// Authors
//   Copyright (C) 2008 Paul Burton <paulburton89@gmail.com>
using System;
using System.Runtime.InteropServices;

using Gtk;
using Gst;
using Gst.Interfaces;
using Gst.BasePlugins;

public class MainWindow : Gtk.Window {
  DrawingArea _da;
  ulong _xWindowId;
  PlayBin2 _playbin;
  HScale _scale;
  Label _lbl;
  bool _updatingScale;
  bool _pipelineOK = false;

  public static void Main (string[] args) {
    Gtk.Application.Init ();
    Gst.Application.Init ();
    MainWindow window = new MainWindow ();
    window.ShowAll ();

    switch (System.Environment.OSVersion.Platform) {
      case PlatformID.Unix:
        window._xWindowId = gdk_x11_drawable_get_xid (window._da.GdkWindow.Handle);
        break;
      case PlatformID.Win32NT:
      case PlatformID.Win32S:
      case PlatformID.Win32Windows:
      case PlatformID.WinCE:
        window._xWindowId = (ulong) gdk_win32_drawable_get_handle (window._da.GdkWindow.Handle);
        break;
    }

    Gtk.Application.Run ();
  }

  public MainWindow ()
  : base (WindowType.Toplevel) {
    VBox vBox = new VBox ();

    _da = new DrawingArea ();
    _da.ModifyBg (Gtk.StateType.Normal, new Gdk.Color (0, 0, 0));
    _da.SetSizeRequest (400, 300);
    _da.DoubleBuffered = false;
    vBox.PackStart (_da);

    _scale = new HScale (0, 1, 0.01);
    _scale.DrawValue = false;
    _scale.ValueChanged += ScaleValueChanged;
    vBox.PackStart (_scale, false, false, 0);

    HBox hBox = new HBox ();

    Button btnOpen = new Button ();
    btnOpen.Label = "Open";
    btnOpen.Clicked += ButtonOpenClicked;

    hBox.PackStart (btnOpen, false, false, 0);

    Button btnPlay = new Button ();
    btnPlay.Label = "Play";
    btnPlay.Clicked += ButtonPlayClicked;

    hBox.PackStart (btnPlay, false, false, 0);

    Button btnPause = new Button ();
    btnPause.Label = "Pause";
    btnPause.Clicked += ButtonPauseClicked;

    hBox.PackStart (btnPause, false, false, 0);

    _lbl = new Label ();
    _lbl.Text = "00:00 / 00:00";

    hBox.PackEnd (_lbl, false, false, 0);

    vBox.PackStart (hBox, false, false, 3);

    Add (vBox);

    WindowPosition = Gtk.WindowPosition.Center;
    DeleteEvent += OnDeleteEvent;

    GLib.Timeout.Add (1000, new GLib.TimeoutHandler (UpdatePos));
  }

  void OnDeleteEvent (object sender, DeleteEventArgs args) {
    Gtk.Application.Quit ();

    if (_playbin != null) {
      _playbin.SetState (Gst.State.Null);
      _playbin.Dispose ();
      _playbin = null;
    }

    args.RetVal = true;
  }

  void ButtonOpenClicked (object sender, EventArgs args) {
    FileChooserDialog dialog = new FileChooserDialog ("Open", this, FileChooserAction.Open, new object[] { "Cancel", ResponseType.Cancel, "Open", ResponseType.Accept });
    dialog.SetCurrentFolder (Environment.GetFolderPath (Environment.SpecialFolder.Personal));

    if (dialog.Run () == (int) ResponseType.Accept) {
      _pipelineOK = false;

      if (_playbin != null) {
        _playbin.SetState (Gst.State.Null);
      } else {
        _playbin = new PlayBin2 ();
      }

      _scale.Value = 0;

      if (_playbin == null)
        Console.WriteLine ("Unable to create element 'playbin'");

      _playbin.Bus.EnableSyncMessageEmission ();
      _playbin.Bus.AddSignalWatch ();

      _playbin.Bus.SyncMessage += delegate (object bus, SyncMessageArgs sargs) {
        Gst.Message msg = sargs.Message;
        if (msg == null || msg.Type != Gst.MessageType.Element ||
            msg.Structure == null || msg.Structure.Name == null ||
            !msg.Structure.Name.Equals ("prepare-xwindow-id"))
          return;

        Element src = msg.Src as Element;
        if (src == null)
          return;

        if (src.HasProperty ("force-aspect-ratio"))
          src["force-aspect-ratio"] = true;

        (src as XOverlay).XwindowId = _xWindowId;
        (src as XOverlay).HandleEvents (true);
      };

      _playbin.Bus.Message += delegate (object bus, MessageArgs margs) {
        Message message = margs.Message;

        switch (message.Type) {
          case Gst.MessageType.Error:
            Enum err;
            string msg;

            message.ParseError (out err, out msg);
            Console.WriteLine (String.Format ("Error message: {0}", msg));
            _pipelineOK = false;
            break;
          case Gst.MessageType.Eos:
            Console.WriteLine ("EOS");
            break;
        }
      };

      _playbin["uri"] = "file://" + dialog.Filename;

      StateChangeReturn sret = _playbin.SetState (Gst.State.Playing);

      if (sret == StateChangeReturn.Async) {
        State state, pending;
        sret = _playbin.GetState (out state, out pending, Clock.Second * 5);
      }

      if (sret == StateChangeReturn.Success) {
        Console.WriteLine ("State change successful");
        _pipelineOK = true;
      } else {
        Console.WriteLine ("State change failed for {0} ({1})\n", dialog.Filename, sret);
      }
    }

    dialog.Destroy ();
  }

  void ButtonPlayClicked (object sender, EventArgs args) {
    if ( (_playbin != null) && _pipelineOK)
      _playbin.SetState (Gst.State.Playing);
  }

  void ButtonPauseClicked (object sender, EventArgs args) {
    if ( (_playbin != null) && _pipelineOK)
      _playbin.SetState (Gst.State.Paused);
  }

  void ScaleValueChanged (object sender, EventArgs args) {
    if (_updatingScale)
      return;

    long duration;
    Gst.Format fmt = Gst.Format.Time;
    Console.WriteLine ("Trying to seek");

    if ( (_playbin != null) && _pipelineOK && _playbin.QueryDuration (ref fmt, out duration) && duration != -1) {
      long pos = (long) (duration * _scale.Value);
      Console.WriteLine ("Seek to {0}/{1} ({2}%)", pos, duration, _scale.Value);

      bool ret = _playbin.Seek (Format.Time, SeekFlags.Flush | SeekFlags.KeyUnit, pos);

      Console.WriteLine ("Seeked {0}successfully", (ret ? "" : "not "));
    }
  }

  bool UpdatePos () {
    Gst.Format fmt = Gst.Format.Time;
    long duration, pos;
    if ( (_playbin != null) && _pipelineOK &&
         _playbin.QueryDuration (ref fmt, out duration) &&
         _playbin.QueryPosition (ref fmt, out pos)) {
      _lbl.Text = string.Format ("{0} / {1}", TimeString (pos), TimeString (duration));

      _updatingScale = true;
      _scale.Value = (double) pos / duration;
      _updatingScale = false;
    }

    return true;
  }

  string TimeString (long t) {
    long secs = t / 1000000000;
    int mins = (int) (secs / 60);
    secs = secs - (mins * 60);

    if (mins >= 60) {
      int hours = (int) (mins / 60);
      mins = mins - (hours * 60);

      return string.Format ("{0}:{1:d2}:{2:d2}", hours, mins, secs);
    }

    return string.Format ("{0}:{1:d2}", mins, secs);
  }

  [DllImport ("libgdk-x11-2.0.so.0") ]
  static extern uint gdk_x11_drawable_get_xid (IntPtr handle);

  [DllImport ("libgdk-win32-2.0-0.dll") ]
  static extern IntPtr gdk_win32_drawable_get_handle (IntPtr handle);
}