// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
// This module is browser compatible.

import {
  assertArgs,
  lastPathSegment,
  stripSuffix,
} from "./../_common/basename.ts";
import { CHAR_COLON } from "./../_common/constants.ts";
import { stripTrailingSeparators } from "./../_common/strip_trailing_separators.ts";
import { isPathSeparator, isWindowsDeviceRoot } from "./_util.ts";

/**
 * Return the last portion of a `path`.
 * Trailing directory separators are ignored, and optional suffix is removed.
 *
 * @param path - path to extract the name from.
 * @param [suffix] - suffix to remove from extracted name.
 */
export function basename(path: string, suffix = ""): string {
  assertArgs(path, suffix);

  // Check for a drive letter prefix so as not to mistake the following
  // path separator as an extra separator at the end of the path that can be
  // disregarded
  let start = 0;
  if (path.length >= 2) {
    const drive = path.charCodeAt(0);
    if (isWindowsDeviceRoot(drive)) {
      if (path.charCodeAt(1) === CHAR_COLON) start = 2;
    }
  }

  const lastSegment = lastPathSegment(path, isPathSeparator, start);
  const strippedSegment = stripTrailingSeparators(lastSegment, isPathSeparator);
  return suffix ? stripSuffix(strippedSegment, suffix) : strippedSegment;
}