/**
 * @file main.c
 *
 * This is the main driver of the program, i.e.,
 * the program, which is then used by the user.
 */

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>
#include <time.h>
#include <omp.h>
#include <math.h>

#include "voronoi.h"

int main(int argc, char** argv)
{
    clock_t begin = clock();

    int xDim = 10000;
    int yDim = 10000;

    //initialize point and associated color arrays
    int numPoints = 20;
    int pointArraySize = numPoints * 2;
    int* points = malloc((sizeof(int)*pointArraySize));
    int (*colors)[3] = malloc(sizeof(int[numPoints+1][3]));

    srand(time(NULL));

    //init base color (black) for edges and points
    colors[0][0] = 0;
    colors[0][1] = 0;
    colors[0][2] = 0;

    printf("initializing points and colors\n");
    for (int i = 0; i < pointArraySize; i = i+2) {
        points[i] = rand() % xDim;
        points[i+1] = rand() % yDim;
    }
    for (int i = 0; i < numPoints; i++) {
        colors[i + 1][0] = rand() % 100;
        colors[i + 1][1] = rand() % 100;
        colors[i + 1][2] = rand() % 100;
    }

    printf("points initialized: \n");
    for (int i = 0; i < pointArraySize; i=i+2) {
        printf("point %d: x: %d y: %d\n", (i/2), points[i], points[i+1]);
    }
    printf("colors initialized: \n");
    for (int i = 0; i < (numPoints + 1); i++) {
        printf("color %d: r: %d g: %d b: %d\n", i, colors[i][0], colors[i][1], colors[i][2]);
    }

    //gather voronoi diagram image data
    printf("allocating image data storage space\n");
    unsigned int(*imageBuffer)[yDim] = malloc(sizeof(int[xDim][yDim]));

    //omp_set_num_threads(20);
    printf("calculating voronoi diagram image data\n");
    //#pragma omp parallel for shared(imageBuffer)
    #pragma acc parallel loop
        for (int y = 0; y < yDim; y++)
        {
            for (int x = 0; x < xDim; x++)
            {
                imageBuffer[x][y] = determineColor(x, y, points, numPoints);
            }
        }
    

    //create voronoi diagram image
    printf("creating/overwriting voronoi diagram to image file 'voronoi.ppm'\n");

    FILE* fout = fopen("voronoi.ppm", "wb");

    if (!fout)
    {
        printf("Unable to open output image file. \n");
        return 0;
    }
    printf("writing image header\n");

    (void)fprintf(fout, "P6\n%d %d\n255\n", xDim, yDim);
    printf("writing image data\n");
    for (int y = 0; y < yDim; y++)
    {
        for (int x = 0; x < xDim; x++)
        {
            int colorIndex = imageBuffer[x][y];
            int * pickedColor = colors[colorIndex];
            static unsigned char color[3];
            color[0] = pickedColor[0];
            color[1] = pickedColor[1];
            color[2] = pickedColor[2];
            (void)fwrite(color, 1, 3, fout);
        }
    }
    printf("finished writing image data\n");
    //close(out);
    (void)fclose(fout);

    free(imageBuffer);
    free(points);
    free(colors);

    clock_t end = clock();
    double time_spent = (double)(end - begin) / CLOCKS_PER_SEC;
    printf("Execution lasted %lf", time_spent);

    return EXIT_SUCCESS;
}