import { useEffect, useMemo, useState, type ReactNode } from 'react'
import { Link } from 'react-router-dom'
import { motion } from 'framer-motion'
import { ArrowRight, Film, FolderOpen, Library as LibraryIcon, Music, PlayCircle, RefreshCw, Tv } from 'lucide-react'

import { imageURL } from '../api/client'
import { libraryAPI } from '../api/library'
import { toolsAPI } from '../api/tools'
import { MediaCard } from '../components/MediaCard'
import type { Library, Media } from '../types'
import { artworkScore, groupSeries, seriesCardLink, type SeriesCard } from '../utils/groupSeries'

type LibraryPreview = {
  library: Library
  items: Media[]
  total: number
  cards: SeriesCard[]
}

const TYPE_ICONS: Record<string, ReactNode> = {
  movie: <Film size={18} />,
  tv: <Tv size={18} />,
  anime: <PlayCircle size={18} />,
  variety: <Tv size={18} />,
  music: <Music size={18} />,
}

const TYPE_LABELS: Record<string, string> = {
  movie: '电影',
  tv: '剧集',
  anime: '动漫',
  variety: '综艺',
  music: '音乐',
}

export function LibrariesPage() {
  const [previews, setPreviews] = useState<LibraryPreview[]>([])
  const [loading, setLoading] = useState(true)
  const [repairing, setRepairing] = useState(false)
  const [repairMsg, setRepairMsg] = useState('')

  async function handleRepairRescrape() {
    if (repairing) return
    setRepairing(true)
    setRepairMsg('')
    try {
      await toolsAPI.repairAndRescrapeAll()
      setRepairMsg('已开始全库修复+重刮，进度可在任务中查看。')
    } catch {
      setRepairMsg('启动失败，请稍后重试。')
    } finally {
      setRepairing(false)
    }
  }

  useEffect(() => {
    let cancelled = false
    async function load() {
      setLoading(true)
      try {
        const libs = await libraryAPI.list()
        const rows = await Promise.all(libs.map(async (library) => {
          try {
            const page = await libraryAPI.listMedia(library.id, 1, 160)
            const cards = latestCards(page.items)
            return { library, items: page.items, total: page.total, cards } satisfies LibraryPreview
          } catch {
            return { library, items: [], total: 0, cards: [] } satisfies LibraryPreview
          }
        }))
        if (!cancelled) setPreviews(rows)
      } finally {
        if (!cancelled) setLoading(false)
      }
    }
    load()
    return () => { cancelled = true }
  }, [])

  const total = useMemo(() => previews.reduce((sum, preview) => sum + preview.total, 0), [previews])

  if (loading) {
    return <p className="px-2 py-8 text-sm text-sand-500">媒体库加载中…</p>
  }

  return (
    <div className="space-y-8">
      <div className="flex flex-wrap items-end justify-between gap-4">
        <div>
          <h1 className="font-display text-3xl font-bold text-ink-600">媒体库</h1>
          <p className="mt-1 text-sm text-ink-50">
            共 {previews.length} 个目录 · {total.toLocaleString()} 个条目。每个目录直接展示最新入库内容。
          </p>
        </div>
        <div className="flex flex-wrap items-center gap-3">
          {repairMsg && <span className="text-xs text-ink-50">{repairMsg}</span>}
          <button
            type="button"
            onClick={handleRepairRescrape}
            disabled={repairing}
            className="btn-outline disabled:cursor-not-allowed disabled:opacity-60"
            title="从媒体路径回填缺失/错误的外部 ID，再批量重刮整库"
          >
            <RefreshCw size={14} className={repairing ? 'animate-spin' : ''} />
            {repairing ? '正在启动…' : '全库修复+重刮'}
          </button>
          <Link to="/admin" className="btn-outline">
            管理媒体库
            <ArrowRight size={14} />
          </Link>
        </div>
      </div>

      {previews.length === 0 ? (
        <div className="flex flex-col items-center justify-center rounded-3xl border border-dashed border-sand-200 bg-white py-24 text-center">
          <LibraryIcon className="mb-4 h-12 w-12 text-gray-400" />
          <p className="text-sm text-ink-50">暂无媒体库，请到管理后台添加目录。</p>
        </div>
      ) : (
        <>
          <section className="space-y-4">
            <div>
              <h2 className="font-display text-2xl font-bold text-ink-600">媒体库入口</h2>
              <p className="text-sm text-ink-50">按目录进入完整媒体库；下方每个目录也会直接展示最新内容。</p>
            </div>
            <div className="grid gap-4 sm:grid-cols-2 xl:grid-cols-3">
              {previews.map((preview, index) => (
                <motion.div
                  key={preview.library.id}
                  initial={{ opacity: 0, y: 12 }}
                  animate={{ opacity: 1, y: 0 }}
                  transition={{ delay: index * 0.03 }}
                >
                  <LibraryEntryCard preview={preview} />
                </motion.div>
              ))}
            </div>
          </section>

          <section className="space-y-6">
            {previews.map((preview, index) => (
              <motion.div
                key={preview.library.id}
                initial={{ opacity: 0, y: 12 }}
                animate={{ opacity: 1, y: 0 }}
                transition={{ delay: index * 0.03 }}
              >
                <LibraryShelf preview={preview} />
              </motion.div>
            ))}
          </section>
        </>
      )}
    </div>
  )
}

function LibraryEntryCard({ preview }: { preview: LibraryPreview }) {
  const library = preview.library
  const artwork = preview.cards
    .sort((a, b) => artworkScore(b.rep) - artworkScore(a.rep) || mediaTime(b.rep) - mediaTime(a.rep))
    .map((card) => card.rep.poster_url || card.rep.backdrop_url)
    .filter(Boolean)
    .slice(0, 4) as string[]

  return (
    <Link
      to={`/library/${library.id}`}
      className="group flex overflow-hidden rounded-3xl border border-sand-200 bg-white p-3 shadow-card transition-all hover:-translate-y-0.5 hover:border-brand-200 hover:shadow-card-hover"
    >
      <div className="grid h-24 w-36 shrink-0 grid-cols-2 gap-1 overflow-hidden rounded-2xl bg-[linear-gradient(135deg,#fff7ed,#f8fafc)]">
        {artwork.length > 0 ? (
          artwork.map((src, index) => (
            <img
              key={`${src}-${index}`}
              src={imageURL(src)}
              alt=""
              loading="lazy"
              referrerPolicy="no-referrer"
              className="h-full w-full object-cover"
              onError={(event) => { event.currentTarget.style.visibility = 'hidden' }}
            />
          ))
        ) : (
          <div className="col-span-2 flex h-full items-center justify-center text-brand-500">
            {TYPE_ICONS[library.type] ?? <FolderOpen size={34} />}
          </div>
        )}
      </div>
      <div className="flex min-w-0 flex-1 flex-col justify-between px-4 py-1">
        <div>
          <div className="mb-1 inline-flex rounded-full bg-sand-100 px-2 py-0.5 text-[10px] font-bold text-sand-600">
            {TYPE_LABELS[library.type] ?? library.type}
          </div>
          <h2 className="truncate font-display text-xl font-black text-ink-600 group-hover:text-brand-600">
            {library.name}
          </h2>
          <p className="mt-1 line-clamp-1 break-all text-xs text-ink-50">{library.path}</p>
        </div>
        <div className="flex items-center justify-between text-xs font-bold">
          <span className="text-sand-600">{preview.total.toLocaleString()} 个条目</span>
          <span className="text-brand-600">浏览全部</span>
        </div>
      </div>
    </Link>
  )
}

function LibraryShelf({ preview }: { preview: LibraryPreview }) {
  const library = preview.library
  const cards = preview.cards.slice(0, 10)

  return (
    <section className="rounded-[1.7rem] border border-sand-200 bg-white/75 p-4 shadow-card">
      <div className="mb-4 flex flex-wrap items-end justify-between gap-3">
        <div className="min-w-0">
          <div className="mb-1 inline-flex items-center gap-2 rounded-full bg-brand-50 px-2.5 py-1 text-[11px] font-bold text-brand-700">
            {TYPE_ICONS[library.type] ?? <LibraryIcon size={14} />}
            {TYPE_LABELS[library.type] ?? library.type}
          </div>
          <h2 className="truncate font-display text-2xl font-black text-ink-600">{library.name}</h2>
          <p className="mt-1 line-clamp-1 break-all text-xs text-ink-50">
            {library.path} · {preview.total.toLocaleString()} 个条目 · 最新 {cards.length} 部
          </p>
        </div>
        <Link to={`/library/${library.id}`} className="btn-outline shrink-0">
          浏览全部
          <ArrowRight size={14} />
        </Link>
      </div>

      {cards.length > 0 ? (
        <div className="flex gap-4 overflow-x-auto pb-2 pr-1">
          {cards.map((card) => (
            <div key={card.key} className="w-[9.5rem] shrink-0 lg:w-[10rem] 2xl:w-[10.5rem]">
              <MediaCard
                media={card.rep}
                count={card.count}
                linkTo={seriesCardLink(card)}
              />
            </div>
          ))}
        </div>
      ) : (
        <div className="rounded-2xl border border-dashed border-sand-200 bg-white px-6 py-10 text-center text-sm text-ink-50">
          该目录暂无可展示内容，扫描媒体库后会出现在这里。
        </div>
      )}
    </section>
  )
}

function latestCards(items: Media[]): SeriesCard[] {
  return groupSeries(items)
    .sort((a, b) => mediaTime(b.rep) - mediaTime(a.rep) || artworkScore(b.rep) - artworkScore(a.rep))
    .slice(0, 10)
}

function mediaTime(media: Media): number {
  return Date.parse(media.updated_at || media.created_at || '') || 0
}