#include <stdio.h>
#include <stdlib.h>
#include "pnginput.h"
#include "pngoutput.h"
#include "colourspace.h"
#include "filter.h"

#define USE_LUV

void read_image( double *pixeldata,
                 pnginput_t *pnginput, int width, int height )
{
    int i, j;

    for( i = 0; i < height; i++ ) {
        unsigned char *curscanline = pnginput_get_scanline( pnginput, i );

        for( j = 0; j < width; j++ ) {
            double bp = ( (double) curscanline[ 0 ] ) / 255.0;
            double gp = ( (double) curscanline[ 1 ] ) / 255.0;
            double rp = ( (double) curscanline[ 2 ] ) / 255.0;
            double r, g, b, x, y, z, lstar, ustar, vstar;

            nonlinear_to_linear_srgb( rp, gp, bp, &r, &g, &b );
            srgb_to_xyz( r, g, b, &x, &y, &z );
            xyz_to_lupvp( x, y, z, &lstar, &ustar, &vstar );

#ifdef USE_LUV
            *pixeldata++ = lstar;
            *pixeldata++ = ustar;
            *pixeldata++ = vstar;
#else
            *pixeldata++ = x;
            *pixeldata++ = y;
            *pixeldata++ = z;
#endif
            curscanline += 3;
        }
    }
}

void output_image_rgb( pngoutput_t *pngoutput, double *idata,
                       int width, int height )
{
    unsigned char *scanline = (unsigned char *) malloc( width * 3 );
    int i, j;

    for( i = 0; i < height; i++ ) {
        unsigned char *pixeldata = scanline;
        fprintf( stderr, "\rscale: Output scanline: %4d", i );
        for( j = 0; j < width; j++ ) {
            double lstar, ustar, vstar, x, y, z, r, g, b, rp, gp, bp;

#ifdef USE_LUV
            lstar = *idata++;
            ustar = *idata++;
            vstar = *idata++;
            lupvp_to_xyz( lstar, ustar, vstar, &x, &y, &z );
#else  /* !USE_LUV */
            x = *idata++;
            y = *idata++;
            z = *idata++;
#endif /* USE_LUV */

            xyz_to_srgb( x, y, z, &r, &g, &b );
            linear_to_nonlinear_srgb( r, g, b, &rp, &gp, &bp );

            *pixeldata++ = (unsigned char) ( ( bp * 255.0 ) + 0.5 );
            *pixeldata++ = (unsigned char) ( ( gp * 255.0 ) + 0.5 );
            *pixeldata++ = (unsigned char) ( ( rp * 255.0 ) + 0.5 );
        }
        pngoutput_scanline( pngoutput, scanline );
    }
    fprintf( stderr, "\n" );
    free( scanline );
}

int main( int argc, char **argv )
{
    pngoutput_t *pngoutput;
    pnginput_t *pnginput;
    int width, height;
    double *pixeldata;
    double *outdata;

    pnginput = pnginput_new( argv[ 1 ] );
    if( !pnginput ) {
        fprintf( stderr, "scale: can't open input %s\n", argv[ 1 ] );
        return 1;
    }
    width = pnginput_get_width( pnginput );
    height = pnginput_get_height( pnginput );

    pixeldata = (double *) malloc( 3 * width * height * sizeof( double ) );
    if( !pixeldata ) {
        fprintf( stderr, "scale: can't allocate pixel data\n" );
        return 1;
    }

    read_image( pixeldata, pnginput, width, height );
    pnginput_delete( pnginput );

    outdata = (double *) malloc( 3 * width * height * sizeof( double ) );
    if( !outdata ) {
        fprintf( stderr, "scale: can't allocate pixel data\n" );
        return 1;
    }

    pngoutput = pngoutput_new( argv[ 2 ], width, height, 0.45 );
    if( !pngoutput ) {
        fprintf( stderr, "scale: can't open output %s\n", argv[ 2 ] );
        return 1;
    }

    image3_highpass( outdata, pixeldata, width, height );

    output_image_rgb( pngoutput, outdata, width, height );
    pngoutput_delete( pngoutput );

    return 0;
}