#include <pthread.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <string.h>
#include <math.h>
pthread_t *tid;

int **numbers;
int thread_count;
int width;
int height;
///gcc -o test main.c -lpthread
/*
void* by_number(void *arg){
    pthread_t id = pthread_self();
    for(int x = 0; x < thread_count; x++){
        if(pthread_equal(id,tid[x])){
            for(int i = 0; i < height; i++){
                for(int j = 0; j < width; j++){
                    if(can_change(x, numbers[i][j]) == 1){
                        numbers[i][j] = 255 - numbers[i][j];
                    }
                }
            }
        }
    }
}
*/

void* by_number(void *arg){
    pthread_t id = pthread_self();
    for(int i = 0; i < height; i++){
        for(int j = 0; j < width; j++){
            for(int x = 0; x < thread_count; x++){
                if(pthread_equal(id,tid[x])){
                    if(can_change(x, numbers[i][j]) == 1){
                        numbers[i][j] = 255 - numbers[i][j];
                    }
                }
            }
        }
    }
}
int can_change(int thread_num, int number){
    int step = 256 / thread_count;
    if(thread_num * step <= number && number < (thread_num + 1) * step) return 1;
    return 0;
}


void* by_block(void *arg){
    pthread_t id = pthread_self();
    for(int x = 0; x < thread_count; x++){
        if(pthread_equal(id,tid[x])){
            for(int i = 0; i < height; i++){
                int j_start = (x) * (ceil(width / thread_count) + 1);
                int j_stop = (x + 1) * (ceil(width / thread_count) + 1) - 1;
                for(j_start; j_start <= j_stop; j_start++){

                    numbers[i][j_start] = 255 - numbers[i][j_start];
                }
            }
        }
    }
}


int main(int argc, char const *argv[])
{
    thread_count = atoi(argv[1]);
    int mode = atoi(argv[2]); //mode 1 - numbers, mode 2 - blocks
    char *file_path = argv[3];
    char *out_name = argv[4];
    FILE *f = fopen(file_path, "r");
    if(f == NULL){
        printf("failed to open the first file");
        return 0;
    }

    FILE *out = fopen(out_name, "w+");
    if(out == NULL){
        printf("failed to open the first file");
        return 0;
    }


    tid = (pthread_t *)malloc(thread_count * sizeof(pthread_t));
    int bufferLength = 255;
    char buffer[bufferLength];
    for(int i = 0; i < 3; i++){
        fgets(buffer, bufferLength, f);
        fputs(buffer, out);
    }
    char *pch = strtok(buffer," ");
    width = atoi(pch);
    pch = strtok (NULL, " ");
    height = atoi(pch);

    numbers = (int **)malloc(height * sizeof(int *));
    for (int i = 0; i < width; i++){
        numbers[i] = (int *)malloc(width * sizeof(int));
    }

    for(int i = 0; i < height; i++){
        for(int j = 0; j < width; j++){
            numbers[i][j] = i + j;
        }
    }

    fgets(buffer, bufferLength, f);
    fputs(buffer, out);
    pch = NULL;

    int number;

    for(int i = 0; i < height; i++){
        for(int j = 0; j < width; j++){
            fscanf(f, "%d", &number);
            numbers[i][j] = number;
        }
    }

    for(int i = 0; i < height; i++){
        for(int j = 0; j < width; j++){
            printf("%i ", numbers[i][j]);
        }
        printf("\n");
    }
    printf("\n");

    if(mode == 1){
        for(int i = 0; i < thread_count; i++){
            pthread_create(&(tid[i]), NULL, &by_block, NULL);
        }
    }

    if(mode == 2){
        for(int i = 0; i < thread_count; i++){
            pthread_create(&(tid[i]), NULL, &by_number, NULL);
        }
    }
    sleep(1);

    for(int i = 0; i < height; i++){
        for(int j = 0; j < width; j++){
            fprintf(out, "%d ", numbers[i][j]);
            printf("%i ", numbers[i][j]);
        }
        fprintf(out, "\n");
        printf("\n");
    }

    printf("%i\n", can_change(0, 3));
    return 0;
}