using System;
using System.IO;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using BuzzGUI.Interfaces;
using libsndfile;

namespace BuzzGUI.Common.InterfaceExtensions
{
	public static class WaveformBaseExtensions
	{
		const int WriteBufferSize = 4096;

		public static void SaveAsWAV(this IWaveformBase w, Stream s)
		{
			Format f;
			if (w.Format == WaveFormat.Float32) f = Format.SF_FORMAT_FLOAT;
			else if (w.Format == WaveFormat.Int32) f = Format.SF_FORMAT_PCM_32;
			else if (w.Format == WaveFormat.Int24) f = Format.SF_FORMAT_PCM_24;
			else f = Format.SF_FORMAT_PCM_16;

			using (var sf = SoundFile.Create(s, w.SampleRate, w.ChannelCount, f | Format.SF_FORMAT_WAV))
			{
				var buffer = new float[WriteBufferSize * w.ChannelCount];

				long frameswritten = 0;
				while (frameswritten < w.SampleCount)
				{
					var n = Math.Min(w.SampleCount - frameswritten, WriteBufferSize);

					for (int ch = 0; ch < w.ChannelCount; ch++)
						w.GetDataAsFloat(buffer, ch, w.ChannelCount, ch, (int)frameswritten, (int)n);

					sf.WriteFloat(buffer, 0, n);

					frameswritten += n;
				}


			}


		}
	}
}