#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>


// If the file,
// Is a regular file 
// Contains a given byte
// Is group readable.
int check_metadata(char *path, unsigned char byte);


int contains_byte(char *path, unsigned char byte);


int main(int argc, char *argv[]) {
    if (argc <= 2) {
        fprintf(stderr, "Usage: %s <filename> <byte>\n", argv[0]);
        return 1;
    }
    unsigned char byte = strtoul(argv[2], NULL, 0);
    if (check_metadata(argv[1],byte)){
        printf("Valid file\n");
    } else {
        printf("Not Valid file\n");
    }
    return 0;
}


// If the file, 
// is a regular file,
// is publically readable.
// contains a given byte, 

int check_metadata(char *path, unsigned char byte) {
    struct stat st;
    if (stat(path, &st) == 0){
        if (S_ISREG(st.st_mode) && (st.st_mode & S_IROTH)
            && contains_byte(path, byte)){
            return 1;
        }
            
    }

    return 0;    
}

int contains_byte(char *path, unsigned char byte) {
    FILE *f = fopen(path, "r");
    if (f == NULL) {
        perror("");
        exit(1);
    }

    //read each byte and compare
    int curr_byte;
    while ((curr_byte = fgetc(f)) != EOF){
        if (curr_byte == byte) {
            fclose(f);
            return 1;
        }
    }

    fclose(f);
    return 0;
}