#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <dirent.h>
#include <string.h>


int contains_lowercase(char *path); 
int traverse(char *directory_path);  

// Try with 
// dir_search .  
// dir_search examples  
int main(int argc, char *argv[]) {
    if (argc <= 1) {
        fprintf(stderr, "Usage: %s <filename>\n", argv[0]);
        return 1;
    }

    int count = traverse(argv[1]);
    printf("Total count %d\n", count);
    return 0;
}

// Count the number of files in the given directory that:
// Are regular files 
// publicly readable
// contains at  least one byte that could represent a lower case letter 
// You do not need to recursively search sub directories
// Assume there are no symbolic links and just directories and regular files
int traverse(char *directory_path) {
    int count = 0;
    DIR *dirp = opendir(directory_path);
    if (dirp == NULL) {
        perror("");
        exit(1);
    }
    char fullpath[PATH_MAX];
    struct dirent *entry;
    while ((entry = readdir(dirp)) != NULL){
        if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0 ) {
            continue;
        }
        snprintf(fullpath, PATH_MAX, "%s/%s", directory_path, entry->d_name);
        struct stat s;
        if (stat(fullpath, &s) == 0){  
            if (S_ISDIR(s.st_mode)) {
               count += traverse(fullpath);
            } else if (S_ISREG(s.st_mode) && (s.st_mode & S_IROTH) && contains_lowercase(fullpath) != -1){
               printf("%s\n", fullpath);
               count++;
            }

        }
    }

    closedir(dirp);   
    return count;
}

int contains_lowercase(char *path) {
    FILE *f = fopen(path, "r");
    if (f == NULL) {
        perror("");
        return -1;
    }

    int curr_byte;
    while ((curr_byte = fgetc(f)) != EOF){
        if (curr_byte >= 'a' && curr_byte <= 'z') {
            fclose(f);
            return curr_byte;
        }
    }

    fclose(f);
    return -1;
}