// Copyright 2015 The Chromium 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 'dart:collection';

import 'package:mockito/mockito.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:flutter/widgets.dart';

final List<String> results = <String>[];

Set<TestRoute> routes = HashSet<TestRoute>();

class TestRoute extends Route<String> with LocalHistoryRoute<String> {
  TestRoute(this.name);
  final String name;

  @override
  List<OverlayEntry> get overlayEntries => _entries;

  final List<OverlayEntry> _entries = <OverlayEntry>[];

  void log(String s) {
    results.add('$name: $s');
  }

  @override
  void install(OverlayEntry insertionPoint) {
    log('install');
    final OverlayEntry entry = OverlayEntry(
      builder: (BuildContext context) => Container(),
      opaque: true
    );
    _entries.add(entry);
    navigator.overlay?.insert(entry, above: insertionPoint);
    routes.add(this);
    super.install(insertionPoint);
  }

  @override
  TickerFuture didPush() {
    log('didPush');
    return super.didPush();
  }

  @override
  void didReplace(Route<dynamic> oldRoute) {
    expect(oldRoute, isInstanceOf<TestRoute>());
    final TestRoute castRoute = oldRoute;
    log('didReplace ${castRoute.name}');
    super.didReplace(castRoute);
  }

  @override
  bool didPop(String result) {
    log('didPop $result');
    bool returnValue;
    if (returnValue = super.didPop(result))
      navigator.finalizeRoute(this);
    return returnValue;
  }

  @override
  void didPopNext(Route<dynamic> nextRoute) {
    expect(nextRoute, isInstanceOf<TestRoute>());
    final TestRoute castRoute = nextRoute;
    log('didPopNext ${castRoute.name}');
    super.didPopNext(castRoute);
  }

  @override
  void didChangeNext(Route<dynamic> nextRoute) {
    expect(nextRoute, anyOf(isNull, isInstanceOf<TestRoute>()));
    final TestRoute castRoute = nextRoute;
    log('didChangeNext ${castRoute?.name}');
    super.didChangeNext(castRoute);
  }

  @override
  void dispose() {
    log('dispose');
    for (OverlayEntry entry in _entries)
      entry.remove();
    _entries.clear();
    routes.remove(this);
    super.dispose();
  }

}

Future<void> runNavigatorTest(
  WidgetTester tester,
  NavigatorState host,
  VoidCallback test,
  List<String> expectations
) async {
  expect(host, isNotNull);
  test();
  expect(results, equals(expectations));
  results.clear();
  await tester.pump();
}

void main() {
  testWidgets('Route settings', (WidgetTester tester) async {
    const RouteSettings settings = RouteSettings(name: 'A');
    expect(settings, hasOneLineDescription);
    final RouteSettings settings2 = settings.copyWith(name: 'B');
    expect(settings2.name, 'B');
    expect(settings2.isInitialRoute, false);
    final RouteSettings settings3 = settings2.copyWith(isInitialRoute: true);
    expect(settings3.name, 'B');
    expect(settings3.isInitialRoute, true);
  });

  testWidgets('Route management - push, replace, pop', (WidgetTester tester) async {
    final GlobalKey<NavigatorState> navigatorKey = GlobalKey<NavigatorState>();
    await tester.pumpWidget(
      Directionality(
        textDirection: TextDirection.ltr,
        child: Navigator(
          key: navigatorKey,
          onGenerateRoute: (_) => TestRoute('initial'),
        ),
      ),
    );
    final NavigatorState host = navigatorKey.currentState;
    await runNavigatorTest(
      tester,
      host,
      () { },
      <String>[
        'initial: install',
        'initial: didPush',
        'initial: didChangeNext null',
      ]
    );
    TestRoute second;
    await runNavigatorTest(
      tester,
      host,
      () { host.push(second = TestRoute('second')); },
      <String>[
        'second: install',
        'second: didPush',
        'second: didChangeNext null',
        'initial: didChangeNext second',
      ]
    );
    await runNavigatorTest(
      tester,
      host,
      () { host.push(TestRoute('third')); },
      <String>[
        'third: install',
        'third: didPush',
        'third: didChangeNext null',
        'second: didChangeNext third',
      ]
    );
    await runNavigatorTest(
      tester,
      host,
      () { host.replace(oldRoute: second, newRoute: TestRoute('two')); },
      <String>[
        'two: install',
        'two: didReplace second',
        'two: didChangeNext third',
        'initial: didChangeNext two',
        'second: dispose',
      ]
    );
    await runNavigatorTest(
      tester,
      host,
      () { host.pop('hello'); },
      <String>[
        'third: didPop hello',
        'third: dispose',
        'two: didPopNext third',
      ]
    );
    await runNavigatorTest(
      tester,
      host,
      () { host.pop('good bye'); },
      <String>[
        'two: didPop good bye',
        'two: dispose',
        'initial: didPopNext two',
      ]
    );
    await tester.pumpWidget(Container());
    expect(results, equals(<String>['initial: dispose']));
    expect(routes.isEmpty, isTrue);
    results.clear();
  });

  testWidgets('Route management - push, remove, pop', (WidgetTester tester) async {
    final GlobalKey<NavigatorState> navigatorKey = GlobalKey<NavigatorState>();
    await tester.pumpWidget(
      Directionality(
        textDirection: TextDirection.ltr,
        child: Navigator(
          key: navigatorKey,
          onGenerateRoute: (_) => TestRoute('first')
        ),
      ),
    );
    final NavigatorState host = navigatorKey.currentState;
    await runNavigatorTest(
      tester,
      host,
      () { },
      <String>[
        'first: install',
        'first: didPush',
        'first: didChangeNext null',
      ]
    );
    TestRoute second;
    await runNavigatorTest(
      tester,
      host,
      () { host.push(second = TestRoute('second')); },
      <String>[
        'second: install',
        'second: didPush',
        'second: didChangeNext null',
        'first: didChangeNext second',
      ]
    );
    await runNavigatorTest(
      tester,
      host,
      () { host.push(TestRoute('third')); },
      <String>[
        'third: install',
        'third: didPush',
        'third: didChangeNext null',
        'second: didChangeNext third',
      ]
    );
    await runNavigatorTest(
      tester,
      host,
      () { host.removeRouteBelow(second); },
      <String>[
        'first: dispose',
      ]
    );
    await runNavigatorTest(
      tester,
      host,
      () { host.pop('good bye'); },
      <String>[
        'third: didPop good bye',
        'third: dispose',
        'second: didPopNext third',
      ]
    );
    await runNavigatorTest(
      tester,
      host,
      () { host.push(TestRoute('three')); },
      <String>[
        'three: install',
        'three: didPush',
        'three: didChangeNext null',
        'second: didChangeNext three',
      ]
    );
    TestRoute four;
    await runNavigatorTest(
      tester,
      host,
      () { host.push(four = TestRoute('four')); },
      <String>[
        'four: install',
        'four: didPush',
        'four: didChangeNext null',
        'three: didChangeNext four',
      ]
    );
    await runNavigatorTest(
      tester,
      host,
      () { host.removeRouteBelow(four); },
      <String>[
        'second: didChangeNext four',
        'three: dispose',
      ]
    );
    await runNavigatorTest(
      tester,
      host,
      () { host.pop('the end'); },
      <String>[
        'four: didPop the end',
        'four: dispose',
        'second: didPopNext four',
      ]
    );
    await tester.pumpWidget(Container());
    expect(results, equals(<String>['second: dispose']));
    expect(routes.isEmpty, isTrue);
    results.clear();
  });

  testWidgets('Route management - push, replace, popUntil', (WidgetTester tester) async {
    final GlobalKey<NavigatorState> navigatorKey = GlobalKey<NavigatorState>();
    await tester.pumpWidget(
      Directionality(
        textDirection: TextDirection.ltr,
        child: Navigator(
          key: navigatorKey,
          onGenerateRoute: (_) => TestRoute('A')
        ),
      ),
    );
    final NavigatorState host = navigatorKey.currentState;
    await runNavigatorTest(
      tester,
      host,
      () { },
      <String>[
        'A: install',
        'A: didPush',
        'A: didChangeNext null',
      ]
    );
    await runNavigatorTest(
      tester,
      host,
      () { host.push(TestRoute('B')); },
      <String>[
        'B: install',
        'B: didPush',
        'B: didChangeNext null',
        'A: didChangeNext B',
      ]
    );
    TestRoute routeC;
    await runNavigatorTest(
      tester,
      host,
      () { host.push(routeC = TestRoute('C')); },
      <String>[
        'C: install',
        'C: didPush',
        'C: didChangeNext null',
        'B: didChangeNext C',
      ]
    );
    expect(routeC.isActive, isTrue);
    TestRoute routeB;
    await runNavigatorTest(
      tester,
      host,
      () { host.replaceRouteBelow(anchorRoute: routeC, newRoute: routeB = TestRoute('b')); },
      <String>[
        'b: install',
        'b: didReplace B',
        'b: didChangeNext C',
        'A: didChangeNext b',
        'B: dispose',
      ]
    );
    await runNavigatorTest(
      tester,
      host,
      () { host.popUntil((Route<dynamic> route) => route == routeB); },
      <String>[
        'C: didPop null',
        'C: dispose',
        'b: didPopNext C',
      ]
    );
    await tester.pumpWidget(Container());
    expect(results, equals(<String>['A: dispose', 'b: dispose']));
    expect(routes.isEmpty, isTrue);
    results.clear();
  });

  testWidgets('Route localHistory - popUntil', (WidgetTester tester) async {
    final TestRoute routeA = TestRoute('A');
    routeA.addLocalHistoryEntry(LocalHistoryEntry(
      onRemove: () { routeA.log('onRemove 0'); }
    ));
    routeA.addLocalHistoryEntry(LocalHistoryEntry(
      onRemove: () { routeA.log('onRemove 1'); }
    ));
    final GlobalKey<NavigatorState> navigatorKey = GlobalKey<NavigatorState>();
    await tester.pumpWidget(
      Directionality(
        textDirection: TextDirection.ltr,
        child: Navigator(
          key: navigatorKey,
          onGenerateRoute: (_) => routeA
        ),
      ),
    );
    final NavigatorState host = navigatorKey.currentState;
    await runNavigatorTest(
      tester,
      host,
      () { host.popUntil((Route<dynamic> route) => !route.willHandlePopInternally); },
      <String>[
        'A: install',
        'A: didPush',
        'A: didChangeNext null',
        'A: didPop null',
        'A: onRemove 1',
        'A: didPop null',
        'A: onRemove 0',
      ]
    );

    await runNavigatorTest(
      tester,
      host,
      () { host.popUntil((Route<dynamic> route) => !route.willHandlePopInternally); },
      <String>[
      ]
    );
  });

  group('PageRouteObserver', () {
    test('calls correct listeners', () {
      final RouteObserver<PageRoute<dynamic>> observer = RouteObserver<PageRoute<dynamic>>();
      final RouteAware pageRouteAware1 = MockRouteAware();
      final MockPageRoute route1 = MockPageRoute();
      observer.subscribe(pageRouteAware1, route1);
      verify(pageRouteAware1.didPush()).called(1);

      final RouteAware pageRouteAware2 = MockRouteAware();
      final MockPageRoute route2 = MockPageRoute();
      observer.didPush(route2, route1);
      verify(pageRouteAware1.didPushNext()).called(1);

      observer.subscribe(pageRouteAware2, route2);
      verify(pageRouteAware2.didPush()).called(1);

      observer.didPop(route2, route1);
      verify(pageRouteAware2.didPop()).called(1);
      verify(pageRouteAware1.didPopNext()).called(1);
    });

    test('does not call listeners for non-PageRoute', () {
      final RouteObserver<PageRoute<dynamic>> observer = RouteObserver<PageRoute<dynamic>>();
      final RouteAware pageRouteAware = MockRouteAware();
      final MockPageRoute pageRoute = MockPageRoute();
      final MockRoute route = MockRoute();
      observer.subscribe(pageRouteAware, pageRoute);
      verify(pageRouteAware.didPush());

      observer.didPush(route, pageRoute);
      observer.didPop(route, pageRoute);
      verifyNoMoreInteractions(pageRouteAware);
    });

    test('does not call listeners when already subscribed', () {
      final RouteObserver<PageRoute<dynamic>> observer = RouteObserver<PageRoute<dynamic>>();
      final RouteAware pageRouteAware = MockRouteAware();
      final MockPageRoute pageRoute = MockPageRoute();
      observer.subscribe(pageRouteAware, pageRoute);
      observer.subscribe(pageRouteAware, pageRoute);
      verify(pageRouteAware.didPush()).called(1);
    });

    test('does not call listeners when unsubscribed', () {
      final RouteObserver<PageRoute<dynamic>> observer = RouteObserver<PageRoute<dynamic>>();
      final RouteAware pageRouteAware = MockRouteAware();
      final MockPageRoute pageRoute = MockPageRoute();
      final MockPageRoute nextPageRoute = MockPageRoute();
      observer.subscribe(pageRouteAware, pageRoute);
      observer.subscribe(pageRouteAware, nextPageRoute);
      verify(pageRouteAware.didPush()).called(2);

      observer.unsubscribe(pageRouteAware);

      observer.didPush(nextPageRoute, pageRoute);
      observer.didPop(nextPageRoute, pageRoute);
      verifyNoMoreInteractions(pageRouteAware);
    });
  });
}

class MockPageRoute extends Mock implements PageRoute<dynamic> { }

class MockRoute extends Mock implements Route<dynamic> { }

class MockRouteAware extends Mock implements RouteAware { }