// MusicRoom - Playlist module
// Playlist CRUD, library rendering, playlist rendering

(function() {
  const M = window.MusicRoom;
  
  // Render the current playlist
  M.renderPlaylist = function() {
    const container = M.$("#playlist");
    container.innerHTML = "";
    if (M.playlist.length === 0) {
      container.innerHTML = '<div class="empty">Playlist empty</div>';
      return;
    }
    M.playlist.forEach((track, i) => {
      const div = document.createElement("div");
      div.className = "track" + (i === M.currentIndex ? " active" : "");
      const title = track.title?.trim() || (track.id || track.filename || "Unknown").replace(/\.[^.]+$/, "");
      const trackId = track.id || track.filename;
      
      // Show remove button only for user playlists (not stream playlists)
      const removeBtn = M.selectedPlaylistId ? `<span class="btn-remove" title="Remove">×</span>` : "";
      div.innerHTML = `<span class="track-title">${title}</span><span class="track-actions">${removeBtn}<span class="duration">${M.fmt(track.duration)}</span></span>`;
      
      div.querySelector(".track-title").onclick = async () => {
        if (M.synced && M.currentStreamId) {
          const res = await fetch("/api/streams/" + M.currentStreamId + "/jump", {
            method: "POST",
            headers: { "Content-Type": "application/json" },
            body: JSON.stringify({ index: i })
          });
          if (res.status === 403) M.flashPermissionDenied();
        } else {
          M.currentIndex = i;
          M.currentFilename = trackId;
          M.serverTrackDuration = track.duration;
          M.$("#track-title").textContent = title;
          M.loadingSegments.clear();
          const cachedUrl = await M.loadTrackBlob(trackId);
          M.audio.src = cachedUrl || M.getTrackUrl(trackId);
          M.audio.currentTime = 0;
          M.localTimestamp = 0;
          M.audio.play();
          M.renderPlaylist();
        }
      };
      
      const removeEl = div.querySelector(".btn-remove");
      if (removeEl) {
        removeEl.onclick = (e) => {
          e.stopPropagation();
          M.removeTrackFromCurrentPlaylist(i);
        };
      }
      
      container.appendChild(div);
    });
  };
  
  // Render the library
  M.renderLibrary = function() {
    const container = M.$("#library");
    container.innerHTML = "";
    if (M.library.length === 0) {
      container.innerHTML = '<div class="empty">No tracks discovered</div>';
      return;
    }
    const canAdd = M.selectedPlaylistId && M.selectedPlaylistId !== "all";
    M.library.forEach((track) => {
      const div = document.createElement("div");
      div.className = "track";
      const title = track.title?.trim() || track.filename.replace(/\.[^.]+$/, "");
      const addBtn = canAdd ? `<span class="btn-add" title="Add to playlist">+</span>` : "";
      div.innerHTML = `<span class="track-title">${title}</span><span class="track-actions">${addBtn}<span class="duration">${M.fmt(track.duration)}</span></span>`;
      
      div.querySelector(".track-title").onclick = async () => {
        // Play directly from library (uses track ID)
        if (!M.synced) {
          M.currentFilename = track.id;
          M.serverTrackDuration = track.duration;
          M.$("#track-title").textContent = title;
          M.loadingSegments.clear();
          const cachedUrl = await M.loadTrackBlob(track.id);
          M.audio.src = cachedUrl || M.getTrackUrl(track.id);
          M.audio.currentTime = 0;
          M.localTimestamp = 0;
          M.audio.play();
        }
      };
      
      const addBtnEl = div.querySelector(".btn-add");
      if (addBtnEl) {
        addBtnEl.onclick = (e) => {
          e.stopPropagation();
          M.addTrackToCurrentPlaylist(track.id);
        };
      }
      
      container.appendChild(div);
    });
  };
  
  // Load library from server
  M.loadLibrary = async function() {
    try {
      const res = await fetch("/api/library");
      M.library = await res.json();
      M.renderLibrary();
    } catch (e) {
      console.warn("Failed to load library");
    }
  };
  
  // Load user playlists from server
  M.loadPlaylists = async function() {
    try {
      const res = await fetch("/api/playlists");
      M.userPlaylists = await res.json();
      M.renderPlaylistSelector();
    } catch (e) {
      console.warn("Failed to load playlists");
    }
  };
  
  // Render playlist selector sidebar
  M.renderPlaylistSelector = function() {
    const list = M.$("#playlists-list");
    if (!list) return;
    list.innerHTML = "";
    // Add "All Tracks" as default option
    const allItem = document.createElement("div");
    allItem.className = "playlist-item" + (M.selectedPlaylistId === "all" ? " active" : "");
    allItem.textContent = "All Tracks";
    allItem.onclick = () => M.loadSelectedPlaylist("all");
    list.appendChild(allItem);
    // Add user playlists
    for (const pl of M.userPlaylists) {
      const item = document.createElement("div");
      item.className = "playlist-item" + (pl.id === M.selectedPlaylistId ? " active" : "");
      item.textContent = pl.name;
      item.onclick = () => M.loadSelectedPlaylist(pl.id);
      list.appendChild(item);
    }
    // Update playlist panel title
    const titleEl = M.$("#playlist-title");
    if (M.selectedPlaylistId === "all") {
      titleEl.textContent = "Playlist - All Tracks";
    } else if (M.selectedPlaylistId) {
      const pl = M.userPlaylists.find(p => p.id === M.selectedPlaylistId);
      titleEl.textContent = pl ? "Playlist - " + pl.name : "Playlist";
    } else {
      titleEl.textContent = "Playlist";
    }
  };
  
  // Load and display a specific playlist
  M.loadSelectedPlaylist = async function(playlistId) {
    if (!playlistId) {
      M.playlist = [];
      M.selectedPlaylistId = null;
      M.renderPlaylist();
      M.renderPlaylistSelector();
      M.renderLibrary();
      return;
    }
    if (playlistId === "all") {
      // Use library as playlist
      M.playlist = [...M.library];
      M.selectedPlaylistId = "all";
      M.currentIndex = 0;
      M.renderPlaylist();
      M.renderPlaylistSelector();
      M.renderLibrary();
      return;
    }
    try {
      const res = await fetch("/api/playlists/" + playlistId);
      if (!res.ok) throw new Error("Failed to load playlist");
      const data = await res.json();
      M.playlist = data.tracks || [];
      M.selectedPlaylistId = playlistId;
      M.currentIndex = 0;
      M.renderPlaylist();
      M.renderPlaylistSelector();
      M.renderLibrary();
    } catch (e) {
      console.warn("Failed to load playlist:", e);
    }
  };
  
  // Create a new playlist
  M.createNewPlaylist = async function() {
    const header = M.$("#playlists-panel .panel-header");
    const btn = M.$("#btn-new-playlist");
    
    // Already in edit mode?
    if (header.querySelector(".new-playlist-input")) return;
    
    // Hide button, show input
    btn.style.display = "none";
    
    const input = document.createElement("input");
    input.type = "text";
    input.className = "new-playlist-input";
    input.placeholder = "Playlist name...";
    
    const submit = document.createElement("button");
    submit.className = "btn-submit-playlist";
    submit.textContent = "›";
    
    header.appendChild(input);
    header.appendChild(submit);
    input.focus();
    
    const cleanup = () => {
      input.remove();
      submit.remove();
      btn.style.display = "";
    };
    
    const doCreate = async () => {
      const name = input.value.trim();
      if (!name) {
        cleanup();
        return;
      }
      try {
        const res = await fetch("/api/playlists", {
          method: "POST",
          headers: { "Content-Type": "application/json" },
          body: JSON.stringify({ name, visibility: "private" })
        });
        if (!res.ok) throw new Error("Failed to create playlist");
        const pl = await res.json();
        await M.loadPlaylists();
        M.selectedPlaylistId = pl.id;
        M.renderPlaylistSelector();
        await M.loadSelectedPlaylist(pl.id);
      } catch (e) {
        alert("Failed to create playlist");
      }
      cleanup();
    };
    
    submit.onclick = doCreate;
    input.onkeydown = (e) => {
      if (e.key === "Enter") doCreate();
      if (e.key === "Escape") cleanup();
    };
    input.onblur = (e) => {
      // Delay to allow click on submit button
      setTimeout(() => {
        if (document.activeElement !== submit) cleanup();
      }, 100);
    };
  };
  
  // Add a track to current playlist
  M.addTrackToCurrentPlaylist = async function(trackId) {
    if (!M.selectedPlaylistId || M.selectedPlaylistId === "all") {
      alert("Select or create a playlist first");
      return;
    }
    try {
      const res = await fetch("/api/playlists/" + M.selectedPlaylistId + "/tracks", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ trackIds: [trackId] })
      });
      if (!res.ok) throw new Error("Failed to add track");
      await M.loadSelectedPlaylist(M.selectedPlaylistId);
    } catch (e) {
      console.warn("Failed to add track:", e);
    }
  };
  
  // Remove a track from current playlist
  M.removeTrackFromCurrentPlaylist = async function(position) {
    if (!M.selectedPlaylistId || M.selectedPlaylistId === "all") return;
    try {
      const res = await fetch("/api/playlists/" + M.selectedPlaylistId + "/tracks/" + position, {
        method: "DELETE"
      });
      if (!res.ok) throw new Error("Failed to remove track");
      await M.loadSelectedPlaylist(M.selectedPlaylistId);
    } catch (e) {
      console.warn("Failed to remove track:", e);
    }
  };
})();