/* Copyright (C) 2025 Aryadev Chavali

 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GNU General Public License Version 2 for
 * details.

 * You may distribute and modify this code under the terms of the GNU General
 * Public License Version 2, which you should have received a copy of along with
 * this program.  If not, please go to <https://www.gnu.org/licenses/>.

 * Created: 2025-04-14
 * Description: String View implementation
 */

#include <lib/sv.h>

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

sv_t sv_make(arena_t *allocator, const char *data, u64 size)
{
  sv_t s = {0};
  if (data)
    s = sv_append(allocator, s, data, size);
  else
  {
    s.data = arena_alloc(allocator, size);
    s.size = size;
  }
  return s;
}

sv_t sv_copy(arena_t *allocator, sv_t sv)
{
  return sv_make(allocator, sv.data, sv.size);
}

sv_t sv_substr(sv_t sv, u64 index, u64 size)
{
  sv_t newsv = {0};
  if (index + size > sv.size)
    return newsv;
  newsv.data = sv.data + index;
  newsv.size = size;
  return newsv;
}

sv_t sv_cut(sv_t sv, u64 index)
{
  return sv_substr(sv, index, sv.size < index ? 0 : sv.size - index);
}

sv_t sv_chop(sv_t sv, u64 size)
{
  return sv_substr(sv, 0, size);
}

sv_t sv_concat(arena_t *allocator, sv_t a, sv_t b)
{
  sv_t c = sv_make(allocator, a.data, a.size + b.size);
  memcpy(c.data + a.size, b.data, b.size);
  return c;
}

sv_t sv_append(arena_t *allocator, sv_t sv, const char *data, u64 size)
{
  if (!allocator)
    return (sv_t){0};

  sv_t newsv = {0};
  newsv.size = sv.size + size;
  newsv.data = arena_realloc(allocator, sv.data, sv.size, newsv.size);
  if (data)
    memcpy(newsv.data + sv.size, data, size);
  return newsv;
}

sv_t sv_prepend(arena_t *allocator, sv_t sv, const char *data, u64 size)
{
  if (!allocator)
    return (sv_t){0};

  // TODO: Can we make this cheaper to do?
  sv_t newsv = sv_make(allocator, NULL, size + sv.size);
  // Copy over `data` to the left side
  memcpy(newsv.data, data, size);
  // Copy old string to the right side
  if (sv.data)
    memcpy(newsv.data + size, sv.data, sv.size);

  return newsv;
}

sv_t sv_fmt(arena_t *allocator, char *fmt, ...)
{
  if (!allocator)
    return (sv_t){0};

  va_list ap_1, ap_2;
  va_start(ap_1, fmt);

  va_copy(ap_2, ap_1);
  u64 size = vsnprintf(NULL, 0, fmt, ap_2);
  va_end(ap_2);

  sv_t sv = sv_make(allocator, NULL, size);
  vsprintf(sv.data, fmt, ap_1);
  va_end(ap_1);

  return sv;
}

i64 sv_find_substr(const sv_t sv, const sv_t substr)
{
  if (substr.size == 0)
    return 0;
  else if (sv.size < substr.size)
    return -1;
  else if (sv.size == substr.size)
    return strncmp(sv.data, substr.data, sv.size) == 0 ? 0 : -1;

  for (u64 i = 0; i < (sv.size - substr.size); ++i)
    if (strncmp(sv.data + i, substr.data, substr.size) == 0)
      return i;
  return -1;
}

i64 sv_find_subcstr(const sv_t sv, const char *substr, u64 size)
{
  return sv_find_substr(sv, SV((char *)substr, size));
}

i64 sv_find_any(const sv_t sv, const char *bag)
{
  for (u64 i = 0; i < sv.size; ++i)
    if (strchr(bag, sv.data[i]))
      return i;
  return -1;
}

u64 sv_while(const sv_t sv, bool (*pred)(char))
{
  u64 i;
  for (i = 0; i < sv.size && pred(sv.data[i]); ++i)
    continue;
  return i;
}

u64 sv_till(const sv_t sv, bool (*pred)(char))
{
  u64 i;
  for (i = 0; i < sv.size && !pred(sv.data[i]); ++i)
    continue;
  return i;
}