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/miler_api.dart';
import 'package:miler/data/mock_backend.dart';
import 'package:miler/data/service_profile.dart';
import 'package:miler/data/work_repository.dart';
import 'package:miler/providers/pickup/pickup_provider.dart';

/// ─────────────────────────────────────────────────────────────────────────
/// FOUR SCREENS, ONE REQUEST
///
/// Home, Bookings, Activity and the post-delivery screen all read the day, and
/// each produced its own `GET /miler/bookings` — on mount, on tab switch, and
/// on every poll. Four timers, four copies, four ideas of what had been
/// accepted, reconciled only by whichever refreshed last.
///
/// The provider still returns a list or throws, which is what every call site
/// was written against. What changed is that they now share one request.
/// ─────────────────────────────────────────────────────────────────────────
void main() {
  TestWidgetsFlutterBinding.ensureInitialized();

  late int requests;
  final provider = PickupProvider();

  void stub({List<Map<String, dynamic>> rows = const [], int code = 200}) {
    requests = 0;
    MilerApi.client = MockClient((req) async {
      // The repository also reads `/miler/assignments` for the hub's stop
      // sequence; it is not the day's request and is not counted. See the same
      // note in `work_repository_test.dart`.
      if (req.url.path.endsWith('/miler/assignments')) {
        return http.Response(
          json.encode({'success': true, 'data': const []}),
          200,
          headers: const {'content-type': 'application/json'},
        );
      }
      requests++;
      return http.Response(
        json.encode({'success': code < 400, 'data': rows}),
        code,
        headers: const {'content-type': 'application/json'},
      );
    });
  }

  Map<String, dynamic> booking(String id) => {
    'bookingid': id,
    'orderid': id,
    'pickupcustomer': 'Stop $id',
    'pickupaddress': '12 Main Rd',
    'status': 'Miler_Assigned',
  };

  setUp(() async {
    MockBackend.enabled = false;
    ServiceProfile.setActive(ServiceProfile.parcel);
    SharedPreferences.setMockInitialValues({'authtoken': 't'});
    await ApiConfig.setToken('t');
    WorkRepository.instance.resetForTest();
    stub(rows: [booking('A')]);
  });

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

  test('the three screen entry points share one request', () async {
    final results = await Future.wait([
      provider.getPickupQueues(),
      provider.getCurrentPickups(),
      provider.getPickupQueuesPicked(),
    ]);

    expect(requests, 1, reason: 'three screens, one GET /miler/bookings');
    for (final r in results) {
      expect(r, hasLength(1));
    }
  });

  test('a tab switch moments later does not re-fetch', () async {
    await provider.getCurrentPickups();
    await provider.getPickupQueuesPicked();
    expect(requests, 1);
  });

  test(
    'every caller gets the same objects, so no screen has its own copy',
    () async {
      final a = await provider.getCurrentPickups();
      final b = await provider.getPickupQueuesPicked();
      expect(identical(a, b), isTrue);
    },
  );

  test('an empty day is an empty list, not an error', () async {
    stub(rows: const []);
    expect(await provider.getCurrentPickups(), isEmpty);
  });

  // ── The milk-man line is dispatched, not written off ──
  //
  // This expected a [LineNotServedException] after zero requests, on the belief
  // that the backend had no endpoint for that line. It has the same one: the
  // console assigns the round on /admin/bookings and the rider reads it back
  // from /miler/bookings. While the two disagreed, a rider on tenant 13 with a
  // booking assigned to him got an empty screen and no error to explain it.
  test('a milk-man rider is asked for, not refused', () async {
    stub(rows: [booking('MILK-1')]);
    ServiceProfile.setActive(ServiceProfile.milkMan);
    WorkRepository.instance.resetForTest();

    final day = await provider.getCurrentPickups();
    expect(day, hasLength(1));
    expect(requests, 1, reason: 'his work has to be asked for to arrive');
  });

  test('a server failure throws rather than reading as an empty day', () async {
    stub(code: 500);
    await expectLater(provider.getCurrentPickups(), throwsA(isA<Exception>()));
  });

  // A filtered read is a different question and must not be served the shared
  // copy of the whole day.
  test('a status-filtered read gets its own request', () async {
    await provider.getCurrentPickups();
    await provider.getPickupQueues(orderstatus: 'Picked_Up');
    expect(requests, 2);
  });
}