using System;

namespace MoonWorks.Audio
{
	// NOTE: all sounds played with a SoundSequence must have the same audio format!
	public class SoundSequence : SourceVoice
	{
		public int NeedSoundThreshold = 0;
		public delegate void OnSoundNeededFunc();
		public OnSoundNeededFunc OnSoundNeeded;

		public SoundSequence(AudioDevice device, ushort formatTag, ushort bitsPerSample, ushort blockAlign, ushort channels, uint samplesPerSecond) : base(device, formatTag, bitsPerSample, blockAlign, channels, samplesPerSecond)
		{
			device.AddSoundSequenceReference(this);
			OnUpdate += Update;
		}

		public SoundSequence(AudioDevice device, StaticSound templateSound) : base(device, templateSound.FormatTag, templateSound.BitsPerSample, templateSound.BlockAlign, templateSound.Channels, templateSound.SamplesPerSecond)
		{
			device.AddSoundSequenceReference(this);
			OnUpdate += Update;
		}

		private void Update()
		{
			lock (StateLock)
			{
				if (IsDisposed) { return; }
				if (State != SoundState.Playing) { return; }

				if (NeedSoundThreshold > 0)
				{
					FAudio.FAudioSourceVoice_GetState(
						Handle,
						out var state,
						FAudio.FAUDIO_VOICE_NOSAMPLESPLAYED
					);

					var queuedBufferCount = state.BuffersQueued;
					for (int i = 0; i < NeedSoundThreshold - queuedBufferCount; i += 1)
					{
						if (OnSoundNeeded != null)
						{
							OnSoundNeeded();
						}
					}
				}
			}
		}

		public void EnqueueSound(StaticSound sound)
		{
#if DEBUG
			if (
				sound.FormatTag != Format.wFormatTag ||
				sound.BitsPerSample != Format.wBitsPerSample ||
				sound.Channels != Format.nChannels ||
				sound.SamplesPerSecond != Format.nSamplesPerSec
			)
			{
				Logger.LogWarn("Playlist audio format mismatch!");
			}
#endif

			lock (StateLock)
			{
				FAudio.FAudioSourceVoice_SubmitSourceBuffer(
					Handle,
					ref sound.Handle,
					IntPtr.Zero
				);
			}
		}
	}
}