/*
 * BUGS:
 * adjacient colours could have higher contrast
 * negative angles 
 */

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>

const float tau=(float)(M_PI*2);

// draw sector
void draw(float angle, char* label){
	const float r=100;
	static float progress=0;
	static float overlap=0;
	float fangle; if(angle<0)fangle=-angle;else fangle=angle-overlap;
	// Mx,y : move to x,y
	// Lx,y : draw line to x,y
	// Arx,ry rot 0,0 x,y : arc with radii rx,ry rotated by rot large-arch or not,clockwise or not to point x,y
	// z : closes the path
	float x1=r*cosf(progress);
	float y1=r*sinf(progress);
	float x2=r*cosf(progress+fangle);
	float y2=r*sinf(progress+fangle);
	float divider=progress+fangle/2;
	unsigned char rr=(unsigned char)(0xff*((divider)/(tau)));
	unsigned char gg=(unsigned char)(0xff*((divider-tau/3)/(tau)));
	unsigned char bb=(unsigned char)(0xff*((divider-2*tau/3)/(tau)));
	printf("<path stroke=\"#000000\" fill=\"#%02x%02x%02x\" d=\"M250,250 L%f,%f A%f,%f 0 %d,%d %f,%f z\"/>",rr,gg,bb,250+x1,250+y1,r,r,(fangle>M_PI),1,250+x2,250+y2);
	float xo=250+(3*r/2*cosf(divider));
	float yo=250+(3*r/2*sinf(divider));
	printf("<line stroke=\"#000000\" x1=\"%f\" y1=\"%f\" x2=\"%f\" y2=\"%f\" />",250+(2*r/3*cosf(divider)),250+(2*r/3*sinf(divider)),xo,yo);
	printf("<text x=\"%f\" y=\"%f\">%s</text>\n",xo,yo,label);
	progress+=fangle;
	overlap-=angle; // multiple overlaps accumulate
	if(overlap<0)overlap=0;
}
// put preliminary data on the stack
float scan_line (FILE* input, float sum){
	char* line=NULL; size_t len=0;
	if(getline(&line,&len,input) != -1){
		{ // chomp
			char* l=&(line[strlen(line)-1]);
			if(*l=='\n')*l='\0';
		}
	/* at the very least, we need a true value.
	 * everything following it can be label or whatever.
	 * if strtof does not find anything (or the value is miniscule), the line is obviously a comment and should be ignored.
	 * (if the value is too huge to handle, the output will be meaningless.)
	 *
	 * If the value is negative, it is meant to overlap with the previous record. Or records.
	 * The value would have to be ignored for computing the sum total.
	 */
		char* label=line;
		float number=strtof(label,&label);
		if(number>0){
			sum=scan_line(input,sum+number);
			float angle=tau*number/sum;
			draw(angle,label);
		}else if(number<0){
			sum=scan_line(input,sum);
			float angle=tau*number/sum;
			draw(angle,label);
		}else{
			sum=scan_line(input,sum);
			printf("<!-- %s -->\n",label);
		}
	}
	free(line);
	return sum;
}

int main(int argc, char** argv){
	FILE* input=stdin;
	// getopts
	// print boilerplate
	puts("<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\"?>\n\
<!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.1/EN\" \"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd\">\n\
<svg\n\
	xmlns=\"http://www.w3.org/2000/svg\"\n\
	version=\"1.1\"\n\
	width=\"500\"\n\
	height=\"500\"\n\
	viewBox=\"0 0 500 500\"\n\
>");
	scan_line(input,0);
	puts("</svg>");
	return 0;
}