch (error) {
      console.error("Failed to quick-create language path:", error)
      toast.error("Failed to create subcategory/course path")
    } finally {
      setQuickCreating(false)
    }
  }

  const loadPracticeQuestionsIfNeeded = async (practiceId: number, forceRefresh = false) => {
    let skipFetch = false
    setPracticeQuestionsState((prev) => {
      const ex = prev[practiceId]
      if (!forceRefresh && ex?.status === "ok") {
        skipFetch = true
        return prev
      }
      if (!forceRefresh && ex?.status === "loading" && Date.now() - ex.startedAt < 15000) {
        skipFetch = true
        return prev
      }
      return { ...prev, [practiceId]: { status: "loading", startedAt: Date.now() } }
    })
    if (skipFetch) return
    try {
      let questions: QuestionSetQuestion[] = []
      let totalCount = 0
      try {
        const res = await withTimeout(getPracticeQuestionsByPractice(practiceId, { limit: 200, offset: 0 }), 12000)
        const payload = res.data?.data
        questions = payload?.questions ?? []
        totalCount = payload?.total_count ?? questions.length
      } catch {
        // Fallback endpoint for environments where /practices/:id/questions can hang.
        const fallback = await withTimeout(getPracticeQuestions(practiceId), 12000)
        questions = fallback.data?.data ?? []
        totalCount = questions.length
      }
      setPracticeQuestionsState((prev) => ({
        ...prev,
        [practiceId]: { status: "ok", questions, totalCount },
      }))
    } catch (error) {
      console.error("Failed to load practice questions:", error)
      setPracticeQuestionsState((prev) => ({
        ...prev,
        [practiceId]: { status: "error", message: "Could not load questions" },
      }))
    }
  }

  const getSubModuleSelection = (smKey: string): SubModuleCardSelection =>
    subModuleCardSelection[smKey] ?? { lessonId: null, practiceId: null }

  const resetPracticeForm = () => setPracticeForm({ title: "", description: "", persona: "" })
  const resetQuestionForm = () =>
    setQuestionForm({
      questionText: "",
      questionType: "MCQ",
      difficulty: "EASY",
      points: 1,
      tips: "",
      explanation: "",
      imageUrl: "",
      voicePrompt: "",
      sampleAnswerVoicePrompt: "",
      audioCorrectAnswerText: "",
      optionA: "",
      optionB: "",
      optionC: "",
      optionD: "",
      correctOption: "A",
      shortAnswer: "",
    })

  const openCreatePracticeDialog = (subModuleId: number) => {
    setPracticeSubmitAttempted(false)
    setPracticeFormTouched(false)
    resetPracticeForm()
    setPracticeDialog({ open: true, mode: "create", subModuleId })
  }

  const openEditPracticeDialog = (subModuleId: number, p: LearningPathPractice) => {
    setPracticeSubmitAttempted(false)
    setPracticeFormTouched(false)
    setPracticeForm({ title: p.title ?? "", description: "", persona: "" })
    setPracticeDialog({ open: true, mode: "edit", subModuleId, practiceId: p.id })
  }

  const practiceFieldErrors = useMemo(() => {
    const title = practiceForm.title.trim()
    return {
      title: title ? undefined : "Title is required.",
    }
  }, [practiceForm.title])

  const practiceCanSave = !practiceFieldErrors.title

  const handleSavePractice = async () => {
    if (!practiceDialog.open) return
    if (!practiceCanSave) {
      setPracticeSubmitAttempted(true)
      return
    }
    setSavingPractice(true)
    try {
      if (practiceDialog.mode === "create") {
        await createPractice({
          sub_course_id: practiceDialog.subModuleId,
          title: practiceForm.title.trim(),
          description: practiceForm.description.trim(),
          persona: practiceForm.persona.trim() || undefined,
        })
        toast.success("Practice created")
      } else if (practiceDialog.practiceId) {
        await updatePractice(practiceDialog.practiceId, {
          title: practiceForm.title.trim(),
          description: practiceForm.description.trim(),
          persona: practiceForm.persona.trim() || undefined,
        })
        toast.success("Practice updated")
      }
      setPracticeDialog({ open: false })
      setPracticeSubmitAttempted(false)
      setPracticeFormTouched(false)
      resetPracticeForm()
      await loadHierarchy()
    } catch (error) {
      console.error("Failed to save practice:", error)
      toast.error("Failed to save practice")
    } finally {
      setSavingPractice(false)
    }
  }

  const openCreateQuestionDialog = (practiceId: number) => {
    setQuestionSubmitAttempted(false)
    setQuestionFormTouched(false)
    resetQuestionForm()
    setQuestionDialog({ open: true, mode: "create", practiceId })
  }

  const openEditQuestionDialog = async (practiceId: number, question: QuestionSetQuestion) => {
    setQuestionSubmitAttempted(false)
    setQuestionFormTouched(false)
    const qid = question.question_id ?? question.id
    resetQuestionForm()
    setLoadingQuestionEditId(qid)
    try {
      const detail = questionDetailById[qid] ?? (await getQuestionById(qid)).data?.data
      if (!detail) {
        toast.error("Could not load question details")
        return
      }
      setQuestionDetailById((prev) => ({ ...prev, [qid]: detail }))
      const options = (detail.options ?? []).slice().sort((a, b) => a.option_order - b.option_order)
      const correctOpt = options.find((o) => o.is_correct)
      const correctOrder = correctOpt?.option_order ?? 1
      let correctOption: "A" | "B" | "C" | "D" = "A"
      if (detail.question_type === "TRUE_FALSE") {
        const t = (correctOpt?.option_text ?? "").trim().toLowerCase()
        if (t === "false" || correctOrder === 2) correctOption = "B"
        else correctOption = "A"
      } else {
        correctOption =
          (["A", "B", "C", "D"][Math.min(Math.max(correctOrder - 1, 0), 3)] as "A" | "B" | "C" | "D") ?? "A"
      }
      const shortAnswer =
        Array.isArray(detail.short_answers) && detail.short_answers.length > 0
          ? typeof detail.short_answers[0] === "string"
            ? detail.short_answers[0]
            : detail.short_answers[0]?.acceptable_answer ?? ""
          : ""
      const qt = detail.question_type
      let questionType: "MCQ" | "TRUE_FALSE" | "SHORT" = "MCQ"
      if (qt === "TRUE_FALSE") questionType = "TRUE_FALSE"
      else if (qt === "SHORT" || qt === "SHORT_ANSWER" || qt === "AUDIO") questionType = "SHORT"
      const difficultyRaw = detail.difficulty_level
      const difficulty =
        difficultyRaw === "EASY" || difficultyRaw === "MEDIUM" || difficultyRaw === "HARD" ? difficultyRaw : "EASY"
      setQuestionForm({
        questionText: detail.question_text ?? "",
        questionType,
        difficulty,
        points: detail.points && detail.points > 0 ? detail.points : 1,
        tips: detail.tips ?? "",
        explanation: detail.explanation ?? "",
        imageUrl: detail.image_url ?? "",
        voicePrompt: detail.voice_prompt ?? "",
        sampleAnswerVoicePrompt: detail.sample_answer_voice_prompt ?? "",
        audioCorrectAnswerText: detail.audio_correct_answer_text ?? "",
        optionA: options[0]?.option_text ?? "",
        optionB: options[1]?.option_text ?? "",
        optionC: options[2]?.option_text ?? "",
        optionD: options[3]?.option_text ?? "",
        correctOption,
        shortAnswer,
      })
      // Open only after the same form shape as create is fully populated (no empty-state flash).
      setQuestionDialog({ open: true, mode: "edit", practiceId, questionId: qid })
    } catch (error) {
      console.error("Failed to load question detail:", error)
      toast.error("Could not load question details")
    } finally {
      setLoadingQuestionEditId(null)
    }
  }

  const buildQuestionPayload = (): CreateQuestionRequest => {
    const payload: CreateQuestionRequest = {
      question_text: questionForm.questionText.trim(),
      question_type: questionForm.questionType,
      difficulty_level: questionForm.difficulty,
      points: Number(questionForm.points) || 1,
      tips: questionForm.tips.trim() || undefined,
      explanation: questionForm.explanation.trim() || undefined,
      image_url: questionForm.imageUrl.trim() || undefined,
      voice_prompt: questionForm.voicePrompt.trim() || undefined,
      sample_answer_voice_prompt: questionForm.sampleAnswerVoicePrompt.trim() || undefined,
      audio_correct_answer_text: questionForm.audioCorrectAnswerText.trim() || undefined,
      status: "PUBLISHED",
    }
    if (questionForm.questionType === "SHORT") {
      payload.short_answers = questionForm.shortAnswer.trim()
        ? [
            { acceptable_answer: questionForm.shortAnswer.trim(), match_type: "EXACT" },
            { acceptable_answer: questionForm.shortAnswer.trim(), match_type: "CASE_INSENSITIVE" },
          ]
        : undefined
      return payload
    }
    const options =
      questionForm.questionType === "TRUE_FALSE"
        ? [
            { option_order: 1, option_text: "True", is_correct: questionForm.correctOption === "A" },
            { option_order: 2, option_text: "False", is_correct: questionForm.correctOption === "B" },
          ]
        : [
            { option_order: 1, option_text: questionForm.optionA.trim(), is_correct: questionForm.correctOption === "A" },
            { option_order: 2, option_text: questionForm.optionB.trim(), is_correct: questionForm.correctOption === "B" },
            { option_order: 3, option_text: questionForm.optionC.trim(), is_correct: questionForm.correctOption === "C" },
            { option_order: 4, option_text: questionForm.optionD.trim(), is_correct: questionForm.correctOption === "D" },
          ].filter((o) => o.option_text)
    payload.options = options
    return payload
  }

  const questionFieldErrors = useMemo(() => {
    const errors: {
      questionText?: string
      points?: string
      shortAnswer?: string
      options?: string
      correctOption?: string
    } = {}
    if (!questionForm.questionText.trim()) errors.questionText = "Question text is required."
    const pts = Number(questionForm.points)
    if (!Number.isFinite(pts) || pts < 1) errors.points = "Enter a valid number (minimum 1)."
    if (questionForm.questionType === "SHORT" && !questionForm.shortAnswer.trim()) {
      errors.shortAnswer = "Expected answer is required for short-answer questions."
    }
    if (questionForm.questionType === "MCQ") {
      const opts = {
        A: questionForm.optionA.trim(),
        B: questionForm.optionB.trim(),
        C: questionForm.optionC.trim(),
        D: questionForm.optionD.trim(),
      }
      const filled = Object.values(opts).filter(Boolean).length
      if (filled < 2) errors.options = "Enter at least two non-empty options."
      const correct = questionForm.correctOption
      if (opts[correct] === "") errors.correctOption = "The marked correct option must include text."
    }
    return errors
  }, [questionForm])

  const questionCanSave = Object.keys(questionFieldErrors).length === 0

  const handleSaveQuestion = async () => {
    if (!questionDialog.open) return
    if (!questionCanSave) {
      setQuestionSubmitAttempted(true)
      return
    }
    setSavingQuestion(true)
    try {
      const payload = buildQuestionPayload()
      if (questionDialog.mode === "create") {
        const created = await createQuestion(payload)
        const questionId = created.data?.data?.id
        if (!questionId) throw new Error("Missing created question id")
        await addQuestionToSet(questionDialog.practiceId, { question_id: questionId })
        toast.success("Question created")
      } else if (questionDialog.questionId) {
        await updateQuestion(questionDialog.questionId, payload)
        toast.success("Question updated")
      }
      setQuestionDialog({ open: false })
      setQuestionSubmitAttempted(false)
      setQuestionFormTouched(false)
      resetQuestionForm()
      await Promise.all([
        loadPracticeQuestionsIfNeeded(questionDialog.practiceId, true),
        loadHierarchy(),
      ])
    } catch (error) {
      console.error("Failed to save question:", error)
      toast.error("Failed to save question")
    } finally {
      setSavingQuestion(false)
    }
  }

  const handleDeletePracticeConfirmed = async () => {
    if (!practiceTargetDelete) return
    setDeletingPractice(true)
    try {
      await deletePractice(practiceTargetDelete.id)
      toast.success("Practice deleted")
      setPracticeTargetDelete(null)
      await loadHierarchy()
    } catch (error) {
      console.error("Failed to delete practice:", error)
      toast.error("Failed to delete practice")
    } finally {
      setDeletingPractice(false)
    }
  }

  const handleDeleteQuestionConfirmed = async () => {
    if (!questionTargetDelete) return
    setDeletingQuestion(true)
    try {
      await deleteQuestion(questionTargetDelete.id)
      toast.success("Question deleted")
      await Promise.all([
        loadPracticeQuestionsIfNeeded(questionTargetDelete.practiceId, true),
        loadHierarchy(),
      ])
      setQuestionTargetDelete(null)
    } catch (error) {
      console.error("Failed to delete question:", error)
      toast.error("Failed to delete question")
    } finally {
      setDeletingQuestion(false)
    }
  }

  const toggleLessonCard = (smKey: string, lessonId: number) => {
    setSubModuleCardSelection((prev) => {
      const cur = prev[smKey] ?? { lessonId: null, practiceId: null }
      const nextLessonId = cur.lessonId === lessonId ? null : lessonId
      return { ...prev, [smKey]: { ...cur, lessonId: nextLessonId } }
    })
  }

  const togglePracticeCard = (smKey: string, practiceId: number) => {
    const currentPracticeId = subModuleCardSelection[smKey]?.practiceId ?? null
    const nextPracticeId = currentPracticeId === practiceId ? null : practiceId
    setSubModuleCardSelection((prev) => {
      const cur = prev[smKey] ?? { lessonId: null, practiceId: null }
      return { ...prev, [smKey]: { ...cur, practiceId: nextPracticeId } }
    })
    if (nextPracticeId !== null) void loadPracticeQuestionsIfNeeded(nextPracticeId)
  }

  return (
    <div className="space-y-6">
      <div className="rounded-2xl border border-grayScale-200 bg-gradient-to-r from-white to-brand-50/30 p-5 shadow-sm">
        <div className="flex items-start gap-3">
          <div className="rounded-xl bg-brand-100 p-2 text-brand-700">
            <Languages className="h-5 w-5" />
          </div>
          <div>
            <h2 className="text-lg font-semibold text-grayScale-900">Human Language Content</h2>
            <p className="mt-1 text-sm text-grayScale-500">
              Dedicated management view for CEFR levels A1 to C3 with no sub-levels.
            </p>
          </div>
        </div>
      </div>

      <Card className="border-grayScale-200/80 shadow-sm">
        <CardHeader>
          <CardTitle className="text-base">Filters</CardTitle>
        </CardHeader>
        <CardContent className="grid grid-cols-1 gap-4 md:grid-cols-3">
          <div className="space-y-1.5">
            <label className="text-xs font-medium uppercase tracking-wide text-grayScale-500">Subcategory</label>
            <select
              className="h-10 w-full rounded-md border border-grayScale-200 bg-white px-3 text-sm"
              value={selectedSubCategoryId}
              onChange={(e) =>
                setSelectedSubCategoryId(e.target.value === "ALL" ? "ALL" : Number(e.target.value))
              }
            >
              <option value="ALL">All subcategories</option>
              {subCategories.map((subCategory) => (
                <option key={subCategory.sub_category_id} value={subCategory.sub_category_id}>
                  {subCategory.sub_category_name}
                </option>
              ))}
            </select>
          </div>
          <div className="space-y-1.5">
            <label className="text-xs font-medium uppercase tracking-wide text-grayScale-500">Course</label>
            <select
              className="h-10 w-full rounded-md border border-grayScale-200 bg-white px-3 text-sm"
              value={selectedCourseId}
              onChange={(e) =>
                setSelectedCourseId(e.target.value === "ALL" ? "ALL" : Number(e.target.value))
              }
            >
              <option value="ALL">All courses</option>
              {availableCourses.map((course) => (
                <option key={course.course_id} value={course.course_id}>
                  {course.course_name}
                </option>
              ))}
            </select>
          </div>
          <div className="space-y-1.5">
            <label className="text-xs font-medium uppercase tracking-wide text-grayScale-500">Fetch lessons by level</label>
            <select
              className="h-10 w-full rounded-md border border-grayScale-200 bg-white px-3 text-sm"
              value={selectedLevel}
              onChange={(e) => setSelectedLevel(e.target.value as CefrLevel | "ALL")}
            >
              <option value="ALL">ALL LEVELS</option>
              {visibleCefrLevels.map((level) => (
                <option key={level} value={level}>
                  {level}
                </option>
              ))}
            </select>
          </div>
        </CardContent>
      </Card>

      {loading ? (
        <div className="flex items-center gap-2 py-8 text-sm text-grayScale-500">
          <SpinnerIcon className="h-4 w-4" />
          Loading human language lessons...
        </div>
      ) : (
        <div className="space-y-3">
          {availableCourses.length === 0 ? (
            <Card className="overflow-hidden border-grayScale-200/80">
              <div className="flex items-center justify-between border-b border-grayScale-100 bg-white px-5 py-4">
                <h3 className="text-lg font-semibold text-grayScale-800">Sub-category Management</h3>
                <div className="relative w-full max-w-sm">
                  <Search className="pointer-events-none absolute left-3 top-1/2 h-4 w-4 -translate-y-1/2 text-grayScale-400" />
                  <input
                    className="h-11 w-full rounded-xl border border-grayScale-200 bg-white pl-9 pr-3 text-sm"
                    placeholder="Search sub-categories..."
                    value={quickSearch}
                    onChange={(e) => setQuickSearch(e.target.value)}
                  />
                </div>
              </div>
              <CardContent className="p-5">
                <div className="rounded-2xl border border-dashed border-grayScale-300 bg-grayScale-50/20 px-6 py-10 text-center">
                  <div className="mx-auto mb-4 grid h-12 w-12 place-items-center rounded-full bg-brand-100 text-brand-700">
                    <Languages className="h-6 w-6" />
                  </div>
                  <h4 className="text-xl font-semibold text-grayScale-800">No sub-categories yet</h4>
                  <p className="mt-2 text-sm text-grayScale-500">
                    Create your first human-language path. Level listing will appear automatically after creation.
                  </p>
                  <div className="mx-auto mt-5 grid max-w-3xl grid-cols-1 gap-2 md:grid-cols-3">
                    <input
                      className="h-10 rounded-md border border-grayScale-200 bg-white px-3 text-sm"
                      placeholder="Subcategory (e.g., English)"
                      value={quickSubCategoryName}
                      onChange={(e) => setQuickSubCategoryName(e.target.value)}
                    />
                    <input
                      className="h-10 rounded-md border border-grayScale-200 bg-white px-3 text-sm"
                      placeholder="Course (e.g., Speaking)"
                      value={quickCourseName}
                      onChange={(e) => setQuickCourseName(e.target.value)}
                    />
                    <Button onClick={handleQuickCreatePath} disabled={quickCreating}>
                      {quickCreating ? "Creating..." : "Add your first sub-category"}
                    </Button>
                  </div>
                </div>
              </CardContent>
            </Card>
          ) : null}

          {availableCourses.length > 0
            ? selectedCourses.map((course: HumanLanguageCourseTree) => {
                const courseLevels = CEFR_LEVELS.filter((level) => {
                  if (level === "A1") return true
                  const node = course.levels.find((item) => item.level.toUpperCase() === level)
                  return (node?.modules?.length ?? 0) > 0
                }).filter((level) => selectedLevel === "ALL" || selectedLevel === level)

                const pathCollapsed = collapsedPathIds.includes(course.course_id)
                const levelsDone = levelsWithContentForCourse(course)
                const nextCefrForPath = CEFR_LEVELS.find((l) => !levelsDone.includes(l))
                const pathNextLevelLoading = creatingKey?.startsWith(`next-level-${course.course_id}-`) ?? false
                const pathLevelsFull = levelsDone.length >= CEFR_LEVELS.length

                return (
                  <Card key={course.course_id} className="overflow-hidden border-grayScale-200/80 shadow-sm">
                    <div className="flex flex-wrap items-center justify-between gap-3 border-b border-grayScale-100 bg-white px-4 py-3">
                      <button
                        type="button"
                        className="flex min-w-0 flex-1 items-center gap-2 text-left"
                        onClick={() => togglePathCollapsed(course.course_id)}
                      >
                        {pathCollapsed ? (
                          <ChevronRight className="h-5 w-5 shrink-0 text-grayScale-500" aria-hidden />
                        ) : (
                          <ChevronDown className="h-5 w-5 shrink-0 text-grayScale-500" aria-hidden />
                        )}
                        <span className="text-base font-semibold text-brand-700">{course.course_name}</span>
                      </button>
                      <div className="flex flex-wrap items-center justify-end gap-2">
                        <Button
                          type="button"
                          size="sm"
                          className="shrink-0"
                          title={
                            pathLevelsFull
                              ? "All CEFR levels already have content for this path"
                              : nextCefrForPath
                                ? `Create ${nextCefrForPath} with Module-1`
                                : undefined
                          }
                          disabled={pathLevelsFull || pathNextLevelLoading}
                          onClick={() => handleCreateNextLevelForCourse(course.course_id)}
                        >
                          {pathNextLevelLoading ? "Creating…" : "Add next CEFR level"}
                        </Button>
                      </div>
                    </div>
                    {!pathCollapsed ? (
                    <CardContent className="space-y-3 p-4">
                      {courseLevels.length === 0 ? (
                        <p className="text-sm text-grayScale-500">No levels match the current level filter.</p>
                      ) : (
                        courseLevels.map((level) => {
                          const levelNode = course.levels.find((item) => item.level.toUpperCase() === level)
                          const modules = levelNode?.modules ?? []
                          const levelKey = `${course.course_id}-${level}`
                          const levelRemoveIds = modules.flatMap((m) => m.sub_modules.map((s) => s.id))
                          const canRemoveLevel = levelRemoveIds.length > 0
                          return (
                            <div key={levelKey} className="overflow-hidden rounded-lg border border-grayScale-200/90">
                              <div className="flex w-full flex-wrap items-center justify-between gap-2 border-b border-grayScale-100 bg-grayScale-50/60 px-4 py-3">
                                <button
                                  type="button"
                                  className="flex min-w-0 flex-1 items-center gap-2 text-left"
                                  onClick={() => toggleLevel(levelKey)}
                                >
                                  {collapsedLevels.includes(levelKey) ? <ChevronRight className="h-4 w-4 shrink-0" /> : <ChevronDown className="h-4 w-4 shrink-0" />}
                                  <span className="text-sm font-semibold text-grayScale-900">{level}</span>
                                  <span className="rounded-md bg-brand-100 px-2 py-0.5 text-xs font-medium text-brand-700">
                                    {modules.length} module(s)
                                  </span>
                                </button>
                                <Button
                                  type="button"
                                  size="sm"
                                  variant="outline"
                                  title={!canRemoveLevel ? "Nothing to remove at this level" : `Remove all content at ${level} for ${course.course_name}`}
                                  className="h-8 shrink-0 gap-1 border-red-200/90 px-2.5 text-xs font-medium text-red-600 hover:bg-red-50"
                                  disabled={!canRemoveLevel || deletingKey === `level-${course.course_id}-${level}`}
                                  onClick={() =>
                                    requestRemove({
                                      ids: levelRemoveIds,
                                      key: `level-${course.course_id}-${level}`,
                                      successMessage: `Level ${level} removed`,
                                      title: `Remove level ${level}?`,
                                      description: `This will permanently delete all modules and sub-modules under ${level} for “${course.course_name}”. This action cannot be undone.`,
                                    })
                                  }
                                >
                                  <Trash2 className="h-3 w-3.5" aria-hidden />
                                  Remove
                                </Button>
                              </div>
                              {!collapsedLevels.includes(levelKey) ? (
                                <div className="space-y-2 p-3">
                                  <div className="flex items-center justify-between gap-2">
                                    <Button
                                      size="sm"
                                      variant="outline"
                                      onClick={() => handleCreateModule(course.course_id, level, modules)}
                                      disabled={creatingKey === `module-${course.course_id}-${level}`}
                                    >
                                      {creatingKey === `module-${course.course_id}-${level}` ? (
                                        <Loader2 className="h-3.5 w-3.5 animate-spin" />
                                      ) : (
                                        <Plus className="h-3.5 w-3.5" />
                                      )}
                                      Add Module
                                    </Button>
                                  </div>
                                  {modules.length === 0 ? (
                                    <p className="text-xs text-grayScale-500">No modules yet. Use “Add Module” to start.</p>
                                  ) : (
                                    modules.map((module) => (
                                      <div key={module.id} className="rounded-lg border border-grayScale-100 bg-grayScale-50/60 p-3">
                                        <div className="flex items-center justify-between gap-2">
                                          <p className="text-sm font-semibold text-grayScale-900">Module: {module.title}</p>
                                          <div className="flex gap-2">
                                            <Button
                                              size="sm"
                                              variant="outline"
                                              onClick={() =>
                                                handleCreateSubModule(course.course_id, level, module.title, module.sub_modules)
                                              }
                                              disabled={creatingKey === `submodule-${course.course_id}-${level}-${parseModuleNumber(module.title) ?? 0}`}
                                            >
                                              {creatingKey === `submodule-${course.course_id}-${level}-${parseModuleNumber(module.title) ?? 0}` ? (
                                                <Loader2 className="h-3.5 w-3.5 animate-spin" />
                                              ) : (
                                                <Plus className="h-3.5 w-3.5" />
                                              )}
                                              Add Sub-module
                                            </Button>
                                            <Button
                                              type="button"
                                              size="sm"
                                              variant="outline"
                                              className="h-8 gap-1 border-red-200/90 px-2.5 text-xs font-medium text-red-600 hover:bg-red-50"
                                              disabled={deletingKey === `module-${module.id}`}
                                              onClick={() =>
                                                requestRemove({
                                                  ids: module.sub_modules.map((s) => s.id),
                                                  key: `module-${module.id}`,
                                                  successMessage: `Module ${module.title} removed`,
                                                  title: `Remove ${module.title}?`,
                                                  description:
                                                    "All sub-modules in this module will be permanently deleted. This action cannot be undone.",
                                                })
                                              }
                                            >
                                              <Trash2 className="h-3 w-3.5" aria-hidden />
                                              Remove
                                            </Button>
                                          </div>
                                        </div>
                                        {module.sub_modules.map((subModule) => {
                                          const smKey = `${course.course_id}-${subModule.id}`
                                          const panelTab = subModulePanelTab[smKey] ?? "lessons"
                                          const cardSel = getSubModuleSelection(smKey)
                                          const lessonRows: LearningPathVideo[] = [...subModule.videos].sort(
                                            (a, b) => a.display_order - b.display_order,
                                          )
                                          const practiceRows: LearningPathPractice[] = [...subModule.practices].sort(
                                            (a, b) => (a.display_order ?? 0) - (b.display_order ?? 0),
                                          )
                                          const selectedLesson =
                                            cardSel.lessonId !== null
                                              ? lessonRows.find((v) => v.id === cardSel.lessonId) ?? null
                                              : null
                                          const selectedPracticeMeta =
                                            cardSel.practiceId !== null
                                              ? practiceRows.find((p) => p.id === cardSel.practiceId) ?? null
                                              : null
                                          const practiceFetch =
                                            cardSel.practiceId !== null ? practiceQuestionsState[cardSel.practiceId] : undefined
                                          return (
                                            <div
                                              key={subModule.id}
                                              className="mt-2 overflow-hidden rounded-lg border border-grayScale-200/90 bg-white shadow-sm"
                                            >
                                              <div className="flex flex-wrap items-center justify-between gap-2 border-b border-grayScale-100 bg-grayScale-50/90 px-3 py-2.5">
                                                <p className="text-sm font-semibold text-grayScale-800">
                                                  Sub-module: {subModule.title}
                                                </p>
                                                {categoryId ? (
                                                  <div className="flex flex-wrap items-center gap-2">
                                                    <Link
                                                      to={`/content/human-language/${categoryId}/${course.course_id}/sub-module/${subModule.id}`}
                                                    >
                                                      <Button type="button" variant="outline" size="sm" className="h-8 text-xs">
                                                        Open editor
                                                      </Button>
                                                    </Link>
                                                    <Button
                                                      type="button"
                                                      size="sm"
                                                      variant="outline"
                                                      className="h-8 gap-1 border-red-200/90 px-2.5 text-xs font-medium text-red-600 hover:bg-red-50"
                                                      disabled={deletingKey === `submodule-${subModule.id}`}
                                                      onClick={() =>
                                                        requestRemove({
                                                          ids: [subModule.id],
                                                          key: `submodule-${subModule.id}`,
                                                          successMessage: `Sub-module ${subModule.title} removed`,
                                                          title: `Remove ${subModule.title}?`,
                                                          description:
                                                            "This sub-module will be permanently deleted. This action cannot be undone.",
                                                        })
                                                      }
                                                    >
                                                      <Trash2 className="h-3 w-3.5" aria-hidden />
                                                      Remove
                                                    </Button>
                                                  </div>
                                                ) : null}
                                              </div>

                                              <div className="border-b border-grayScale-100 bg-white px-3">
                                                <div className="-mb-px flex items-center justify-between gap-4">
                                                  <div className="flex gap-6">
                                                  <button
                                                    type="button"
                                                    onClick={() =>
                                                      setSubModulePanelTab((prev) => ({ ...prev, [smKey]: "lessons" }))
                                                    }
                                                    className={`relative pb-3 pt-2 text-sm font-semibold transition-colors ${
                                                      panelTab === "lessons"
                                                        ? "text-brand-600"
                                                        : "text-grayScale-400 hover:text-grayScale-700"
                                                    }`}
                                                  >
                                                    Lessons
                                                    {panelTab === "lessons" ? (
                                                      <span className="absolute inset-x-0 bottom-0 h-0.5 rounded-full bg-brand-500" />
                                                    ) : null}
                                                  </button>
                                                  <button
                                                    type="button"
                                                    onClick={() =>
                                                      setSubModulePanelTab((prev) => ({ ...prev, [smKey]: "practices" }))
                                                    }
                                                    className={`relative pb-3 pt-2 text-sm font-semibold transition-colors ${
                                                      panelTab === "practices"
                                                        ? "text-brand-600"
                                                        : "text-grayScale-400 hover:text-grayScale-700"
                                                    }`}
                                                  >
                                                    Practices
                                                    {panelTab === "practices" ? (
                                                      <span className="absolute inset-x-0 bottom-0 h-0.5 rounded-full bg-brand-500" />
                                                    ) : null}
                                                  </button>
                                                  </div>
                                                  {panelTab === "practices" ? (
                                                    <Button
                                                      type="button"
                                                      size="sm"
                                                      variant="outline"
                                                      className="h-7 px-2 text-[11px]"
                                                      onClick={() => openCreatePracticeDialog(subModule.id)}
                                                    >
                                                      <Plus className="h-3.5 w-3.5" />
                                                      New practice
                                                    </Button>
                                                  ) : null}
                                                </div>
                                              </div>

                                              <div className="p-3">
                                                {panelTab === "lessons" ? (
                                                  lessonRows.length === 0 ? (
                                                    <div className="rounded-lg border border-dashed border-grayScale-200 bg-grayScale-50/40 px-4 py-8 text-center text-sm text-grayScale-500">
                                                      No lesson videos yet. Use{" "}
                                                      <span className="font-medium text-grayScale-700">Open editor</span> to add
                                                      videos.
                                                    </div>
                                                  ) : (
                                                    <div className="space-y-3">
                                                      <div className="grid grid-cols-1 gap-2 sm:grid-cols-2 lg:grid-cols-3">
                                                        {lessonRows.map((v, idx) => {
                                                          const isActive = cardSel.lessonId === v.id
                                                          return (
                                                            <button
                                                              key={v.id}
                                                              type="button"
                                                              onClick={() => toggleLessonCard(smKey, v.id)}
                                                              className={cn(
                                                                "flex flex-col gap-1.5 rounded-xl border bg-white p-3 text-left shadow-sm transition-all hover:border-brand-200 hover:shadow-md",
                                                                isActive
                                                                  ? "border-brand-400 ring-2 ring-brand-400/30"
                                                                  : "border-grayScale-100",
                                                              )}
                                                            >
                                                              <div className="flex items-start gap-2">
                                                                <div className="rounded-lg bg-brand-50 p-1.5 text-brand-600">
                                                                  <Video className="h-3.5 w-3.5" aria-hidden />
                                                                </div>
                                                                <div className="min-w-0 flex-1">
                                                                  <p className="line-clamp-2 text-sm font-semibold text-grayScale-900">
                                                                    {v.title}
                                                                  </p>
                                                                  <p className="mt-0.5 text-[11px] text-grayScale-500">
                                                                    Lesson {idx + 1} · {formatDurationSeconds(v.duration ?? 0)} · Order{" "}
                                                                    {v.display_order}
                                                                  </p>
                                                                </div>
                                                              </div>
                                                            </button>
                                                          )
                                                        })}
                                                      </div>
                                                      {selectedLesson ? (
                                                        <div className="rounded-xl border border-grayScale-200 bg-grayScale-50/60 p-4">
                                                          <p className="text-xs font-semibold uppercase tracking-wide text-grayScale-500">
                                                            Lesson content
                                                          </p>
                                                          <h4 className="mt-1 text-base font-semibold text-grayScale-900">
                                                            {selectedLesson.title}
                                                          </h4>
                                                          <dl className="mt-3 grid grid-cols-1 gap-2 text-sm sm:grid-cols-2">
                                                            <div>
                                                              <dt className="text-xs text-grayScale-500">Display order</dt>
                                                              <dd className="font-medium text-grayScale-800">
                                                                {selectedLesson.display_order}
                                                              </dd>
                                                            </div>
                                                            <div>
                                                              <dt className="text-xs text-grayScale-500">Duration</dt>
                                                              <dd className="tabular-nums font-medium text-grayScale-800">
                                                                {formatDurationSeconds(selectedLesson.duration ?? 0)}
                                                              </dd>
                                                            </div>
                                                            <div className="sm:col-span-2">
                                                              <dt className="text-xs text-grayScale-500">Video</dt>
                                                              <dd className="mt-0.5 break-all">
                                                                {selectedLesson.video_url ? (
                                                                  <a
                                                                    href={selectedLesson.video_url}
                                                                    target="_blank"
                                                                    rel="noopener noreferrer"
                                                                    className="text-sm font-medium text-brand-600 hover:underline"
                                                                  >
                                                                    {selectedLesson.video_url}
                                                                  </a>
                                                                ) : (
                                                                  <span className="text-sm text-grayScale-400">
                                                                    No video URL set — use Open editor to add one.
                                                                  </span>
                                                                )}
                                                                {selectedLesson.video_url
                                                                  ? renderMediaPreview(
                                                                      selectedLesson.video_url,
                                                                      "video",
                                                                      "mt-3",
                                                                      "Video preview",
                                                                    )
                                                                  : null}
                                                              </dd>
                                                            </div>
                                                          </dl>
                                                        </div>
                                                      ) : (
                                                        <p className="text-center text-xs text-grayScale-400">
                                                          Select a lesson card to view full content.
                                                        </p>
                                                      )}
                                                    </div>
                                                  )
                                                ) : practiceRows.length === 0 ? (
                                                  <div className="rounded-lg border border-dashed border-grayScale-200 bg-grayScale-50/40 px-4 py-8 text-center text-sm text-grayScale-500">
                                                    No practices yet. Use{" "}
                                                    <span className="font-medium text-grayScale-700">Open editor</span> to create a
                                                    practice.
                                                  </div>
                                                ) : (
                                                  <div className="space-y-3">
                                                    <div className="grid grid-cols-1 gap-2 sm:grid-cols-2 lg:grid-cols-3">
                                                      {practiceRows.map((p, pIdx) => {
                                                        const isActive = cardSel.practiceId === p.id
                                                        return (
                                                          <button
                                                            key={p.id}
                                                            type="button"
                                                            onClick={() => togglePracticeCard(smKey, p.id)}
                                                            className={cn(
                                                              "flex flex-col gap-1.5 rounded-xl border bg-white p-3 text-left shadow-sm transition-all hover:border-brand-200 hover:shadow-md",
                                                              isActive
                                                                ? "border-brand-400 ring-2 ring-brand-400/30"
                                                                : "border-grayScale-100",
                                                            )}
                                                          >
                                                            <div className="flex items-start justify-between gap-2">
                                                              <div className="rounded-lg bg-violet-50 p-1.5 text-violet-600">
                                                                <ClipboardList className="h-3.5 w-3.5" aria-hidden />
                                                              </div>
                                                              <div className="min-w-0 flex-1">
                                                                <p className="line-clamp-2 text-sm font-semibold text-grayScale-900">
                                                                  {p.title}
                                                                </p>
                                                                <p className="mt-0.5 text-[11px] text-grayScale-500">
                                                                  Practice {pIdx + 1}
                                                                </p>
                                                                <div className="mt-1 flex flex-wrap items-center gap-1.5">
                                                                  <Badge
                                                                    className={`rounded-full px-2 py-0.5 text-[10px] font-semibold capitalize ${practiceStatusStyle(p.status)}`}
                                                                  >
                                                                    {(p.status ?? "—").replace(/_/g, " ").toLowerCase()}
                                                                  </Badge>
                                                                  <span className="text-[11px] text-grayScale-500">
                                                                    {p.question_count} Q · order {p.display_order ?? "—"}
                                                                  </span>
                                                                </div>
                                                              </div>
                                                              <div className="flex shrink-0 items-center gap-1">
                                                                <Button
                                                                  type="button"
                                                                  size="sm"
                                                                  variant="ghost"
                                                                  className="h-7 px-2 text-[10px]"
                                                                  onClick={(e) => {
                                                                    e.stopPropagation()
                                                                    openEditPracticeDialog(subModule.id, p)
                                                                  }}
                                                                >
                                                                  Edit
                                                                </Button>
                                                                <Button
                                                                  type="button"
                                                                  size="sm"
                                                                  variant="ghost"
                                                                  className="h-7 px-2 text-[10px] text-red-600 hover:bg-red-50 hover:text-red-700"
                                                                  onClick={(e) => {
                                                                    e.stopPropagation()
                                                                    setPracticeTargetDelete({ id: p.id, title: p.title })
                                                                  }}
                                                                >
                                                                  Delete
                                                                </Button>
                                                              </div>
                                                            </div>
                                                          </button>
                                                        )
                                                      })}
                                                    </div>
                                                    {cardSel.practiceId !== null && selectedPracticeMeta ? (
                                                      <div className="overflow-hidden rounded-xl border border-grayScale-200/90 bg-gradient-to-b from-white to-grayScale-50/80 shadow-sm">
                                                        <div className="border-b border-grayScale-100 bg-white/90 px-4 py-3.5">
                                                          <div className="flex flex-wrap items-start justify-between gap-3">
                                                            <div className="min-w-0 flex-1">
                                                              <p className="text-[11px] font-semibold uppercase tracking-[0.08em] text-grayScale-400">
                                                                Question bank
                                                              </p>
                                                              <h4 className="mt-0.5 truncate text-base font-semibold text-grayScale-900">
                                                                {selectedPracticeMeta.title}
                                                              </h4>
                                                              {practiceFetch?.status === "ok" ? (
                                                                <p className="mt-1 text-xs text-grayScale-500">
                                                                  {practiceFetch.totalCount}{" "}
                                                                  {practiceFetch.totalCount === 1 ? "question" : "questions"} in this
                                                                  practice
                                                                </p>
                                                              ) : null}
                                                            </div>
                                                            <div className="flex shrink-0 flex-wrap items-center gap-2">
                                                              <Button
                                                                type="button"
                                                                size="sm"
                                                                variant="outline"
                                                                className="h-8 text-xs"
                                                                onClick={() => openCreateQuestionDialog(selectedPracticeMeta.id)}
                                                              >
                                                                <Plus className="h-3.5 w-3.5" />
                                                                Add question
                                                              </Button>
                                                              {practiceFetch?.status === "ok" ? (
                                                                <span className="rounded-full bg-brand-50 px-2.5 py-1 text-xs font-semibold text-brand-700 ring-1 ring-inset ring-brand-100">
                                                                  {practiceFetch.questions.length} loaded
                                                                </span>
                                                              ) : null}
                                                              {categoryId ? (
                                                                <Button type="button" variant="outline" size="sm" className="h-8 text-xs" asChild>
                                                                  <Link
                                                                    to={`/content/human-language/${categoryId}/${course.course_id}/sub-module/${subModule.id}/practices/${selectedPracticeMeta.id}/questions`}
                                                                  >
                                                                    Edit in full view
                                                                  </Link>
                                                                </Button>
                                                              ) : null}
                                                            </div>
                                                          </div>
                                                        </div>
                                                        <div className="p-4">
                                                        {!practiceFetch || practiceFetch.status === "loading" ? (
                                                          <div className="flex flex-col items-center justify-center gap-2 py-12 text-sm text-grayScale-500">
                                                            <Loader2 className="h-5 w-5 animate-spin text-brand-500" aria-hidden />
                                                            Loading questions…
                                                          </div>
                                                        ) : practiceFetch.status === "error" ? (
                                                          <div className="rounded-lg border border-red-100 bg-red-50/50 px-4 py-3">
                                                            <div className="flex items-start gap-2">
                                                              <HelpCircle className="mt-0.5 h-4 w-4 shrink-0 text-red-600" aria-hidden />
                                                              <div className="space-y-2">
                                                                <p className="text-sm font-medium text-red-800">{practiceFetch.message}</p>
                                                                <Button
                                                                  type="button"
                                                                  size="sm"
                                                                  variant="outline"
                                                                  className="border-red-200 text-red-700 hover:bg-red-50"
                                                                  onClick={() => void loadPracticeQuestionsIfNeeded(selectedPracticeMeta.id)}
                                                                >
                                                                  Retry
                                                                </Button>
                                                              </div>
                                                            </div>
                                                          </div>
                                                        ) : practiceFetch.questions.length === 0 ? (
                                                          <div className="rounded-lg border border-dashed border-grayScale-200 bg-white px-4 py-10 text-center">
                                                            <ClipboardList className="mx-auto mb-2 h-8 w-8 text-grayScale-300" aria-hidden />
                                                            <p className="text-sm text-grayScale-600">
                                                              No questions in this practice yet.
                                                            </p>
                                                            <p className="mt-1 text-xs text-grayScale-500">
                                                              Add them via <span className="font-medium text-grayScale-700">Open editor</span>{" "}
                                                              or <span className="font-medium text-grayScale-700">Edit in full view</span>.
                                                            </p>
                                                          </div>
                                                        ) : (
                                                          <ul className="max-h-[min(28rem,calc(100vh-16rem))] space-y-3 overflow-y-auto pr-1 [scrollbar-gutter:stable]">
                                                            {practiceFetch.questions.map((q, qIdx) => {
                                                              const qType = String(q.question_type ?? "—")
                                                              const embeddedUrls = extractUrls(q.question_text || "")
                                                              return (
                                                                <li
                                                                  key={q.question_id ?? q.id}
                                                                  className="relative overflow-hidden rounded-xl border border-grayScale-100 bg-white shadow-sm ring-1 ring-black/[0.02] transition-shadow hover:shadow-md"
                                                                >
                                                                  <div className="absolute left-0 top-0 h-full w-1 bg-gradient-to-b from-brand-400 to-violet-500" />
                                                                  <div className="flex gap-3 px-4 py-4 pl-5">
                                                                    <div
                                                                      className="flex h-10 w-10 shrink-0 items-center justify-center rounded-xl bg-gradient-to-br from-brand-500/15 to-violet-500/15 text-sm font-bold tabular-nums text-brand-800"
                                                                      aria-hidden
                                                                    >
                                                                      {qIdx + 1}
                                                                    </div>
                                                                    <div className="min-w-0 flex-1 space-y-3">
                                                                      <div className="flex flex-wrap items-center justify-between gap-2">
                                                                        <div className="flex flex-wrap items-center gap-2">
                                                                        <Badge
                                                                          className={cn(
                                                                            "h-6 rounded-md px-2 py-0 text-[11px] font-semibold",
                                                                            questionTypeBadgeClass(qType),
                                                                          )}
                                                                        >
                                                                          {formatQuestionTypeLabel(qType)}
                                                                        </Badge>
                                                                        {q.points != null && q.points > 0 ? (
                                                                          <span className="rounded-md bg-grayScale-100 px-2 py-0.5 text-[11px] font-medium tabular-nums text-grayScale-700">
                                                                            {q.points} pts
                                                                          </span>
                                                                        ) : null}
                                                                        {q.difficulty_level ? (
                                                                          <span className="rounded-md bg-amber-50 px-2 py-0.5 text-[11px] font-medium text-amber-900 ring-1 ring-inset ring-amber-100">
                                                                            {q.difficulty_level}
                                                                          </span>
                                                                        ) : null}
                                                                        </div>
                                                                        <div className="flex items-center gap-1">
                                                                          <Button
                                                                            type="button"
                                                                            size="sm"
                                                                            variant="ghost"
                                                                            className="h-7 gap-1 px-2 text-[10px]"
                                                                            disabled={
                                                                              loadingQuestionEditId ===
                                                                              (q.question_id ?? q.id)
                                                                            }
                                                                            onClick={() =>
                                                                              void openEditQuestionDialog(
                                                                                selectedPracticeMeta.id,
                                                                                q,
                                                                              )
                                                                            }
                                                                          >
                                                                            {loadingQuestionEditId ===
                                                                            (q.question_id ?? q.id) ? (
                                                                              <Loader2 className="h-3 w-3 animate-spin" aria-hidden />
                                                                            ) : null}
                                                                            Edit
                                                                          </Button>
                                                                          <Button
                                                                            type="button"
                                                                            size="sm"
                                                                            variant="ghost"
                                                                            className="h-7 px-2 text-[10px] text-red-600 hover:bg-red-50 hover:text-red-700"
                                                                            onClick={() =>
                                                                              setQuestionTargetDelete({
                                                                                id: q.question_id ?? q.id,
                                                                                practiceId: selectedPracticeMeta.id,
                                                                                text: q.question_text || "Question",
                                                                              })
                                                                            }
                                                                          >
                                                                            Delete
                                                                          </Button>
                                                                        </div>
                                                                      </div>
                                                                      <div>
                                                                        <p className="text-[13px] font-medium uppercase tracking-wide text-grayScale-400">
                                                                          Prompt
                                                                        </p>
                                                                        <p className="mt-1 text-[15px] leading-relaxed text-grayScale-900">
                                                                          {q.question_text?.trim() || (
                                                                            <span className="italic text-grayScale-400">No prompt text</span>
                                                                          )}
                                                                        </p>
                                                                      </div>
                                                                      {embeddedUrls.length > 0 ? (
                                                                        <div className="space-y-2">
                                                                          <p className="flex items-center gap-1.5 text-[11px] font-semibold uppercase tracking-wide text-grayScale-500">
                                                                            <Link2 className="h-3 w-3" aria-hidden />
                                                                            Media in prompt
                                                                          </p>
                                                                          <div className="grid gap-2 sm:grid-cols-2">
                                                                            {embeddedUrls.map((u) => (
                                                                              <div key={u}>{renderMediaPreview(u, undefined, "", "Embedded link")}</div>
                                                                            ))}
                                                                          </div>
                                                                        </div>
                                                                      ) : null}
                                                                      {q.tips ? (
                                                                        <div className="rounded-lg border border-amber-100 bg-amber-50/40 px-3 py-2.5">
                                                                          <p className="flex items-center gap-1.5 text-[11px] font-semibold text-amber-900">
                                                                            <Lightbulb className="h-3.5 w-3.5" aria-hidden />
                                                                            Learner tip
                                                                          </p>
                                                                          <p className="mt-1 text-sm leading-relaxed text-amber-950/90">{q.tips}</p>
                                                                        </div>
                                                                      ) : null}
                                                                      {q.image_url ||
                                                                      q.voice_prompt ||
                                                                      q.sample_answer_voice_prompt ? (
                                                                        <div className="space-y-2 border-t border-grayScale-100 pt-3">
                                                                          <p className="text-[11px] font-semibold uppercase tracking-wide text-grayScale-500">
                                                                            Assets
                                                                          </p>
                                                                          <div className="grid gap-2 sm:grid-cols-2">
                                                                            {q.image_url
                                                                              ? renderMediaPreview(q.image_url, "image", "", "Image")
                                                                              : null}
                                                                            {q.voice_prompt
                                                                              ? renderMediaPreview(q.voice_prompt, "audio", "", "Voice prompt")
                                                                              : null}
                                                                            {q.sample_answer_voice_prompt
                                                                              ? renderMediaPreview(
                                                                                  q.sample_answer_voice_prompt,
                                                                                  "audio",
                                                                                  "",
                                                                                  "Sample answer (audio)",
                                                                                )
                                                                              : null}
                                                                          </div>
                                                                        </div>
                                                                      ) : null}
                                                                    </div>
                                                                  </div>
                                                                </li>
                                                              )
                                                            })}
                                                          </ul>
                                                        )}
                                                        {practiceFetch?.status === "ok" &&
                                                        practiceFetch.totalCount > practiceFetch.questions.length ? (
                                                          <div className="mt-4 rounded-lg border border-grayScale-100 bg-white/80 px-3 py-2 text-center text-xs text-grayScale-600">
                                                            Showing <span className="font-semibold">{practiceFetch.questions.length}</span> of{" "}
                                                            <span className="font-semibold">{practiceFetch.totalCount}</span> questions. Open{" "}
                                                            <span className="font-medium text-grayScale-800">Edit in full view</span> for the
                                                            rest.
                                                          </div>
                                                        ) : null}
                                                        </div>
                                                      </div>
                                                    ) : (
                                                      <p className="text-center text-xs text-grayScale-400">
                                                        Select a practice card to view its questions.
                                                      </p>
                                                    )}
                                                  </div>
                                                )}
                                              </div>
                                            </div>
                                          )
                                        })}
                                      </div>
                                    ))
                                  )}
                                </div>
                              ) : null}
                            </div>
                          )
                        })
                      )}
                    </CardContent>
                    ) : null}
                  </Card>
                )
              })
            : null}
        </div>
      )}

      <Dialog open={pendingRemove !== null} onOpenChange={(open) => !open && setPendingRemove(null)}>
        <DialogContent className="sm:max-w-md">
          <DialogHeader>
            <DialogTitle>{pendingRemove?.title ?? "Confirm removal"}</DialogTitle>
            <DialogDescription>{pendingRemove?.description}</DialogDescription>
          </DialogHeader>
          <DialogFooter className="gap-2 sm:gap-0">
            <Button type="button" variant="outline" onClick={() => setPendingRemove(null)}>
              Cancel
            </Button>
            <Button type="button" className="bg-red-600 hover:bg-red-700" onClick={() => void executePendingRemove()}>
              Remove
            </Button>
          </DialogFooter>
        </DialogContent>
      </Dialog>

      <Dialog
        open={practiceDialog.open}
        onOpenChange={(open) => {
          if (!open) {
            setPracticeDialog({ open: false })
            setPracticeSubmitAttempted(false)
            setPracticeFormTouched(false)
          }
        }}
      >
        <DialogContent className="sm:max-w-lg">
          <DialogHeader>
            <DialogTitle>{practiceDialog.open && practiceDialog.mode === "edit" ? "Edit Practice" : "Create Practice"}</DialogTitle>
            <DialogDescription>
              Manage practice metadata directly from this page.
              {!practiceCanSave ? (
                <span className="mt-1 block text-amber-700/90">Required fields must be completed before you can save.</span>
              ) : null}
            </DialogDescription>
          </DialogHeader>
          <div className="space-y-3">
            <div className="space-y-1">
              <label className="text-xs font-medium text-grayScale-600">Title</label>
              <input
                value={practiceForm.title}
                onChange={(e) => {
                  setPracticeFormTouched(true)
                  setPracticeForm((p) => ({ ...p, title: e.target.value }))
                }}
                className={cn(
                  "h-10 w-full rounded-md border px-3 text-sm",
                  (practiceSubmitAttempted || practiceFormTouched) && practiceFieldErrors.title
                    ? "border-red-300 ring-1 ring-red-200"
                    : "border-grayScale-200",
                )}
                placeholder="Practice title"
                aria-invalid={Boolean(
                  (practiceSubmitAttempted || practiceFormTouched) && practiceFieldErrors.title,
                )}
              />
              {(practiceSubmitAttempted || practiceFormTouched) && practiceFieldErrors.title ? (
                <p className="text-xs text-red-600">{practiceFieldErrors.title}</p>
              ) : null}
            </div>
            <div className="space-y-1">
              <label className="text-xs font-medium text-grayScale-600">Description</label>
              <textarea
                value={practiceForm.description}
                onChange={(e) => {
                  setPracticeFormTouched(true)
                  setPracticeForm((p) => ({ ...p, description: e.target.value }))
                }}
                className="min-h-[88px] w-full rounded-md border border-grayScale-200 px-3 py-2 text-sm"
                placeholder="Optional description"
              />
            </div>
            <div className="space-y-1">
              <label className="text-xs font-medium text-grayScale-600">Persona</label>
              <input
                value={practiceForm.persona}
                onChange={(e) => {
                  setPracticeFormTouched(true)
                  setPracticeForm((p) => ({ ...p, persona: e.target.value }))
                }}
                className="h-10 w-full rounded-md border border-grayScale-200 px-3 text-sm"
                placeholder="Optional persona"
              />
            </div>
          </div>
          <DialogFooter>
            <Button type="button" variant="outline" onClick={() => setPracticeDialog({ open: false })}>
              Cancel
            </Button>
            <Button type="button" onClick={() => void handleSavePractice()} disabled={savingPractice || !practiceCanSave}>
              {savingPractice ? "Saving..." : "Save"}
            </Button>
          </DialogFooter>
        </DialogContent>
      </Dialog>

      <Dialog open={practiceTargetDelete !== null} onOpenChange={(open) => !open && setPracticeTargetDelete(null)}>
        <DialogContent className="sm:max-w-md">
          <DialogHeader>
            <DialogTitle>Delete practice?</DialogTitle>
            <DialogDescription>
              {practiceTargetDelete ? `This will permanently delete "${practiceTargetDelete.title}".` : ""}
            </DialogDescription>
          </DialogHeader>
          <DialogFooter>
            <Button type="button" variant="outline" onClick={() => setPracticeTargetDelete(null)}>
              Cancel
            </Button>
            <Button
              type="button"
              className="bg-red-600 hover:bg-red-700"
              onClick={() => void handleDeletePracticeConfirmed()}
              disabled={deletingPractice}
            >
              {deletingPractice ? "Deleting..." : "Delete"}
            </Button>
          </DialogFooter>
        </DialogContent>
      </Dialog>

      <Dialog
        open={questionDialog.open}
        onOpenChange={(open) => {
          if (!open) {
            setQuestionDialog({ open: false })
            setQuestionSubmitAttempted(false)
            setQuestionFormTouched(false)
          }
        }}
      >
        <DialogContent className="max-h-[85vh] overflow-y-auto sm:max-w-2xl">
          <DialogHeader>
            <DialogTitle>{questionDialog.open && questionDialog.mode === "edit" ? "Edit question" : "Add question"}</DialogTitle>
            <DialogDescription>
              Use the same fields as when creating: type, scoring, prompts, media URLs, and answer options. Changes apply to this
              practice only.
              {!questionCanSave ? (
                <span className="mt-1 block text-amber-700/90">
                  Fix the highlighted fields before saving. Save stays disabled until the form is valid.
                </span>
              ) : null}
            </DialogDescription>
          </DialogHeader>
          <div className="grid grid-cols-1 gap-3 sm:grid-cols-2">
            <div className="space-y-1 sm:col-span-2">
              <label className="text-xs font-medium text-grayScale-600">Question text</label>
              <textarea
                value={questionForm.questionText}
                onChange={(e) => {
                  setQuestionFormTouched(true)
                  setQuestionForm((f) => ({ ...f, questionText: e.target.value }))
                }}
                className={cn(
                  "min-h-[96px] w-full rounded-md border px-3 py-2 text-sm",
                  (questionSubmitAttempted || questionFormTouched) && questionFieldErrors.questionText
                    ? "border-red-300 ring-1 ring-red-200"
                    : "border-grayScale-200",
                )}
                placeholder="Type question"
                aria-invalid={Boolean(
                  (questionSubmitAttempted || questionFormTouched) && questionFieldErrors.questionText,
                )}
              />
              {(questionSubmitAttempted || questionFormTouched) && questionFieldErrors.questionText ? (
                <p className="text-xs text-red-600">{questionFieldErrors.questionText}</p>
              ) : null}
            </div>
            <div className="space-y-1">
              <label className="text-xs font-medium text-grayScale-600">Type</label>
              <select
                value={questionForm.questionType}
                onChange={(e) => {
                  setQuestionFormTouched(true)
                  setQuestionForm((f) => ({ ...f, questionType: e.target.value as "MCQ" | "TRUE_FALSE" | "SHORT" }))
                }}
                className="h-10 w-full rounded-md border border-grayScale-200 px-3 text-sm"
              >
                <option value="MCQ">MCQ</option>
                <option value="TRUE_FALSE">True/False</option>
                <option value="SHORT">Short answer</option>
              </select>
            </div>
            <div className="space-y-1">
              <label className="text-xs font-medium text-grayScale-600">Difficulty</label>
              <select
                value={questionForm.difficulty}
                onChange={(e) => {
                  setQuestionFormTouched(true)
                  setQuestionForm((f) => ({ ...f, difficulty: e.target.value }))
                }}
                className="h-10 w-full rounded-md border border-grayScale-200 px-3 text-sm"
              >
                <option value="EASY">EASY</option>
                <option value="MEDIUM">MEDIUM</option>
                <option value="HARD">HARD</option>
              </select>
            </div>
            <div className="space-y-1">
              <label className="text-xs font-medium text-grayScale-600">Points</label>
              <input
                type="number"
                min={1}
                value={questionForm.points}
                onChange={(e) => {
                  setQuestionFormTouched(true)
                  setQuestionForm((f) => ({ ...f, points: Number(e.target.value) }))
                }}
                className={cn(
                  "h-10 w-full rounded-md border px-3 text-sm",
                  (questionSubmitAttempted || questionFormTouched) && questionFieldErrors.points
                    ? "border-red-300 ring-1 ring-red-200"
                    : "border-grayScale-200",
                )}
                aria-invalid={Boolean(
                  (questionSubmitAttempted || questionFormTouched) && questionFieldErrors.points,
                )}
              />
              {(questionSubmitAttempted || questionFormTouched) && questionFieldErrors.points ? (
                <p className="text-xs text-red-600">{questionFieldErrors.points}</p>
              ) : null}
            </div>
            {questionForm.questionType === "SHORT" ? (
              <div className="space-y-1 sm:col-span-2">
                <label className="text-xs font-medium text-grayScale-600">Expected short answer</label>
                <input
                  value={questionForm.shortAnswer}
                  onChange={(e) => {
                    setQuestionFormTouched(true)
                    setQuestionForm((f) => ({ ...f, shortAnswer: e.target.value }))
                  }}
                  className={cn(
                    "h-10 w-full rounded-md border px-3 text-sm",
                    (questionSubmitAttempted || questionFormTouched) && questionFieldErrors.shortAnswer
                      ? "border-red-300 ring-1 ring-red-200"
                      : "border-grayScale-200",
                  )}
                  aria-invalid={Boolean(
                    (questionSubmitAttempted || questionFormTouched) && questionFieldErrors.shortAnswer,
                  )}
                />
                {(questionSubmitAttempted || questionFormTouched) && questionFieldErrors.shortAnswer ? (
                  <p className="text-xs text-red-600">{questionFieldErrors.shortAnswer}</p>
                ) : null}
              </div>
            ) : (
              <div className="space-y-2 sm:col-span-2">
                <label className="text-xs font-medium text-grayScale-600">Options</label>
                {questionForm.questionType === "TRUE_FALSE" ? (
                  <div className="grid grid-cols-2 gap-2">
                    <Button
                      type="button"
                      variant={questionForm.correctOption === "A" ? "default" : "outline"}
                      onClick={() => {
                        setQuestionFormTouched(true)
                        setQuestionForm((f) => ({ ...f, correctOption: "A" }))
                      }}
                    >
                      True
                    </Button>
                    <Button
                      type="button"
                      variant={questionForm.correctOption === "B" ? "default" : "outline"}
                      onClick={() => {
                        setQuestionFormTouched(true)
                        setQuestionForm((f) => ({ ...f, correctOption: "B" }))
                      }}
                    >
                      False
                    </Button>
                  </div>
                ) : (
                  <div className="grid grid-cols-1 gap-2 sm:grid-cols-2">
                    {(["A", "B", "C", "D"] as const).map((opt) => (
                      <div key={opt} className="flex items-center gap-2">
                        <Button
                          type="button"
                          size="sm"
                          variant={questionForm.correctOption === opt ? "default" : "outline"}
                          onClick={() => {
                            setQuestionFormTouched(true)
                            setQuestionForm((f) => ({ ...f, correctOption: opt }))
                          }}
                        >
                          {opt}
                        </Button>
                        <input
                          value={questionForm[`option${opt}` as "optionA" | "optionB" | "optionC" | "optionD"]}
                          onChange={(e) => {
                            setQuestionFormTouched(true)
                            setQuestionForm((f) => ({
                              ...f,
                              [`option${opt}`]: e.target.value,
                            }))
                          }}
                          className="h-9 w-full rounded-md border border-grayScale-200 px-3 text-sm"
                          placeholder={`Option ${opt}`}
                        />
                      </div>
                    ))}
                  </div>
                )}
                {(questionSubmitAttempted || questionFormTouched) && questionFieldErrors.options ? (
                  <p className="text-xs text-red-600">{questionFieldErrors.options}</p>
                ) : null}
                {(questionSubmitAttempted || questionFormTouched) && questionFieldErrors.correctOption ? (
                  <p className="text-xs text-red-600">{questionFieldErrors.correctOption}</p>
                ) : null}
              </div>
            )}
            <div className="space-y-1 sm:col-span-2">
              <label className="text-xs font-medium text-grayScale-600">Tips</label>
              <textarea
                value={questionForm.tips}
                onChange={(e) => {
                  setQuestionFormTouched(true)
                  setQuestionForm((f) => ({ ...f, tips: e.target.value }))
                }}
                className="min-h-[74px] w-full rounded-md border border-grayScale-200 px-3 py-2 text-sm"
              />
            </div>
            <div className="space-y-1 sm:col-span-2">
              <label className="text-xs font-medium text-grayScale-600">Explanation / sample answer</label>
              <textarea
                value={questionForm.explanation}
                onChange={(e) => {
                  setQuestionFormTouched(true)
                  setQuestionForm((f) => ({ ...f, explanation: e.target.value }))
                }}
                className="min-h-[74px] w-full rounded-md border border-grayScale-200 px-3 py-2 text-sm"
              />
            </div>
            <div className="space-y-1 sm:col-span-2">
              <label className="text-xs font-medium text-grayScale-600">Image URL</label>
              <input
                value={questionForm.imageUrl}
                onChange={(e) => {
                  setQuestionFormTouched(true)
                  setQuestionForm((f) => ({ ...f, imageUrl: e.target.value }))
                }}
                className="h-10 w-full rounded-md border border-grayScale-200 px-3 text-sm"
              />
            </div>
            <div className="space-y-1">
              <label className="text-xs font-medium text-grayScale-600">Voice prompt URL</label>
              <input
                value={questionForm.voicePrompt}
                onChange={(e) => {
                  setQuestionFormTouched(true)
                  setQuestionForm((f) => ({ ...f, voicePrompt: e.target.value }))
                }}
                className="h-10 w-full rounded-md border border-grayScale-200 px-3 text-sm"
              />
            </div>
            <div className="space-y-1">
              <label className="text-xs font-medium text-grayScale-600">Sample answer voice URL</label>
              <input
                value={questionForm.sampleAnswerVoicePrompt}
                onChange={(e) => {
                  setQuestionFormTouched(true)
                  setQuestionForm((f) => ({ ...f, sampleAnswerVoicePrompt: e.target.value }))
                }}
                className="h-10 w-full rounded-md border border-grayScale-200 px-3 text-sm"
              />
            </div>
            <div className="space-y-1 sm:col-span-2">
              <label className="text-xs font-medium text-grayScale-600">Audio / spoken correct answer text</label>
              <textarea
                value={questionForm.audioCorrectAnswerText}
                onChange={(e) => {
                  setQuestionFormTouched(true)
                  setQuestionForm((f) => ({ ...f, audioCorrectAnswerText: e.target.value }))
                }}
                className="min-h-[64px] w-full rounded-md border border-grayScale-200 px-3 py-2 text-sm"
                placeholder="Optional; used for audio-style grading when applicable"
              />
            </div>
          </div>
          <DialogFooter>
            <Button type="button" variant="outline" onClick={() => setQuestionDialog({ open: false })}>
              Cancel
            </Button>
            <Button type="button" onClick={() => void handleSaveQuestion()} disabled={savingQuestion || !questionCanSave}>
              {savingQuestion ? "Saving..." : "Save question"}
            </Button>
          </DialogFooter>
        </DialogContent>
      </Dialog>

      <Dialog open={questionTargetDelete !== null} onOpenChange={(open) => !open && setQuestionTargetDelete(null)}>
        <DialogContent className="sm:max-w-md">
          <DialogHeader>
            <DialogTitle>Delete question?</DialogTitle>
            <DialogDescription>
              {questionTargetDelete ? `This will permanently delete "${questionTargetDelete.text}".` : ""}
            </DialogDescription>
          </DialogHeader>
          <DialogFooter>
            <Button type="button" variant="outline" onClick={() => setQuestionTargetDelete(null)}>
              Cancel
            </Button>
            <Button
              type="button"
              className="bg-red-600 hover:bg-red-700"
              onClick={() => void handleDeleteQuestionConfirmed()}
              disabled={deletingQuestion}
            >
              {deletingQuestion ? "Deleting..." : "Delete"}
            </Button>
          </DialogFooter>
        </DialogContent>
      </Dialog>
    </div>
  )
}