/* Calcite, src/kernel/fs.c
 * Copyright 2025 Benji Dial
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * 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
 * for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program. If not, see <https://www.gnu.org/licenses/>.
 */

#include "iso9660.h"
#include "utility.h"
#include "debug.h"
#include "heap.h"
#include "fs.h"

#include <kernel-public/files.h>

enum fs_access_result create_fs_info(
  const struct drive_info *drive, struct fs_info *fs_out, const char *fs_type) {

  if (strequ(fs_type, "iso9660"))
    return create_iso9660_info(drive, fs_out);

  return FAR_UNKNOWN_FS_TYPE;

}

struct set_fs {
  const char *name;
  const struct fs_info *fs;
};

struct set_fs *set_fses;
int set_fses_buffer_length = 0;
int set_fses_count = 0;

#define SET_FSES_INITIAL_LENGTH 16

void set_fs(const char *name, const struct fs_info *fs) {

  assert(get_fs(name) == 0)

  if (set_fses_buffer_length == 0) {
    set_fses = heap_alloc(SET_FSES_INITIAL_LENGTH * sizeof(struct set_fs));
    set_fses_buffer_length = SET_FSES_INITIAL_LENGTH;
  }

  else if (set_fses_count == set_fses_buffer_length) {
    struct set_fs *new_set_fses = heap_alloc(2 * set_fses_buffer_length * sizeof(struct set_fs));
    memcpy(new_set_fses, set_fses, set_fses_count * sizeof(struct set_fs));
    heap_dealloc(set_fses, set_fses_count * sizeof(struct set_fs));
    set_fses = new_set_fses;
    set_fses_buffer_length *= 2;
  }

  set_fses[set_fses_count].name = name;
  set_fses[set_fses_count].fs = fs;
  ++set_fses_count;

}

const struct fs_info *get_fs(const char *name) {
  for (int i = 0; i < set_fses_count; ++i)
    if (strequ(set_fses[i].name, name))
      return set_fses[i].fs;
  return 0;
}

enum fs_access_result look_up_file(
  const char *uri, const struct fs_info **fs_out, void **node_out) {

  int colon = 0;
  while (1) {
    if (uri[colon] == ':')
      break;
    if (uri[colon] == 0)
      panic("bad uri")
    ++colon;
  }

  if (uri[colon + 1] != '/' || uri[colon + 2] != '/')
    panic("bad uri")

  char *uri_copy = heap_alloc(colon + 1);
  memcpy(uri_copy, uri, colon);
  uri_copy[colon] = 0;

  *fs_out = get_fs(uri_copy);

  heap_dealloc(uri_copy, colon + 1);

  if (!*fs_out)
    return FAR_NOT_FOUND;

  return (*(*fs_out)->look_up_file)(*fs_out, node_out, &uri[colon + 3]);

}