import { useEffect, useState, useCallback } from "react";
import { useNavigate } from "react-router-dom";
import api from "../lib/api";
import Hero from "../components/Hero";
import Row from "../components/Row";
import MovieDetailModal from "../components/MovieDetailModal";

export default function Browse() {
  const nav = useNavigate();
  const [featured, setFeatured] = useState(null);
  const [movies, setMovies] = useState([]);
  const [genres, setGenres] = useState([]);
  const [continueWatching, setContinueWatching] = useState([]);
  const [watchlist, setWatchlist] = useState([]);
  const [selected, setSelected] = useState(null);
  const [progressMap, setProgressMap] = useState({});

  const load = useCallback(async () => {
    const [{ data: f }, { data: ms }, { data: gs }, { data: cw }, { data: wl }] = await Promise.all([
      api.get("/movies/featured").catch(() => ({ data: null })),
      api.get("/movies"),
      api.get("/movies/genres"),
      api.get("/progress/continue").catch(() => ({ data: [] })),
      api.get("/watchlist").catch(() => ({ data: [] })),
    ]);
    setFeatured(f);
    setMovies(ms);
    setGenres(gs);
    setContinueWatching(cw);
    setWatchlist(wl);
    const map = {};
    for (const m of cw) map[m.id] = m.progress;
    setProgressMap(map);
  }, []);

  useEffect(() => { load(); }, [load]);

  const handlePlay = (m) => nav(`/watch/${m.id}`);
  const handleMore = (m) => setSelected(m);
  const handleAddList = async (m) => {
    try { await api.post(`/watchlist/${m.id}`); load(); } catch {}
  };

  const byGenre = (g) => movies.filter((m) => m.genres?.includes(g));
  const trending = movies.slice(0, 10);
  const newReleases = [...movies].sort((a, b) => b.year - a.year).slice(0, 12);

  return (
    <div className="min-h-screen bg-[#050505]" data-testid="browse-page">
      {featured && (
        <Hero
          movie={featured}
          onPlay={handlePlay}
          onMore={handleMore}
          onAddList={handleAddList}
        />
      )}

      <div className="-mt-20 relative z-10 pb-24">
        {continueWatching.length > 0 && (
          <Row title="Resume" movies={continueWatching} onCardClick={handleMore} progressMap={progressMap} />
        )}
        <Row title="Popular" movies={trending} onCardClick={handleMore} progressMap={progressMap} />
        <Row title="Fresh Arrivals" movies={newReleases} onCardClick={handleMore} progressMap={progressMap} />
        {watchlist.length > 0 && (
          <Row title="Your Shelf" movies={watchlist} onCardClick={handleMore} progressMap={progressMap} />
        )}
        {genres.slice(0, 6).map((g) => {
          const list = byGenre(g);
          if (!list.length) return null;
          return <Row key={g} title={g} movies={list} onCardClick={handleMore} progressMap={progressMap} />;
        })}
      </div>

      <MovieDetailModal
        movie={selected}
        open={!!selected}
        onClose={() => setSelected(null)}
        onWatchlistChange={load}
      />
    </div>
  );
}