import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_map/flutter_map.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:motorcycle_dash/features/routes/route_planner_screen.dart';
import 'package:motorcycle_dash/services/auth/auth_providers.dart';
import 'package:motorcycle_dash/services/auth/auth_user.dart';
import 'package:motorcycle_dash/services/map/map_provider_interface.dart';
import 'package:motorcycle_dash/services/map/map_providers.dart';
import 'package:motorcycle_dash/services/map/open_street_map_provider.dart';
import 'package:motorcycle_dash/services/map/unified_map_view.dart';
import 'package:motorcycle_dash/services/routes/route_providers.dart';

class FakeMapProvider extends Fake implements OpenStreetMapProvider {
  @override
  Widget buildMapView({
    required BuildContext context,
    required AppLatLng center,
    required double zoom,
    double bearing = 0.0,
    required List<AppMapMarker> markers,
    required List<AppPolyline> polylines,
    required bool isFollowMode,
    required MapConfig config,
    required ValueChanged<AppLatLng>? onPositionChanged,
    required VoidCallback? onUserInteraction,
  }) => const SizedBox.expand();
}

void main() {
  const riderPosition = AppLatLng(33.749, -84.388);
  const overview = AppLatLng(39.5, -98.35);

  Future<ProviderContainer> openPlanner(
    WidgetTester tester,
    Future<AppLatLng?> location, {
    bool realMap = false,
    bool initiallyFollowing = true,
  }) async {
    await tester.pumpWidget(
      ProviderScope(
        overrides: [
          currentUserProvider.overrideWith(
            (ref) => const AuthUser(uid: 'rider'),
          ),
          routePlannerLocationProvider.overrideWith((ref) => location),
          mapFollowStateProvider.overrideWith(
            (ref) => MapFollowNotifier()..setFollow(initiallyFollowing),
          ),
          if (!realMap)
            openStreetMapProviderInstance.overrideWithValue(FakeMapProvider()),
        ],
        child: const MaterialApp(home: RoutePlannerScreen()),
      ),
    );
    await tester.pumpAndSettle();
    return ProviderScope.containerOf(
      tester.element(find.byType(RoutePlannerScreen)),
    );
  }

  UnifiedMapView map(WidgetTester tester) =>
      tester.widget(find.byType(UnifiedMapView));

  for (final size in [const Size(360, 640), const Size(800, 360)]) {
    testWidgets(
      'known rider position centers the planner at $size without adding a stop',
      (tester) async {
        await tester.binding.setSurfaceSize(size);
        addTearDown(() => tester.binding.setSurfaceSize(null));
        final container = await openPlanner(
          tester,
          Future.value(riderPosition),
        );

        expect(map(tester).center, riderPosition);
        expect(map(tester).zoom, 12);
        expect(container.read(routePlannerNotifierProvider).stops, isEmpty);
      },
    );
  }

  testWidgets('pending or absent location shows an overview without blocking', (
    tester,
  ) async {
    final location = Completer<AppLatLng?>();
    await openPlanner(tester, location.future);

    expect(find.text('ROUTE PLANNER'), findsOneWidget);
    expect(map(tester).center, overview);
    expect(map(tester).zoom, 3);

    location.complete(null);
    await tester.pumpAndSettle();
    expect(map(tester).center, overview);
    expect(map(tester).zoom, 3);
  });

  testWidgets('cached position arriving later updates the overview', (
    tester,
  ) async {
    final location = Completer<AppLatLng?>();
    await openPlanner(tester, location.future);
    expect(map(tester).zoom, 3);

    location.complete(riderPosition);
    await tester.pumpAndSettle();
    expect(map(tester).center, riderPosition);
    expect(map(tester).zoom, 12);
  });

  testWidgets(
    'previously panned map does not prevent initial cached centering',
    (tester) async {
      final location = Completer<AppLatLng?>();
      await openPlanner(
        tester,
        location.future,
        realMap: true,
        initiallyFollowing: false,
      );
      final controller = tester
          .widget<FlutterMap>(find.byType(FlutterMap))
          .mapController!;
      expect(controller.camera.center.latitude, overview.latitude);

      location.complete(riderPosition);
      await tester.pumpAndSettle();
      expect(
        controller.camera.center.latitude,
        closeTo(riderPosition.latitude, 0.00001),
      );
      expect(
        controller.camera.center.longitude,
        closeTo(riderPosition.longitude, 0.00001),
      );
      expect(controller.camera.zoom, 12);
    },
  );

  testWidgets('route stops take priority over a late cached rider position', (
    tester,
  ) async {
    final location = Completer<AppLatLng?>();
    final container = await openPlanner(tester, location.future);
    container
        .read(routePlannerNotifierProvider.notifier)
        .addStop(displayName: 'Route start', latitude: 35.6, longitude: -83.5);
    await tester.pumpAndSettle();

    expect(map(tester).center, const AppLatLng(35.6, -83.5));
    expect(map(tester).zoom, 12);
    location.complete(riderPosition);
    await tester.pumpAndSettle();
    expect(map(tester).center, const AppLatLng(35.6, -83.5));
    expect(map(tester).zoom, 12);
  });

  test(
    'location source only reads cache and tolerates unavailable GPS',
    () async {
      const channel = MethodChannel('flutter.baseflow.com/geolocator');
      final calls = <String>[];
      final messenger =
          TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger;
      messenger.setMockMethodCallHandler(channel, (call) async {
        calls.add(call.method);
        throw PlatformException(code: 'PERMISSION_DENIED');
      });
      addTearDown(() => messenger.setMockMethodCallHandler(channel, null));
      final container = ProviderContainer();
      addTearDown(container.dispose);

      expect(await container.read(routePlannerLocationProvider.future), isNull);
      expect(calls, ['getLastKnownPosition']);
    },
  );

  for (final position in [riderPosition, null, const AppLatLng(0, 0)]) {
    test(
      'cached location source validates $position without starting GPS',
      () async {
        const channel = MethodChannel('flutter.baseflow.com/geolocator');
        final calls = <String>[];
        final messenger =
            TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger;
        messenger.setMockMethodCallHandler(channel, (call) async {
          calls.add(call.method);
          return position == null
              ? null
              : {
                  'latitude': position.latitude,
                  'longitude': position.longitude,
                };
        });
        addTearDown(() => messenger.setMockMethodCallHandler(channel, null));
        final container = ProviderContainer();
        addTearDown(container.dispose);

        expect(
          await container.read(routePlannerLocationProvider.future),
          position == riderPosition ? riderPosition : null,
        );
        expect(calls, ['getLastKnownPosition']);
      },
    );
  }
}