import 'dart:io';

import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:nuvolari/core/region/geo.dart';
import 'package:nuvolari/core/region/region_config.dart';
import 'package:nuvolari/core/region/region_repository.dart';
import 'package:nuvolari/features/places/places_repository.dart';
import 'package:nuvolari/features/places/saved_place.dart';
import 'package:nuvolari/features/places/saved_places.dart';

/// Inside the Piedmont bounding box.
const torino = GeoPoint(7.686, 45.070);
const cuneo = GeoPoint(7.549, 44.393);

/// Well outside it.
const roma = GeoPoint(12.496, 41.902);

RegionConfig loadPiemonte() =>
    RegionConfig.parse(File('assets/regions/piemonte.json').readAsStringSync());

({ProviderContainer container, InMemoryPlacesStore store}) harness(
  RegionConfig region, {
  List<SavedPlace>? initial,
}) {
  final store = InMemoryPlacesStore(initial);
  final container = ProviderContainer(
    overrides: [
      regionConfigProvider.overrideWith((ref) async => region),
      placesStoreProvider.overrideWithValue(store),
    ],
  );
  addTearDown(container.dispose);
  return (container: container, store: store);
}

Future<List<SavedPlace>> settled(ProviderContainer container) =>
    container.read(savedPlacesProvider.future);

void main() {
  late RegionConfig region;

  setUpAll(() {
    region = loadPiemonte();
  });

  group('SavedPlace serialisation', () {
    test('round-trips through JSON', () {
      final place = SavedPlace(
        id: 'p1',
        name: 'Casa',
        point: torino,
        createdAt: DateTime.utc(2026, 3, 4, 10),
      );

      expect(SavedPlace.fromJson(place.toJson()), place);
    });

    test('rejects a malformed document', () {
      expect(
        () => SavedPlace.fromJson(<String, Object?>{'id': 'p1'}),
        throwsFormatException,
      );
      expect(
        () => SavedPlace.fromJson(<String, Object?>{
          'id': '',
          'name': 'Casa',
          'lat': 45.0,
          'lng': 7.0,
          'createdAt': 0,
        }),
        throwsFormatException,
      );
    });
  });

  group('adding a place', () {
    test('saves it and puts it first', () async {
      final h = harness(region);
      await settled(h.container);
      final notifier = h.container.read(savedPlacesProvider.notifier);

      await notifier.add(name: 'Casa', point: torino);
      await notifier.add(name: 'Lavoro', point: cuneo);

      final places = h.container.read(savedPlacesProvider).value!;
      expect(places.map((p) => p.name), orderedEquals(['Lavoro', 'Casa']));
    });

    test('persists to the store', () async {
      final h = harness(region);
      await settled(h.container);

      await h.container
          .read(savedPlacesProvider.notifier)
          .add(name: 'Casa', point: torino);

      expect(await h.store.load(), hasLength(1));
      expect((await h.store.load()).single.name, 'Casa');
    });

    test('trims the name', () async {
      final h = harness(region);
      await settled(h.container);

      final place = await h.container
          .read(savedPlacesProvider.notifier)
          .add(name: '  Casa  ', point: torino);

      expect(place.name, 'Casa');
    });

    test('rejects a blank name', () async {
      final h = harness(region);
      await settled(h.container);

      await expectLater(
        h.container
            .read(savedPlacesProvider.notifier)
            .add(name: '   ', point: torino),
        throwsA(
          isA<SavedPlaceException>().having(
            (e) => e.rejection,
            'rejection',
            SavedPlaceRejection.emptyName,
          ),
        ),
      );
    });

    test('rejects a name past the limit', () async {
      final h = harness(region);
      await settled(h.container);

      await expectLater(
        h.container
            .read(savedPlacesProvider.notifier)
            .add(name: 'x' * (SavedPlace.maxNameLength + 1), point: torino),
        throwsA(
          isA<SavedPlaceException>().having(
            (e) => e.rejection,
            'rejection',
            SavedPlaceRejection.nameTooLong,
          ),
        ),
      );
    });

    test('rejects a duplicate name regardless of case', () async {
      final h = harness(region);
      await settled(h.container);
      final notifier = h.container.read(savedPlacesProvider.notifier);
      await notifier.add(name: 'Casa', point: torino);

      await expectLater(
        notifier.add(name: 'casa', point: cuneo),
        throwsA(
          isA<SavedPlaceException>().having(
            (e) => e.rejection,
            'rejection',
            SavedPlaceRejection.duplicateName,
          ),
        ),
      );
    });

    // Saving a place the app has no data for would look like it worked and then
    // show nothing forever. Better to refuse while the user still knows what
    // they were trying to do.
    test('rejects a point outside the region', () async {
      final h = harness(region);
      await settled(h.container);

      await expectLater(
        h.container
            .read(savedPlacesProvider.notifier)
            .add(name: 'Roma', point: roma),
        throwsA(
          isA<SavedPlaceException>().having(
            (e) => e.rejection,
            'rejection',
            SavedPlaceRejection.outsideRegion,
          ),
        ),
      );
      expect(h.container.read(savedPlacesProvider).value, isEmpty);
    });

    test('stops at the limit', () async {
      final h = harness(region);
      await settled(h.container);
      final notifier = h.container.read(savedPlacesProvider.notifier);

      for (var i = 0; i < SavedPlaces.maxPlaces + 5; i++) {
        await notifier.add(name: 'Posto $i', point: torino);
      }

      expect(
        h.container.read(savedPlacesProvider).value,
        hasLength(SavedPlaces.maxPlaces),
      );
    });
  });

  group('identity', () {
    // Ids used to come straight from the microsecond clock, so two places saved
    // in the same microsecond collided and rename, remove and the duplicate
    // check all acted on the wrong place.
    test('rapid adds get distinct ids', () async {
      final h = harness(region);
      await settled(h.container);
      final notifier = h.container.read(savedPlacesProvider.notifier);

      for (var i = 0; i < 10; i++) {
        await notifier.add(name: 'Posto $i', point: torino);
      }

      final ids = h.container
          .read(savedPlacesProvider)
          .value!
          .map((place) => place.id)
          .toSet();
      expect(ids, hasLength(10));
    });
  });

  group('renaming and removing', () {
    test('rename changes only the name', () async {
      final h = harness(region);
      await settled(h.container);
      final notifier = h.container.read(savedPlacesProvider.notifier);
      final place = await notifier.add(name: 'Casa', point: torino);

      await notifier.rename(place.id, 'Casa nuova');

      final updated = h.container.read(savedPlacesProvider).value!.single;
      expect(updated.name, 'Casa nuova');
      expect(updated.id, place.id);
      expect(updated.point, torino);
      expect(updated.createdAt, place.createdAt);
    });

    test('rename rejects a name another place already uses', () async {
      final h = harness(region);
      await settled(h.container);
      final notifier = h.container.read(savedPlacesProvider.notifier);
      await notifier.add(name: 'Casa', point: torino);
      final second = await notifier.add(name: 'Lavoro', point: cuneo);

      await expectLater(
        notifier.rename(second.id, 'Casa'),
        throwsA(isA<SavedPlaceException>()),
      );
    });

    test('rename to its own name is allowed', () async {
      final h = harness(region);
      await settled(h.container);
      final notifier = h.container.read(savedPlacesProvider.notifier);
      final place = await notifier.add(name: 'Casa', point: torino);

      await notifier.rename(place.id, 'Casa');

      expect(h.container.read(savedPlacesProvider).value!.single.name, 'Casa');
    });

    test('remove deletes it from state and from the store', () async {
      final h = harness(region);
      await settled(h.container);
      final notifier = h.container.read(savedPlacesProvider.notifier);
      final place = await notifier.add(name: 'Casa', point: torino);

      await notifier.remove(place.id);

      expect(h.container.read(savedPlacesProvider).value, isEmpty);
      expect(await h.store.load(), isEmpty);
    });

    test('removing an unknown id changes nothing', () async {
      final h = harness(region);
      await settled(h.container);
      final notifier = h.container.read(savedPlacesProvider.notifier);
      await notifier.add(name: 'Casa', point: torino);

      await notifier.remove('does-not-exist');

      expect(h.container.read(savedPlacesProvider).value, hasLength(1));
    });
  });

  group('loading', () {
    test('reads what the store already held', () async {
      final existing = SavedPlace(
        id: 'p1',
        name: 'Casa',
        point: torino,
        createdAt: DateTime.utc(2026),
      );
      final h = harness(region, initial: [existing]);

      expect(await settled(h.container), <SavedPlace>[existing]);
    });
  });

  group('byDistanceFrom', () {
    test('orders nearest first', () {
      final near = SavedPlace(
        id: 'a',
        name: 'Vicino',
        point: torino,
        createdAt: DateTime.utc(2026),
      );
      final far = SavedPlace(
        id: 'b',
        name: 'Lontano',
        point: cuneo,
        createdAt: DateTime.utc(2026),
      );

      final ordered = byDistanceFrom(torino, <SavedPlace>[far, near]);

      expect(ordered.map((p) => p.id), orderedEquals(['a', 'b']));
    });
  });
}