#include <stdlib.h>
#include <types.h>
#include <string.h>


/*
A custom standard for strings for use in the Espresso kernel.
*/

struct kstring {
  size_t s_len;
  char* data; /* NOT null-terminated */
};

/*
if the length of initial_data is more than initial_len, only initial_len bytes will be copied.
if the length of initial_data is less then initial_len, the rest of the bytes are zeroed.
if initial_data is null, no data is copied and the string in set to zero.
*/
struct kstring* make_kstring(size_t initial_len, const char* initial_data)
{
  struct kstring* str = malloc(sizeof(struct kstring));

  if (!str)
  {
    return NULL;
  }

  str->s_len = initial_len;
  str->data = malloc(initial_len);

  if (!str->data)
  {
    return NULL;
  }
  
  memset(str->data, 0, initial_len);

  if (initial_data)
  {
    size_t slen = strlen(initial_data);

    if (slen < initial_len)
    {
      strncpy(str->data, initial_data, slen);
    }
    else if (slen > initial_len)
    {
      strncpy(str->data, initial_data, initial_len);
    }
    else
    {
      strcpy(str->data, initial_data);
    }
  }

  return str;
}