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

#define MAX_COMMENT_LENGTH 256
#define MAX_COMMENTS 100
#define MAX_IMAGE_WIDTH 600
#define MAX_IMAGE_HEIGHT 600

struct Pixel {
    int r;
    int g;
    int b;
} Pixel;

struct PPM {
    char format[2 + 1]; //2 letter code for PPM format, +1 for 2 spaces
    List *comments;
    int width; //number of columns
    int height; //number of rows
    int max; //maximum colour value (usually 255)
    struct Pixel **rgb;
} PPM;

struct PPM * getPPM(FILE *fd);
void showPPM(struct PPM *i);

int main() {
    FILE *file = fopen("black.ppm", "r");
    if(file == NULL) return 1;
    else {
        struct PPM *newPPM = getPPM(file);
        showPPM(newPPM);
    }
    return 0;
}

struct PPM * getPPM(FILE *fd) {
    if(fd == NULL) {
        perror("File does not exist!");
        return NULL;
    }

    struct PPM *newPPMFile = malloc(sizeof(PPM));
    List *commentList = List_create();

    fscanf(fd, "%2c\n", newPPMFile->format);
    newPPMFile->format[2] = '\0'; //Need to end the string with \0
    //printf("%s\n", newPPMFile->format);

    char comment[MAX_COMMENTS][MAX_COMMENT_LENGTH];
    int i = 0;
    while(fscanf(fd, "# %79[^\n] \n", comment[i]) == 1) {
        comment[i][MAX_COMMENT_LENGTH - 1] = '\0';
        List_append(commentList, comment[i]);
        i++;
    }
    newPPMFile->comments = commentList;
    //List_print(newPPMFile->comments);

    //Read width and height
    if (fscanf(fd, "%d %d", &newPPMFile->width, &newPPMFile->height) != 2) {
        perror("Error reading width and height!");
        return NULL; //Error
    }
    //printf("%d %d\n", newPPMFile->width, newPPMFile->height);

    //Read max rgb value
    if(fscanf(fd, "%d", &newPPMFile->max) != 1) {
        perror("Error reading max colour value!");
        return NULL; //Error
    }
    //printf("%d\n", newPPMFile->max);

    //new array of width rows, height columns
    struct Pixel rgbArray[newPPMFile->height][newPPMFile->width];
    int x, y;
    for(y = 0; y < newPPMFile->height; y++) {
        for(x = 0; x < newPPMFile->width; x++) {
            struct Pixel newPixel;
            if (fscanf(fd, "%d%d%d\n", &newPixel.r, &newPixel.g, &newPixel.b) == 3) {
                rgbArray[y][x] = newPixel;
                //printf("%d %d %d\n", rgbArray[y][x].r, rgbArray[y][x].g, rgbArray[y][x].b);
             } else {
                //Handle error...
                perror("NO RGB??");
            }
        }
    }
    newPPMFile->rgb = rgbArray;

    return newPPMFile;
}

void showPPM(struct PPM *i) {
    /* Print PPM format */
    printf("%s\n", i->format);

    /* Print comments */
    List_print(i->comments);

    /* Print width and height */
    printf("%d %d\n", i->width, i->height);

    /* Print max rgb value */
    printf("%d\n", i->max);

    int x, y;
    for(y = 0; y < i->height; y++) {
        for(x = 0; x < i->width; x++) {
            struct Pixel newPixel = i->rgb[y][x];
            printf("%d %d %d\n", newPixel.r, newPixel.g, newPixel.b);
        }
    }
}