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

#define MAX_RAND 10000

struct sphere_t {
	double x;
	double y;
	double z;
	double r;
};

double random_number() {
	// returns a random floating point number between 0.0 and RAND_MAX
	return fmod(rand() * ((double) rand() / RAND_MAX), MAX_RAND); 
}

int main(int argc, char *argv[]) {
	// read N from the first command line argument
	int N = atoi(argv[1]);

	struct sphere_t * sphere = malloc(sizeof(struct sphere_t) * N);
	// fill with random numbers
	for (int i = 0; i < N; i++) {
		sphere[i].x = random_number();
		sphere[i].y = random_number();
		sphere[i].z = random_number();
		sphere[i].r = random_number() / 4.0;
	}

	// calculate areas
	double * area = calloc(N, sizeof(double));
	for (int i = 0; i < N; i++) {
		area[i] = 4.0 * M_PI * pow(sphere[i].r, 2.0);
	}

	// calculate volume
	double * volume = calloc(N, sizeof(double));
	for (int i = 0; i < N; i++) {
		volume[i] = (4.0 / 3.0) * M_PI * pow(sphere[i].r, 3.0);
	}
	
	// calculate the number of spheres each sphere intersects
	int * intersects = calloc(N, sizeof(int));
	for (int i = 0; i < N; i++) {
		for (int j = 0; j < N; j++) {
			if (i == j) continue; // same circle

			// calculate distance between two spheres
			double d = sqrt(pow(sphere[j].x - sphere[i].x, 2.0) + pow(sphere[j].y - sphere[i].y, 2.0) + pow(sphere[j].z - sphere[i].z, 2.0));
			// if the distance is less than the sum of the radii, they intersect
			if (d < (sphere[j].r + sphere[i].r)) intersects[i]++;
		}
	}

	// print out all information to the screen (consider piping this to a file)
	printf("x, y, z, r, area, volume, intersects\n");
	for (int i = 0; i < N; i++) {
		printf("%lf, %lf, %lf, %lf, %lf, %lf, %d\n", sphere[i].x, sphere[i].y, sphere[i].z, sphere[i].r, area[i], volume[i], intersects[i]);
	}
}