#include <fftw3.h>
#include <math.h>
#include <stdlib.h>
#include <stdio.h>
#include <png.h>
#include <stdarg.h>
#define PNG_DEBUG 3

#define N 512 
/**
lame --decode soundfile.mp3 - | sox - -t raw -r 24000 -f -b 32 -c 1 - | ./main  && display test.png

**/

png_structp png_ptr;
png_infop info_ptr;
png_bytep * row_pointers;
int width=1300, height=N/2;
png_byte color_type;
png_byte bit_depth;
int x,y;



/* Hamming window */
void makewindow(float *window,int length){ 
	int i;
	for(i=0;i<length;i++){
		window[i] = 0.54-0.46*cos((2*M_PI*i)/(length-1));
	}
}

void windowdata(float *window, fftwf_complex *in, int length){
	int i;
	for(i=0;i<length;i++){
		in[i][0] = window[i]*in[i][0];
		in[i][1] = window[i]*in[i][1];
	}
}

void filldata(fftwf_complex *in,int length){
	int i;
	for(i=0;i<length;i++){
		 fread(&in[i][0],4,1,stdin);
		//printf("%f ", in[i][0]);
		in[i][1] = 0;
	}

}

void abort_(const char * s, ...)
{
        va_list args;
        va_start(args, s);
        vfprintf(stderr, s, args);
        fprintf(stderr, "\n");
        va_end(args);
        abort();
}


void write_png_file(char* file_name)
{
        /* create file */
        FILE *fp = fopen(file_name, "wb");
        if (!fp)
                abort_("[write_png_file] File %s could not be opened for writing", file_name);


        /* initialize stuff */
        png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);

        if (!png_ptr)
                abort_("[write_png_file] png_create_write_struct failed");

        info_ptr = png_create_info_struct(png_ptr);
        if (!info_ptr)
                abort_("[write_png_file] png_create_info_struct failed");

        if (setjmp(png_jmpbuf(png_ptr)))
                abort_("[write_png_file] Error during init_io");

        png_init_io(png_ptr, fp);


        /* write header */
        if (setjmp(png_jmpbuf(png_ptr)))
                abort_("[write_png_file] Error during writing header");
	bit_depth=8;
	color_type=PNG_COLOR_TYPE_RGB;
        png_set_IHDR(png_ptr, info_ptr, width, height,
                     bit_depth, color_type, PNG_INTERLACE_NONE,
                     PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);

        png_write_info(png_ptr, info_ptr);


        /* write bytes */
        if (setjmp(png_jmpbuf(png_ptr)))
                abort_("[write_png_file] Error during writing bytes");

        png_write_image(png_ptr, row_pointers);


        /* end write */
        if (setjmp(png_jmpbuf(png_ptr)))
                abort_("[write_png_file] Error during end of write");

        png_write_end(png_ptr, NULL);

        /* cleanup heap allocation */
        for (y=0; y<height; y++)
                free(row_pointers[y]);
        free(row_pointers);

        fclose(fp);
}


void fill_line(fftwf_complex *out,int linenumber){
	float absolutevalue;
	float dbvalue;
	png_byte* row = row_pointers[linenumber];
	for(x=0;x<width;x++){
		absolutevalue = ((out[x][0]*out[x][0])+(out[x][1]*out[x][1]));
		dbvalue = (10*log10(absolutevalue)+85)*0.1;
		if(dbvalue < 0) dbvalue = 0;
		if(dbvalue > 255) dbvalue = 255;
		//printf("%f ",dbvalue);
	 png_byte *ptr = &(row[x*3]);
	 ptr[0] = 255-(int)dbvalue;//(int)dbvalue;  //R
	 ptr[1] = 255-(int)dbvalue;  //G
	 ptr[2] = 255-(int)dbvalue;  //B
	}
//	printf("\n");

}
void fill_row(fftwf_complex *out,int rownumber){
	float absolutevalue;
	float dbvalue;
	float tmp;
	png_byte* row;
	for(y=0;y<height;y++){
		row = row_pointers[y];
		absolutevalue = ((out[height-1-y][0]*out[height-1-y][0])+(out[height-1-y][1]*out[height-1-y][1]));
		dbvalue = (10*log10(absolutevalue)+60)*2;
	 png_byte *ptr = &(row[rownumber*3]);
		if(dbvalue < 0) dbvalue = 0;
		if(dbvalue > 255) {
			//printf("%f\n",dbvalue-255);
			 tmp = 50+(int)(dbvalue - 255);//(int)dbvalue;  //R
			if(tmp > 255) tmp=255;	
			ptr[0] = (int)tmp;
			dbvalue = 255;

			}
		else ptr[0] = 0;
		
		//printf("%f ",dbvalue);
	 ptr[0] = (int)dbvalue;//(int)dbvalue;  //R
	 ptr[1] = (int)dbvalue;  //G
	 ptr[2] = (int)dbvalue;  //B
	 //ptr[1] = (int)dbvalue;  //G
	 //ptr[2] = 0;  //B
	}
//	printf("\n");

}

int main(int argc, char **argv){

	fftwf_complex *in, *out;
	float *window;
	fftwf_plan p;
	int i=0;


	in = (fftwf_complex*) fftwf_malloc(sizeof(fftwf_complex)*N);
	out = (fftwf_complex*) fftwf_malloc(sizeof(fftwf_complex)*N);
	window = malloc(sizeof(float)*N);
	makewindow(window,N);
	p = fftwf_plan_dft_1d(N,in,out,FFTW_FORWARD,FFTW_ESTIMATE);
	row_pointers = (png_bytep*) malloc(sizeof(png_bytep) * height);
	for(y=0;y<height;y++)
		row_pointers[y] = (png_byte*)malloc(width*3);

	int z;
	for(z=0;z<width;z++){
		filldata(in,N);
		windowdata(window,in,N);
		fftwf_execute(p);
		fill_row(out,z);
	}


	//fill_image();

	//row_pointers[0][2] = 30;
	write_png_file(argv[1]);




	fftwf_destroy_plan(p);
	fftwf_free(in);
	fftwf_free(out);
	free(window);
return 0;

}