package domain

import (
	"strings"
	"time"
)

// ParentKind identifies which hierarchy entity owns a practice (exactly one).
type ParentKind string

const (
	ParentKindCourse ParentKind = "COURSE"
	ParentKindModule ParentKind = "MODULE"
	ParentKindLesson ParentKind = "LESSON"
)

// PracticePublishStatus controls learner visibility for a practice shell (independent of question_set.status).
type PracticePublishStatus string

const (
	PracticePublishDraft     PracticePublishStatus = "DRAFT"
	PracticePublishPublished PracticePublishStatus = "PUBLISHED"
)

// ParsePracticePublishStatusInput maps API input. Empty or unknown values default to PUBLISHED for backward compatibility.
func ParsePracticePublishStatusInput(raw string) PracticePublishStatus {
	switch strings.TrimSpace(strings.ToUpper(raw)) {
	case string(PracticePublishDraft):
		return PracticePublishDraft
	case string(PracticePublishPublished):
		return PracticePublishPublished
	default:
		return PracticePublishPublished
	}
}

// PracticePublishStatusFromDB maps persisted values into the domain type.
func PracticePublishStatusFromDB(raw string) PracticePublishStatus {
	return ParsePracticePublishStatusInput(raw)
}

// Practice is question-set content (story, persona, tips) scoped to a course, module, or lesson.
type Practice struct {
	ID                 int64                 `json:"id"`
	ParentKind         ParentKind            `json:"parent_kind"`
	ParentID           int64                 `json:"parent_id"`
	Title              string                `json:"title"`
	StoryDescription   *string               `json:"story_description,omitempty"`
	StoryImage         *string               `json:"story_image,omitempty"`
	PersonaID          *int64                `json:"persona_id,omitempty"`
	QuestionSetID      int64                 `json:"question_set_id"`
	PublishStatus      PracticePublishStatus `json:"publish_status"`
	QuickTips          *string               `json:"quick_tips,omitempty"`
	CreatedAt          time.Time             `json:"created_at"`
	UpdatedAt          *time.Time            `json:"updated_at,omitempty"`
}

// VisibleToLearners is true when the practice shell should appear in subscribed learner catalogs and progression.
func (p Practice) VisibleToLearners() bool {
	return p.PublishStatus == PracticePublishPublished
}

type CreatePracticeInput struct {
	ParentKind       ParentKind `json:"parent_kind" validate:"required,oneof=COURSE MODULE LESSON"`
	ParentID         int64      `json:"parent_id" validate:"required,gt=0"`
	Title            string     `json:"title" validate:"required"`
	StoryDescription *string    `json:"story_description,omitempty"`
	StoryImage       *string    `json:"story_image,omitempty"`
	PersonaID        *int64     `json:"persona_id,omitempty"`
	QuestionSetID    int64      `json:"question_set_id" validate:"required,gt=0"`
	QuickTips        *string    `json:"quick_tips,omitempty"`
	// Omit or empty for backward compatibility defaults to PUBLISHED; set DRAFT to save hidden from learners until published.
	PublishStatus string `json:"publish_status,omitempty" validate:"omitempty,oneof=DRAFT draft PUBLISHED published"`
}

type UpdatePracticeInput struct {
	Title            *string `json:"title,omitempty"`
	StoryDescription *string `json:"story_description,omitempty"`
	StoryImage       *string `json:"story_image,omitempty"`
	PersonaID        *int64  `json:"persona_id,omitempty"`
	QuestionSetID    *int64  `json:"question_set_id,omitempty"`
	QuickTips        *string `json:"quick_tips,omitempty"`
	PublishStatus    *string `json:"publish_status,omitempty" validate:"omitempty,oneof=DRAFT draft PUBLISHED published"`
}