/*==LICENSE==*

CyanWorlds.com Engine - MMOG client, server and tools
Copyright (C) 2011 Cyan Worlds, Inc.

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.

Additional permissions under GNU GPL version 3 section 7

If you modify this Program, or any covered work, by linking or
combining it with any of RAD Game Tools Bink SDK, Autodesk 3ds Max SDK,
NVIDIA PhysX SDK, Microsoft DirectX SDK, OpenSSL library, Independent
JPEG Group JPEG library, Microsoft Windows Media SDK, or Apple QuickTime SDK
(or a modified version of those libraries),
containing parts covered by the terms of the Bink SDK EULA, 3ds Max EULA,
PhysX SDK EULA, DirectX SDK EULA, OpenSSL and SSLeay licenses, IJG
JPEG Library README, Windows Media SDK EULA, or QuickTime SDK EULA, the
licensors of this Program grant you additional
permission to convey the resulting work. Corresponding Source for a
non-source form of such a combination shall include the source code for
the parts of OpenSSL and IJG JPEG Library used as well as that of the covered
work.

You can contact Cyan Worlds, Inc. by email legal@cyan.com
 or by snail mail at:
      Cyan Worlds, Inc.
      14617 N Newport Hwy
      Mead, WA   99021

*==LICENSE==*/
//////////////////////////////////////////////////////////////////////////////
//																			//
//	plFastWavReader - Quick, dirty, and highly optimized class for reading	//
//					  in the samples of a WAV file when you're in a hurry.	//
//					  ONLY WORKS WITH PCM (i.e. uncompressed) DATA			//
//																			//
//// Notes ///////////////////////////////////////////////////////////////////
//																			//
//	11.5.2001 - Created by mcn.												//
//																			//
//////////////////////////////////////////////////////////////////////////////

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "hsTypes.h"
#include "plFastWavReader.h"


//// Local Helpers ///////////////////////////////////////////////////////////

class plRIFFChunk
{
	public:
		char	fID[ 4 ];
		UInt32	fSize;

		void	Read( FILE *fp )
		{
			fread( fID, 1, 4, fp );
			fread( &fSize, sizeof( UInt32 ), 1, fp );
		}

		bool	IsA( const char *type )
		{
			return ( memcmp( fID, type, 4 ) == 0 ) ? true : false;
		}
};

class plRIFFHeader
{
	protected:
		plRIFFChunk		fChunk;
		bool			fValid;
		char			fFormat[ 4 ];

	public:
		plRIFFHeader( FILE *fp )
		{
			fValid = false;
			fChunk.Read( fp );
			if( fChunk.IsA( "RIFF" ) )
			{
				if( fread( &fFormat, 1, 4, fp ) == 4 )
				{
					fValid = true;
				}
			}
		}

		bool	IsValid( void )
		{
			return fValid;
		}

		bool	IsA( const char *type )
		{
			return ( memcmp( fFormat, type, 4 ) == 0 ) ? true : false;
		}
};

//// Constructor/Destructor //////////////////////////////////////////////////

plFastWAV::plFastWAV( const char *path, plAudioCore::ChannelSelect whichChan ) : fFileHandle( nil )
{
	hsAssert( path != nil, "Invalid path specified in plFastWAV reader" );

	strncpy( fFilename, path, sizeof( fFilename ) );
	fWhichChannel = whichChan;

	fFileHandle = fopen( path, "rb" );
	if( fFileHandle != nil )
	{
		/// Read in our header and calc our start position
		plRIFFHeader	riffHdr( fFileHandle );

		if( !riffHdr.IsValid() )
		{
			IError( "Invalid RIFF file header in plFastWAV" );
			return;
		}

		if( !riffHdr.IsA( "WAVE" ) )
		{
			IError( "Invalid RIFF file type in plFastWAV" );
			return;
		}

		fChunkStart = ftell( fFileHandle );

		// Seek and read the "fmt " header
		plRIFFChunk		chunk;
		if( !ISeekToChunk( "fmt ", &chunk ) )
		{
			IError( "Unable to find fmt chunk in WAV file" );
			return;
		}

		if( fread( &fHeader, 1, sizeof( plWAVHeader ), fFileHandle ) != sizeof( plWAVHeader ) )
		{
			IError( "Invalid WAV file header in plFastWAV" );
			return;
		}

		// Check format
		if( fHeader.fFormatTag != kPCMFormatTag )
		{
			IError( "Invalid format in plFastWAV" );
			return;
		}

		// Seek to and get the position of the data chunk
		if( !ISeekToChunk( "data", &chunk ) )
		{
			IError( "Unable to find data chunk in WAV file" );
			return;
		}
		fDataStartPos = ftell( fFileHandle );
		fDataSize = chunk.fSize;

		// HACKY FIX FOR BAD WAV FILES
		fDataSize -= ( fDataSize & ( fHeader.fBlockAlign - 1 ) );

		if( fWhichChannel != plAudioCore::kAll )
		{
			fChannelAdjust = 2;
			fChannelOffset = ( fWhichChannel == plAudioCore::kLeft ) ? 0 : 1;
		}
		else
		{
			fChannelAdjust = 1;
			fChannelOffset = 0;
		}

		fFakeHeader = fHeader;
		fFakeHeader.fAvgBytesPerSec /= fChannelAdjust;
		fFakeHeader.fNumChannels /= (UInt16)fChannelAdjust;
		fFakeHeader.fBlockAlign /= (UInt16)fChannelAdjust;

		SetPosition( 0 );
//		fCurrDataPos = 0;
	}
}

plFastWAV::~plFastWAV()
{
	if( fFileHandle != nil )
		fclose( fFileHandle );
}

bool	plFastWAV::ISeekToChunk( const char *type, plRIFFChunk *c )
{
	plRIFFChunk		chunk;


	// Start from chunk start and search through all the, well, chunks :)
	fseek( fFileHandle, fChunkStart, SEEK_SET );
	while( !feof( fFileHandle ) )
	{
		chunk.Read( fFileHandle );
		if( chunk.IsA( type ) )
		{
			*c = chunk;
			return true;
		}

		// Seek past this one
		fseek( fFileHandle, chunk.fSize, SEEK_CUR );
	}

	return false;
}

void plFastWAV::Open()
{
	if(fFileHandle)
		return;
	
	fFileHandle = fopen( fFilename, "rb" );
	if(!fFileHandle) 
		return;

	fCurrDataPos = 0;

	fseek( fFileHandle, fDataStartPos, SEEK_SET );
}

void	plFastWAV::Close( void )
{
	if( fFileHandle != nil )
	{
		fclose( fFileHandle );
		fFileHandle = nil;
	}
}

void	plFastWAV::IError( const char *msg )
{
	hsAssert( false, msg );
	Close();
}

plWAVHeader	&plFastWAV::GetHeader( void )
{
	hsAssert( IsValid(), "GetHeader() called on an invalid WAV file" );

	return fFakeHeader;
}

float	plFastWAV::GetLengthInSecs( void )
{
	hsAssert( IsValid(), "GetLengthInSecs() called on an invalid WAV file" );

	return (float)( fDataSize / fChannelAdjust ) / (float)fHeader.fAvgBytesPerSec;
}

hsBool	plFastWAV::SetPosition( UInt32 numBytes )
{
	hsAssert( IsValid(), "GetHeader() called on an invalid WAV file" );


	fCurrDataPos = numBytes * fChannelAdjust + ( fChannelOffset * fHeader.fBlockAlign / fChannelAdjust );
	
	hsAssert( fCurrDataPos <= fDataSize, "Invalid new position while seeking WAV file" );

	return ( fseek( fFileHandle, fDataStartPos + fCurrDataPos, SEEK_SET ) == 0 ) ? true : false;
}

hsBool	plFastWAV::Read( UInt32 numBytes, void *buffer )
{
	hsAssert( IsValid(), "GetHeader() called on an invalid WAV file" );


	if( fWhichChannel != plAudioCore::kAll )
	{
		size_t	numRead, sampleSize = fHeader.fBlockAlign / fChannelAdjust;
		static UInt8	trashBuffer[ 32 ];

		UInt32 numBytesFull = numBytes;
		if( fCurrDataPos + ( numBytes * fChannelAdjust ) > fDataSize )
			numBytesFull -= sampleSize;

		for( numRead = 0; numRead < numBytesFull; numRead += sampleSize )
		{
			size_t thisRead = fread( buffer, 1, sampleSize, fFileHandle );
			if( thisRead != sampleSize )
				return false;

//			fseek( fFileHandle, sampleSize * ( fChannelAdjust - 1 ), SEEK_CUR );
			thisRead = fread( trashBuffer, 1, sampleSize, fFileHandle );
			if( thisRead != sampleSize )
				return false;

			buffer = (void *)( (UInt8 *)buffer + sampleSize );
			fCurrDataPos += sampleSize * fChannelAdjust;
		}

		if( numRead < numBytes )
		{
			if( numBytes - numRead > sampleSize )
			{
				hsAssert( false, "Invalid logic in plFastWAV::Read()" );
				return false;
			}

	
			// Must not have enough room left, so no more skipping
			size_t thisRead = fread( buffer, 1, sampleSize, fFileHandle );

			if( thisRead != sampleSize )
				return false;

			buffer = (void *)( (UInt8 *)buffer + sampleSize );
			fCurrDataPos += sampleSize;
		}

		hsAssert( fCurrDataPos <= fDataSize, "Invalid new position while reading WAV file" );
	}
	else
	{	
		size_t numRead = fread( buffer, 1, numBytes, fFileHandle );
		
		fCurrDataPos += numRead;
		hsAssert( fCurrDataPos <= fDataSize, "Invalid new position while reading WAV file" );

		if( numRead < numBytes )
			return false;
	}

	return true;
}

UInt32	plFastWAV::NumBytesLeft( void )
{
	hsAssert( IsValid(), "GetHeader() called on an invalid WAV file" );
	hsAssert( fCurrDataPos <= fDataSize, "Invalid current position while reading WAV file" );

	return ( fDataSize - fCurrDataPos ) / fChannelAdjust;
}