import 'dart:async';
import 'dart:math' as math;
import 'package:cloud_firestore/cloud_firestore.dart';
import '../../database/database.dart';
import '../map/map_provider_interface.dart';
import 'social_feed_models.dart';

class SocialFeedService {
  final FirebaseFirestore? firestore;
  final StreamController<List<SocialFeedItem>> _localFeedController =
      StreamController<List<SocialFeedItem>>.broadcast();

  List<SocialFeedItem> _memoryFeed = [];
  bool _initialized = false;
  StreamSubscription? _firestoreSub;

  SocialFeedService({this.firestore}) {
    _initFeed();
  }

  void _initFeed() {
    if (_initialized) return;
    _initialized = true;

    final fs = firestore;
    if (fs != null) {
      _memoryFeed = [];
      _firestoreSub = fs
          .collection('social_feed')
          .orderBy('timestamp', descending: true)
          .limit(50)
          .snapshots()
          .listen((snapshot) {
        final realItems = snapshot.docs.map((doc) {
          final data = doc.data();
          return SocialFeedItem.fromJson({...data, 'id': doc.id, 'isDemo': false});
        }).toList();

        _memoryFeed = realItems;
        _localFeedController.add(List.unmodifiable(_memoryFeed));
      }, onError: (_) {});
      return;
    }

    // Populate with Stitch SOC-01 canonical community items (flagged as demo sample)
    _memoryFeed = [
      SocialFeedItem(
        id: 'feed_post_1',
        authorUid: 'uid_marcus',
        authorDisplayName: 'Marcus Vance',
        authorHandle: 'ApexMarcus',
        authorAvatarPreset: 'helmet_carbon_cyan',
        authorBadge: 'PRO',
        clubName: 'Bay Area Twisties Club',
        locationName: "Alice's Restaurant",
        timestamp: DateTime.now().subtract(const Duration(minutes: 28)),
        rideTitle: 'Sunday Skyline & Pescadero Carve',
        bikeModel: '2024 Ducati Streetfighter V4',
        distanceMiles: 68.4,
        durationSeconds: 4440, // 1h 14m
        maxLeanAngleDeg: 51.0,
        maxLeanSide: 'RIGHT',
        paceFactor: '1.32x Spirited',
        hazardCount: 0,
        elevationFt: 2140,
        discipline: RidingDiscipline.canyonSport,
        regionName: 'Bay Area, CA',
        isFeatured: true,
        snapshotType: FeedSnapshotType.routeTrack,
        isGpsVerified: false,
        isDemo: true,
        fistBumpCount: 42,
        fistBumpUserIds: const ['uid_rider_2', 'uid_rider_3'],
        routePoints: const [
          AppLatLng(37.3861, -122.2641),
          AppLatLng(37.3600, -122.2400),
          AppLatLng(37.3200, -122.2100),
          AppLatLng(37.2800, -122.2400),
          AppLatLng(37.2500, -122.1800),
        ],
        comments: [
          FeedPostComment(
            id: 'c1',
            authorUid: 'uid_sarah',
            authorDisplayName: 'Sarah Chen',
            authorHandle: 'SarahSweep',
            content: 'Clean line through section 3! Pavement was prime today.',
            createdAt: DateTime.now().subtract(const Duration(minutes: 15)),
          ),
        ],
      ),
      SocialFeedItem(
        id: 'feed_post_2',
        authorUid: 'uid_sarah',
        authorDisplayName: 'Sarah Chen',
        authorHandle: 'SarahSweep',
        authorAvatarPreset: 'helmet_aerodynamic_grey',
        authorBadge: 'ROAD CAPTAIN',
        clubName: 'Pacific Coast Riders',
        locationName: 'Mulholland Hwy',
        timestamp: DateTime.now().subtract(const Duration(hours: 2)),
        rideTitle: 'The Snake & Rock Store Pace Lap',
        bikeModel: 'Yamaha MT-09 SP',
        distanceMiles: 44.2,
        durationSeconds: 2900, // 48m 20s
        maxLeanAngleDeg: 48.0,
        maxLeanSide: 'PEAK',
        paceFactor: '1.25x Swift',
        hazardCount: 0,
        elevationFt: 1850,
        discipline: RidingDiscipline.canyonSport,
        regionName: 'SoCal, CA',
        isFeatured: false,
        snapshotType: FeedSnapshotType.scenicPhoto,
        photoUrl: 'assets/images/rock_store_lookout.png',
        photoCaption: 'Rock Store Lookout',
        isGpsVerified: false,
        isDemo: true,
        fistBumpCount: 28,
        fistBumpUserIds: const ['uid_marcus'],
        comments: const [],
      ),
      SocialFeedItem(
        id: 'feed_post_3',
        authorUid: 'uid_dave',
        authorDisplayName: 'Dave Sterling',
        authorHandle: 'GhostRider99',
        authorAvatarPreset: 'helmet_matte_stealth',
        authorBadge: 'FOUNDER',
        clubName: 'Angeles Crest Squad',
        locationName: 'Newcomb\'s Ranch',
        timestamp: DateTime.now().subtract(const Duration(hours: 5)),
        rideTitle: 'Angeles Crest Mountain Pace Run',
        bikeModel: 'BMW S1000RR M-Sport',
        distanceMiles: 82.0,
        durationSeconds: 5200,
        maxLeanAngleDeg: 53.5,
        maxLeanSide: 'LEFT',
        paceFactor: '1.45x Fast',
        hazardCount: 1,
        elevationFt: 5300,
        discipline: RidingDiscipline.trackDay,
        regionName: 'Angeles Crest, CA',
        isFeatured: true,
        snapshotType: FeedSnapshotType.routeTrack,
        isGpsVerified: false,
        isDemo: true,
        fistBumpCount: 65,
        fistBumpUserIds: const ['uid_marcus', 'uid_sarah'],
        routePoints: const [
          AppLatLng(34.2000, -118.1500),
          AppLatLng(34.2500, -118.0800),
          AppLatLng(34.3300, -118.0000),
        ],
        comments: const [],
      ),
      SocialFeedItem(
        id: 'feed_post_4',
        authorUid: 'uid_alex',
        authorDisplayName: 'Alex Mercer',
        authorHandle: 'TrailScout',
        authorAvatarPreset: 'helmet_carbon_cyan',
        authorBadge: 'ADV LEAD',
        clubName: 'Blue Ridge Trail Explorers',
        locationName: 'Blood Mountain Gap',
        timestamp: DateTime.now().subtract(const Duration(hours: 7)),
        rideTitle: 'Chattahoochee Forest Pass & Water Crossings',
        bikeModel: 'KTM 890 Adventure R',
        distanceMiles: 58.6,
        durationSeconds: 6100,
        maxLeanAngleDeg: 34.0,
        maxLeanSide: 'PEAK',
        paceFactor: '1.15x Trail Pace',
        hazardCount: 2,
        elevationFt: 3420,
        discipline: RidingDiscipline.advDualSport,
        regionName: 'North Georgia, GA',
        isFeatured: true,
        snapshotType: FeedSnapshotType.routeTrack,
        isGpsVerified: false,
        isDemo: true,
        fistBumpCount: 39,
        fistBumpUserIds: const ['uid_marcus'],
        routePoints: const [
          AppLatLng(34.7330, -83.9180),
          AppLatLng(34.7500, -83.9000),
          AppLatLng(34.7800, -83.8800),
        ],
        comments: const [],
      ),
      SocialFeedItem(
        id: 'feed_post_5',
        authorUid: 'uid_ben',
        authorDisplayName: 'Ben Holloway',
        authorHandle: 'IronButtBen',
        authorAvatarPreset: 'helmet_aerodynamic_grey',
        authorBadge: 'TOUR MASTER',
        clubName: 'Smoky Mountain Cruisers',
        locationName: 'Cherohala Skyway Overlook',
        timestamp: DateTime.now().subtract(const Duration(hours: 11)),
        rideTitle: 'Cherohala Skyway Endurance Sweep',
        bikeModel: 'BMW R1250GS Adventure',
        distanceMiles: 148.2,
        durationSeconds: 11200,
        maxLeanAngleDeg: 39.5,
        maxLeanSide: 'RIGHT',
        paceFactor: '1.20x Touring',
        hazardCount: 0,
        elevationFt: 5400,
        discipline: RidingDiscipline.touring,
        regionName: 'Tellico Plains, TN',
        isFeatured: true,
        snapshotType: FeedSnapshotType.routeTrack,
        isGpsVerified: false,
        isDemo: true,
        fistBumpCount: 51,
        fistBumpUserIds: const ['uid_sarah', 'uid_alex'],
        routePoints: const [
          AppLatLng(35.3500, -84.1500),
          AppLatLng(35.3700, -84.0500),
          AppLatLng(35.3900, -83.9500),
        ],
        comments: const [],
      ),
    ];

    _localFeedController.add(List.unmodifiable(_memoryFeed));
  }

  List<SocialFeedItem> get currentFeed => List.unmodifiable(_memoryFeed);

  List<SocialFeedItem> getFilteredItems({
    FeedFilter filter = FeedFilter.allActivity,
    String? userClubName,
    RidingDiscipline discipline = RidingDiscipline.all,
    String? searchQuery,
    double? minDistanceMiles,
    bool? verifiedGpsOnly,
    String? userUid,
    List<String>? followingUids,
  }) {
    return _filterItems(
      _memoryFeed,
      filter,
      userClubName,
      discipline: discipline,
      searchQuery: searchQuery,
      minDistanceMiles: minDistanceMiles,
      verifiedGpsOnly: verifiedGpsOnly,
      userUid: userUid,
      followingUids: followingUids,
    );
  }

  Stream<List<SocialFeedItem>> getFeedStream({
    FeedFilter filter = FeedFilter.allActivity,
    String? userClubName,
    RidingDiscipline discipline = RidingDiscipline.all,
    String? searchQuery,
    double? minDistanceMiles,
    bool? verifiedGpsOnly,
    String? userUid,
    List<String>? followingUids,
  }) {
    late StreamController<List<SocialFeedItem>> controller;
    StreamSubscription<List<SocialFeedItem>>? sub;

    List<SocialFeedItem> filterCurrent(List<SocialFeedItem> list) {
      return _filterItems(
        list,
        filter,
        userClubName,
        discipline: discipline,
        searchQuery: searchQuery,
        minDistanceMiles: minDistanceMiles,
        verifiedGpsOnly: verifiedGpsOnly,
        userUid: userUid,
        followingUids: followingUids,
      );
    }

    controller = StreamController<List<SocialFeedItem>>(
      onListen: () {
        controller.add(filterCurrent(_memoryFeed));
        sub = _localFeedController.stream.listen((list) {
          if (!controller.isClosed) {
            controller.add(filterCurrent(list));
          }
        });
      },
      onCancel: () {
        sub?.cancel();
      },
    );

    return controller.stream;
  }

  List<SocialFeedItem> _filterItems(
    List<SocialFeedItem> items,
    FeedFilter filter,
    String? userClubName, {
    RidingDiscipline discipline = RidingDiscipline.all,
    String? searchQuery,
    double? minDistanceMiles,
    bool? verifiedGpsOnly,
    String? userUid,
    List<String>? followingUids,
  }) {
    var result = List<SocialFeedItem>.from(items);

    // 1. Primary Stream / Tab Scoping
    switch (filter) {
      case FeedFilter.allActivity:
        break; // All posts
      case FeedFilter.forYou:
        // Featured & high-signal runs: featured, or lean >= 40°, or distance >= 20 mi, or elevation >= 1500, or fist bumps >= 20
        result = result
            .where((i) =>
                i.isFeatured ||
                i.maxLeanAngleDeg >= 40.0 ||
                i.distanceMiles >= 20.0 ||
                i.elevationFt >= 1500 ||
                i.fistBumpCount >= 20)
            .toList();
        break;
      case FeedFilter.clubOnly:
        if (userClubName == null || userClubName.isEmpty) {
          result = result.where((i) => i.clubName != null && i.clubName!.isNotEmpty).toList();
        } else {
          result = result.where((i) => i.clubName?.toLowerCase() == userClubName.toLowerCase()).toList();
        }
        break;
      case FeedFilter.nearbyPacks:
        result = result.where((i) => i.distanceMiles < 60.0).toList();
        break;
      case FeedFilter.following:
        if (followingUids != null && followingUids.isNotEmpty) {
          result = result.where((i) => followingUids.contains(i.authorUid)).toList();
        } else {
          // Fallback to recognized squad/badge riders if user has no following graph yet
          result = result.where((i) => i.authorBadge != null && i.authorBadge!.isNotEmpty).toList();
        }
        break;
    }

    // 2. Discipline / Riding Style Filter
    if (discipline != RidingDiscipline.all) {
      result = result.where((i) => i.discipline == discipline).toList();
    }

    // 3. Search Query Filter (road, canyon, bike, rider)
    if (searchQuery != null && searchQuery.trim().isNotEmpty) {
      final q = searchQuery.trim().toLowerCase();
      result = result.where((i) =>
          i.rideTitle.toLowerCase().contains(q) ||
          i.locationName.toLowerCase().contains(q) ||
          i.bikeModel.toLowerCase().contains(q) ||
          i.authorHandle.toLowerCase().contains(q) ||
          (i.regionName?.toLowerCase().contains(q) ?? false)).toList();
    }

    // 4. Quality Thresholds
    if (minDistanceMiles != null && minDistanceMiles > 0) {
      result = result.where((i) => i.distanceMiles >= minDistanceMiles).toList();
    }
    if (verifiedGpsOnly == true) {
      result = result.where((i) => i.hasVerifiedGps).toList();
    }

    return result;
  }

  /// Toggle fist bump on a post.
  Future<void> toggleFistBump({
    required String postId,
    required String userUid,
  }) async {
    final index = _memoryFeed.indexWhere((p) => p.id == postId);
    if (index == -1) return;

    final post = _memoryFeed[index];
    final isBumped = post.isFistBumpedBy(userUid);
    final updatedList = List<String>.from(post.fistBumpUserIds);
    final updatedCount = isBumped ? post.fistBumpCount - 1 : post.fistBumpCount + 1;

    if (isBumped) {
      updatedList.remove(userUid);
    } else {
      updatedList.add(userUid);
    }

    final updatedPost = post.copyWith(
      fistBumpCount: updatedCount < 0 ? 0 : updatedCount,
      fistBumpUserIds: updatedList,
    );

    _memoryFeed[index] = updatedPost;
    _localFeedController.add(List.unmodifiable(_memoryFeed));

    final fs = firestore;
    if (fs != null) {
      try {
        await fs.collection('social_feed').doc(postId).update({
          'fistBumpCount': updatedPost.fistBumpCount,
          'fistBumpUserIds': updatedPost.fistBumpUserIds,
        });
      } catch (_) {}
    }
  }

  /// Add a comment to a feed post.
  Future<void> addComment({
    required String postId,
    required FeedPostComment comment,
  }) async {
    final index = _memoryFeed.indexWhere((p) => p.id == postId);
    if (index == -1) return;

    final post = _memoryFeed[index];
    final updatedComments = List<FeedPostComment>.from(post.comments)..add(comment);
    final updatedPost = post.copyWith(comments: updatedComments);

    _memoryFeed[index] = updatedPost;
    _localFeedController.add(List.unmodifiable(_memoryFeed));

    final fs = firestore;
    if (fs != null) {
      try {
        await fs.collection('social_feed').doc(postId).update({
          'comments': updatedComments.map((c) => c.toJson()).toList(),
        });
      } catch (_) {}
    }
  }

  /// Share a recent completed ride session to the community feed.
  ///
  /// When [authoritativeRide] is provided, telemetry metrics (distance,
  /// duration, max lean angle, lean side, elevation gain, and ride ID) are
  /// derived strictly from [authoritativeRide] so manual/forged telemetry
  /// overrides cannot be injected at the submission layer.
  Future<SocialFeedItem> shareRecentRide({
    required String authorUid,
    required String authorDisplayName,
    required String authorHandle,
    String? authorAvatarPreset,
    String? authorBadge,
    String? clubName,
    required String locationName,
    required String rideTitle,
    required String bikeModel,
    double distanceMiles = 0.0,
    int durationSeconds = 0,
    double maxLeanAngleDeg = 0.0,
    String maxLeanSide = 'RIGHT',
    String paceFactor = '1.0x Cruiser',
    int hazardCount = 0,
    int elevationFt = 0,
    RidingDiscipline discipline = RidingDiscipline.canyonSport,
    String? regionName,
    bool isFeatured = false,
    FeedSnapshotType snapshotType = FeedSnapshotType.routeTrack,
    List<AppLatLng> routePoints = const [],
    List<FeedTelemetrySample> telemetrySamples = const [],
    Ride? authoritativeRide,
    int? rideId,
    bool? isGpsVerified,
  }) async {
    double resolvedDistance = distanceMiles;
    int resolvedDurationSeconds = durationSeconds;
    double resolvedMaxLean = maxLeanAngleDeg;
    String resolvedLeanSide = maxLeanSide;
    int resolvedElevationFt = elevationFt;
    int? resolvedRideId = rideId;

    if (authoritativeRide != null) {
      resolvedRideId = authoritativeRide.id;
      resolvedDistance = authoritativeRide.distanceMiles > 0
          ? authoritativeRide.distanceMiles
          : authoritativeRide.distance;
      resolvedDurationSeconds = authoritativeRide.movingTime > 0
          ? authoritativeRide.movingTime
          : (authoritativeRide.endTime != null
              ? authoritativeRide.endTime!
                  .difference(authoritativeRide.startTime)
                  .inSeconds
                  .clamp(0, 864000)
              : 0);
      resolvedMaxLean = math.max(
        authoritativeRide.maxLeanLeft,
        authoritativeRide.maxLeanRight,
      );
      if (authoritativeRide.maxLeanLeft == 0 &&
          authoritativeRide.maxLeanRight == 0) {
        resolvedLeanSide = 'NONE';
      } else {
        resolvedLeanSide =
            authoritativeRide.maxLeanRight >= authoritativeRide.maxLeanLeft
                ? 'RIGHT'
                : 'LEFT';
      }
      resolvedElevationFt =
          (authoritativeRide.elevationGain * 3.28084).round();
    }

    final gatedTelemetrySamples = telemetrySamples
        .map((s) => s.withMovingLeanGate())
        .toList(growable: false);

    final meetsGpsVerification = SocialFeedItem.verifyGpsCriteria(
      isDemo: false,
      distanceMiles: resolvedDistance,
      durationSeconds: resolvedDurationSeconds,
      routePoints: routePoints,
      telemetrySamples: gatedTelemetrySamples,
    );
    final effectiveGpsVerified = (isGpsVerified ?? true) && meetsGpsVerification;

    final newPost = SocialFeedItem(
      id: 'feed_post_${DateTime.now().millisecondsSinceEpoch}',
      rideId: resolvedRideId,
      authorUid: authorUid,
      authorDisplayName: authorDisplayName,
      authorHandle: authorHandle,
      authorAvatarPreset: authorAvatarPreset,
      authorBadge: authorBadge ?? 'PRO',
      clubName: clubName,
      locationName: locationName,
      timestamp: DateTime.now(),
      rideTitle: rideTitle,
      bikeModel: bikeModel,
      distanceMiles: resolvedDistance,
      durationSeconds: resolvedDurationSeconds,
      maxLeanAngleDeg: resolvedMaxLean,
      maxLeanSide: resolvedLeanSide,
      paceFactor: paceFactor,
      hazardCount: hazardCount,
      elevationFt: resolvedElevationFt,
      discipline: discipline,
      regionName: regionName,
      isFeatured: isFeatured,
      snapshotType: snapshotType,
      routePoints: routePoints,
      telemetrySamples: gatedTelemetrySamples,
      isGpsVerified: effectiveGpsVerified,
      isDemo: false,
      fistBumpCount: 1,
      fistBumpUserIds: [authorUid],
      comments: const [],
    );

    _memoryFeed.insert(0, newPost);
    _localFeedController.add(List.unmodifiable(_memoryFeed));

    final fs = firestore;
    if (fs != null) {
      try {
        await fs.collection('social_feed').doc(newPost.id).set(newPost.toJson());
      } catch (_) {}
    }

    return newPost;
  }

  void dispose() {
    _firestoreSub?.cancel();
    _localFeedController.close();
  }
}