#include "STLTextWriter.h"
#include "time.h"

// I did not write this Image-reading library. You can find the original author at the following link.
// https://github.com/nothings/stb/blob/master/stb_image.h
#define STB_IMAGE_IMPLEMENTATION
//#define STBI_MALLOC
//#define STBI_REALLOC
//#define STBI_FREE
#include "stb_image.h"

// minimum value function for integers
int imin(int num1, int num2){
	if(num1 < num2){
		return num1;
	}
	else{
		return num2;
	}
}

// minimum value function for doubles
double dmin(double num1, double num2){
	if(num1 <= num2){
		return num1;
	}
	else{
		return num2;
	}
}

// minimum value function for doubles
double dmax(double num1, double num2){
	if(num1 >= num2){
		return num1;
	}
	else{
		return num2;
	}
}

// makes an array index wrap to the other end if it does out of bounds
int indmod(int index, int size){ // index modulus
	index %= size;
	if(index < 0){
		index += size;
	}
	return index;
}

// does literally everything else
int main(int argc, char *argv[]){
	double point1[3] = {0,0,0};
	double point2[3] = {0,0,0};
	double point3[3] = {0,0,0};
	double point4[3] = {0,0,0};
	int hmheight = 0;
	int hmwidth = 0;
	int n = 0;
	double const dpi = 1.0/8;
	char filepath[300];
	char modelpath[300];
	int extlen = 0;
	char newext[] = "stl";

	srand(time(NULL));
	printf("\n\n");

	//check for filename
	if(argc < 2){
		printf("Enter file path/name: ");
		scanf("%300s",&filepath);
	}
	else{
		strcpy(filepath, argv[1]);
	}

	// populate heightmap
	unsigned char *data = stbi_load(filepath, &hmwidth, &hmheight, &n, 0);
	if(data == NULL){
		printf("data = NULL\n\n");
		exit(1);
	}
	double* heightmap;
	heightmap = (double*)malloc(hmheight * hmwidth * sizeof(double));
	if(heightmap == NULL){
		printf("Memory for heightmap could not be allocated.\n\n");
		exit(1);
	}

	for(int i = 0; i < hmwidth; i++){
		for(int j = 0; j < hmheight; j++){
			heightmap[i*hmheight+j] = 0.5f;
		}
	}

	for(int i = 0; i < hmwidth; i++){
		for(int j = 0; j < hmheight; j++){
			for(int k = 0; k < n; k++){
				heightmap[i*hmheight+j] += *(data+i*hmheight*n+j*n) / (127.0f*n);
			}
			heightmap[i*hmheight+j] = dmax(heightmap[i*hmheight+j], 0.1f);
		}
	}
	stbi_image_free(data);
	printf("STATUS___Read data into heightmap\n");

	// bustin' out the spreadsheet again
	// Uncomment the code below to get a .csv spreadsheet of the heightmap
	/*
	FILE *dumpfile;
	dumpfile = fopen("heightmap.csv", "w");
	for(int i = 0; i < hmheight*hmwidth; i++){
		fprintf(dumpfile, "%f,", heightmap[i]);
		if(i % hmwidth == 0){
			fprintf(dumpfile, "\n");
		}
	}
	fclose(dumpfile);
	*/

	// get model file name
	for(int i = strlen(filepath)-1; i >= 0; i--){
		if(filepath[i] == '.'){
			extlen = i;
			filepath[i+1] = '\0';
			break;
		}
		if(i == 0){
			printf("Could not recognize file path/name\n\n");
			exit(1);
		}
	}
	strcpy(modelpath, filepath);
	strcat(modelpath, newext);

	// writing to file
	FILE *modelfile;
	modelfile = fopen(modelpath, "w");
	startSTL(modelfile);

	// drawing the top of the mesh
	for(int i = 0; i < hmwidth-1; i++){	// i is the distance from the left edge
		for(int j = 0; j < hmheight-1; j++){	// j is the distance from the bottom edge
			point1[0] = i*dpi;
			point1[1] = j*dpi;
			point1[2] = heightmap[i+((hmheight-1-j)*hmwidth)];

			point2[0] = (i+1)*dpi;
			point2[1] = j*dpi;
			point2[2] = heightmap[(i+1)+((hmheight-1-j)*hmwidth)];

			point3[0] = i*dpi;
			point3[1] = (j+1)*dpi;
			point3[2] = heightmap[i+((hmheight-2-j)*hmwidth)];

			point4[0] = (i+1)*dpi;
			point4[1] = (j+1)*dpi;
			point4[2] = heightmap[(i+1)+((hmheight-2-j)*hmwidth)];

			drawTriangle(modelfile, point1, point2, point4);
			drawTriangle(modelfile, point1, point4, point3);
		}
	}
	printf("STATUS___Drew top of mesh\n");

	//drawing the sides of the mesh
	for(int i = 0; i < hmwidth-1; i++){
		// Front edge
		point1[0] = i*dpi;
		point1[1] = 0;
		point1[2] = 0;

		point2[0] = i*dpi;
		point2[1] = 0;
		point2[2] = heightmap[i+(hmwidth*(hmheight-1))];

		point3[0] = (i+1)*dpi;
		point3[1] = 0;
		point3[2] = 0;

		point4[0] = (i+1)*dpi;
		point4[1] = 0;
		point4[2] = heightmap[i+1+(hmwidth*(hmheight-1))];

		drawTriangle(modelfile, point1, point4, point2);
		drawTriangle(modelfile, point1, point3, point4);

		// Back edge
		point1[0] = i*dpi;
		point1[1] = (hmheight-1)*dpi;
		point1[2] = 0;

		point2[0] = i*dpi;
		point2[1] = (hmheight-1)*dpi;
		point2[2] = heightmap[i];

		point3[0] = (i+1)*dpi;
		point3[1] = (hmheight-1)*dpi;
		point3[2] = 0;

		point4[0] = (i+1)*dpi;
		point4[1] = (hmheight-1)*dpi;
		point4[2] = heightmap[i+1];

		drawTriangle(modelfile, point1, point2, point4);
		drawTriangle(modelfile, point1, point4, point3);
	}
	printf("STATUS___Drew front and back of mesh\n");
	for(int j = 0; j < hmheight-1; j++){
		// Left edge
		point1[0] = 0;
		point1[1] = (hmheight-j-1)*dpi;
		point1[2] = 0;

		point2[0] = 0;
		point2[1] = (hmheight-j-1)*dpi;
		point2[2] = heightmap[j*hmwidth];

		point3[0] = 0;
		point3[1] = (hmheight-j-2)*dpi;
		point3[2] = 0;

		point4[0] = 0;
		point4[1] = (hmheight-j-2)*dpi;
		point4[2] = heightmap[(j+1)*hmwidth];

		drawTriangle(modelfile, point1, point4, point2);
		drawTriangle(modelfile, point1, point3, point4);

		// Right edge
		point1[0] = (hmwidth-1)*dpi;
		point1[1] = (hmheight-j-1)*dpi;
		point1[2] = 0;

		point2[0] = (hmwidth-1)*dpi;
		point2[1] = (hmheight-j-1)*dpi;
		point2[2] = heightmap[(j*hmwidth)+hmwidth-1];

		point3[0] = (hmwidth-1)*dpi;
		point3[1] = (hmheight-j-2)*dpi;
		point3[2] = 0;

		point4[0] = (hmwidth-1)*dpi;
		point4[1] = (hmheight-j-2)*dpi;
		point4[2] = heightmap[((j+1)*hmwidth)+hmwidth-1];

		drawTriangle(modelfile, point1, point2, point4);
		drawTriangle(modelfile, point1, point4, point3);
	}
	printf("STATUS___Drew left and right sides of mesh\n");

	//drawing the bottom of the mesh
	point1[0] = 0;
	point1[1] = 0;
	point1[2] = 0;
	point2[0] = 0;
	point2[1] = dpi;
	point2[2] = 0;
	point3[0] = dpi;
	point3[1] = 0;
	point3[2] = 0;
	drawTriangle(modelfile, point1, point2, point3);
	point4[2] = 0;
	for(int i = 1; i < imin(hmheight, hmwidth)-1; i++){
		point1[0] = 0;
		point1[1] = i * dpi;
		point2[0] = 0;
		point2[1] = (i+1) * dpi;
		point3[0] = i * dpi;
		point3[1] = 0;
		point4[0] = (i+1) * dpi;
		point4[1] = 0;
		drawTriangle(modelfile, point1, point2, point4);
		drawTriangle(modelfile, point1, point4, point3);

		point1[0] = (hmwidth - i - 2) * dpi;
		point1[1] = (hmheight - 1) * dpi;
		point2[0] = (hmwidth - i - 1) * dpi;
		point2[1] = (hmheight - 1) * dpi;
		point3[0] = (hmwidth - 1) * dpi;
		point3[1] = (hmheight - i - 2) * dpi;
		point4[0] = (hmwidth - 1) * dpi;
		point4[1] = (hmheight - i - 1) * dpi;
		drawTriangle(modelfile, point1, point2, point4);
		drawTriangle(modelfile, point1, point4, point3);
	}
	point1[0] = (hmwidth - 2) * dpi;
	point1[1] = (hmheight - 1) * dpi;
	point2[0] = (hmwidth - 1) * dpi;
	point2[1] = (hmheight - 1) * dpi;
	point3[0] = (hmwidth - 1) * dpi;
	point3[1] = (hmheight - 2) * dpi;
	drawTriangle(modelfile, point1, point2, point3);
	if(hmheight > hmwidth){
		for(int i = 0; i < abs(hmheight-hmwidth); i++){
			point1[0] = (hmwidth-1) * dpi;
			point1[1] = i * dpi;
			point2[0] = (hmwidth-1) * dpi;
			point2[1] = (i+1) * dpi;
			point3[0] = 0;
			point3[1] = (hmwidth+i-1) * dpi;
			point4[0] = 0;
			point4[1] = (hmwidth+i) * dpi;

			drawTriangle(modelfile, point1, point3, point2);
			drawTriangle(modelfile, point2, point3, point4);
		}
	}
	else if(hmheight < hmwidth){
		for(int i = 0; i < abs(hmheight-hmwidth); i++){
			point1[1] = (0) * dpi;
			point1[0] = (hmheight+i-1) * dpi;
			point2[1] = (0) * dpi;
			point2[0] = (hmheight+i) * dpi;
			point3[1] = (hmheight-1) * dpi;
			point3[0] = (i) * dpi;
			point4[1] = (hmheight-1) * dpi;
			point4[0] = (i+1) * dpi;

			drawTriangle(modelfile, point1, point3, point2);
			drawTriangle(modelfile, point2, point3, point4);
		}
	}
/*
	// reference triangle that points at the origin
	point1[0] = 0;
	point1[1] = 0;
	point2[0] = -0.1;
	point2[1] = 0.1;
	point2[2] = -0.1;
	point3[0] = 0.1;
	point3[1] = -0.1;
	point3[2] = -0.1;
	drawTriangle(modelfile, point1, point2, point3);
*/
	printf("STATUS___Drew bottom of mesh\n\n\n");

	endSTL(modelfile);
	fclose(modelfile);
	free(heightmap);

	return 0;
}