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

// We define a helper function to print boolean values
void print_bool(const char* prefix, int value) {
    printf("%s%s\n", prefix, value ? "true" : "false");
}

int main() {
    // Here's a sample of the functions available in string.h and ctype.h.
    // Since these are functions from the standard library, not methods on
    // the string object itself, we need to pass the string in question as
    // an argument to the function.

    print_bool("Contains:  ", strstr("test", "es") != NULL);
    printf("Count:     %d\n", (int)strlen("test") - (int)strlen(strstr("test", "t")));
    print_bool("HasPrefix: ", strncmp("test", "te", 2) == 0);
    print_bool("HasSuffix: ", strcmp(strrchr("test", 's'), "st") == 0);
    printf("Index:     %d\n", (int)(strchr("test", 'e') - "test"));

    // Join is not available in C, so we'll implement it
    char* join(const char* strings[], int count, const char* delimiter) {
        size_t total_length = 0;
        for (int i = 0; i < count; i++) {
            total_length += strlen(strings[i]);
        }
        total_length += strlen(delimiter) * (count - 1);

        char* result = malloc(total_length + 1);
        result[0] = '\0';

        for (int i = 0; i < count; i++) {
            strcat(result, strings[i]);
            if (i < count - 1) {
                strcat(result, delimiter);
            }
        }

        return result;
    }

    const char* strings[] = {"a", "b"};
    char* joined = join(strings, 2, "-");
    printf("Join:      %s\n", joined);
    free(joined);

    printf("Repeat:    %.*s\n", 5, "aaaaa");
    
    char replace_str[] = "foo";
    for (char* p = replace_str; *p; p++) {
        if (*p == 'o') *p = '0';
    }
    printf("Replace:   %s\n", replace_str);

    char* token = strtok("a-b-c-d-e", "-");
    printf("Split:     ");
    while (token != NULL) {
        printf("%s ", token);
        token = strtok(NULL, "-");
    }
    printf("\n");

    char lower[] = "TEST";
    for (char* p = lower; *p; p++) *p = tolower(*p);
    printf("ToLower:   %s\n", lower);

    char upper[] = "test";
    for (char* p = upper; *p; p++) *p = toupper(*p);
    printf("ToUpper:   %s\n", upper);

    return 0;
}