// RID-1 regression coverage: SyncObserver completed-ride enqueue error handling.
//
// Before this hardening the observer called SyncManager.enqueueRide() as a
// naked Future. Because SyncOutbox.enqueue() throws StateError at capacity and
// ArgumentError on invalid input, a failing enqueue surfaced as an unhandled
// async exception and silently discarded the ride's durable sync intent.
//
// flutter_test fails a test on any unhandled async error, so these tests are a
// genuine regression: they fail against the pre-fix observer.
import 'package:flutter/foundation.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:motorcycle_dash/models/recording_health_status.dart';
import 'package:motorcycle_dash/features/rides/ride_state_machine.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_observer.dart';
import 'package:motorcycle_dash/services/sync/sync_outbox.dart';

/// SyncManager seam that can fail the next N enqueue attempts, then delegate to
/// the real implementation. Test-only; no production change was required.
class _FailingSyncManager extends SyncManager {
  _FailingSyncManager(super.outbox);

  int enqueueAttempts = 0;
  int failuresRemaining = 0;

  /// Payload that must never reach diagnostics.
  static const String secretPayload = 'RID-1-SENSITIVE-TOKEN-do-not-log';

  @override
  Future<SyncItem> enqueueRide(
    int localRideId, {
    String? targetProviderId,
    bool autoProcess = true,
  }) async {
    enqueueAttempts++;
    if (failuresRemaining > 0) {
      failuresRemaining--;
      throw StateError(secretPayload);
    }
    return super.enqueueRide(
      localRideId,
      targetProviderId: targetProviderId,
      autoProcess: autoProcess,
    );
  }
}

void main() {
  TestWidgetsFlutterBinding.ensureInitialized();

  late SharedPreferences prefs;
  late List<String> logLines;
  late DebugPrintCallback originalDebugPrint;

  setUp(() async {
    SharedPreferences.setMockInitialValues({});
    prefs = await SharedPreferences.getInstance();
    logLines = [];
    originalDebugPrint = debugPrint;
    debugPrint = (String? message, {int? wrapWidth}) {
      if (message != null) logLines.add(message);
    };
  });

  tearDown(() {
    debugPrint = originalDebugPrint;
  });

  RideSession riding(int dbId) => RideSession(
        dbId: dbId,
        state: RideState.riding,
        healthStatus: RecordingHealthStatus.recordingActive,
      );

  RideSession finishedOf(RideSession previous) => previous.copyWith(
        state: RideState.finished,
        healthStatus: RecordingHealthStatus.recordingComplete,
      );

  List<String> failureLines() =>
      logLines.where((l) => l.contains('Enqueue failed')).toList();

  group('RID-1: SyncObserver enqueue hardening', () {
    test('enqueue failure is handled and does not escape as an unhandled '
        'async error', () async {
      final outbox = SyncOutbox(prefs);
      final manager = _FailingSyncManager(outbox)..failuresRemaining = 1;
      addTearDown(manager.dispose);
      final observer = SyncObserver(manager);

      final previous = riding(900);
      observer.onRideSessionChanged(previous, finishedOf(previous));
      await pumpEventQueue(times: 20);

      expect(manager.enqueueAttempts, 1);
      expect(outbox.count, 0,
          reason: 'a failed enqueue must not create an outbox item');
      expect(failureLines(), hasLength(1),
          reason: 'failure must be reported, not silently swallowed');
    });

    test('diagnostics carry only the exception class, never its payload',
        () async {
      final outbox = SyncOutbox(prefs);
      final manager = _FailingSyncManager(outbox)..failuresRemaining = 1;
      addTearDown(manager.dispose);
      final observer = SyncObserver(manager);

      final previous = riding(901);
      observer.onRideSessionChanged(previous, finishedOf(previous));
      await pumpEventQueue(times: 20);

      expect(failureLines().single, contains('StateError'));
      expect(logLines.join('\n'),
          isNot(contains(_FailingSyncManager.secretPayload)),
          reason: 'no token/secret/data may leak into diagnostics');
    });

    test('repeat completion notifications keep enqueue and logging bounded '
        'to one', () async {
      final outbox = SyncOutbox(prefs);
      final manager = _FailingSyncManager(outbox)..failuresRemaining = 5;
      addTearDown(manager.dispose);
      final observer = SyncObserver(manager);

      final previous = riding(902);
      final completed = finishedOf(previous);
      observer.onRideSessionChanged(previous, completed);
      observer.onRideSessionChanged(previous, completed);
      observer.onRideSessionChanged(completed, completed);
      await pumpEventQueue(times: 20);

      expect(manager.enqueueAttempts, 1,
          reason: 'no duplicate enqueue behaviour introduced');
      expect(failureLines(), hasLength(1), reason: 'bounded error logging');
    });

    test('a later legitimate completion still enqueues after a failure',
        () async {
      final outbox = SyncOutbox(prefs);
      final manager = _FailingSyncManager(outbox)..failuresRemaining = 1;
      addTearDown(manager.dispose);
      final observer = SyncObserver(manager);

      final failed = riding(903);
      observer.onRideSessionChanged(failed, finishedOf(failed));
      await pumpEventQueue(times: 20);
      expect(outbox.count, 0);

      final later = riding(904);
      observer.onRideSessionChanged(later, finishedOf(later));
      await pumpEventQueue(times: 20);

      expect(manager.enqueueAttempts, 2);
      expect(outbox.getItem(904, 'fake'), isNotNull,
          reason: 'the observer must stay functional after a handled failure');
      // Durable persistence is what the outbox guarantees. The item is
      // subsequently marked failed by processQueue() because this unit
      // registers no 'fake' provider - that is existing SyncManager behaviour
      // and outside RID-1 scope, so only durable presence is asserted here.
      expect(prefs.getString(outbox.storageKey), contains('"localRideId":904'),
          reason: 'the recovered enqueue must reach durable storage');
    });

    test('successful enqueue remains observable synchronously', () {
      // Existing contract relied on by cloud_sync_hardening_test.dart, which
      // asserts outbox.count without awaiting. The RID-1 wrapper must not
      // delay the callee's synchronous prefix.
      final outbox = SyncOutbox(prefs);
      final manager = SyncManager(outbox);
      addTearDown(manager.dispose);
      final observer = SyncObserver(manager);

      final previous = riding(905);
      observer.onRideSessionChanged(previous, finishedOf(previous));

      expect(outbox.count, equals(1));

      observer.onRideSessionChanged(previous, finishedOf(previous));
      expect(outbox.count, equals(1));
    });
  });
}