import 'dart:async';

import 'package:fluffychat/pangea/analytics_data/analytics_data_service.dart';
import 'package:fluffychat/pangea/analytics_data/analytics_update_events.dart';
import 'package:fluffychat/pangea/analytics_misc/constructs_event.dart';
import 'package:fluffychat/pangea/analytics_misc/constructs_model.dart';
import 'package:fluffychat/pangea/constructs/construct_identifier.dart';
import 'package:fluffychat/pangea/constructs/construct_level_enum.dart';
import 'package:fluffychat/pangea/lemmas/user_set_lemma_info.dart';

class LevelUpdate {
  final int prevLevel;
  final int newLevel;

  LevelUpdate({required this.prevLevel, required this.newLevel});
}

class AnalyticsUpdate {
  final List<OneConstructUse> addedConstructs;
  final String? targetID;

  AnalyticsUpdate(this.addedConstructs, {this.targetID});
}

class ConstructLevelUpdate {
  final ConstructIdentifier constructId;
  final ConstructLevelEnum level;
  final String? targetID;

  ConstructLevelUpdate({
    required this.constructId,
    required this.level,
    this.targetID,
  });
}

class AnalyticsUpdateDispatcher {
  final AnalyticsDataService dataService;

  final StreamController<AnalyticsStreamUpdate> constructUpdateStream =
      StreamController<AnalyticsStreamUpdate>.broadcast();

  final StreamController<String?> activityAnalyticsStream =
      StreamController<String?>.broadcast();

  final StreamController<Set<ConstructIdentifier>> unlockedConstructsStream =
      StreamController<Set<ConstructIdentifier>>.broadcast();

  final StreamController<LevelUpdate> levelUpdateStream =
      StreamController<LevelUpdate>.broadcast();

  final StreamController<Set<ConstructIdentifier>> newConstructsStream =
      StreamController<Set<ConstructIdentifier>>.broadcast();

  final StreamController<ConstructLevelUpdate> constructLevelUpdateStream =
      StreamController<ConstructLevelUpdate>.broadcast();

  final StreamController<MapEntry<ConstructIdentifier, UserSetLemmaInfo>>
  _lemmaInfoUpdateStream =
      StreamController<
        MapEntry<ConstructIdentifier, UserSetLemmaInfo>
      >.broadcast();

  AnalyticsUpdateDispatcher(this.dataService);

  void dispose() {
    constructUpdateStream.close();
    activityAnalyticsStream.close();
    unlockedConstructsStream.close();
    levelUpdateStream.close();
    constructLevelUpdateStream.close();
    _lemmaInfoUpdateStream.close();
  }

  Stream<UserSetLemmaInfo> lemmaUpdateStream(ConstructIdentifier constructId) =>
      _lemmaInfoUpdateStream.stream
          .where((update) => update.key == constructId)
          .map((update) => update.value);

  void sendActivityAnalyticsUpdate(String? activityAnalytics) =>
      activityAnalyticsStream.add(activityAnalytics);

  void sendLemmaInfoUpdate(
    ConstructIdentifier constructId,
    UserSetLemmaInfo lemmaInfo,
  ) => _lemmaInfoUpdateStream.add(MapEntry(constructId, lemmaInfo));

  Future<void> sendBlockedConstructsUpdate(
    Set<ConstructIdentifier> blockedConstructs,
    String language,
  ) async {
    for (final blockedConstruct in blockedConstructs) {
      await dataService.updateBlockedConstructs(blockedConstruct, language);
    }
    final update = AnalyticsStreamUpdate(blockedConstructs: blockedConstructs);
    constructUpdateStream.add(update);
  }

  void sendEmptyAnalyticsUpdate() {
    constructUpdateStream.add(AnalyticsStreamUpdate());
  }

  Future<void> sendServerAnalyticsUpdate(
    List<ConstructAnalyticsEvent> events,
    String language,
  ) async {
    await dataService.updateServerAnalytics(events, language);
    sendEmptyAnalyticsUpdate();
  }

  Future<void> sendLocalAnalyticsUpdate(
    AnalyticsUpdate analyticsUpdate,
    String language,
  ) async {
    final events = await dataService.updateLocalAnalytics(
      analyticsUpdate,
      language,
    );
    for (final event in events) {
      _dispatch(event);
    }
  }

  void _dispatch(AnalyticsUpdateEvent event) {
    switch (event) {
      case final LevelUpEvent e:
        _onLevelUp(e.from, e.to);
        break;
      case final MorphUnlockedEvent e:
        _onUnlockMorphLemmas(e.unlocked);
        break;
      case final XPGainedEvent e:
        _onXPGained(e.points, e.targetID);
        break;
      case final ConstructLevelUpEvent e:
        _onConstructLevelUp(e.constructId, e.level, e.targetID);
        break;
      case final NewConstructsEvent e:
        _onNewConstruct(e.newConstructs);
        break;
    }
  }

  void _onLevelUp(final int lowerLevel, final int upperLevel) {
    levelUpdateStream.add(
      LevelUpdate(prevLevel: lowerLevel, newLevel: upperLevel),
    );
  }

  void _onUnlockMorphLemmas(Set<ConstructIdentifier> unlocked) {
    const excludedLemmas = {'not_proper'};

    final filtered = {
      for (final id in unlocked)
        if (!excludedLemmas.contains(id.lemma.toLowerCase())) id,
    };

    if (filtered.isNotEmpty) {
      unlockedConstructsStream.add(filtered);
    }
  }

  void _onXPGained(int points, String? targetID) {
    final update = AnalyticsStreamUpdate(points: points, targetID: targetID);
    constructUpdateStream.add(update);
  }

  void _onConstructLevelUp(
    ConstructIdentifier constructId,
    ConstructLevelEnum level,
    String? targetID,
  ) {
    constructLevelUpdateStream.add(
      ConstructLevelUpdate(
        constructId: constructId,
        level: level,
        targetID: targetID,
      ),
    );
  }

  void _onNewConstruct(Set<ConstructIdentifier> constructIds) {
    if (constructIds.isEmpty) return;
    newConstructsStream.add(constructIds);
  }
}