using UnityEngine;
using System.Collections;
using System.Runtime.InteropServices;

//-----------------------------------------------------------------------------
// Copyright 2012-2017 RenderHeads Ltd.  All rights reserved.
//-----------------------------------------------------------------------------

namespace RenderHeads.Media.AVProMovieCapture
{
	/// <summary>
	/// Captures audio from an audio listener and adds it to a buffer
	/// The AVPro Movie Capture plugin pulls the data from this buffer and flushes it periodically
	/// </summary>
	[RequireComponent(typeof(AudioListener))]
	[AddComponentMenu("AVPro Movie Capture/Unity Audio Capture (requires AudioListener)", 500)]
	public class UnityAudioCapture : MonoBehaviour
	{
		[SerializeField]
		private bool _debugLogging = false;

		private const int BufferSize = 16;
		private float[] _buffer = new float[0];
		private float[] _readBuffer = new float[0];
		private int _bufferIndex;
		private GCHandle _bufferHandle;
		private int _numChannels;

		private int _overflowCount;
		private object _lockObject = new object();

		public float[] Buffer { get { return _readBuffer; } }
		public int BufferLength { get { return _bufferIndex; } }
		public int NumChannels { get { return _numChannels; } }
		public System.IntPtr BufferPtr { get { return _bufferHandle.AddrOfPinnedObject(); } }

		public int OverflowCount
		{
			get { return _overflowCount; }
		}

		void OnEnable()
		{
			int bufferLength = 0;
			int numBuffers = 0;
			AudioSettings.GetDSPBufferSize(out bufferLength, out numBuffers);

#if UNITY_5_4_OR_NEWER || UNITY_5
			_numChannels = GetNumChannels(AudioSettings.driverCapabilities);
			//if (AudioSettings.speakerMode != AudioSpeakerMode.Raw &&
			if (AudioSettings.speakerMode < AudioSettings.driverCapabilities)
			{
				_numChannels = GetNumChannels(AudioSettings.speakerMode);
			}
			if (_debugLogging)
			{
				Debug.Log(string.Format("[UnityAudioCapture] SampleRate: {0}hz SpeakerMode: {1} BestDriverMode: {2} (DSP using {3} buffers of {4} bytes using {5} channels)", AudioSettings.outputSampleRate, AudioSettings.speakerMode.ToString(), AudioSettings.driverCapabilities.ToString(), numBuffers, bufferLength, _numChannels));
			}
#else
		_numChannels = GetNumChannels(AudioSettings.driverCaps);
		if (AudioSettings.speakerMode != AudioSpeakerMode.Raw &&
            AudioSettings.speakerMode < AudioSettings.driverCaps)
		{
			_numChannels = GetNumChannels(AudioSettings.speakerMode);
		}

		if (_debugLogging)
		{
			Debug.Log(string.Format("[UnityAudioCapture] SampleRate: {0}hz SpeakerMode: {1} BestDriverMode: {2} (DSP using {3} buffers of {4} bytes using {5} channels)", AudioSettings.outputSampleRate, AudioSettings.speakerMode.ToString(), AudioSettings.driverCaps.ToString(), numBuffers, bufferLength, _numChannels));
		}
#endif

			_buffer = new float[bufferLength * _numChannels * numBuffers * BufferSize];
			_readBuffer = new float[bufferLength * _numChannels * numBuffers * BufferSize];
			_bufferIndex = 0;
			_bufferHandle = GCHandle.Alloc(_readBuffer, GCHandleType.Pinned);
			_overflowCount = 0;
		}

		void OnDisable()
		{
			lock (_lockObject)
			{
				_bufferIndex = 0;
				if (_bufferHandle.IsAllocated)
					_bufferHandle.Free();
				_readBuffer = _buffer = null;
			}
			_numChannels = 0;
		}

		public System.IntPtr ReadData(out int length)
		{
			lock (_lockObject)
			{
				System.Array.Copy(_buffer, 0, _readBuffer, 0, _bufferIndex);
				length = _bufferIndex;
				_bufferIndex = 0;
			}
			return _bufferHandle.AddrOfPinnedObject();
		}

		public void FlushBuffer()
		{
			lock (_lockObject)
			{
				_bufferIndex = 0;
				_overflowCount = 0;
			}
		}

		void OnAudioFilterRead(float[] data, int channels)
		{
			if (_buffer != null)
			{
				// TODO: use double buffering
				lock (_lockObject)
				{
					int length = Mathf.Min(data.Length, _buffer.Length - _bufferIndex);

					//System.Array.Copy(data, 0, _buffer, _bufferIndex, length);
					for (int i = 0; i < length; i++)
					{
						_buffer[i + _bufferIndex] = data[i];
					}
					_bufferIndex += length;

					if (length < data.Length)
					{
						_overflowCount++;
						Debug.LogWarning("[AVProMovieCapture] Audio buffer overflow, may cause sync issues.  Disable this component if not recording Unity audio.");
					}
				}
			}
		}


		static public int GetNumChannels(AudioSpeakerMode mode)
		{
			int result = 0;
			switch (mode)
			{
				//case AudioSpeakerMode.Raw:
				//	break;
				case AudioSpeakerMode.Mono:
					result = 1;
					break;
				case AudioSpeakerMode.Stereo:
					result = 2;
					break;
				case AudioSpeakerMode.Quad:
					result = 4;
					break;
				case AudioSpeakerMode.Surround:
					result = 5;
					break;
				case AudioSpeakerMode.Mode5point1:
					result = 6;
					break;
				case AudioSpeakerMode.Mode7point1:
					result = 8;
					break;
				case AudioSpeakerMode.Prologic:
					result = 2;
					break;
			}
			return result;
		}
	}
}