// https://stackoverflow.com/questions/2693631/read-ppm-file-and-store-it-in-an-array-coded-with-c?fbclid=IwAR3p0n1sx_IIooYmhb2aVdFww0x-FR3Zso_Uw4IHaayPpm5lWQkGTg6SYck
#include "ppm.h"

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

PPMImage *readPPM(const char *filename)
{
    char buff[16];
    PPMImage *img;
    FILE *fp;
    int c, rgb_comp_color;
    //open PPM file for reading
    fp = fopen(filename, "rb");
    if (!fp) {
        fprintf(stderr, "Unable to open file '%s'\n", filename);
        exit(1);
    }

    //read image format
    if (!fgets(buff, sizeof(buff), fp)) {
        perror(filename);
        exit(1);
    }

    //check the image format
    if (buff[0] != 'P' || (buff[1] != '6' && buff[1] != '3')) {
        printf("SDADASD %c%c\n", buff[0], buff[1]);
        fprintf(stderr, "Invalid image format (must be 'P6' or P3)\n");
        exit(1);
    }

    //alloc memory form image
    img = (PPMImage *)malloc(sizeof(PPMImage));
    if (!img) {
        fprintf(stderr, "Unable to allocate memory\n");
        exit(1);
    }

    if (buff[1] == '6') {
        img->type = 0;
    } else {
        img->type = 1;
    }

    //check for comments
    c = getc(fp);
    while (c == '#') {
        while (getc(fp) != '\n') ;
        c = getc(fp);
    }

    ungetc(c, fp);
    //read image size information
    if (fscanf(fp, "%d %d", &img->x, &img->y) != 2) {
        fprintf(stderr, "Invalid image size (error loading '%s')\n", filename);
        exit(1);
    }

    //read rgb component
    if (fscanf(fp, "%d", &rgb_comp_color) != 1) {
        fprintf(stderr, "Invalid rgb component (error loading '%s')\n", filename);
        exit(1);
    }

    if (img->type == 1) {
        img->data = (PPMPixel*)malloc(img->x * img->y * sizeof(PPMPixel));
        int i;
        for (i = 0; i < img->x * img->y; ++i) {
            int r, g, b;
            fscanf(fp, "%d%d%d", &r, &g, &b);
            img->data[i].red = (unsigned char)r;
            img->data[i].green = (unsigned char)g;
            img->data[i].blue = (unsigned char)b;
        }
        fclose(fp);
        return img;
    }

    //check rgb component depth
    if (rgb_comp_color!= RGB_COMPONENT_COLOR) {
        fprintf(stderr, "'%s' does not have 8-bits components\n", filename);
        exit(1);
    }

    while (fgetc(fp) != '\n') ;
    //memory allocation for pixel data
    img->data = (PPMPixel*)malloc(img->x * img->y * sizeof(PPMPixel));

    if (!img) {
        fprintf(stderr, "Unable to allocate memory\n");
        exit(1);
    }

    //read pixel data from file
    int i;
    int j;
    for (i = 0; i < img->y; i++) {
        for (j = 0; j < img->x; j++) {
            unsigned char r, g, b;
            r = fgetc(fp);
            g = fgetc(fp);
            b = fgetc(fp);
            img->data[i * img->x + j].red = r;
            img->data[i * img->x + j].green = g;
            img->data[i * img->x + j].blue = b;
        }
    }

    fclose(fp);
    return img;
}

void writePPM(const char *filename, PPMImage *img)
{
    FILE *fp;
    //open file for output
    fp = fopen(filename, "wb");
    if (!fp) {
        fprintf(stderr, "Unable to open file '%s'\n", filename);
        exit(1);
    }

    if (img->type == 1) {
        fprintf(fp, "P3\n");
        fprintf(fp, "%d %d\n", img->x, img->y);
        fprintf(fp, "%d\n", RGB_COMPONENT_COLOR);
        int i;
        for (i = 0; i < img->x * img->y; ++i) {
            int r = (int)img->data[i].red;
            int g = (int)img->data[i].green;
            int b = (int)img->data[i].blue;
            fprintf(fp, "%d %d %d\n", r, g, b);
        }
        fclose(fp);
    }

    //write the header file
    //image format
    fprintf(fp, "P6\n");

    //comments
    fprintf(fp, "# Created by %s\n",CREATOR);

    //image size
    fprintf(fp, "%d %d\n",img->x,img->y);

    // rgb component depth
    fprintf(fp, "%d\n",RGB_COMPONENT_COLOR);

    // pixel data
    fwrite(img->data, 3 * img->x, img->y, fp);
    fclose(fp);
}

void changeColorPPM(PPMImage *img)
{
    int i;
    if(img){

        for(i=0;i<img->x*img->y;i++){
            img->data[i].red=RGB_COMPONENT_COLOR - img->data[i].red;
            img->data[i].green=RGB_COMPONENT_COLOR - img->data[i].green;
            img->data[i].blue=RGB_COMPONENT_COLOR - img->data[i].blue;
        }
    }
}

void writePGM(const char *filename, PPMImage *img) {
    FILE *fp;
    //open file for output
    fp = fopen(filename, "wb");
    if (!fp) {
        fprintf(stderr, "Unable to open file '%s'\n", filename);
        exit(1);
    }

    fprintf(fp, "P2\n");
    fprintf(fp, "%d %d\n", img->x, img->y);
    fprintf(fp, "%d\n", RGB_COMPONENT_COLOR);

    int i;
    int j;
    for (i = 0; i < img->y; ++i) {
        for (j = 0; j < img->x; ++j) {
            fprintf(fp, "%d", img->data[i * img->x + j].red);
            if (j != img->x) {
                fprintf(fp, " ");
            }
        }
        fprintf(fp, "\n");
    }
}