#include "src/kernel/path.h"
#include "src/kernel/fs.h"
#include "src/lib/memory.h"
#include "src/lib/string.h"
#include "src/lib/util.h"

path_t *path_open(const fs_node_t *root, const path_t *source, const char *path) {
  uint64_t length = string_length(path);
  char *path_own = memory_allocate(length + 1);
  memory_copy(path, length + 1, path_own);

  path_t *result = memory_allocate(sizeof(path_t));

  char *path_components[PATH_DEPTH];
  uint8_t path_length = (uint8_t)string_split(path_own, '/', PATH_DEPTH, path_components);
  if (!string_empty(path_components[0])) {
    for (uint8_t i = 0; i < source->depth; i++) {
      result->stack[result->depth++] = fs_open_again(source->stack[i]);
    }
  }

  for (uint8_t i = 0; i < path_length; i++) {
    if (string_empty(path_components[i]) || string_equal(path_components[i], ".")) {
      continue;
    } else if (string_equal(path_components[i], "..")) {
      if (result->depth) {
        fs_close(result->stack[--result->depth]);
      }
    } else {
      const fs_node_t *prev = result->depth ? result->stack[result->depth - 1] : root;
      fs_node_t *next = prev->is_dir ? fs_open_by(prev, path_components[i]) : NUL;
      if (!next || result->depth >= PATH_DEPTH) {
        path_close(result);
        memory_free(path_own);
        return NUL;
      } else {
        result->stack[result->depth++] = next;
      }
    }
  }

  memory_free(path_own);

  return result;
}

fs_node_t *path_open_file(const fs_node_t *root, const path_t *source, const char *path) {
  path_t *p = path_open(root, source, path);
  if (!p) {
    return NUL;
  }
  if (!p->depth || p->stack[p->depth - 1]->is_dir) {
    path_close(p);
    return NUL;
  }
  fs_node_t *n = fs_open_again(p->stack[p->depth - 1]);
  path_close(p);
  return n;
}

fs_node_t *path_open_directory(const fs_node_t *root, const path_t *source, const char *path) {
  path_t *p = path_open(root, source, path);
  if (!p) {
    return NUL;
  }
  if (!p->depth) {
    path_close(p);
    return (fs_node_t *)root;
  }
  if (!p->stack[p->depth - 1]->is_dir) {
    path_close(p);
    return NUL;
  }
  fs_node_t *n = fs_open_again(p->stack[p->depth - 1]);
  path_close(p);
  return n;
}

void path_close(path_t *path) {
  for (uint64_t i = 0; i < path->depth; i++) {
    fs_close(path->stack[i]);
  }
  memory_free(path);
}