// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
import { getFileInfoType } from "./_get_file_info_type.ts";

/**
 * Asynchronously ensures that the directory exists. If the directory structure
 * does not exist, it is created. Like `mkdir -p`.
 *
 * Requires the `--allow-read` and `--allow-write` flag.
 *
 * @param dir The path of the directory to ensure, as a string or URL.
 * @returns A promise that resolves once the directory exists.
 *
 * @example
 * ```ts
 * import { ensureDir } from "@std/fs/ensure-dir";
 *
 * await ensureDir("./bar");
 * ```
 */
export async function ensureDir(dir: string | URL) {
  try {
    const fileInfo = await Deno.lstat(dir);
    if (!fileInfo.isDirectory) {
      throw new Error(
        `Ensure path exists, expected 'dir', got '${
          getFileInfoType(fileInfo)
        }'`,
      );
    }
    return;
  } catch (err) {
    if (!(err instanceof Deno.errors.NotFound)) {
      throw err;
    }
  }

  // The dir doesn't exist. Create it.
  // This can be racy. So we catch AlreadyExists and check lstat again.
  try {
    await Deno.mkdir(dir, { recursive: true });
  } catch (err) {
    if (!(err instanceof Deno.errors.AlreadyExists)) {
      throw err;
    }

    const fileInfo = await Deno.lstat(dir);
    if (!fileInfo.isDirectory) {
      throw new Error(
        `Ensure path exists, expected 'dir', got '${
          getFileInfoType(fileInfo)
        }'`,
      );
    }
  }
}

/**
 * Synchronously ensures that the directory exists. If the directory structure
 * does not exist, it is created. Like `mkdir -p`.
 *
 * Requires the `--allow-read` and `--allow-write` flag.
 *
 * @param dir The path of the directory to ensure, as a string or URL.
 * @returns A void value that returns once the directory exists.
 *
 * @example
 * ```ts
 * import { ensureDir } from "@std/fs/ensure-dir";
 *
 * await ensureDir("./bar");
 * ```
 */
export function ensureDirSync(dir: string | URL) {
  try {
    const fileInfo = Deno.lstatSync(dir);
    if (!fileInfo.isDirectory) {
      throw new Error(
        `Ensure path exists, expected 'dir', got '${
          getFileInfoType(fileInfo)
        }'`,
      );
    }
    return;
  } catch (err) {
    if (!(err instanceof Deno.errors.NotFound)) {
      throw err;
    }
  }

  // The dir doesn't exist. Create it.
  // This can be racy. So we catch AlreadyExists and check lstat again.
  try {
    Deno.mkdirSync(dir, { recursive: true });
  } catch (err) {
    if (!(err instanceof Deno.errors.AlreadyExists)) {
      throw err;
    }

    const fileInfo = Deno.lstatSync(dir);
    if (!fileInfo.isDirectory) {
      throw new Error(
        `Ensure path exists, expected 'dir', got '${
          getFileInfoType(fileInfo)
        }'`,
      );
    }
  }
}
