using System;
using System.Collections.Generic;
using OpenTK.Audio.OpenAL;
using OpenTK.Audio;

namespace AudioStreamer
{
	public class OpenALPlayback : AudioInput
	{
		AudioContext context = new AudioContext();
		
		int alsourceid;
		Stack<int> buffers;

		Random rand = new Random();

		public OpenALPlayback()
		{
			
			alsourceid = AL.GenSource();
			this.buffers = new Stack<int>();
		}

		public void Connect(AudioOutput output)
		{
			output.NewAudioAvailable += newAudioAvailable;
		}


		void newAudioAvailable(AudioOutput sender, Int16[] samples)
		{
			int processed;
			AL.GetSource(alsourceid, ALGetSourcei.BuffersProcessed, out processed);

			if (processed > 0){
				int[] pb = AL.SourceUnqueueBuffers(alsourceid, processed);
				foreach (int buf in pb){
					buffers.Push(buf);
				}
			}

			int buffer;

			if (buffers.Count > 0){
				buffer = buffers.Pop();
			} else {
				buffer = AL.GenBuffer();
			}

			AL.BufferData<Int16>(buffer, ALFormat.Mono16, samples, sizeof(Int16) * samples.Length, 44100);
			AL.SourceQueueBuffer(this.alsourceid, buffer);

			int state;

			AL.GetSource(alsourceid,ALGetSourcei.SourceState, out state);
			if ((ALSourceState)state != ALSourceState.Playing){
				AL.SourcePlay(alsourceid);
				Console.WriteLine("source restart");
			}
		}

	}
}