import 'dart:convert';

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:miler/data/api_config.dart';
import 'package:miler/data/consignment_state.dart';
import 'package:miler/data/miler_api.dart';
import 'package:miler/data/mock_backend.dart';
import 'package:miler/data/service_profile.dart';
import 'package:miler/views/Dashboard/pickups/pickups.dart';

/// ─────────────────────────────────────────────────────────────────────────
/// TWO BACKENDS, ONE BUILD
///
/// `Collected_By_Miler` and `start-delivery` ship behind a server-side flag
/// that is **off in production today**, so both lifecycles are live at once:
///
///   old  `pickup-complete` releases hyperlocal work itself. The consignment
///        is already `Out_for_Delivery` when it reaches the Deliveries tab and
///        there is nothing for **Start delivery** to call.
///   new  the pivot stops at `Collected_By_Miler` and the press is what puts
///        the load on the road.
///
/// The app must be right in both **without mirroring the flag**, because a
/// mirrored flag is a second source of truth that can be wrong — and would be
/// wrong for every rider for however long it took to ship an app release after
/// the server toggled. So the behaviour is inferred from what the data says:
/// `consignmentstatus` on the row, then the consignment itself, then the
/// `can_start_delivery` / `can_deliver` permissions.
///
/// These pin both modes, and pin that the old one costs no request.
/// ─────────────────────────────────────────────────────────────────────────
void main() {
  TestWidgetsFlutterBinding.ensureInitialized();

  late List<http.Request> sent;

  http.Response jsonRes(Object body, [int code = 200]) => http.Response(
    json.encode(body),
    code,
    headers: const {'content-type': 'application/json'},
  );

  void stubRoutes(Map<String, http.Response> routes) {
    sent = <http.Request>[];
    MilerApi.client = MockClient((req) async {
      sent.add(req);
      for (final e in routes.entries) {
        if (req.url.path.endsWith(e.key)) return e.value;
      }
      return jsonRes({'success': true});
    });
  }

  setUp(() async {
    MockBackend.enabled = false;
    SharedPreferences.setMockInitialValues({
      'userid': 38,
      'authtoken': 'test-token',
    });
    await ApiConfig.setToken('test-token');
    ServiceProfile.setActive(ServiceProfile.milkMan);
    stubRoutes(const {});
  });

  tearDown(() {
    MilerApi.client = http.Client();
    MockBackend.enabled = kMockBackend;
    ServiceProfile.setActive(ServiceProfile.parcel);
  });

  Map<String, dynamic> stop({String? consignmentStatus}) => {
    'orderid': 'ORDER-1',
    'pickupid': 75,
    'consignmentid': 46,
    if (consignmentStatus != null) 'consignmentstatus': consignmentStatus,
    'orderstatus': 'picked',
  };

  group('old backend — the pivot already released the load', () {
    test('the press costs no request at all', () async {
      stubRoutes(const {});
      final released = await releaseForDelivery(
        stop(consignmentStatus: 'Out_for_Delivery'),
      );

      expect(released, isTrue);
      expect(
        sent,
        isEmpty,
        reason:
            'a start-delivery the server can only refuse is not a harmless '
            'no-op — it is a 4xx per rider press in the backend\'s log',
      );
    });

    test('a stop already delivered elsewhere is not re-released', () async {
      stubRoutes(const {});
      expect(
        await releaseForDelivery(stop(consignmentStatus: 'Delivered')),
        isTrue,
      );
      expect(sent, isEmpty);
    });
  });

  group('new backend — the rider makes the release', () {
    test('a collected consignment is started on the server', () async {
      stubRoutes({
        '/start-delivery': jsonRes({
          'success': true,
          'data': {'status': 'Out_for_Delivery'},
        }),
      });

      expect(
        await releaseForDelivery(stop(consignmentStatus: 'Collected_By_Miler')),
        isTrue,
      );
      expect(sent.single.method, 'POST');
      expect(
        sent.single.url.path.endsWith('/miler/consignments/46/start-delivery'),
        isTrue,
      );
      expect(sent.single.headers['Idempotency-Key'], isNotNull);
    });

    test('a refusal is answered by the consignment, not assumed', () async {
      // `INVALID_STATE` means "not Collected_By_Miler" — which covers both a
      // real refusal and a consignment another device already released.
      stubRoutes({
        '/start-delivery': jsonRes({
          'success': false,
          'code': 'INVALID_STATE',
          'message': 'consignment is not collected',
        }, 400),
        '/miler/consignments/46': jsonRes({
          'success': true,
          'data': {'status': 'Out_for_Delivery'},
        }),
      });

      expect(
        await releaseForDelivery(stop(consignmentStatus: 'Collected_By_Miler')),
        isTrue,
        reason: 'already on the road is not a reason to block the rider',
      );
    });

    test('a genuine refusal does not fake a release', () async {
      stubRoutes({
        '/start-delivery': jsonRes({
          'success': false,
          'code': 'INVALID_STATE',
          'message': 'consignment is at the hub',
        }, 400),
        '/miler/consignments/46': jsonRes({
          'success': true,
          'data': {'status': 'Inwarded_at_Hub'},
        }),
      });

      expect(
        await releaseForDelivery(stop(consignmentStatus: 'Collected_By_Miler')),
        isFalse,
        reason:
            'showing ACTIVE for a consignment the hub still holds is the '
            'fiction that made deliver fail at the door with nothing on '
            'screen to explain it',
      );
    });
  });

  group('a row that says nothing falls back to asking', () {
    test('the consignment is read when the row carries no status', () async {
      stubRoutes({
        '/miler/consignments/46': jsonRes({
          'success': true,
          'data': {'status': 'Out_for_Delivery'},
        }),
      });

      expect(await releaseForDelivery(stop()), isTrue);
      expect(sent.single.method, 'GET');
      expect(sent.single.url.path.endsWith('/miler/consignments/46'), isTrue);
    });

    test('the permission flags answer when the word does not', () {
      // A status this build has never heard of, plus the server's own verdict
      // on what may be done with it.
      expect(
        ConsignmentGate.stateFromDetailForTest({
          'status': 'Handed_To_Locker_Bank',
          'can_deliver': true,
        }),
        ConsignmentState.outForDelivery,
      );
      expect(
        ConsignmentGate.stateFromDetailForTest({
          'status': 'Awaiting_Rider_Departure',
          'can_start_delivery': true,
        }),
        ConsignmentState.collectedByMiler,
      );
    });

    test('no consignment id is not a release', () async {
      expect(await releaseForDelivery({'orderid': 'ORDER-9'}), isFalse);
    });
  });

  group('a skipped stop and the server agree about whether it is open', () {
    test('a consignment the hub still calls out-for-delivery stays open', () {
      expect(ConsignmentState.outForDelivery.isOpenAfterSkip, isTrue);
      expect(ConsignmentState.collectedByMiler.isOpenAfterSkip, isTrue);
    });

    test('a consignment the hub closed is closed', () {
      expect(ConsignmentState.delivered.isOpenAfterSkip, isFalse);
      expect(ConsignmentState.rtoInitiated.isOpenAfterSkip, isFalse);
      expect(ConsignmentState.returnedToSender.isOpenAfterSkip, isFalse);
      expect(ConsignmentState.cancelled.isOpenAfterSkip, isFalse);
    });

    test('a read that failed is not permission to close a stop', () {
      expect(
        ConsignmentState.unknown.isOpenAfterSkip,
        isTrue,
        reason:
            'a terminal local record over a consignment the hub still '
            'calls open is two systems disagreeing about whose problem a '
            'parcel is, with only the rider\'s screen saying "nobody\'s"',
      );
    });
  });
}