import { type DiscoverItem, type DiscoverMatchResult, tmdbImageUrl } from "@umt/contracts";
import { ExternalLink, LoaderCircle, Search, Star } from "lucide-react";
import { useState } from "react";
import { Link, useNavigate, useSearchParams } from "react-router";
import { toast } from "sonner";
import { useBangumiCalendar, useDiscoverMatch, useDoubanHot } from "~/api/discover.ts";
import { EmptyState, ErrorState, LoadingState } from "~/components/console/empty-state.tsx";
import { consolePath } from "~/components/console/nav.ts";
import { PageHeader } from "~/components/console/page-header.tsx";
import { Button } from "~/components/ui/button.tsx";
import { Dialog, DialogContent, DialogDescription, DialogHeader, DialogTitle } from "~/components/ui/dialog.tsx";
import { Tabs, TabsList, TabsTrigger } from "~/components/ui/tabs.tsx";
import { errorMessage } from "~/lib/api.ts";

// 发现(对照 MP 推荐页):bgm.tv 每日放送、豆瓣热门电影 / 剧集。点条目按名称 + 年份匹配 TMDB 作品,
// 确定的直接进作品页(可订阅、搜资源),不确定的列候选让人选。

export const meta = () => [{ title: "发现 · UHD 媒体自动化控制台" }];

type View = "anime" | "movie" | "tv";
const VIEWS: { value: View; label: string }[] = [
  { value: "anime", label: "番剧放送" },
  { value: "movie", label: "热门电影" },
  { value: "tv", label: "热门剧集" },
];

/** bgm 周一 = 1 … 周日 = 7 */
const todayWeekday = () => ((new Date().getDay() + 6) % 7) + 1;

export default function DiscoverPage() {
  const [sp, setSp] = useSearchParams();
  const view = (VIEWS.some((v) => v.value === sp.get("view")) ? sp.get("view") : "anime") as View;
  const [day, setDay] = useState(todayWeekday);
  const cal = useBangumiCalendar(view === "anime");
  const hot = useDoubanHot(view === "tv" ? "tv" : "movie", view !== "anime");
  const match = useDiscoverMatch();
  const navigate = useNavigate();
  const [picking, setPicking] = useState<{ item: DiscoverItem; result: DiscoverMatchResult } | null>(null);
  const [busyId, setBusyId] = useState<string | null>(null);

  const open = async (it: DiscoverItem) => {
    setBusyId(`${it.source}:${it.id}`);
    try {
      const r = await match.mutateAsync(it);
      if (r.match) navigate(consolePath("media", "tmdb", r.match.type, r.match.id));
      else setPicking({ item: it, result: r });
    } catch (err) {
      toast.error(errorMessage(err, "匹配 TMDB 失败"));
    } finally {
      setBusyId(null);
    }
  };

  const q = view === "anime" ? cal : hot;
  const items =
    view === "anime" ? (cal.data?.days.find((d) => d.weekday === day)?.items ?? []) : (hot.data?.items ?? []);

  return (
    <>
      <PageHeader title="发现" description="bgm.tv 每日放送与豆瓣热门；点开匹配到 TMDB 作品后可订阅或搜资源" />
      <Tabs value={view} onValueChange={(v) => setSp(new URLSearchParams({ view: v }), { replace: true })}>
        <TabsList className="mb-4">
          {VIEWS.map((v) => (
            <TabsTrigger key={v.value} value={v.value}>
              {v.label}
            </TabsTrigger>
          ))}
        </TabsList>
      </Tabs>
      {view === "anime" && cal.data ? (
        <div className="mb-4 flex flex-wrap gap-1.5">
          {cal.data.days.map((d) => (
            <Button
              key={d.weekday}
              size="sm"
              variant={d.weekday === day ? "default" : "outline"}
              onClick={() => setDay(d.weekday)}
            >
              {d.label}
              <span className="text-micro opacity-70">{d.items.length}</span>
            </Button>
          ))}
        </div>
      ) : null}
      {q.isLoading ? (
        <LoadingState rows={4} />
      ) : q.error ? (
        <ErrorState error={q.error} onRetry={() => void q.refetch()} />
      ) : items.length === 0 ? (
        <EmptyState title="没有条目" />
      ) : (
        <ul className="grid grid-cols-2 gap-3 sm:grid-cols-3 md:grid-cols-4 lg:grid-cols-6">
          {items.map((it) => (
            <li key={`${it.source}:${it.id}`}>
              <ItemCard item={it} busy={busyId === `${it.source}:${it.id}`} onOpen={() => void open(it)} />
            </li>
          ))}
        </ul>
      )}
      {picking ? <PickDialog {...picking} onClose={() => setPicking(null)} /> : null}
    </>
  );
}

function ItemCard({ item, busy, onOpen }: { item: DiscoverItem; busy: boolean; onOpen: () => void }) {
  const [failed, setFailed] = useState(false);
  return (
    <button
      type="button"
      onClick={onOpen}
      disabled={busy}
      className="group flex w-full min-w-0 flex-col overflow-hidden rounded-lg border border-border/70 text-left transition-colors hover:border-foreground/40 disabled:opacity-70"
    >
      <div className="relative aspect-[2/3] w-full bg-muted">
        {item.cover && !failed ? (
          <img
            src={item.cover}
            alt=""
            loading="lazy"
            referrerPolicy="no-referrer"
            onError={() => setFailed(true)}
            className="h-full w-full object-cover"
          />
        ) : null}
        {busy ? (
          <span className="absolute inset-0 grid place-items-center bg-background/60">
            <LoaderCircle className="h-5 w-5 animate-spin" />
          </span>
        ) : null}
      </div>
      <div className="min-w-0 px-2 py-1.5">
        <p className="truncate text-caption font-medium text-foreground" title={item.title}>
          {item.title}
        </p>
        <p className="flex items-center gap-2 text-meta text-muted-foreground">
          <span>{item.date ?? item.year ?? "—"}</span>
          {item.rating ? (
            <span className="inline-flex items-center gap-0.5">
              <Star className="h-3 w-3" />
              {item.rating.toFixed(1)}
            </span>
          ) : null}
        </p>
      </div>
    </button>
  );
}

function PickDialog({
  item,
  result,
  onClose,
}: {
  item: DiscoverItem;
  result: DiscoverMatchResult;
  onClose: () => void;
}) {
  return (
    <Dialog open onOpenChange={(o) => !o && onClose()}>
      <DialogContent className="sm:max-w-lg">
        <DialogHeader>
          <DialogTitle>选择 TMDB 作品</DialogTitle>
          <DialogDescription>
            「{item.title}」{item.year ? `（${item.year}）` : ""}没能自动确定对应的 TMDB 作品。
          </DialogDescription>
        </DialogHeader>
        {result.candidates.length ? (
          <ul className="grid gap-2">
            {result.candidates.map((c) => (
              <li key={`${c.type}:${c.id}`}>
                <Link
                  to={consolePath("media", "tmdb", c.type, c.id)}
                  onClick={onClose}
                  className="flex items-center gap-3 rounded-lg border border-border/70 p-2 hover:border-foreground/40 hover:bg-accent"
                >
                  <span className="h-14 w-10 shrink-0 overflow-hidden rounded bg-muted">
                    {c.posterPath ? (
                      <img
                        src={tmdbImageUrl(c.posterPath, "w92") ?? ""}
                        alt=""
                        className="h-full w-full object-cover"
                      />
                    ) : null}
                  </span>
                  <span className="min-w-0">
                    <span className="block truncate text-caption font-medium">{c.title}</span>
                    <span className="text-meta text-muted-foreground">
                      {c.type === "movie" ? "电影" : "剧集"} · {c.year ?? "—"}
                    </span>
                  </span>
                </Link>
              </li>
            ))}
          </ul>
        ) : (
          <p className="text-caption text-muted-foreground">TMDB 上没有找到相近的作品。</p>
        )}
        <div className="flex flex-wrap gap-2">
          <Button asChild variant="outline" size="sm">
            <Link to={`${consolePath("search")}?q=${encodeURIComponent(item.title)}`} onClick={onClose}>
              <Search />
              按名称搜索
            </Link>
          </Button>
          <Button asChild variant="ghost" size="sm">
            <a href={item.url} target="_blank" rel="noreferrer">
              <ExternalLink />
              {item.source === "bangumi" ? "bgm.tv" : "豆瓣"}
            </a>
          </Button>
        </div>
      </DialogContent>
    </Dialog>
  );
}