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

#include "strops.hpp"

size_t strops_copy(char *dst, const char *src, size_t size)
{
    size_t srclen;
    size --;
    srclen = strlen(src);

    if (srclen > size)
        srclen = size;

    memcpy(dst, src, srclen);
    dst[srclen] = '\0';

    return (srclen);
}

char* strops_stristr(char* haystack, char* needle)
{
    do {
    const char* h = haystack;
    const char* n = needle;
    while (tolower((unsigned char) *h) == tolower((unsigned char ) *n) && *n) {
      h++;
      n++;
    }
    if (*n == 0) {
      return (char *) haystack;
    }
  } while (*haystack++);
  return 0;
}

void strops_replace(char *buf, size_t buf_size, const char *search, const char *replace)
{
    size_t search_len = strlen(search);
    size_t replace_len = strlen(replace);

    char *r = buf; // read pointer
    char *w = buf; // write pointer

    while (*r && (w - buf) < (signed int)(buf_size - 1)) {
        if (strncmp(r, search, search_len) == 0) {
            // Ensure space
            size_t remaining = buf_size - (w - buf) - 1;
            size_t copy_len = (replace_len < remaining) ? replace_len : remaining;

            memcpy(w, replace, copy_len);
            w += copy_len;
            r += search_len;
        } else {
            *w++ = *r++;
        }
    }

    *w = '\0'; // terminate
}