/*
 * PortAudio Portable Real-Time Audio Library
 * Latest Version at: http://www.portaudio.com
 *
 * Copyright (c) 1999-2010 Phil Burk and Ross Bencina
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files
 * (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge,
 * publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

/*
 * The text above constitutes the entire PortAudio license; however,
 * the PortAudio community also makes the following non-binding requests:
 *
 * Any person wishing to distribute modifications to the Software is
 * requested to send the modifications to the original developer so that
 * they can be incorporated into the canonical version. It is also
 * requested that these non-binding requests be included along with the
 * license above.
 */

/**
  * Very simple WAV file writer for saving captured audio.
  */

#include <stdio.h>
#include <stdlib.h>
#include "write_wav.h"


/* Write long word data to a little endian format byte array. */
static void WriteLongLE( unsigned char **addrPtr, unsigned long data )
{
    unsigned char *addr = *addrPtr;
    *addr++ =  (unsigned char) data;
    *addr++ =  (unsigned char) (data>>8);
    *addr++ =  (unsigned char) (data>>16);
    *addr++ =  (unsigned char) (data>>24);
    *addrPtr = addr;
}

/* Write short word data to a little endian format byte array. */
static void WriteShortLE( unsigned char **addrPtr,  unsigned short data )
{
    unsigned char *addr = *addrPtr;
    *addr++ =  (unsigned char) data;
    *addr++ =  (unsigned char) (data>>8);
    *addrPtr = addr;
}

/* Write IFF ChunkType data to a byte array. */
static void WriteChunkType( unsigned char **addrPtr, unsigned long cktyp )
{
    unsigned char *addr = *addrPtr;
    *addr++ =  (unsigned char) (cktyp>>24);
    *addr++ =  (unsigned char) (cktyp>>16);
    *addr++ =  (unsigned char) (cktyp>>8);
    *addr++ =  (unsigned char) cktyp;
    *addrPtr = addr;
}

#define WAV_HEADER_SIZE (4 + 4 + 4 + /* RIFF+size+WAVE */ \
        4 + 4 + 16 + /* fmt chunk */ \
        4 + 4 ) /* data chunk */


/*********************************************************************************
 * Open named file and write WAV header to the file.
 * The header includes the DATA chunk type and size.
 * Returns number of bytes written to file or negative error code.
 */
long Audio_WAV_OpenWriter( WAV_Writer *writer, const char *fileName, int frameRate, int samplesPerFrame )
{
    unsigned int  bytesPerSecond;
    unsigned char header[ WAV_HEADER_SIZE ];
    unsigned char *addr = header;
    int numWritten;

    writer->dataSize = 0;
    writer->dataSizeOffset = 0;

    writer->fid = fopen( fileName, "wb" );
    if( writer->fid == NULL )
    {
        return -1;
    }

/* Write RIFF header. */
    WriteChunkType( &addr, RIFF_ID );

/* Write RIFF size as zero for now. Will patch later. */
    WriteLongLE( &addr, 0 );

/* Write WAVE form ID. */
    WriteChunkType( &addr, WAVE_ID );

/* Write format chunk based on AudioSample structure. */
    WriteChunkType( &addr, FMT_ID );
    WriteLongLE( &addr, 16 );
    WriteShortLE( &addr, WAVE_FORMAT_PCM );
        bytesPerSecond = frameRate * samplesPerFrame * sizeof( short);
    WriteShortLE( &addr, (short) samplesPerFrame );
    WriteLongLE( &addr, frameRate );
    WriteLongLE( &addr,  bytesPerSecond );
    WriteShortLE( &addr, (short) (samplesPerFrame * sizeof( short)) ); /* bytesPerBlock */
    WriteShortLE( &addr, (short) 16 ); /* bits per sample */

/* Write ID and size for 'data' chunk. */
    WriteChunkType( &addr, DATA_ID );
/* Save offset so we can patch it later. */
    writer->dataSizeOffset = (int) (addr - header);
    WriteLongLE( &addr, 0 );

    numWritten = fwrite( header, 1, sizeof(header), writer->fid );
    if( numWritten != sizeof(header) ) return -1;

    return (int) numWritten;
}

/*********************************************************************************
 * Write to the data chunk portion of a WAV file.
 * Returns bytes written or negative error code.
 */
long Audio_WAV_WriteShorts( WAV_Writer *writer,
        short *samples,
        int numSamples
        )
{
    unsigned char buffer[2];
    unsigned char *bufferPtr;
    int i;
    short *p = samples;
    int numWritten;
    int bytesWritten;
    if( numSamples <= 0 )
    {
        return -1;
    }

    for( i=0; i<numSamples; i++ )
    {
        bufferPtr = buffer;
        WriteShortLE( &bufferPtr, *p++ );
        numWritten = fwrite( buffer, 1, sizeof( buffer), writer->fid );
        if( numWritten != sizeof(buffer) ) return -1;
    }
    bytesWritten = numSamples * sizeof(short);
    writer->dataSize += bytesWritten;
    return (int) bytesWritten;
}

/*********************************************************************************
 * Close WAV file.
 * Update chunk sizes so it can be read by audio applications.
 */
long Audio_WAV_CloseWriter( WAV_Writer *writer )
{
    unsigned char buffer[4];
    unsigned char *bufferPtr;
    int numWritten;
    int riffSize;

    /* Go back to beginning of file and update DATA size */
    int result = fseek( writer->fid, writer->dataSizeOffset, SEEK_SET );
    if( result < 0 ) return result;

    bufferPtr = buffer;
    WriteLongLE( &bufferPtr, writer->dataSize );
    numWritten = fwrite( buffer, 1, sizeof( buffer), writer->fid );
    if( numWritten != sizeof(buffer) ) return -1;

    /* Update RIFF size */
    result = fseek( writer->fid, 4, SEEK_SET );
    if( result < 0 ) return result;

    riffSize = writer->dataSize + (WAV_HEADER_SIZE - 8);
    bufferPtr = buffer;
    WriteLongLE( &bufferPtr, riffSize );
    numWritten = fwrite( buffer, 1, sizeof( buffer), writer->fid );
    if( numWritten != sizeof(buffer) ) return -1;

    fclose( writer->fid );
    writer->fid = NULL;
    return writer->dataSize;
}

/*********************************************************************************
 * Simple test that write a sawtooth waveform to a file.
 */
#if 0
int main( void )
{
    int i;
    WAV_Writer writer;
    int result;
#define NUM_SAMPLES  (200)
    short data[NUM_SAMPLES];
    short saw = 0;

    for( i=0; i<NUM_SAMPLES; i++ )
    {
        data[i] = saw;
        saw += 293;
    }


    result =  Audio_WAV_OpenWriter( &writer, "rendered_midi.wav", 44100, 1 );
    if( result < 0 ) goto error;

    for( i=0; i<15; i++ )
    {
        result =  Audio_WAV_WriteShorts( &writer, data, NUM_SAMPLES );
        if( result < 0 ) goto error;
    }

    result =  Audio_WAV_CloseWriter( &writer );
    if( result < 0 ) goto error;


    return 0;

error:
    printf("ERROR: result = %d\n", result );
    return result;
}
#endif