import { useMemo } from 'react'
import { Link, useParams } from 'react-router-dom'
import { toast } from 'sonner'
import {
  Area,
  AreaChart,
  CartesianGrid,
  Cell,
  Legend,
  Pie,
  PieChart,
  ResponsiveContainer,
  Tooltip,
  XAxis,
  YAxis,
} from 'recharts'
import { Copy, Download, MousePointerClick, PauseCircle, Send, Sparkles, Users } from 'lucide-react'
import { DetailPageLayout } from '@/layouts/DetailPageLayout'
import { ActivityTimeline, DetailSection } from '@/components/detail/ActivityTimeline'
import { KeyValueGrid } from '@/components/detail/KeyValueGrid'
import { ChartCard } from '@/components/charts/ChartCard'
import { StatCard } from '@/components/dashboard/StatCard'
import { Badge } from '@/components/ui/badge'
import { Button } from '@/components/ui/button'
import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from '@/components/ui/table'
import { campaignRecipients, campaigns } from '@/mocks/data'
import { campaignChannelBreakdown, campaignDailySends } from '@/mocks/charts'
import { formatEtb } from '@/lib/utils'
import type { Campaign, CampaignRecipient } from '@/mocks/data'
import type { TimelineEvent } from '@/components/detail/ActivityTimeline'

const statusTone: Record<Campaign['status'], 'success' | 'default' | 'warning' | 'muted'> = {
  sent: 'success',
  sending: 'default',
  scheduled: 'warning',
  draft: 'muted',
}

const recipientTone: Record<CampaignRecipient['status'], 'success' | 'default' | 'warning' | 'danger'> = {
  redeemed: 'success',
  clicked: 'default',
  opened: 'default',
  delivered: 'warning',
  bounced: 'danger',
}

export function CampaignDetailPage() {
  const { id } = useParams()
  const campaign = campaigns.find((c) => c.id === id)

  const recipients = useMemo(() => (id ? (campaignRecipients[id] ?? []) : []), [id])

  const breakdown = useMemo(() => {
    if (!campaign) return []
    const preset = id ? campaignChannelBreakdown[id] : undefined
    if (preset) return preset
    return [
      { name: 'Delivered', value: campaign.delivered, fill: '#A8C73A' },
      { name: 'Bounced', value: campaign.bounced, fill: '#E28A1A' },
    ].filter((slice) => slice.value > 0)
  }, [campaign, id])

  const daily = useMemo(() => (id ? (campaignDailySends[id] ?? []) : []), [id])

  const funnel = useMemo(() => {
    if (!campaign) return null
    const pct = (value: number, base: number) => (base > 0 ? Math.round((value / base) * 100) : 0)
    return {
      deliveryRate: pct(campaign.delivered, campaign.recipients),
      openRate: pct(campaign.opened, campaign.delivered),
      clickRate: pct(campaign.clicked, campaign.delivered),
      redeemRate: pct(campaign.redeemed, campaign.delivered),
    }
  }, [campaign])

  const timeline = useMemo<TimelineEvent[]>(() => {
    if (!campaign) return []
    const events: TimelineEvent[] = [
      {
        id: 'created',
        at: campaign.createdAt,
        title: 'Campaign created',
        detail: `${campaign.createdBy} drafted this ${campaign.channel} campaign`,
      },
    ]
    if (campaign.scheduledFor) {
      events.push({
        id: 'scheduled',
        at: campaign.scheduledFor,
        title: 'Scheduled to send',
        detail: `${campaign.recipients.toLocaleString()} recipients queued`,
        tone: 'warning',
      })
    }
    if (campaign.sentAt) {
      events.push({
        id: 'sent',
        at: campaign.sentAt,
        title: campaign.status === 'sending' ? 'Sending started' : 'Campaign sent',
        detail: `${campaign.delivered.toLocaleString()} delivered · ${campaign.bounced.toLocaleString()} bounced`,
        tone: campaign.bounced > 0 ? 'warning' : 'success',
      })
      if (campaign.opened > 0) {
        events.push({
          id: 'opened',
          at: new Date(new Date(campaign.sentAt).getTime() + 45 * 60 * 1000).toISOString(),
          title: 'First opens recorded',
          detail: `${campaign.opened.toLocaleString()} opens · ${campaign.clicked.toLocaleString()} clicks`,
        })
      }
      if (campaign.redeemed > 0) {
        events.push({
          id: 'redeemed',
          at: new Date(new Date(campaign.sentAt).getTime() + 6 * 60 * 60 * 1000).toISOString(),
          title: 'Redemptions attributed',
          detail: `${campaign.redeemed.toLocaleString()} orders traced back to this campaign`,
          tone: 'success',
        })
      }
    }
    return events.sort((a, b) => new Date(b.at).getTime() - new Date(a.at).getTime())
  }, [campaign])

  if (!campaign || !funnel) {
    return (
      <DetailPageLayout backTo="/campaigns" backLabel="Back to campaigns" title="Campaign not found">
        <Button asChild>
          <Link to="/campaigns">Back to campaigns</Link>
        </Button>
      </DetailPageLayout>
    )
  }

  const canSend = campaign.status === 'draft' || campaign.status === 'scheduled'

  return (
    <DetailPageLayout
      backTo="/campaigns"
      backLabel="Back to campaigns"
      title={campaign.name}
      subtitle={`${campaign.channel} · ${campaign.segmentName} · created by ${campaign.createdBy}`}
      badges={<Badge variant={statusTone[campaign.status]}>{campaign.status}</Badge>}
      actions={
        <>
          {canSend ? (
            <Button
              size="sm"
              className="h-9 gap-1.5"
              onClick={() => toast.success(`“${campaign.name}” queued to send now`)}
            >
              <Send className="h-3.5 w-3.5" />
              Send now
            </Button>
          ) : (
            <Button
              size="sm"
              variant="outline"
              className="h-9 gap-1.5"
              disabled={campaign.status === 'sent'}
              onClick={() => toast.success(`“${campaign.name}” paused`)}
            >
              <PauseCircle className="h-3.5 w-3.5" />
              Pause
            </Button>
          )}
          <Button
            size="sm"
            variant="outline"
            className="h-9 gap-1.5"
            onClick={() => toast.success(`Duplicated “${campaign.name}” as a draft`)}
          >
            <Copy className="h-3.5 w-3.5" />
            Duplicate
          </Button>
          <Button
            size="sm"
            variant="outline"
            className="h-9 gap-1.5"
            onClick={() => toast.success(`Exporting report for “${campaign.name}”`)}
          >
            <Download className="h-3.5 w-3.5" />
            Export report
          </Button>
        </>
      }
      sidebar={
        <DetailSection title="Lifecycle" description="Derived campaign activity">
          <ActivityTimeline events={timeline} empty="Nothing has happened yet" />
        </DetailSection>
      }
    >
      <div className="space-y-5">
        <div className="grid gap-4 sm:grid-cols-2 xl:grid-cols-5">
          <StatCard
            label="Recipients"
            value={campaign.recipients.toLocaleString()}
            hint="Segment size at send"
            icon={Users}
            tone="brand"
          />
          <StatCard
            label="Delivered"
            value={campaign.delivered.toLocaleString()}
            hint={`${funnel.deliveryRate}% of recipients`}
            icon={Send}
            tone="forest"
          />
          <StatCard
            label="Opened"
            value={campaign.opened.toLocaleString()}
            hint={`${funnel.openRate}% of delivered`}
            icon={Sparkles}
            tone="orange"
          />
          <StatCard
            label="Clicked"
            value={campaign.clicked.toLocaleString()}
            hint={`${funnel.clickRate}% of delivered`}
            icon={MousePointerClick}
            tone="muted"
          />
          <StatCard
            label="Redeemed"
            value={campaign.redeemed.toLocaleString()}
            hint={`${funnel.redeemRate}% of delivered`}
            icon={Sparkles}
            tone="brand"
          />
        </div>

        <DetailSection title="Campaign configuration" description="What was sent, to whom, and when">
          <KeyValueGrid
            columns={3}
            items={[
              { label: 'Channel', value: <Badge variant="outline">{campaign.channel}</Badge> },
              {
                label: 'Segment',
                value: (
                  <Link to={`/marketing/${campaign.segmentId}`} className="text-brand-700 hover:underline">
                    {campaign.segmentName}
                  </Link>
                ),
              },
              { label: 'Status', value: <Badge variant={statusTone[campaign.status]}>{campaign.status}</Badge> },
              { label: 'Recipients', value: campaign.recipients.toLocaleString() },
              { label: 'Budget', value: formatEtb(campaign.budgetEtb) },
              { label: 'Created by', value: campaign.createdBy },
              { label: 'Created at', value: new Date(campaign.createdAt).toLocaleString() },
              {
                label: campaign.sentAt ? 'Sent at' : 'Scheduled for',
                value: campaign.sentAt
                  ? new Date(campaign.sentAt).toLocaleString()
                  : campaign.scheduledFor
                    ? new Date(campaign.scheduledFor).toLocaleString()
                    : '—',
              },
              { label: 'Bounced', value: campaign.bounced.toLocaleString() },
            ]}
          />
          <div className="mt-5 rounded-xl border bg-muted/30 p-4">
            <p className="text-xs font-medium uppercase tracking-wide text-muted-foreground">Message</p>
            <p className="mt-1 text-sm text-foreground">{campaign.message}</p>
          </div>
        </DetailSection>

        <div className={daily.length > 0 ? 'grid gap-4 xl:grid-cols-2' : 'grid gap-4'}>
          <ChartCard title="Delivery breakdown" description="Delivered versus bounced">
            {breakdown.length === 0 ? (
              <div className="flex h-full items-center justify-center text-sm text-muted-foreground">
                No delivery data yet
              </div>
            ) : (
              <ResponsiveContainer width="100%" height="100%">
                <PieChart>
                  <Pie
                    data={breakdown}
                    dataKey="value"
                    nameKey="name"
                    innerRadius={45}
                    outerRadius={75}
                    paddingAngle={3}
                  >
                    {breakdown.map((slice) => (
                      <Cell key={slice.name} fill={slice.fill} />
                    ))}
                  </Pie>
                  <Tooltip formatter={(v) => Number(v).toLocaleString()} />
                  <Legend verticalAlign="bottom" height={24} iconType="circle" />
                </PieChart>
              </ResponsiveContainer>
            )}
          </ChartCard>
          {daily.length > 0 ? (
            <ChartCard title="Daily sends" description="Delivered, opened and clicked per day">
              <ResponsiveContainer width="100%" height="100%">
                <AreaChart data={daily} margin={{ left: 4, right: 12 }}>
                  <CartesianGrid strokeDasharray="3 3" stroke="#e5e7eb" />
                  <XAxis dataKey="day" tick={{ fontSize: 12 }} />
                  <YAxis tick={{ fontSize: 12 }} />
                  <Tooltip formatter={(v) => Number(v).toLocaleString()} />
                  <Legend verticalAlign="top" height={24} iconType="circle" />
                  <Area
                    type="monotone"
                    dataKey="delivered"
                    name="Delivered"
                    stroke="#A8C73A"
                    fill="#A8C73A"
                    fillOpacity={0.2}
                  />
                  <Area
                    type="monotone"
                    dataKey="opened"
                    name="Opened"
                    stroke="#E28A1A"
                    fill="#E28A1A"
                    fillOpacity={0.2}
                  />
                  <Area
                    type="monotone"
                    dataKey="clicked"
                    name="Clicked"
                    stroke="#141414"
                    fill="#141414"
                    fillOpacity={0.1}
                  />
                </AreaChart>
              </ResponsiveContainer>
            </ChartCard>
          ) : null}
        </div>

        <DetailSection
          title="Recipients"
          description={`${recipients.length} sampled from ${campaign.recipients.toLocaleString()} sends`}
        >
          <Table>
            <TableHeader>
              <TableRow className="hover:bg-transparent">
                <TableHead>Name</TableHead>
                <TableHead className="hidden sm:table-cell">Phone</TableHead>
                <TableHead>Status</TableHead>
                <TableHead className="hidden md:table-cell">Sent at</TableHead>
              </TableRow>
            </TableHeader>
            <TableBody>
              {recipients.length === 0 ? (
                <TableRow>
                  <TableCell colSpan={4} className="h-24 text-center text-muted-foreground">
                    No recipient sample available for this campaign
                  </TableCell>
                </TableRow>
              ) : (
                recipients.map((r) => (
                  <TableRow key={r.id}>
                    <TableCell className="font-medium">
                      {r.customerId ? (
                        <Link to={`/crm/${r.customerId}`} className="text-brand-700 hover:underline">
                          {r.name}
                        </Link>
                      ) : (
                        r.name
                      )}
                    </TableCell>
                    <TableCell className="hidden whitespace-nowrap sm:table-cell">{r.phone}</TableCell>
                    <TableCell>
                      <Badge variant={recipientTone[r.status]}>{r.status}</Badge>
                    </TableCell>
                    <TableCell className="hidden whitespace-nowrap md:table-cell">
                      {new Date(r.sentAt).toLocaleString()}
                    </TableCell>
                  </TableRow>
                ))
              )}
            </TableBody>
          </Table>
        </DetailSection>
      </div>
    </DetailPageLayout>
  )
}