import 'dart:async';

import 'package:commons_core/commons_core.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:tane/db/enums.dart';
import 'package:tane/services/offer_mapper.dart';
import 'package:tane/state/offers_cubit.dart';

/// In-memory [OfferTransport] for tests: addressable by id, discover matches by
/// geohash prefix. No relay, no network.
class FakeOfferTransport implements OfferTransport {
  final List<Offer> _offers = [];

  @override
  Future<PublishResult> publish(Offer offer) async {
    _offers.removeWhere((o) => o.id == offer.id);
    _offers.add(offer);
    return PublishResult(accepted: true, transportRef: offer.id);
  }

  @override
  Stream<Offer> discover(DiscoveryQuery query) {
    final controller = StreamController<Offer>();
    for (final o in _offers) {
      if (o.approxGeohash.startsWith(query.geohashPrefix)) controller.add(o);
    }
    return controller.stream; // left open (live), like a real subscription
  }

  @override
  Future<void> retract(String offerId) async =>
      _offers.removeWhere((o) => o.id == offerId);

  @override
  Future<void> close() async {}
}

void main() {
  group('OfferMapper', () {
    test('maps local sharing intent to the network offer type', () {
      expect(OfferMapper.offerTypeFor(OfferStatus.shared), OfferType.gift);
      expect(OfferMapper.offerTypeFor(OfferStatus.exchange), OfferType.exchange);
      expect(OfferMapper.offerTypeFor(OfferStatus.sell), OfferType.sale);
    });

    test('never publishes a private lot', () {
      expect(() => OfferMapper.offerTypeFor(OfferStatus.private),
          throwsArgumentError);
    });

    test('builds an offer, keeping price only for a sale', () {
      final gift = OfferMapper.fromSharedLot(
        lotId: 'lot-1',
        authorPubkeyHex: 'ab' * 32,
        summary: 'Tomate rosa',
        sharing: OfferStatus.shared,
        areaGeohash: 'sp3e9',
        priceAmount: 5, // should be dropped for a gift
      );
      expect(gift.type, OfferType.gift);
      expect(gift.id, 'lot-1');
      expect(gift.priceAmount, isNull);

      final sale = OfferMapper.fromSharedLot(
        lotId: 'lot-2',
        authorPubkeyHex: 'ab' * 32,
        summary: 'Judía',
        sharing: OfferStatus.sell,
        areaGeohash: 'sp3e9',
        priceAmount: 3,
        priceCurrency: 'G1',
      );
      expect(sale.type, OfferType.sale);
      expect(sale.priceAmount, 3);
      expect(sale.priceCurrency, 'G1');
    });
  });

  group('OffersCubit', () {
    test('discovers published offers by geohash prefix', () async {
      final transport = FakeOfferTransport();
      await transport.publish(OfferMapper.fromSharedLot(
        lotId: 'lot-1',
        authorPubkeyHex: 'ab' * 32,
        summary: 'Tomate rosa de Barbastro',
        sharing: OfferStatus.shared,
        areaGeohash: 'sp3e9',
      ));
      final cubit = OffersCubit(transport);

      await cubit.discover('sp3');
      await pumpEventQueue();

      expect(cubit.state.hasSearched, isTrue);
      expect(cubit.state.searching, isFalse);
      expect(cubit.state.offers, hasLength(1));
      expect(cubit.state.offers.single.summary, 'Tomate rosa de Barbastro');
      await cubit.close();
    });

    test('a different area finds nothing', () async {
      final transport = FakeOfferTransport();
      await transport.publish(OfferMapper.fromSharedLot(
        lotId: 'lot-1',
        authorPubkeyHex: 'ab' * 32,
        summary: 'Pimiento',
        sharing: OfferStatus.shared,
        areaGeohash: 'sp3e9',
      ));
      final cubit = OffersCubit(transport);
      await cubit.discover('u09');
      await pumpEventQueue();
      expect(cubit.state.offers, isEmpty);
      await cubit.close();
    });

    test('publish reports the transport verdict', () async {
      final cubit = OffersCubit(FakeOfferTransport());
      final result = await cubit.publish(OfferMapper.fromSharedLot(
        lotId: 'lot-9',
        authorPubkeyHex: 'ab' * 32,
        summary: 'Calabaza',
        sharing: OfferStatus.exchange,
        areaGeohash: 'sp3e9',
        exchangeTerms: 'a cambio de legumbre',
      ));
      expect(result.accepted, isTrue);
      expect(cubit.state.publishing, isFalse);
      await cubit.close();
    });

    test('offline (no transport): degrades gracefully, never throws', () async {
      final cubit = OffersCubit(null);
      expect(cubit.isOnline, isFalse);
      await cubit.discover('sp3');
      expect(cubit.state.error, 'offline');
      final result = await cubit.publish(OfferMapper.fromSharedLot(
        lotId: 'x',
        authorPubkeyHex: 'ab' * 32,
        summary: 'x',
        sharing: OfferStatus.shared,
        areaGeohash: 'sp3e9',
      ));
      expect(result.accepted, isFalse);
      await cubit.close();
    });
  });
}