// Nanga Kathai marketing site. Reads a few songs and the catalogue counts from the live Supabase
// backend (same tables as lib/data/catalog_repository.dart; row-level security only returns
// approved songs) and plays them in the browser. Settings come from config.js (tools/build_site.py).
(() => {
  'use strict';
  const cfg = window.NK_CONFIG || {};
  const API = `${cfg.supabaseUrl}/rest/v1`;
  const headers = { apikey: cfg.supabaseKey, Authorization: `Bearer ${cfg.supabaseKey}` };
  const FEATURED = 6;

  // Same occasion labels and colours as lib/core/models.dart.
  const OCCASIONS = {
    huttu: ['Huttu', '#3B6E8F'],
    habba: ['Habba', '#B5541E'],
    madhuvae: ['Madhuvae', '#9C2F4A'],
    devotional: ['Devotional', '#6B4FA0'],
    folk: ['Folk songs', '#2E7D5B'],
    saavu: ['Saavu', '#4A4F57'],
    instrumental: ['Instrumental', '#8A5A2B'],
  };

  const $ = (sel, el = document) => el.querySelector(sel);
  const esc = (s) => String(s ?? '').replace(/[&<>"']/g, (c) => ({ '&': '&amp;', '<': '&lt;', '>': '&gt;', '"': '&quot;', "'": '&#39;' }[c]));
  const fmt = (sec) => `${Math.floor(sec / 60)}:${String(Math.round(sec % 60)).padStart(2, '0')}`;
  const icons = {
    play: '<svg viewBox="0 0 24 24" fill="currentColor"><path d="M8 5.5v13a1 1 0 0 0 1.5.86l10.5-6.5a1 1 0 0 0 0-1.72L9.5 4.64A1 1 0 0 0 8 5.5z"/></svg>',
    pause: '<svg viewBox="0 0 24 24" fill="currentColor"><rect x="6" y="5" width="4" height="14" rx="1"/><rect x="14" y="5" width="4" height="14" rx="1"/></svg>',
  };

  async function get(path, extra = {}) {
    const res = await fetch(`${API}/${path}`, { headers: { ...headers, ...extra } });
    if (!res.ok) throw new Error(`${res.status} ${path}`);
    return res;
  }

  // One song from each of the biggest albums, so the sample shows some variety.
  async function loadSongs() {
    const [artists, albums, tracks] = await Promise.all([
      get('artists?select=id,name_latin').then((r) => r.json()),
      get('albums?select=id,title_latin,cover_url').then((r) => r.json()),
      get('tracks?select=id,title_latin,album_id,occasion,duration_ms,audio_key_128,cover_url,'
        + 'track_artists(artist_id,position,role)&status=eq.approved&order=created_at.asc').then((r) => r.json()),
    ]);
    const artistName = new Map(artists.map((a) => [a.id, a.name_latin]));
    const albumById = new Map(albums.map((a) => [a.id, a]));
    const byAlbum = new Map();
    for (const t of tracks) {
      if (!byAlbum.has(t.album_id)) byAlbum.set(t.album_id, []);
      byAlbum.get(t.album_id).push(t);
    }
    const picks = [...byAlbum.values()].sort((a, b) => b.length - a.length).slice(0, FEATURED).map((list) => list[0]);
    const songs = picks.map((r) => {
      const album = albumById.get(r.album_id);
      const singers = (r.track_artists || []).filter((t) => t.role === 'singer')
        .sort((a, b) => a.position - b.position).map((t) => artistName.get(t.artist_id)).filter(Boolean);
      const [label, color] = OCCASIONS[r.occasion] || OCCASIONS.folk;
      return {
        id: r.id,
        title: r.title_latin,
        credit: singers.join(', ') || album?.title_latin || 'Badaga song',
        album: album?.title_latin,
        label,
        color,
        coverUrl: r.cover_url || album?.cover_url || null,
        audioUrl: `${cfg.mediaBaseUrl}/${r.audio_key_128}`,
        seconds: (r.duration_ms || 0) / 1000,
      };
    });
    return { songs, songCount: tracks.length, albumCount: byAlbum.size };
  }

  const cover = (s) => `<div class="cover" style="background:${s.color}">${s.coverUrl
    ? `<img src="${esc(s.coverUrl)}" alt="" loading="lazy" onerror="this.remove()">` : '<span>&#9834;</span>'}</div>`;

  // ---------- Player ----------
  const audio = new Audio();
  audio.preload = 'none';
  let songs = [];
  let current = -1;

  function play(i) {
    if (i === current) { audio.paused ? audio.play() : audio.pause(); return; }
    current = i;
    const s = songs[i];
    audio.src = s.audioUrl;
    audio.play().catch(() => {});
    $('#phone-title').textContent = s.title;
    $('#phone-credit').textContent = s.credit;
    $('#phone-art').innerHTML = cover(s);
    if ('mediaSession' in navigator) {
      navigator.mediaSession.metadata = new MediaMetadata({
        title: s.title, artist: s.credit, album: s.album || 'Nanga Kathai',
        artwork: [{ src: s.coverUrl || '/img/icon-256.png', sizes: '256x256' }],
      });
    }
    sync();
  }

  function sync() {
    document.querySelectorAll('.sample').forEach((el, i) => {
      const on = i === current && !audio.paused;
      el.classList.toggle('playing', i === current);
      el.querySelector('.sample-btn').innerHTML = on ? icons.pause : icons.play;
      el.querySelector('.sample-btn').setAttribute('aria-label', `${on ? 'Pause' : 'Play'} ${songs[i].title}`);
    });
    const btn = $('#phone-play');
    btn.innerHTML = audio.paused ? icons.play : icons.pause;
    btn.setAttribute('aria-label', audio.paused ? 'Play' : 'Pause');
  }

  audio.addEventListener('play', sync);
  audio.addEventListener('pause', sync);
  audio.addEventListener('ended', () => (current < songs.length - 1 ? play(current + 1) : sync()));
  audio.addEventListener('timeupdate', () => {
    if (!audio.duration) return;
    $('#phone-bar').style.width = `${(audio.currentTime / audio.duration) * 100}%`;
    $('#phone-time').textContent = fmt(audio.currentTime);
    $('#phone-total').textContent = fmt(audio.duration);
  });

  $('#phone-play').onclick = () => play(current < 0 ? 0 : current);
  $('#phone-next').onclick = () => songs.length && play((current + 1) % songs.length);
  $('#phone-prev').onclick = () => songs.length && play(current <= 0 ? 0 : current - 1);

  loadSongs().then((data) => {
    songs = data.songs;
    $('#count-songs').textContent = data.songCount;
    $('#count-albums').textContent = data.albumCount;
    $('#samples').innerHTML = songs.map((s, i) => `
      <li class="sample">
        <button class="sample-btn" aria-label="Play ${esc(s.title)}">${icons.play}</button>
        ${cover(s)}
        <div class="t"><b>${esc(s.title)}</b><span>${esc(s.credit)}</span></div>
        <span class="tag" style="--c:${s.color}">${esc(s.label)}</span>
        <span class="dur">${s.seconds ? fmt(s.seconds) : ''}</span>
      </li>`).join('');
    $('#samples').querySelectorAll('.sample').forEach((el, i) => { el.onclick = () => play(i); });
    if (songs[0]) {
      $('#phone-title').textContent = songs[0].title;
      $('#phone-credit').textContent = songs[0].credit;
      $('#phone-art').innerHTML = cover(songs[0]);
      $('#phone-total').textContent = fmt(songs[0].seconds);
    }
  }).catch((err) => {
    console.error(err);
    $('#samples').innerHTML = '<li class="empty">The songs could not be loaded right now. Please refresh the page.</li>';
  });

  // ---------- Store links: "coming soon" until the URLs are set in config.js ----------
  document.querySelectorAll('[data-store]').forEach((a) => {
    const url = cfg[a.dataset.store];
    if (url) {
      a.href = url;
      a.classList.remove('soon');
      a.querySelector('small').textContent = a.dataset.store === 'playUrl' ? 'Get it on' : 'Download on the';
    } else {
      a.removeAttribute('href');
    }
  });
  $('#year').textContent = new Date().getFullYear();
})();