// ============================
// Volume adjustment
// ============================
document.querySelectorAll("audio").forEach((audio) => {
  audio.volume = 0.5;
});

// ============================
// Fisher-Yates Shuffle
// ============================
function fisherYatesShuffle(arr) {
  for (let i = arr.length - 1; i > 0; i--) {
    const j = Math.floor(Math.random() * (i + 1));
    [arr[i], arr[j]] = [arr[j], arr[i]];
  }
  return arr;
}

// ============================
// Fetch & build playlist safely
// ============================
async function loadMusicData() {
  try {
    const response = await fetch("https://api.veltron.net");

    if (!response.ok) {
      console.error("HTTP error:", response.status);
      return [];
    }

    const text = await response.text();

    let data;
    try {
      data = JSON.parse(text);
    } catch (e) {
      console.error("Invalid JSON returned from API");
      return [];
    }

    if (!data?.ols || !Array.isArray(data.ols)) {
      console.error("Invalid API structure");
      return [];
    }

    const section = data.ols.find(
      (item) => item?.["@id"] === "frutigerAeroBliss"
    );

    if (!section?.li || !Array.isArray(section.li)) {
      console.error("Playlist section missing or invalid");
      return [];
    }

    const baseUrl = "https://cdn.veltron.net/aero";

    const playlist = section.li
    .map((item) => {
      const mp3 = item?.a?.["@data-src-mp3"];
      const title = item?.a?.title;

      if (!mp3 || !title) return null;

      return {
        title,
        url: baseUrl + mp3.split("/").pop(),
         background: item.a["@data-background"] || "",
         artist: item.a["@data-artist"] || "",
         spotifyLink: item.a["@data-spotify"] || "",
         youtubeLink: item.a["@data-youtube"] || ""
      };
    })
    .filter(Boolean);

    return fisherYatesShuffle(playlist);
  } catch (err) {
    console.error("Failed to load music data:", err);
    return [];
  }
}

// ============================
// DOM Elements
// ============================
const NAV_MUSIC = document.getElementById("navMusic");
const BUTTON_PLAY = document.getElementById("navMusicPlay");
const BUTTON_PAUSE = document.getElementById("navMusicPause");
const BUTTON_PREVIOUS = document.getElementById("navMusicPrevious");
const BUTTON_NEXT = document.getElementById("navMusicNext");
const CURRENT_SONG_INFO = document.getElementById("currentSongInfo");

// ============================
// State
// ============================
let songs = [];
let currentIndex = 0;
let isPlaying = false;

// ============================
// Persistence
// ============================
function saveState() {
  sessionStorage.setItem("isPlaying", isPlaying);
}

function loadState() {
  const saved = sessionStorage.getItem("isPlaying");
  if (saved !== null) {
    isPlaying = saved === "true";
  }
}

// ============================
// Load Song (SAFE)
// ============================
function loadSong(index) {
  if (!songs?.length) return;
  if (index < 0 || index >= songs.length) return;

  const song = songs[index];
  if (!song?.url) {
    console.warn("Skipping invalid song:", index);
    return;
  }

  NAV_MUSIC.src = song.url;
  CURRENT_SONG_INFO.innerText = `Featured song: ${song.title}`;
  NAV_MUSIC.load();
}

// ============================
// UI State
// ============================
function updateButtonStates() {
  if (isPlaying) {
    BUTTON_PLAY.classList.add("active");
    BUTTON_PAUSE.classList.remove("active");
  } else {
    BUTTON_PAUSE.classList.add("active");
    BUTTON_PLAY.classList.remove("active");
  }
}

// ============================
// Controls
// ============================
BUTTON_PLAY.addEventListener("click", () => {
  if (!songs.length) return;

  isPlaying = true;
  NAV_MUSIC.play();
  updateButtonStates();
  saveState();
});

BUTTON_PAUSE.addEventListener("click", () => {
  isPlaying = false;
  NAV_MUSIC.pause();
  updateButtonStates();
  saveState();
});

BUTTON_PREVIOUS.addEventListener("click", () => {
  if (!songs.length) return;

  currentIndex = currentIndex === 0 ? songs.length - 1 : currentIndex - 1;
  loadSong(currentIndex);

  if (isPlaying) NAV_MUSIC.play();
  saveState();
});

BUTTON_NEXT.addEventListener("click", () => {
  if (!songs.length) return;

  currentIndex = (currentIndex + 1) % songs.length;
  loadSong(currentIndex);

  if (isPlaying) NAV_MUSIC.play();
  saveState();
});

// ============================
// Auto-next
// ============================
NAV_MUSIC.addEventListener("ended", () => {
  if (!songs.length) return;

  currentIndex = (currentIndex + 1) % songs.length;
  loadSong(currentIndex);

  if (isPlaying) NAV_MUSIC.play();
  saveState();
});

// ============================
// Init
// ============================
window.addEventListener("load", async () => {
  songs = await loadMusicData();

  if (!songs.length) {
    console.error("No songs loaded.");
    CURRENT_SONG_INFO.innerText = "No music available";
    return;
  }

  loadState();
  loadSong(currentIndex);

  if (isPlaying) {
    NAV_MUSIC.play().catch(() => {});
  }

  updateButtonStates();
});

// ============================
// Pause other audio elements
// ============================
document.addEventListener(
  "play",
  (e) => {
    const audios = document.getElementsByTagName("audio");
    for (let i = 0; i < audios.length; i++) {
      if (audios[i] !== e.target) {
        audios[i].pause();
      }
    }
  },
  true
);