const queryInput = document.getElementById('query');
const searchBtn = document.getElementById('searchBtn');
const searchTypeSelect = document.getElementById('searchType');
const results = document.getElementById('results');
const statusEl = document.getElementById('status');
const dialog = document.getElementById('albumDialog');
const dialogTitle = document.getElementById('dialogTitle');
const dialogArtist = document.getElementById('dialogArtist');
const trackList = document.getElementById('trackList');
const sendBtn = document.getElementById('sendBtn');
const cleanupToggle = document.getElementById('cleanupToggle');
const updateLibraryBtn = document.getElementById('updateLibraryBtn');
const updateFrontendBtn = document.getElementById('updateFrontendBtn');

let selectedAlbum = null;

const CLEANUP_KEY = 'cleanupExtras';
cleanupToggle.checked = localStorage.getItem(CLEANUP_KEY) === 'true';

cleanupToggle.addEventListener('change', () => {
  localStorage.setItem(CLEANUP_KEY, String(cleanupToggle.checked));
});

function setStatus(text, isError = false) {
  statusEl.textContent = text;
  statusEl.style.color = isError ? 'var(--danger)' : 'var(--text)';
}

function formatDuration(ms) {
  const totalSec = Math.floor(ms / 1000);
  const min = Math.floor(totalSec / 60);
  const sec = totalSec % 60;
  return `${min}:${String(sec).padStart(2, '0')}`;
}

async function fetchJson(url, options = {}) {
  const response = await fetch(url, options);
  const data = await response.json();
  if (!response.ok) {
    throw new Error(data.error || `HTTP ${response.status}`);
  }
  return data;
}

function createAlbumCard(album, preselectedTrackNames = []) {
  const card = document.createElement('article');
  card.className = 'album-card';

  card.innerHTML = `
    ${album.image ? `<img class="album-cover" src="${album.image}" alt="${album.name}" />` : '<div class="album-cover"></div>'}
    <div class="album-body">
      <h3>${album.name}</h3>
      <p>${album.artist}</p>
      <p>${album.totalTracks} Tracks - ${album.releaseDate || 'unbekannt'}</p>
      <button type="button">Album auswaehlen</button>
    </div>
  `;

  card.querySelector('button').addEventListener('click', () => openAlbumDialog(album.id, preselectedTrackNames));
  return card;
}

function createTrackCard(track) {
  const card = document.createElement('article');
  card.className = 'album-card';

  card.innerHTML = `
    ${track.image ? `<img class="album-cover" src="${track.image}" alt="${track.albumName}" />` : '<div class="album-cover"></div>'}
    <div class="album-body">
      <h3>${track.trackName}</h3>
      <p>${track.artist}</p>
      <p>Album: ${track.albumName}</p>
      <button type="button">Album fuer Track auswaehlen</button>
    </div>
  `;

  card.querySelector('button').addEventListener('click', () => openAlbumDialog(track.albumId, [track.trackName]));
  return card;
}

function createArtistCard(artist) {
  const card = document.createElement('article');
  card.className = 'album-card';

  card.innerHTML = `
    ${artist.image ? `<img class="album-cover" src="${artist.image}" alt="${artist.name}" />` : '<div class="album-cover"></div>'}
    <div class="album-body">
      <h3>${artist.name}</h3>
      <p>${artist.followers || 0} Follower</p>
      <p>Artist</p>
      <button type="button">Alben anzeigen</button>
    </div>
  `;

  card.querySelector('button').addEventListener('click', () => loadArtistAlbums(artist.id, artist.name));
  return card;
}

function renderItems(type, items) {
  results.innerHTML = '';

  if (!items.length) {
    results.innerHTML = '<p>Keine Treffer gefunden.</p>';
    return;
  }

  for (const item of items) {
    let card;
    if (type === 'track') card = createTrackCard(item);
    if (type === 'artist') card = createArtistCard(item);
    if (type === 'album') card = createAlbumCard(item);
    if (card) results.appendChild(card);
  }
}

async function openAlbumDialog(albumId, preselectedTrackNames = []) {
  setStatus('Lade Albumdetails...');

  try {
    const album = await fetchJson(`/api/spotify/album/${albumId}`);
    const preselected = new Set(preselectedTrackNames || []);

    selectedAlbum = album;

    dialogTitle.textContent = album.name;
    dialogArtist.textContent = `Artist: ${album.artist}`;

    trackList.innerHTML = '';
    for (const track of album.tracks) {
      const row = document.createElement('label');
      row.className = 'track-row';
      const isChecked = preselected.size > 0 ? preselected.has(track.name) : true;
      row.innerHTML = `
        <input type="checkbox" ${isChecked ? 'checked' : ''} data-track-name="${track.name.replace(/"/g, '&quot;')}" />
        <span>${track.trackNumber}. ${track.name}</span>
        <small>(${formatDuration(track.durationMs)})</small>
      `;
      trackList.appendChild(row);
    }

    dialog.showModal();
    setStatus('Album bereit. Tracks auswaehlen und senden.');
  } catch (err) {
    setStatus(err.message, true);
  }
}

async function loadArtistAlbums(artistId, artistName) {
  setStatus(`Lade Alben von ${artistName}...`);

  try {
    const data = await fetchJson(`/api/spotify/artist/${artistId}/albums`);
    renderItems('album', data.albums || []);
    setStatus(`${data.albums.length} Alben von ${artistName} gefunden.`);
  } catch (err) {
    setStatus(err.message, true);
  }
}

async function searchSpotify() {
  const q = queryInput.value.trim();
  const type = searchTypeSelect.value;

  if (!q) {
    setStatus('Bitte Suchbegriff eingeben.', true);
    return;
  }

  setStatus('Suche in Spotify...');
  results.innerHTML = '';

  try {
    const data = await fetchJson(`/api/spotify/search?q=${encodeURIComponent(q)}&type=${encodeURIComponent(type)}`);
    const items = data.items || [];
    renderItems(type, items);
    setStatus(`${items.length} Treffer gefunden (${type}).`);
  } catch (err) {
    setStatus(err.message, true);
  }
}

async function sendToLidarr(event) {
  event.preventDefault();

  if (!selectedAlbum) {
    setStatus('Kein Album ausgewaehlt.', true);
    return;
  }

  const checked = Array.from(trackList.querySelectorAll('input[type="checkbox"]:checked'));
  const selectedTrackNames = checked.map((input) => input.dataset.trackName);

  if (!selectedTrackNames.length) {
    setStatus('Bitte mindestens einen Track auswaehlen.', true);
    return;
  }

  setStatus('Sende Album an Lidarr...');
  sendBtn.disabled = true;

  try {
    const data = await fetchJson('/api/lidarr/send-album', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({
        albumName: selectedAlbum.name,
        artistName: selectedAlbum.artist,
        selectedTrackNames,
        cleanupExtras: cleanupToggle.checked
      })
    });

    const cleanupMsg = data.cleanup?.attempted
      ? ` Cleanup: ${data.cleanup.deleted} Dateien geloescht.`
      : '';

    setStatus(`Album erfolgreich an Lidarr uebergeben (ID ${data.albumId}).${cleanupMsg}`);
    dialog.close();
  } catch (err) {
    setStatus(`Fehler: ${err.message}`, true);
  } finally {
    sendBtn.disabled = false;
  }
}

async function updateLibrary() {
  setStatus('Starte Lidarr Bibliothek-Update...');
  updateLibraryBtn.disabled = true;

  try {
    const data = await fetchJson('/api/lidarr/update-library', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' }
    });
    setStatus(`Bibliothek-Update gestartet (${data.commandNames.join(', ')}).`);
  } catch (err) {
    setStatus(`Fehler beim Bibliothek-Update: ${err.message}`, true);
  } finally {
    updateLibraryBtn.disabled = false;
  }
}

async function updateFrontendFromGit() {
  setStatus('Hole aktuelle Git-Daten...');
  updateFrontendBtn.disabled = true;

  try {
    const data = await fetchJson('/api/system/update-frontend', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' }
    });

    if (data.updated) {
      setStatus(`Frontend aktualisiert (${data.before} -> ${data.after}). Seite wird neu geladen...`);
      setTimeout(() => window.location.reload(), 1200);
    } else {
      setStatus(`Bereits aktuell (${data.after}).`);
    }
  } catch (err) {
    setStatus(`Frontend-Update fehlgeschlagen: ${err.message}`, true);
  } finally {
    updateFrontendBtn.disabled = false;
  }
}

searchBtn.addEventListener('click', searchSpotify);
queryInput.addEventListener('keydown', (event) => {
  if (event.key === 'Enter') {
    searchSpotify();
  }
});
sendBtn.addEventListener('click', sendToLidarr);
updateLibraryBtn.addEventListener('click', updateLibrary);
updateFrontendBtn.addEventListener('click', updateFrontendFromGit);