import { useState, useEffect, useRef } from "react";
import Hls from "hls.js";
import { metaData } from "../config";
import Play from "@mui/icons-material/PlayArrow";
import Pause from "@mui/icons-material/Pause";
import "@styles/player.css";

const API_URL = "https://api.codey.lol";
const STATIONS = {
  main: { label: "Main" },
  rock: { label: "Rock" },
  rap: { label: "Rap" },
  electronic: { label: "Electronic" },
  classical: { label: "Classical" },
  pop: { label: "Pop" },
};

let activeInterval = null;
let currentStationForInterval = null;

function clearGlobalMetadataInterval() {
  if (activeInterval) {
    clearInterval(activeInterval);
    activeInterval = null;
    currentStationForInterval = null;
  }
}

export function Player() {
  const [activeStation, setActiveStation] = useState("main");
  const [isPlaying, setIsPlaying] = useState(false);
  const [trackTitle, setTrackTitle] = useState("");
  const [trackArtist, setTrackArtist] = useState("");
  const [trackGenre, setTrackGenre] = useState("");
  const [trackAlbum, setTrackAlbum] = useState("");
  const [coverArt, setCoverArt] = useState("/images/radio_art_default.jpg");
  const [elapsed, setElapsed] = useState(0);
  const [duration, setDuration] = useState(0);

  const audioRef = useRef(null);
  const hlsRef = useRef(null);
  const uuidRef = useRef(null);
  const lastStationData = useRef(null);

  const formatTime = (seconds) => {
    const m = String(Math.floor(seconds / 60)).padStart(2, "0");
    const s = String(Math.floor(seconds % 60)).padStart(2, "0");
    return `${m}:${s}`;
  };

  const progress = duration > 0 ? (elapsed / duration) * 100 : 0;

  const playStream = () => {
    const lcStation = activeStation.toLowerCase();
    const streamUrl = `https://stream.codey.lol/hls/${lcStation}/${lcStation}.m3u8?t=${Date.now()}`;

    // Cleanup existing stream
    if (hlsRef.current) {
      hlsRef.current.destroy();
      hlsRef.current = null;
    }

    const audio = audioRef.current;
    if (!audio) return;

    if (audio.canPlayType("application/vnd.apple.mpegurl")) {
      // Native support (Safari)
      audio.src = streamUrl;
      audio.play().then(() => setIsPlaying(true)).catch(console.error);
    } else if (Hls.isSupported()) {
      const hls = new Hls({
        maxBufferLength: 30,
        maxMaxBufferLength: 60,
        abrEwmaFastLive: 2.0,
        abrEwmaSlowLive: 6.0,
        abrBandWidthFactor: 0.95, // Bias toward higher quality
        autoStartLoad: true,
        startLevel: -1, // adaptive start
      });

      hls.loadSource(streamUrl);
      hls.attachMedia(audio);

      hls.on(Hls.Events.ERROR, (_, data) => {
        if (data.fatal) {
          console.error("HLS fatal error:", data);
          hls.destroy();
        }
      });

      hlsRef.current = hls;
      audio.play().then(() => setIsPlaying(true)).catch(console.error);
    } else {
      console.error("HLS not supported");
    }
  };

  const togglePlayback = () => {
    const audio = audioRef.current;
    if (!audio) return;

    if (isPlaying) {
      audio.pause();
      setIsPlaying(false);
    } else {
      audio.play().then(() => setIsPlaying(true)).catch(console.error);
    }
  };

  useEffect(() => {
    const audio = audioRef.current;
    if (audio) {
      audio.pause();
      audio.src = "";
      setIsPlaying(false);
    }

    playStream();

    return () => {
      if (hlsRef.current) {
        hlsRef.current.destroy();
        hlsRef.current = null;
      }
    };
  }, [activeStation]);

  useEffect(() => {
    clearGlobalMetadataInterval();
    currentStationForInterval = activeStation;

    const setPageTitle = (artist, song) => {
      document.title = `${metaData.title} - Radio - ${artist} - ${song} [${activeStation}]`;
    };

    const fetchTrackData = async () => {
      try {
        const response = await fetch(`${API_URL}/radio/np?station=${activeStation}`, {
          method: "POST",
        });
        const data = await response.json();

        if (currentStationForInterval !== activeStation) return;

        if (data.artist === "N/A" && data.song === "N/A") {
          if (lastStationData.current !== "offline") {
            setTrackTitle("Offline");
            setTrackArtist("");
            setTrackAlbum("");
            setTrackGenre("");
            setCoverArt("/images/radio_art_default.jpg");
            setElapsed(0);
            setDuration(0);
            lastStationData.current = "offline";
          }
          return;
        }

        if (data.uuid === uuidRef.current) {
          if (lastStationData.current === data.uuid) {
            setElapsed(data.elapsed);
            setDuration(data.duration);
          }
          return;
        }

        uuidRef.current = data.uuid;
        lastStationData.current = data.uuid;
        setTrackTitle(data.song);
        setTrackArtist(data.artist);
        setTrackGenre(data.genre !== "N/A" ? data.genre : "");
        setTrackAlbum(data.album);
        setPageTitle(data.artist, data.song);
        setCoverArt(`${API_URL}/radio/album_art?station=${activeStation}&_=${Date.now()}`);
        setElapsed(data.elapsed);
        setDuration(data.duration);
      } catch (error) {
        console.error("Failed to fetch track data:", error);
      }
    };

    fetchTrackData();
    activeInterval = setInterval(fetchTrackData, 1000);

    return () => clearGlobalMetadataInterval();
  }, [activeStation]);

  const remaining = duration - elapsed;

  const progressColorClass =
    progress >= 90
      ? "bg-red-500 dark:bg-red-400"
      : progress >= 75 || remaining <= 20
      ? "bg-yellow-400 dark:bg-yellow-300"
      : "bg-blue-500 dark:bg-blue-400";

  return (
    <>
      <div className="station-tabs flex gap-2 justify-center mb-4 flex-wrap z-10 relative">
        {Object.entries(STATIONS).map(([key, { label }]) => (
          <button
            key={key}
            className={`px-3 py-1 rounded-full text-sm font-semibold transition-colors ${
              activeStation === key
                ? "bg-neutral-800 text-white dark:bg-white dark:text-black"
                : "bg-neutral-200 text-black dark:bg-neutral-700 dark:text-white"
            }`}
            onClick={() => setActiveStation(key)}
            aria-pressed={activeStation === key}
          >
            {label}
          </button>
        ))}
      </div>

      <div className="c-containter">
        <div className="music-container mt-8">
          <section className="album-cover">
            <div className="music-player__album" title="Album">{trackAlbum}</div>
            <img
              src={coverArt}
              className="cover"
              title={trackAlbum ? `"${trackAlbum}" Cover Art` : "Cover Art"}
              alt={trackAlbum ? `"${trackAlbum}" Cover Art` : "Cover Art"}
            />
          </section>

          <section className="music-player">
            <h1 className="music-player__header">serious.FM</h1>
            <h1 className="music-player__title">{trackTitle}</h1>
            <h2 className="music-player__author">{trackArtist}</h2>
            {trackGenre && <h2 className="music-player__genre">{trackGenre}</h2>}

            <div className="music-time">
              <p className="music-time__current">{formatTime(elapsed)}</p>
              <p className="music-time__last">{formatTime(remaining)}</p>
            </div>

            <div className="w-full h-2 rounded bg-neutral-300 dark:bg-neutral-700 overflow-hidden">
              <div
                className={`h-full transition-all duration-200 ${progressColorClass}`}
                style={{ width: `${progress}%` }}
              ></div>
            </div>

            <div className="music-control">
              <div
                className="music-control__play"
                onClick={togglePlayback}
                role="button"
                tabIndex={0}
                aria-pressed={isPlaying}
              >
                {!isPlaying ? <Play /> : <Pause />}
              </div>
            </div>
          </section>
        </div>

        <audio ref={audioRef} preload="none" />
      </div>
    </>
  );
}