#include <stdlib.h>
#include <stdio.h>
#include <portaudio.h>


#define SAMPLE_RATE  (8000)
#define FRAMES_PER_BUFFER (512)
#define NUM_CHANNELS    (2)
#define DITHER_FLAG     (1) 
#define WRITE_TO_FILE   (1)
 
#define PA_SAMPLE_TYPE  paInt16
#define SAMPLE_SILENCE  (0)
#define PRINTF_S_FORMAT "%d"

typedef short SAMPLE;

typedef struct
{
    int          frameIndex;  /* Index into sample array. */
    int          maxFrameIndex;
    SAMPLE      *recordedSamples;
}paTestData;


static int recordCallback( const void *inputBuffer, void *outputBuffer,
			   unsigned long framesPerBuffer,
			   const PaStreamCallbackTimeInfo* timeInfo,
			   PaStreamCallbackFlags statusFlags,
			   void *userData ){
    
    paTestData *data = (paTestData*)userData;
    const SAMPLE *rptr = (const SAMPLE*)inputBuffer;
    SAMPLE *wptr = &data->recordedSamples[data->frameIndex * NUM_CHANNELS];
    long framesToCalc;
    long i;
    int finished;
    unsigned long framesLeft = data->maxFrameIndex - data->frameIndex;
    
    (void) outputBuffer; /* Prevent unused variable warnings. */
    (void) timeInfo;
    (void) statusFlags;
    (void) userData;
 
    if( framesLeft < framesPerBuffer )
    {
	framesToCalc = framesLeft;
	finished = paComplete;
    }
    else
    {
	framesToCalc = framesPerBuffer;
	finished = paContinue;
    }
 
    if( inputBuffer == NULL )
    {
	for( i=0; i<framesToCalc; i++ )
	{
	    *wptr++ = SAMPLE_SILENCE;  /* left */
	    if( NUM_CHANNELS == 2 ) *wptr++ = SAMPLE_SILENCE;  /* right */
	}
    }
    else
    {
	for( i=0; i<framesToCalc; i++ )
	{
	    *wptr++ = *rptr++;  /* left */
	    if( NUM_CHANNELS == 2 ) *wptr++ = *rptr++;  /* right */
	}
    }
    data->frameIndex += framesToCalc;
    return finished;
}

static int playCallback( const void *inputBuffer, void *outputBuffer,
			 unsigned long framesPerBuffer,
			 const PaStreamCallbackTimeInfo* timeInfo,
			 PaStreamCallbackFlags statusFlags,
			 void *userData )
{
    paTestData *data = (paTestData*)userData;
    SAMPLE *rptr = &data->recordedSamples[data->frameIndex * NUM_CHANNELS];
    SAMPLE *wptr = (SAMPLE*)outputBuffer;
    unsigned int i;
    int finished;
    unsigned int framesLeft = data->maxFrameIndex - data->frameIndex;
 
    (void) inputBuffer; /* Prevent unused variable warnings. */
    (void) timeInfo;
    (void) statusFlags;
    (void) userData;
 
    if( framesLeft < framesPerBuffer )
    {
	/* final buffer... */
	for( i=0; i<framesLeft; i++ )
	{
	    *wptr++ = *rptr++;  /* left */
	    if( NUM_CHANNELS == 2 ) *wptr++ = *rptr++;  /* right */
	}
	for( ; i<framesPerBuffer; i++ )
	{
	    *wptr++ = 0;  /* left */
	    if( NUM_CHANNELS == 2 ) *wptr++ = 0;  /* right */
	}
	data->frameIndex += framesLeft;
	finished = paComplete;
    }
    else
    {
	for( i=0; i<framesPerBuffer; i++ )
	{
	    *wptr++ = *rptr++;  /* left */
	    if( NUM_CHANNELS == 2 ) *wptr++ = *rptr++;  /* right */
	}
	data->frameIndex += framesPerBuffer;
	finished = paContinue;
    }
    return finished;
}
 
int record(int NUM_SECONDS){
    PaStream*           stream;	       
    PaError             err = paNoError;
    PaStreamParameters  inputParameters, outputParameters;   
    paTestData          data;
    int                 numBytes;
    int                 i;
    SAMPLE              max, val;
    int                 totalFrames;
    double              average;
    int                 numSamples;     
    data.maxFrameIndex = totalFrames = NUM_SECONDS * SAMPLE_RATE;
    data.frameIndex = 0;
    numSamples = totalFrames * NUM_CHANNELS;
    numBytes = numSamples * sizeof(SAMPLE);
    data.recordedSamples = (SAMPLE *) malloc( numBytes ); 
    if( data.recordedSamples == NULL )
    {
	printf("Could not allocate record array.\n");
	goto done;
    }
    for( i=0; i<numSamples; i++ ) data.recordedSamples[i] = 0;
 
    err = Pa_Initialize();
    if( err != paNoError ) goto done;
 
    inputParameters.device = Pa_GetDefaultInputDevice(); 
    if (inputParameters.device == paNoDevice) {
	fprintf(stderr,"Error: No default input device.\n");
	goto done;
    }
    inputParameters.channelCount = 2;                    
    inputParameters.sampleFormat = PA_SAMPLE_TYPE;
    inputParameters.suggestedLatency = Pa_GetDeviceInfo( inputParameters.device )->defaultLowInputLatency;
    inputParameters.hostApiSpecificStreamInfo = NULL;
 
    /* Record some audio. -------------------------------------------- */    
    err = Pa_OpenStream(
	&stream,
	&inputParameters,
	NULL,                  /* &outputParameters, */
	SAMPLE_RATE,
	FRAMES_PER_BUFFER,
	paClipOff,      /* we won't output out of range samples so don't bother clipping them */
	recordCallback,
	&data );
    if( err != paNoError ) goto done;
 
    err = Pa_StartStream( stream );
    if( err != paNoError ) goto done;
    printf("=== NOW RECORDING ===\n"); fflush(stdout);
 
    while( ( err = Pa_IsStreamActive( stream ) ) == 1 )
    {
	Pa_Sleep(1000);
	printf("index = %d\n", data.frameIndex ); fflush(stdout);
    }
    if( err < 0 ) goto done;
 
    err = Pa_CloseStream( stream );
    if( err != paNoError ) goto done;
 
    /* Measure maximum peak amplitude. */
    max = 0;
    average = 0.0;
    for( i=0; i<numSamples; i++ )
    {
	val = data.recordedSamples[i];
	if( val < 0 ) val = -val; /* ABS */
	if( val > max )
	{
	    max = val;
	}
	average += val;
    }
 
    average = average / (double)numSamples;
 
    /* printf("sample max amplitude = "PRINTF_S_FORMAT"\n", max ); */
    /* printf("sample average = %lf\n", average ); */
 
    /* Write recorded data to a file. */
#if WRITE_TO_FILE
    {
	FILE  *fid;
	fid = fopen("recorded.raw", "wb");
	if( fid == NULL )
	{
	    printf("Could not open file.");
	}
	else
	{
	    fwrite( data.recordedSamples, NUM_CHANNELS * sizeof(SAMPLE), totalFrames, fid );
	    fclose( fid );
	    /* printf("Wrote data to 'recorded.raw'\n"); */
	}
    }
#endif
   
done:
    Pa_Terminate();
    if( data.recordedSamples )       /* Sure it is NULL or valid. */
	free( data.recordedSamples );
    if( err != paNoError )
    {
	fprintf( stderr, "An error occured while using the portaudio stream\n" );
	fprintf( stderr, "Error number: %d\n", err );
	fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) );
	err = 1;          /* Always return 0 or 1, but no other return codes. */
    }
}