using System;
using System.IO;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;

namespace libsndfile
{
	public enum FileMode
	{
		SFM_READ = 0x10,
		SFM_WRITE = 0x20,
		SFM_RDWR = 0x30
	};

	public enum ErrorValue
	{	
		SF_ERR_NO_ERROR				= 0,
		SF_ERR_UNRECOGNISED_FORMAT	= 1,
		SF_ERR_SYSTEM				= 2,
		SF_ERR_MALFORMED_FILE		= 3,
		SF_ERR_UNSUPPORTED_ENCODING	= 4
	};

	[Flags]
	public enum Format
	{	/* Major formats. */
		SF_FORMAT_WAV			= 0x010000,		/* Microsoft WAV format (little endian default). */
		SF_FORMAT_AIFF			= 0x020000,		/* Apple/SGI AIFF format (big endian). */
		SF_FORMAT_AU			= 0x030000,		/* Sun/NeXT AU format (big endian). */
		SF_FORMAT_RAW			= 0x040000,		/* RAW PCM data. */
		SF_FORMAT_PAF			= 0x050000,		/* Ensoniq PARIS file format. */
		SF_FORMAT_SVX			= 0x060000,		/* Amiga IFF / SVX8 / SV16 format. */
		SF_FORMAT_NIST			= 0x070000,		/* Sphere NIST format. */
		SF_FORMAT_VOC			= 0x080000,		/* VOC files. */
		SF_FORMAT_IRCAM			= 0x0A0000,		/* Berkeley/IRCAM/CARL */
		SF_FORMAT_W64			= 0x0B0000,		/* Sonic Foundry's 64 bit RIFF/WAV */
		SF_FORMAT_MAT4			= 0x0C0000,		/* Matlab (tm) V4.2 / GNU Octave 2.0 */
		SF_FORMAT_MAT5			= 0x0D0000,		/* Matlab (tm) V5.0 / GNU Octave 2.1 */
		SF_FORMAT_PVF			= 0x0E0000,		/* Portable Voice Format */
		SF_FORMAT_XI			= 0x0F0000,		/* Fasttracker 2 Extended Instrument */
		SF_FORMAT_HTK			= 0x100000,		/* HMM Tool Kit format */
		SF_FORMAT_SDS			= 0x110000,		/* Midi Sample Dump Standard */
		SF_FORMAT_AVR			= 0x120000,		/* Audio Visual Research */
		SF_FORMAT_WAVEX			= 0x130000,		/* MS WAVE with WAVEFORMATEX */
		SF_FORMAT_SD2			= 0x160000,		/* Sound Designer 2 */
		SF_FORMAT_FLAC			= 0x170000,		/* FLAC lossless file format */
		SF_FORMAT_CAF			= 0x180000,		/* Core Audio File format */
		SF_FORMAT_WVE			= 0x190000,		/* Psion WVE format */
		SF_FORMAT_OGG			= 0x200000,		/* Xiph OGG container */
		SF_FORMAT_MPC2K			= 0x210000,		/* Akai MPC 2000 sampler */
		SF_FORMAT_RF64			= 0x220000,		/* RF64 WAV file */

		/* Subtypes from here on. */

		SF_FORMAT_PCM_S8		= 0x0001,		/* Signed 8 bit data */
		SF_FORMAT_PCM_16		= 0x0002,		/* Signed 16 bit data */
		SF_FORMAT_PCM_24		= 0x0003,		/* Signed 24 bit data */
		SF_FORMAT_PCM_32		= 0x0004,		/* Signed 32 bit data */

		SF_FORMAT_PCM_U8		= 0x0005,		/* Unsigned 8 bit data (WAV and RAW only) */

		SF_FORMAT_FLOAT			= 0x0006,		/* 32 bit float data */
		SF_FORMAT_DOUBLE		= 0x0007,		/* 64 bit float data */

		SF_FORMAT_ULAW			= 0x0010,		/* U-Law encoded. */
		SF_FORMAT_ALAW			= 0x0011,		/* A-Law encoded. */
		SF_FORMAT_IMA_ADPCM		= 0x0012,		/* IMA ADPCM. */
		SF_FORMAT_MS_ADPCM		= 0x0013,		/* Microsoft ADPCM. */

		SF_FORMAT_GSM610		= 0x0020,		/* GSM 6.10 encoding. */
		SF_FORMAT_VOX_ADPCM		= 0x0021,		/* OKI / Dialogix ADPCM */

		SF_FORMAT_G721_32		= 0x0030,		/* 32kbs G721 ADPCM encoding. */
		SF_FORMAT_G723_24		= 0x0031,		/* 24kbs G723 ADPCM encoding. */
		SF_FORMAT_G723_40		= 0x0032,		/* 40kbs G723 ADPCM encoding. */

		SF_FORMAT_DWVW_12		= 0x0040, 		/* 12 bit Delta Width Variable Word encoding. */
		SF_FORMAT_DWVW_16		= 0x0041, 		/* 16 bit Delta Width Variable Word encoding. */
		SF_FORMAT_DWVW_24		= 0x0042, 		/* 24 bit Delta Width Variable Word encoding. */
		SF_FORMAT_DWVW_N		= 0x0043, 		/* N bit Delta Width Variable Word encoding. */

		SF_FORMAT_DPCM_8		= 0x0050,		/* 8 bit differential PCM (XI only) */
		SF_FORMAT_DPCM_16		= 0x0051,		/* 16 bit differential PCM (XI only) */

		SF_FORMAT_VORBIS		= 0x0060,		/* Xiph Vorbis encoding. */

		/* Endian-ness options. */

		SF_ENDIAN_FILE			= 0x00000000,	/* Default file endian-ness. */
		SF_ENDIAN_LITTLE		= 0x10000000,	/* Force little endian-ness. */
		SF_ENDIAN_BIG			= 0x20000000,	/* Force big endian-ness. */
		SF_ENDIAN_CPU			= 0x30000000,	/* Force CPU endian-ness. */

		SF_FORMAT_SUBMASK		= 0x0000FFFF,
		SF_FORMAT_TYPEMASK		= 0x0FFF0000,
		SF_FORMAT_ENDMASK		= 0x30000000
	};

	public enum Command
	{	
		SFC_GET_LIB_VERSION				= 0x1000,
		SFC_GET_LOG_INFO				= 0x1001,
		SFC_GET_CURRENT_SF_INFO			= 0x1002,


		SFC_GET_NORM_DOUBLE				= 0x1010,
		SFC_GET_NORM_FLOAT				= 0x1011,
		SFC_SET_NORM_DOUBLE				= 0x1012,
		SFC_SET_NORM_FLOAT				= 0x1013,
		SFC_SET_SCALE_FLOAT_INT_READ	= 0x1014,
		SFC_SET_SCALE_INT_FLOAT_WRITE	= 0x1015,

		SFC_GET_SIMPLE_FORMAT_COUNT		= 0x1020,
		SFC_GET_SIMPLE_FORMAT			= 0x1021,

		SFC_GET_FORMAT_INFO				= 0x1028,

		SFC_GET_FORMAT_MAJOR_COUNT		= 0x1030,
		SFC_GET_FORMAT_MAJOR			= 0x1031,
		SFC_GET_FORMAT_SUBTYPE_COUNT	= 0x1032,
		SFC_GET_FORMAT_SUBTYPE			= 0x1033,

		SFC_CALC_SIGNAL_MAX				= 0x1040,
		SFC_CALC_NORM_SIGNAL_MAX		= 0x1041,
		SFC_CALC_MAX_ALL_CHANNELS		= 0x1042,
		SFC_CALC_NORM_MAX_ALL_CHANNELS	= 0x1043,
		SFC_GET_SIGNAL_MAX				= 0x1044,
		SFC_GET_MAX_ALL_CHANNELS		= 0x1045,

		SFC_SET_ADD_PEAK_CHUNK			= 0x1050,
		SFC_SET_ADD_HEADER_PAD_CHUNK	= 0x1051,

		SFC_UPDATE_HEADER_NOW			= 0x1060,
		SFC_SET_UPDATE_HEADER_AUTO		= 0x1061,

		SFC_FILE_TRUNCATE				= 0x1080,

		SFC_SET_RAW_START_OFFSET		= 0x1090,

		SFC_SET_DITHER_ON_WRITE			= 0x10A0,
		SFC_SET_DITHER_ON_READ			= 0x10A1,

		SFC_GET_DITHER_INFO_COUNT		= 0x10A2,
		SFC_GET_DITHER_INFO				= 0x10A3,

		SFC_GET_EMBED_FILE_INFO			= 0x10B0,

		SFC_SET_CLIPPING				= 0x10C0,
		SFC_GET_CLIPPING				= 0x10C1,

		SFC_GET_INSTRUMENT				= 0x10D0,
		SFC_SET_INSTRUMENT				= 0x10D1,

		SFC_GET_LOOP_INFO				= 0x10E0,

		SFC_GET_BROADCAST_INFO			= 0x10F0,
		SFC_SET_BROADCAST_INFO			= 0x10F1,

		SFC_GET_CHANNEL_MAP_INFO		= 0x1100,
		SFC_SET_CHANNEL_MAP_INFO		= 0x1101,

		SFC_RAW_DATA_NEEDS_ENDSWAP		= 0x1110,

		/* Support for Wavex Ambisonics Format */
		SFC_WAVEX_SET_AMBISONIC			= 0x1200,
		SFC_WAVEX_GET_AMBISONIC			= 0x1201,

		SFC_SET_VBR_ENCODING_QUALITY	= 0x1300,

		/* Following commands for testing only. */
		SFC_TEST_IEEE_FLOAT_REPLACE		= 0x6001,

		/*
		** SFC_SET_ADD_* values are deprecated and will disappear at some
		** time in the future. They are guaranteed to be here up to and
		** including version 1.0.8 to avoid breakage of existng software.
		** They currently do nothing and will continue to do nothing.
		*/
		SFC_SET_ADD_DITHER_ON_WRITE		= 0x1070,
		SFC_SET_ADD_DITHER_ON_READ		= 0x1071
	};

	public enum LoopMode
	{	
		SF_LOOP_NONE = 800,
		SF_LOOP_FORWARD,
		SF_LOOP_BACKWARD,
		SF_LOOP_ALTERNATING
	};

	[StructLayout(LayoutKind.Sequential)]
	public struct SF_INFO
	{
		public long frames;
		public int samplerate;
		public int channels;
		public Format format;
		public int sections;
		public int seekable;
	}

	[StructLayout(LayoutKind.Sequential)]
	public struct SF_FORMAT_INFO
	{	
		public int format;
		IntPtr name;
		IntPtr extension;

		public string Name { get { return Marshal.PtrToStringAnsi(name); } }
		public string Extension { get { return Marshal.PtrToStringAnsi(extension); } }
	}

	[StructLayout(LayoutKind.Sequential)]
	public struct SF_INSTRUMENT
	{
		[CLSCompliant(false)]
		[StructLayout(LayoutKind.Sequential)]
		public struct Loop
		{
			public LoopMode mode;
			public uint start;
			public uint end;
			public uint count;
		} 

		public int gain;
		public byte basenote, detune;
		public byte velocity_lo, velocity_hi;
		public byte key_lo, key_hi;
		public int loop_count;

		[CLSCompliant(false)]
		[MarshalAs(UnmanagedType.ByValArray, SizeConst = 16)]
		public Loop[] loops;
	
	}

	[StructLayout(LayoutKind.Sequential)]
	public struct SF_VIRTUAL_IO
	{
		[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
		public delegate long sf_vio_get_filelen(IntPtr user_data);

		[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
		public delegate long sf_vio_seek(long offset, int whence, IntPtr user_data);

		[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
		public delegate long sf_vio_read(IntPtr ptr, long count, IntPtr user_data);

		[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
		public delegate long sf_vio_write(IntPtr ptr, long count, IntPtr user_data);

		[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
		public delegate long sf_vio_tell(IntPtr user_data);

		public sf_vio_get_filelen get_filelen;
		public sf_vio_seek seek;
		public sf_vio_read read;
		public sf_vio_write write;
		public sf_vio_tell tell;
	}


	public class SoundFile : IDisposable
	{
		[DllImport("libsndfile-1", CallingConvention = CallingConvention.Cdecl)]
		extern static IntPtr sf_open(string path, FileMode mode, ref SF_INFO sfinfo);

		[DllImport("libsndfile-1", CallingConvention = CallingConvention.Cdecl)]
		extern static IntPtr sf_open_virtual(ref SF_VIRTUAL_IO sfvirtual, FileMode mode, ref SF_INFO sfinfo, IntPtr user_data);

		[DllImport("libsndfile-1", CallingConvention = CallingConvention.Cdecl)]
		extern static ErrorValue sf_close(IntPtr sndfile);

		[DllImport("libsndfile-1", CallingConvention = CallingConvention.Cdecl)]
		extern static int sf_error(IntPtr sndfile);

		[DllImport("libsndfile-1", CallingConvention = CallingConvention.Cdecl)]
		extern static IntPtr sf_strerror(IntPtr sndfile);

		[DllImport("libsndfile-1", CallingConvention = CallingConvention.Cdecl)]
		extern static long sf_readf_float(IntPtr sndfile, [Out] float[] ptr, long frames);

		[DllImport("libsndfile-1", CallingConvention = CallingConvention.Cdecl)]
		extern static long sf_writef_float(IntPtr sndfile, IntPtr ptr, long frames);

		[DllImport("libsndfile-1", CallingConvention = CallingConvention.Cdecl, EntryPoint = "sf_command")]
		extern static int sf_command_int(IntPtr sndfile, Command command, ref int data, int datasize);

		[DllImport("libsndfile-1", CallingConvention = CallingConvention.Cdecl, EntryPoint="sf_command")]
		extern static int sf_command_SF_FORMAT_INFO(IntPtr sndfile, Command command, ref SF_FORMAT_INFO data, int datasize);

		[DllImport("libsndfile-1", CallingConvention = CallingConvention.Cdecl, EntryPoint = "sf_command")]
		extern static int sf_command_SF_INSTRUMENT(IntPtr sndfile, Command command, ref SF_INSTRUMENT data, int datasize);

		[DllImport("libsndfile-1", CallingConvention = CallingConvention.Cdecl, EntryPoint = "sf_command")]
		extern static int sf_command_StringBuilder(IntPtr sndfile, Command command, StringBuilder data, int datasize);


		IntPtr sndfile;
		SF_INFO sfinfo;
		SF_VIRTUAL_IO sfvirtual;
		GCHandle sfvirtualHandle;
		GCHandle streamHandle;

		public SF_INFO Info { get { return sfinfo; } }
		public long FrameCount { get { return sfinfo.frames; } }
		public int SampleRate { get { return sfinfo.samplerate; } }
		public int ChannelCount { get { return sfinfo.channels; } }
		public Format Format { get { return sfinfo.format; } }
		public int SectionCount { get { return sfinfo.sections; } }
		public bool IsSeekable { get { return sfinfo.seekable != 0; } }

		public SoundFile(string path, FileMode mode, SF_INFO sfinfo)
		{
			this.sfinfo = sfinfo;
			sndfile = sf_open(path, mode, ref this.sfinfo);
			if (sndfile == IntPtr.Zero)	throw new Exception(Marshal.PtrToStringAnsi(sf_strerror(IntPtr.Zero)));
		}

		public SoundFile(Stream stream, FileMode mode, SF_INFO sfinfo)
		{
			sfvirtualHandle = GCHandle.Alloc(sfvirtual);
			streamHandle = GCHandle.Alloc(stream);

			sfvirtual.get_filelen = stream_get_filelen;
			sfvirtual.seek = stream_seek;
			sfvirtual.read = stream_read;
			sfvirtual.write = stream_write;
			sfvirtual.tell = stream_tell;

			this.sfinfo = sfinfo;
			sndfile = sf_open_virtual(ref sfvirtual, mode, ref this.sfinfo, GCHandle.ToIntPtr(streamHandle));
			if (sndfile == IntPtr.Zero) throw new Exception(Marshal.PtrToStringAnsi(sf_strerror(IntPtr.Zero)));
		}

		public static SoundFile OpenRead(string path) { return new SoundFile(path, FileMode.SFM_READ, new SF_INFO()); }
		public static SoundFile OpenRead(Stream stream) { return new SoundFile(stream, FileMode.SFM_READ, new SF_INFO()); }
		
		public static SoundFile Create(string path, int samplerate, int channels, Format format) 
		{
			var sfinfo = new SF_INFO();
			sfinfo.samplerate = samplerate;
			sfinfo.channels = channels;
			sfinfo.format = format;
			return new SoundFile(path, FileMode.SFM_WRITE, sfinfo); 
		}

		public static SoundFile Create(Stream stream, int samplerate, int channels, Format format)
		{
			var sfinfo = new SF_INFO();
			sfinfo.samplerate = samplerate;
			sfinfo.channels = channels;
			sfinfo.format = format;
			return new SoundFile(stream, FileMode.SFM_WRITE, sfinfo);
		}

		public void Close()
		{
			if (sndfile != IntPtr.Zero)
			{
				var res = sf_close(sndfile);
				if (res != ErrorValue.SF_ERR_NO_ERROR) throw new Exception(res.ToString());
				sndfile = IntPtr.Zero;
				sfinfo = new SF_INFO();

			}

			if (sfvirtualHandle.IsAllocated) sfvirtualHandle.Free();
			if (streamHandle.IsAllocated) streamHandle.Free();

		}

		public void Dispose()
		{
			Close();
		}

		public long ReadFloat(float[] output, long framecount)
		{
			if (output.Length < framecount * ChannelCount) throw new ArgumentException("output.Length < framecount * ChannelCount");
			return sf_readf_float(sndfile, output, framecount);
		}

		public long WriteFloat(float[] input, int offset, long framecount)
		{
			if (input.Length - offset < framecount * ChannelCount) throw new ArgumentException("input.Length - offset < framecount * ChannelCount");
			var gch = GCHandle.Alloc(input);
			var r = sf_writef_float(sndfile, Marshal.UnsafeAddrOfPinnedArrayElement(input, offset), framecount);
			gch.Free();
			return r;
		}

		public static int SimpleFormatCount
		{
			get
			{
				int count = 0;
				sf_command_int(IntPtr.Zero, Command.SFC_GET_SIMPLE_FORMAT_COUNT, ref count, 4);
				return count;
			}
		}

		public static int FormatMajorCount
		{
			get
			{
				int count = 0;
				sf_command_int(IntPtr.Zero, Command.SFC_GET_FORMAT_MAJOR_COUNT, ref count, 4);
				return count;
			}
		}

		public static SF_FORMAT_INFO GetSimpleFormat(int format)
		{
			var fi = new SF_FORMAT_INFO();
			fi.format = format;
			var res = sf_command_SF_FORMAT_INFO(IntPtr.Zero, Command.SFC_GET_SIMPLE_FORMAT, ref fi, 3 * IntPtr.Size);
			return fi;
		}

		public static SF_FORMAT_INFO GetFormatMajor(int format)
		{
			var fi = new SF_FORMAT_INFO();
			fi.format = format;
			var res = sf_command_SF_FORMAT_INFO(IntPtr.Zero, Command.SFC_GET_FORMAT_MAJOR, ref fi, 3 * IntPtr.Size);
			return fi;
		}

		public static IEnumerable<SF_FORMAT_INFO> SimpleFormats
		{
			get
			{
				int count = SimpleFormatCount;
				for (int i = 0; i < count; i++)
					yield return GetSimpleFormat(i);
			}
		}

		public static IEnumerable<SF_FORMAT_INFO> FormatsMajor
		{
			get
			{
				int count = FormatMajorCount;
				for (int i = 0; i < count; i++)
					yield return GetFormatMajor(i);
			}
		}

		public string LogInfo
		{
			get
			{
				var sb = new StringBuilder(65536);
				sf_command_StringBuilder(sndfile, Command.SFC_GET_LOG_INFO, sb, sb.Capacity);
				return sb.ToString();
			}
		}

		public SF_INSTRUMENT Instrument
		{
			get
			{
				var i = new SF_INSTRUMENT();
				var res = sf_command_SF_INSTRUMENT(sndfile, Command.SFC_GET_INSTRUMENT, ref i, Marshal.SizeOf(i));
				if (res == 0)
				{
					i.basenote = 60;
					i.velocity_hi = 127;
					i.key_hi = 127;
				}
				return i;
			}
		}

		public bool Clipping
		{
			get
			{
				int data = 0;
				return sf_command_int(sndfile, Command.SFC_GET_CLIPPING, ref data, 0) != 0;
			}
			set
			{
				int data = 0;
				sf_command_int(sndfile, Command.SFC_SET_CLIPPING, ref data, value ? 1 : 0);
			}
		}

		#region Stream IO

		static long stream_get_filelen(IntPtr user_data)
		{
			var s = GCHandle.FromIntPtr(user_data).Target as Stream;
			return s.Length;
		}

		static long stream_seek(long offset, int whence, IntPtr user_data)
		{
			var s = GCHandle.FromIntPtr(user_data).Target as Stream;
			switch (whence)
			{
				case 0: return s.Seek(offset, SeekOrigin.Begin);
				case 1: return s.Seek(offset, SeekOrigin.Current);
				case 2: return s.Seek(offset, SeekOrigin.End);
			}
			return 0;
		}

		static long stream_read(IntPtr ptr, long count, IntPtr user_data)
		{
			var s = GCHandle.FromIntPtr(user_data).Target as Stream;

			var buffer = new byte[count];
			int bytesread = s.Read(buffer, 0, buffer.Length);
			Marshal.Copy(buffer, 0, ptr, bytesread);

			return bytesread;
		}

		static long stream_write(IntPtr ptr, long count, IntPtr user_data)
		{
			var s = GCHandle.FromIntPtr(user_data).Target as Stream;
	
			var buffer = new byte[count];
			Marshal.Copy(ptr, buffer, 0, (int)count);
			s.Write(buffer, 0, buffer.Length);

			return count;
		}

		static long stream_tell(IntPtr user_data)
		{
			var s = GCHandle.FromIntPtr(user_data).Target as Stream;
			return s.Position;
		}

		#endregion

	}
}