//
// Created by rick on 01-02-21.
//

#include <string.h>
#include <sys/param.h>
#include <sys/types.h>

int memcpy(void *dst, const void *src, size_t amount) {
    for (size_t i = 0; i < amount; i++) {
        ((char *) dst)[i] = ((const char *) src)[i];
    }
    return 0;
}

int memset(void *dst, int data, size_t amount) {
    for (size_t i = 0; i < amount; ++i) {
        ((char *) dst)[i] = (char) data;
    }
    return 0;
}


int strcpy(char *dst, const char *src) {
    return memcpy(dst, src, strlen(src) + 1);
}

int strncpy(char *dst, const char *src, size_t n) {
    return memcpy(dst, src, MIN(strlen(src), n) + 1);
}

size_t strlen(const char *str) {
    int length = 0;
    while (str[length] != 0) {
        length++;
    }
    return length;
}

int strcmp(const char *s1, const char *s2) {
    int len1 = strlen(s1);
    int len2 = strlen(s2);
    return strncmp(s1, s2, MAX(len1, len2));
}

const char *strchr(const char *s, char c) {
    int index = 0;
    while (1) {
        if (s[index] == c) {
            return &s[index];
        }
        if (s[index] == 0) {
            return NULL;
        }
        index++;
    }
}

int memcmp(const void *s1, const void *s2, size_t n) {
    uint8_t a, b;
    for (size_t i = 0; i < n; ++i) {
        a = ((uint8_t *) s1)[i];
        b = ((uint8_t *) s2)[i];
        if (a > b) return 1;
        if (b < a) return -1;
    }
    return 0;
}

int strncmp(const char *s1, const char *s2, int n) {
    for (int i = 0; i < n; ++i) {
        if (s1[i] == 0 && s2[i] == 0) {
            return 0;
        }
        if (s1[i] == 0) {
            return -1;
        }
        if (s2[i] == 0) {
            return 1;
        }
        if (s1[i] > s2[i]) {
            return -1;
        }
        if (s1[i] < s2[i]) {
            return 1;
        }
    }
    return 0;
}

char *strcat(char *dest, const char *src) {
    size_t count = strlen(src);
    return strncat(dest, src, count);
}

char *strncat(char *dest, const char *src, size_t n) {
    size_t start = strlen(dest);
    for (size_t index = 0; index < n; index++) {
        char val = src[index];
        dest[start + index] = val;
        if (val == 0) {
            dest[start + index] = 0;
            break;
        }
    }
    return dest;
}