using System;
using System.IO;
using System.Xml;
using System.Text;
using System.Drawing;
using System.Windows.Forms;
using System.Runtime.InteropServices;

public class CDSetup:Form
{
  private Button btnAdd;
  private Button btnCopy;
  private EventHandler copyHandler;
  private EventHandler addHandler;
  private ListBox playlists;
  private ListBox toCopy;
  private string iTunesLibrary = null;
  private string stagingArea = null;
  private XmlDataDocument itunesDoc;

  // http://www.codeproject.com/csharp/csdoesshell1.asp
  [DllImport("shell32.dll")] public static extern Int32 SHGetFolderPath(IntPtr a, Int32 b, IntPtr c, UInt32 d, StringBuilder e);
  // stolen from the platform SDK header files
  const int CSIDL_CDBURN_AREA = 59;

  public CDSetup()
  {
    ClientSize = new System.Drawing.Size(400, 300);
    Text = "ITUNES PLAYLISTS => MP3 CD";

    addHandler = new EventHandler(AddPlaylist);
    btnAdd = new Button();
    btnAdd.Size = new Size(80,30);
    btnAdd.Location = new Point(310,10);
    btnAdd.Text="Add";
    btnAdd.Click += addHandler;
    Controls.Add(btnAdd);

    copyHandler = new EventHandler(CopyCd);
    btnCopy = new Button();
    btnCopy.Size = new Size(80,30);
    btnCopy.Location = new Point(310,260);
    btnCopy.Text="Copy";
    btnCopy.Click += copyHandler;
    Controls.Add(btnCopy);

    playlists = new ListBox();
    playlists.Size = new Size(140,280);
    playlists.Location = new Point(10,10);
    Controls.Add(playlists);

    toCopy = new ListBox();
    toCopy.Size = new Size(140,280);
    toCopy.Location = new Point(160,10);
    Controls.Add(toCopy);
    Console.WriteLine("Looking for necessary files...");
    try
    {
      iTunesLibrary = FindItunesLibrary();
      Console.WriteLine("Found iTunes library at " + iTunesLibrary);
      stagingArea = FindStagingArea();
      Console.WriteLine("Found staging area at " + stagingArea);
      itunesDoc = new XmlDataDocument();
      StreamReader sr = new StreamReader(iTunesLibrary);
      itunesDoc.Load(sr);
      sr.Close();
      XmlNodeList list = itunesDoc.SelectNodes("/plist/dict/key[text()='Playlists']/following-sibling::array/dict");
      foreach (XmlNode node in list)
        playlists.Items.Add(node.SelectSingleNode("key[text()='Name']/following-sibling::string").InnerText);
    }
    catch (Exception ex)
    {
      Console.WriteLine("Initialization error: " + ex.Message);
    }
  }

  // I'm not sure if iTunes can be configured to live somewhere else.
  // Also not sure if locale affects its file names.
  private static string FindItunesLibrary()
  {
    string location = Environment.GetFolderPath(Environment.SpecialFolder.MyMusic);
    if (File.Exists(location + "\\iTunes\\iTunes Music Library.xml"))
      return location + "\\iTunes\\iTunes Music Library.xml";
    throw new Exception("Unable to locate iTunes library");
  }

  private static string FindStagingArea()
  {
    StringBuilder location = new StringBuilder(1024);
    SHGetFolderPath(IntPtr.Zero, CSIDL_CDBURN_AREA, IntPtr.Zero, 0, location);
    if (Directory.Exists(location.ToString()))
      return location.ToString();
    throw new Exception("Unable to locate staging area");
  }

  private void AddPlaylist(Object source, EventArgs e)
  {
    if (playlists.SelectedItem != null)
      toCopy.Items.Add(playlists.Text);
  }

  // that .Substring(1) is ugly, but I couldn't figure out a better way to get
  // the local path from file://localhost/C:/whatever.
  public static string FileNameFromUri(string address)
  {
    Uri uri = new Uri(address);
    if (uri.IsFile && uri.Host == "localhost")
      return System.Web.HttpUtility.UrlDecode(uri.PathAndQuery).Substring(1);
    throw new Exception("URI does not point to a local file");
  }

  // since this is an event handler, it'll probably lock up the window while it's
  // adding songs to burn.  That could take a while since xpath is slow and the
  // document here can be huge.  I don't know how to launch a thread in C#.
  private void CopyCd(Object source, EventArgs e)
  {
    try
    {
      foreach (string playlist in toCopy.Items)
      {
        Directory.CreateDirectory(stagingArea + "\\" + playlist);
        System.Console.WriteLine("Searching playlist "+playlist);
        // longest xpath query I ever wrote.
        XmlNodeList tracks = itunesDoc.SelectNodes("/plist/dict/key[text()='Playlists']/following-sibling::array/dict/key[text()='Name']/following-sibling::string[text()='"+playlist+"']/following-sibling::key[text()='Playlist Items']/following-sibling::array/dict/key[text()='Track ID']/following-sibling::integer");
        if (tracks == null)
          throw new Exception("Unable to find tracks for this playlist, probably an XPath error or iTunes changed their format");
        foreach (XmlNode track in tracks)
        {
          XmlNode trackNode = itunesDoc.SelectSingleNode("/plist/dict/key[text()='Tracks']/following-sibling::dict/key[text()='"+track.InnerText+"']/following-sibling::dict");
          if (trackNode == null)
            throw new Exception("Unable to find track node, probably an XPath error or iTunes changed their format");
          XmlNode trackFile = trackNode.SelectSingleNode("key[text()='Location']/following-sibling::string");
          if (trackFile == null)
            throw new Exception("Unable to find track file, probably an XPath error or iTunes changed their format");
          XmlNode trackType = trackNode.SelectSingleNode("key[text()='Track Type']/following-sibling::string");
          // we only want files, not streams
          if (trackType == null || trackType.InnerText != "File")
          {
            System.Console.WriteLine("Skipping track of unknown type: " + ((trackType == null) ? "" : trackType.InnerText));
            continue;
          }
          // only MP3 files, not ACC
          XmlNode trackKind = trackNode.SelectSingleNode("key[text()='Kind']/following-sibling::string");
          if (trackKind == null || trackKind.InnerText != "MPEG audio file")
          {
            System.Console.WriteLine("Skipping track of unknown kind: " + ((trackKind == null) ? "" : trackKind.InnerText));
            continue;
          }
          try
          {
            string filePath = FileNameFromUri(trackFile.InnerText);
            if (filePath != null && File.Exists(filePath))
              File.Copy(filePath, stagingArea + "\\" + playlist + "\\" + Path.GetFileName(filePath));
            else
              throw new Exception("Can't find " + Path.GetFileName(filePath));
          }
          catch(Exception ex)
          {
            System.Console.WriteLine("Error: " + ex.Message);
          }
        }
      }
      MessageBox.Show("No fatal errors occurred.", "All done.");
    }
    catch (Exception ex)
    {
      Console.WriteLine("Serious Error: " + ex.Message);
      MessageBox.Show("ERRORED!", "ERRORED!");
    }
  }

  static void Main()
  {
    Application.Run(new CDSetup());
  }
}