#include "hv/string.h"

void *hv_memset(void *dst, int value, size_t len)
{
    unsigned char *p = (unsigned char *)dst;
    while (len-- != 0u) {
        *p++ = (unsigned char)value;
    }
    return dst;
}

void *hv_memcpy(void *dst, const void *src, size_t len)
{
    unsigned char *d = (unsigned char *)dst;
    const unsigned char *s = (const unsigned char *)src;
    while (len-- != 0u) {
        *d++ = *s++;
    }
    return dst;
}

void *hv_memmove(void *dst, const void *src, size_t len)
{
    unsigned char *d = (unsigned char *)dst;
    const unsigned char *s = (const unsigned char *)src;
    if (d == s || len == 0u) {
        return dst;
    }
    if (d < s) {
        while (len-- != 0u) {
            *d++ = *s++;
        }
    } else {
        d += len;
        s += len;
        while (len-- != 0u) {
            *--d = *--s;
        }
    }
    return dst;
}

int hv_memcmp(const void *a, const void *b, size_t len)
{
    const unsigned char *pa = (const unsigned char *)a;
    const unsigned char *pb = (const unsigned char *)b;
    for (size_t i = 0; i < len; i++) {
        if (pa[i] != pb[i]) {
            return (int)pa[i] - (int)pb[i];
        }
    }
    return 0;
}

size_t hv_strlen(const char *s)
{
    size_t n = 0;
    while (s[n] != '\0') {
        n++;
    }
    return n;
}

int hv_strcmp(const char *a, const char *b)
{
    while (*a != '\0' && *a == *b) {
        a++;
        b++;
    }
    return (int)(unsigned char)*a - (int)(unsigned char)*b;
}

int hv_strncmp(const char *a, const char *b, size_t n)
{
    for (size_t i = 0; i < n; i++) {
        if (a[i] == '\0' || a[i] != b[i]) {
            return (int)(unsigned char)a[i] - (int)(unsigned char)b[i];
        }
    }
    return 0;
}

void *memset(void *dst, int value, size_t len)
{
    return hv_memset(dst, value, len);
}

void *memcpy(void *dst, const void *src, size_t len)
{
    return hv_memcpy(dst, src, len);
}

void *memmove(void *dst, const void *src, size_t len)
{
    return hv_memmove(dst, src, len);
}

int memcmp(const void *a, const void *b, size_t len)
{
    return hv_memcmp(a, b, len);
}