import 'dart:convert';
import 'dart:io';
import 'dart:typed_data';

import 'package:crypto/crypto.dart';
import 'package:drift/drift.dart' as drift;
import 'package:drift/native.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:http/http.dart' as http;
import 'package:http/testing.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:motorcycle_dash/database/database.dart';
import 'package:motorcycle_dash/services/sync/r2_upload_service.dart';
import 'package:motorcycle_dash/services/sync/sync_bundle_worker.dart';
import 'package:motorcycle_dash/services/sync/sync_manager.dart';
import 'package:motorcycle_dash/services/sync/sync_models.dart';
import 'package:motorcycle_dash/services/sync/sync_outbox.dart';
import 'package:motorcycle_dash/services/sync/sync_provider.dart';

class _R2ThenFirestoreProvider implements SyncProvider {
  int attempts = 0;
  bool firestoreAvailable = false;
  final List<String> uploadedRemoteIds = [];

  @override
  String get providerId => 'firebase';

  @override
  Future<bool> isAvailable() async => true;

  @override
  Future<bool> requiresAuthentication() async => false;

  @override
  Future<bool> isRideConfirmedInCloud(String remoteRideId) async => false;

  @override
  Future<CloudConfirmationResult> verifyCloudConfirmation(String remoteRideId) async =>
      CloudConfirmationResult.missing(remoteRideId: remoteRideId);

  @override
  Future<SyncResult> uploadRide(SyncItem item) async {
    attempts++;
    uploadedRemoteIds.add('ride_stable_123');
    if (!firestoreAvailable) {
      return SyncResult.temporaryFailure(
        'Firestore unavailable after R2 upload.',
      );
    }
    return SyncResult.success(remoteId: 'ride_stable_123');
  }
}

void main() {
  TestWidgetsFlutterBinding.ensureInitialized();

  group('R2 and Firestore retry hardening', () {
    test(
      'retries target one deterministic R2 object, including changed bundle bytes',
      () async {
        final remoteIds = <String>[];
        final objectKeys = <String>[];
        final client = MockClient((request) async {
          remoteIds.add(request.headers['X-Remote-Ride-Id']!);
          final remoteRideId = request.headers['X-Remote-Ride-Id']!;
          final objectKey = 'users/pilot_123/rides/$remoteRideId/telemetry.zip';
          objectKeys.add(objectKey);
          return http.Response(
            jsonEncode({'objectKey': objectKey, 'size': 4}),
            200,
          );
        });
        final service = R2UploadService(
          client: client,
          workerBaseUrl: 'https://worker.test',
        );

        final first = await service.uploadTelemetryBundle(
          idToken: 'token',
          remoteRideId: 'ride_stable_123',
          zipBytes: Uint8List.fromList([1, 2, 3, 4]),
          sha256Hash: 'a' * 64,
          appVersion: '1.0.2',
        );
        final retry = await service.uploadTelemetryBundle(
          idToken: 'token',
          remoteRideId: 'ride_stable_123',
          zipBytes: Uint8List.fromList([4, 3, 2, 1]),
          sha256Hash: 'b' * 64,
          appVersion: '1.0.2',
        );

        expect(first.success, isTrue);
        expect(retry.success, isTrue);
        expect(remoteIds, ['ride_stable_123', 'ride_stable_123']);
        expect(objectKeys.toSet(), hasLength(1));
        expect(first.objectKey, retry.objectKey);
      },
    );

    test(
      'R2 success then Firestore failure remains durable and retries one cloud ride',
      () async {
        SharedPreferences.setMockInitialValues({});
        final prefs = await SharedPreferences.getInstance();
        final outbox = SyncOutbox(prefs);
        final provider = _R2ThenFirestoreProvider();
        var now = DateTime(2026, 9, 3, 12);
        final manager = SyncManager(
          outbox,
          initialProviders: [provider],
          defaultProviderId: 'firebase',
          nowProvider: () => now,
        );

        await manager.enqueueRide(42, autoProcess: false);
        await manager.processQueue();
        expect(outbox.getItem(42, 'firebase')?.status, SyncStatus.retryWait);
        expect(outbox.isRideSynced(42, 'firebase'), isFalse);

        provider.firestoreAvailable = true;
        now = now.add(const Duration(seconds: 5));
        await manager.processQueue();

        expect(outbox.getItem(42, 'firebase')?.status, SyncStatus.synced);
        expect(provider.attempts, 2);
        expect(provider.uploadedRemoteIds.toSet(), {'ride_stable_123'});
        manager.dispose();
      },
    );

    test(
      'interrupted uploading state reloads as retryable queued work',
      () async {
        final item = SyncItem(
          localRideId: 42,
          providerId: 'firebase',
          status: SyncStatus.uploading,
          createdAt: DateTime(2026, 9, 3),
        );
        SharedPreferences.setMockInitialValues({
          'motorsignal_sync_outbox_manifest_v2_local': jsonEncode([
            item.toJson(),
          ]),
        });

        final prefs = await SharedPreferences.getInstance();
        final reloaded = SyncOutbox(prefs);
        expect(reloaded.getItem(42, 'firebase')?.status, SyncStatus.queued);
      },
    );

    test(
      'completed ride bundle is byte-stable when regenerated for a retry',
      () async {
        final db = AppDatabase.forTesting(NativeDatabase.memory());
        addTearDown(db.close);
        final rideId = await db
            .into(db.rides)
            .insert(
              RidesCompanion.insert(
                startTime: DateTime(2026, 9, 3, 10),
                endTime: drift.Value(DateTime(2026, 9, 3, 11)),
                distanceMiles: const drift.Value(12.4),
              ),
            );
        final worker = SyncBundleWorker(db);

        final first = await worker.generateCompressedBundle(rideId);
        final retry = await worker.generateCompressedBundle(rideId);

        expect(first, isNotNull);
        expect(retry, isNotNull);
        expect(
          sha256.convert(first!).toString(),
          sha256.convert(retry!).toString(),
        );
      },
    );

    test(
      'production path upserts one Firestore document after R2 and records its hash',
      () {
        final providerSource = File(
          'lib/services/sync/firebase_sync_provider.dart',
        ).readAsStringSync();
        final workerSource = File(
          'cloudflare/motorsignal-r2-worker/src/index.ts',
        ).readAsStringSync();

        expect(
          workerSource,
          contains(
            r'const objectKey = `users/${authenticatedUid}/rides/${remoteRideId}/telemetry.zip`;',
          ),
        );
        expect(
          workerSource,
          contains('await env.R2_BUCKET.put(objectKey, payloadBuffer,'),
        );
        expect(
          providerSource.indexOf('uploadTelemetryBundle('),
          lessThan(
            providerSource.indexOf(
              ".collection('users').doc(user.uid).collection('rides').doc(remoteRideId).set(",
            ),
          ),
        );
        expect(providerSource, contains("'sha256': sha256Hash"));
        expect(
          providerSource,
          contains(
            ".doc(remoteRideId).set(firestorePayload, SetOptions(merge: true))",
          ),
        );
        expect(providerSource, contains("'telemetryBundlePath': objectKey"));
      },
    );
  });
}