// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'package:flutter/foundation.dart';

import 'go_route.dart';
import 'go_router_delegate.dart';
import 'path_parser.dart';

/// Each GoRouteMatch instance represents an instance of a GoRoute for a
/// specific portion of a location.
class GoRouteMatch {
  /// Constructor for GoRouteMatch, each instance represents an instance of a
  /// GoRoute for a specific portion of a location.
  GoRouteMatch({
    required this.route,
    required this.subloc,
    required this.fullpath,
    required this.encodedParams,
    required this.queryParams,
    required this.extra,
    required this.error,
    this.pageKey,
  })  : assert(subloc.startsWith('/')),
        assert(Uri.parse(subloc).queryParameters.isEmpty),
        assert(fullpath.startsWith('/')),
        assert(Uri.parse(fullpath).queryParameters.isEmpty) {
    if (kDebugMode) {
      for (final MapEntry<String, String> p in encodedParams.entries) {
        assert(p.value == Uri.encodeComponent(Uri.decodeComponent(p.value)),
            'encodedParams[${p.key}] is not encoded properly: "${p.value}"');
      }
    }
  }

  // ignore: public_member_api_docs
  factory GoRouteMatch.matchNamed({
    required GoRoute route,
    required String name, // e.g. person
    required String fullpath, // e.g. /family/:fid/person/:pid
    required Map<String, String> params, // e.g. {'fid': 'f2', 'pid': 'p1'}
    required Map<String, String> queryParams, // e.g. {'from': '/family/f2'}
    required Object? extra,
  }) {
    assert(route.name != null);
    assert(route.name!.toLowerCase() == name.toLowerCase());

    // check that we have all the params we need
    final List<String> paramNames = <String>[];
    patternToRegExp(fullpath, paramNames);
    for (final String paramName in paramNames) {
      if (!params.containsKey(paramName)) {
        throw Exception('missing param "$paramName" for $fullpath');
      }
    }

    // check that we have don't have extra params
    for (final String key in params.keys) {
      if (!paramNames.contains(key)) {
        throw Exception('unknown param "$key" for $fullpath');
      }
    }

    final Map<String, String> encodedParams = <String, String>{
      for (final MapEntry<String, String> param in params.entries)
        param.key: Uri.encodeComponent(param.value)
    };

    final String subloc = _locationFor(fullpath, encodedParams);
    return GoRouteMatch(
      route: route,
      subloc: subloc,
      fullpath: fullpath,
      encodedParams: encodedParams,
      queryParams: queryParams,
      extra: extra,
      error: null,
    );
  }

  // ignore: public_member_api_docs
  static GoRouteMatch? match({
    required GoRoute route,
    required String restLoc, // e.g. person/p1
    required String parentSubloc, // e.g. /family/f2
    required String path, // e.g. person/:pid
    required String fullpath, // e.g. /family/:fid/person/:pid
    required Map<String, String> queryParams,
    required Object? extra,
  }) {
    assert(!path.contains('//'));

    final RegExpMatch? match = route.matchPatternAsPrefix(restLoc);
    if (match == null) {
      return null;
    }

    final Map<String, String> encodedParams = route.extractPathParams(match);
    final String pathLoc = _locationFor(path, encodedParams);
    final String subloc = GoRouterDelegate.fullLocFor(parentSubloc, pathLoc);
    return GoRouteMatch(
      route: route,
      subloc: subloc,
      fullpath: fullpath,
      encodedParams: encodedParams,
      queryParams: queryParams,
      extra: extra,
      error: null,
    );
  }

  /// The matched route.
  final GoRoute route;

  /// Matched sub-location.
  final String subloc; // e.g. /family/f2

  /// Matched full path.
  final String fullpath; // e.g. /family/:fid

  /// Parameters for the matched route, URI-encoded.
  final Map<String, String> encodedParams;

  /// Query parameters for the matched route.
  final Map<String, String> queryParams;

  /// An extra object to pass along with the navigation.
  final Object? extra;

  /// An exception if there was an error during matching.
  final Exception? error;

  /// Optional value key of type string, to hold a unique reference to a page.
  final ValueKey<String>? pageKey;

  /// Parameters for the matched route, URI-decoded.
  Map<String, String> get decodedParams => <String, String>{
        for (final MapEntry<String, String> param in encodedParams.entries)
          param.key: Uri.decodeComponent(param.value)
      };

  /// for use by the Router architecture as part of the GoRouteMatch
  @override
  String toString() => 'GoRouteMatch($fullpath, $encodedParams)';

  /// expand a path w/ param slots using params, e.g. family/:fid => family/f1
  static String _locationFor(String pattern, Map<String, String> params) =>
      patternToPath(pattern, params);
}