lib/src/style/url.dart

// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import '../characters.dart' as chars;
import '../internal_style.dart';
import '../utils.dart';

/// The style for URL paths.
class UrlStyle extends InternalStyle {
  UrlStyle();

  final name = 'url';
  final separator = '/';
  final separators = const ['/'];

  // Deprecated properties.

  final separatorPattern = new RegExp(r'/');
  final needsSeparatorPattern =
      new RegExp(r"(^[a-zA-Z][-+.a-zA-Z\d]*://|[^/])$");
  final rootPattern = new RegExp(r"[a-zA-Z][-+.a-zA-Z\d]*://[^/]*");
  final relativeRootPattern = new RegExp(r"^/");

  bool containsSeparator(String path) => path.contains('/');

  bool isSeparator(int codeUnit) => codeUnit == chars.SLASH;

  bool needsSeparator(String path) {
    if (path.isEmpty) return false;

    // A URL that doesn't end in "/" always needs a separator.
    if (!isSeparator(path.codeUnitAt(path.length - 1))) return true;

    // A URI that's just "scheme://" needs an extra separator, despite ending
    // with "/".
    return path.endsWith("://") && rootLength(path) == path.length;
  }

  int rootLength(String path, {bool withDrive: false}) {
    if (path.isEmpty) return 0;
    if (isSeparator(path.codeUnitAt(0))) return 1;

    var index = path.indexOf("/");
    if (index > 0 && path.startsWith('://', index - 1)) {
      // The root part is up until the next '/', or the full path. Skip
      // '://' and search for '/' after that.
      index = path.indexOf('/', index + 2);
      if (index <= 0) return path.length;

      // file: URLs sometimes consider Windows drive letters part of the root.
      // See https://url.spec.whatwg.org/#file-slash-state.
      if (!withDrive || path.length < index + 3) return index;
      if (!path.startsWith('file://')) return index;
      if (!isDriveLetter(path, index + 1)) return index;
      return path.length == index + 3 ? index + 3 : index + 4;
    }
    return 0;
  }

  bool isRootRelative(String path) =>
      path.isNotEmpty && isSeparator(path.codeUnitAt(0));

  String getRelativeRoot(String path) => isRootRelative(path) ? '/' : null;

  String pathFromUri(Uri uri) => uri.toString();

  Uri relativePathToUri(String path) => Uri.parse(path);
  Uri absolutePathToUri(String path) => Uri.parse(path);
}