/// <summary>
/// Decodes a Lavalink track string.
/// </summary>
/// <param name="track">Track string to decode.</param>
/// <returns>Decoded Lavalink track.</returns>
public static LavalinkTrack DecodeTrack(string track)
{
var raw = Convert.FromBase64String(track);
var msgval = BitConverter.ToInt32(raw, 0);
msgval = (int)SwapEndianness((uint)msgval);
var msgFlags = (int)((msgval & 0xC0000000L) >> 30);
var msgSize = msgval & 0x3FFFFFFF;
var decoded = new LavalinkTrack
{
TrackString = track
};
using (var ms = new MemoryStream(msgSize))
{
ms.Write(raw, 4, msgSize);
ms.Position = 0;
using (var br = new BinaryReader(ms))
{
var version = (msgFlags & 1) == 1 ? br.ReadByte() & 0xFF : 1;
var len = br.ReadInt16();
len = SwapEndianness(len);
raw = br.ReadBytes(len);
decoded.Title = UTF8.GetString(raw, 0, len);
len = br.ReadInt16();
len = SwapEndianness(len);
raw = br.ReadBytes(len);
decoded.Author = UTF8.GetString(raw, 0, len);
decoded._length = (long)SwapEndianness((ulong)br.ReadInt64());
len = br.ReadInt16();
len = SwapEndianness(len);
raw = br.ReadBytes(len);
decoded.Identifier = UTF8.GetString(raw, 0, len);
decoded.IsStream = br.ReadBoolean();
var isthere = br.ReadBoolean();
if (isthere)
{
len = br.ReadInt16();
len = SwapEndianness(len);
raw = br.ReadBytes(len);
decoded.Uri = version >= 2 ? new Uri(UTF8.GetString(raw, 0, len)) : null;
}
}
}
return(decoded);
}
/// <summary>
/// Queues the specified track for playback.
/// </summary>
/// <param name="track">Track to play.</param>
/// <returns></returns>
public void Play(LavalinkTrack track)
{
if (!this.IsConnected)
{
throw new InvalidOperationException("This connection is not valid.");
}
this.CurrentState.CurrentTrack = track;
this.Node.SendPayload(new LavalinkPlay(this, track));
}
/// <summary>
/// Queues the specified track for playback.
/// </summary>
/// <param name="track">Track to play.</param>
public async Task PlayAsync(LavalinkTrack track)
{
if (!this.IsConnected)
{
throw new InvalidOperationException("This connection is not valid.");
}
this.CurrentState.CurrentTrack = track;
await this.Node.SendPayloadAsync(new LavalinkPlay(this, track)).ConfigureAwait(false);
}
/// <summary>
/// Decodes a Lavalink track string.
/// </summary>
/// <param name="track">Track string to decode.</param>
/// <returns>Decoded Lavalink track.</returns>
public static LavalinkTrack DecodeTrack(string track)
{
// https://github.com/sedmelluq/lavaplayer/blob/804cd1038229230052d9b1dee5e6d1741e30e284/main/src/main/java/com/sedmelluq/discord/lavaplayer/player/DefaultAudioPlayerManager.java#L63-L64
const int TRACK_INFO_VERSIONED = 1;
//const int TRACK_INFO_VERSION = 2;
var raw = Convert.FromBase64String(track);
var decoded = new LavalinkTrack
{
TrackString = track
};
using (var ms = new MemoryStream(raw))
using (var br = new JavaBinaryReader(ms))
{
// https://github.com/sedmelluq/lavaplayer/blob/b0c536098c4f92e6d03b00f19221021f8f50b19b/main/src/main/java/com/sedmelluq/discord/lavaplayer/tools/io/MessageInput.java#L37-L39
var messageHeader = br.ReadInt32();
var messageFlags = (int)((messageHeader & 0xC0000000L) >> 30);
var messageSize = messageHeader & 0x3FFFFFFF;
//if (messageSize != raw.Length)
// Warn($"Size conflict: {messageSize} but was {raw.Length}");
// https://github.com/sedmelluq/lavaplayer/blob/804cd1038229230052d9b1dee5e6d1741e30e284/main/src/main/java/com/sedmelluq/discord/lavaplayer/player/DefaultAudioPlayerManager.java#L268
// java bytes are signed
// https://docs.oracle.com/javase/7/docs/api/java/io/DataInput.html#readByte()
var version = (messageFlags & TRACK_INFO_VERSIONED) != 0 ? (br.ReadSByte() & 0xFF) : 1;
//if (version != TRACK_INFO_VERSION)
// Warn($"Version conflict: Expected {TRACK_INFO_VERSION} but got {version}");
decoded.Title = br.ReadJavaUtf8();
decoded.Author = br.ReadJavaUtf8();
decoded._length = br.ReadInt64();
decoded.Identifier = br.ReadJavaUtf8();
decoded.IsStream = br.ReadBoolean();
var uri = br.ReadNullableString();
if (uri != null && version >= 2)
{
decoded.Uri = new Uri(uri);
}
else
{
decoded.Uri = null;
}
}
return(decoded);
}
/// <summary>
/// Queues the specified track for playback. The track will be played from specified start timestamp to specified end timestamp.
/// </summary>
/// <param name="track">Track to play.</param>
/// <param name="start">Timestamp to start playback at.</param>
/// <param name="end">Timestamp to stop playback at.</param>
/// <returns></returns>
public void PlayPartial(LavalinkTrack track, TimeSpan start, TimeSpan end)
{
if (!this.IsConnected)
{
throw new InvalidOperationException("This connection is not valid.");
}
if (start.TotalMilliseconds < 0 || end <= start)
{
throw new ArgumentException("Both start and end timestamps need to be greater or equal to zero, and the end timestamp needs to be greater than start timestamp.");
}
this.CurrentState.CurrentTrack = track;
this.Node.SendPayload(new LavalinkPlayPartial(this, track, start, end));
}
