import 'dart:async';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firebase_core/firebase_core.dart';
import 'club_models.dart';
import 'club_wall_models.dart';

/// Manages Club Wall discussion board posts, pinned announcements,
/// fist-bump kudos, and rider comments.
class ClubWallService {
  final FirebaseFirestore? _firestore;

  // In-memory cache of posts by clubId for responsive local state & fallback
  final Map<String, List<ClubWallPost>> _localPosts = {};
  final Map<String, StreamController<List<ClubWallPost>>> _controllers = {};

  ClubWallService({FirebaseFirestore? firestore})
      : _firestore = firestore ?? _resolveFirestore();

  static FirebaseFirestore? _resolveFirestore() {
    try {
      if (Firebase.apps.isNotEmpty) return FirebaseFirestore.instance;
    } catch (_) {}
    return null;
  }

  StreamController<List<ClubWallPost>> _getController(String clubId) {
    return _controllers.putIfAbsent(
      clubId,
      () => StreamController<List<ClubWallPost>>.broadcast(),
    );
  }

  List<ClubWallPost> _getSeedPosts(String clubId) {
    final now = DateTime.now();
    return [
      ClubWallPost(
        id: '${clubId}_seed_1',
        clubId: clubId,
        authorUid: 'seed_pres',
        authorDisplayName: 'Marcus Vance',
        authorHandle: '@marcus_v',
        authorDisplayRank: 'President',
        authorRole: ClubRole.owner,
        content: '🏍️ SATURDAY RIDE BRIEFING: Staging at Ridgepoint Shell at 08:30 AM. Route is Blood Mountain Loop (78 miles, standard pace). Ensure tire pressures and chain tension are checked. Road Captain will lead paceline.',
        createdAt: now.subtract(const Duration(hours: 3)),
        isPinned: true,
        fistBumpCount: 14,
        fistBumpUserIds: const ['seed_user_2', 'seed_user_3'],
        comments: [
          ClubWallComment(
            id: 'c1',
            postId: '${clubId}_seed_1',
            authorUid: 'seed_rc',
            authorDisplayName: 'Dave Miller',
            authorHandle: '@dave_m',
            authorDisplayRank: 'Road Captain',
            authorRole: ClubRole.admin,
            content: 'GPX route cue sheet uploaded to the club rides tab. We will fuel up at mile 42.',
            createdAt: now.subtract(const Duration(hours: 2)),
          ),
        ],
      ),
      ClubWallPost(
        id: '${clubId}_seed_2',
        clubId: clubId,
        authorUid: 'seed_tg',
        authorDisplayName: 'Samir Chen',
        authorHandle: '@samir_c',
        authorDisplayRank: 'Tail Gunner',
        authorRole: ClubRole.member,
        content: 'Sweep radar active on channel 4. Let\'s maintain 2-second stagger spacing through the canyon twisties. See everyone at staging!',
        createdAt: now.subtract(const Duration(hours: 5)),
        isPinned: false,
        fistBumpCount: 9,
        fistBumpUserIds: const ['seed_user_1'],
      ),
      ClubWallPost(
        id: '${clubId}_seed_3',
        clubId: clubId,
        authorUid: 'seed_mem',
        authorDisplayName: 'Sarah Jenkins',
        authorHandle: '@sjenkins',
        authorDisplayRank: 'Road Marshal',
        authorRole: ClubRole.member,
        content: 'Just fitted new Pirelli Diablo Rosso IVs, ready for the elevation climbs this weekend! 💨 Weather radar looks clear.',
        createdAt: now.subtract(const Duration(hours: 8)),
        isPinned: false,
        fistBumpCount: 6,
      ),
    ];
  }

  /// Real-time stream of wall posts for a club.
  Stream<List<ClubWallPost>> clubWallStream(String clubId) {
    final controller = _getController(clubId);

    // Initialize seed posts if not present
    if (!_localPosts.containsKey(clubId)) {
      _localPosts[clubId] = _getSeedPosts(clubId);
      Timer.run(() {
        if (!controller.isClosed) {
          controller.add(_sortPosts(_localPosts[clubId]!));
        }
      });
    } else {
      Timer.run(() {
        if (!controller.isClosed) {
          controller.add(_sortPosts(_localPosts[clubId]!));
        }
      });
    }

    // Attempt to listen to Firestore if available
    final firestore = _firestore;
    if (firestore != null) {
      firestore
          .collection('clubs')
          .doc(clubId)
          .collection('wall_posts')
          .orderBy('createdAt', descending: true)
          .limit(50)
          .snapshots()
          .listen(
        (snap) {
          if (snap.docs.isNotEmpty) {
            final firestorePosts =
                snap.docs.map((d) => ClubWallPost.fromFirestore(d)).toList();
            _localPosts[clubId] = firestorePosts;
            if (!controller.isClosed) {
              controller.add(_sortPosts(firestorePosts));
            }
          }
        },
        onError: (_) {
          // Graceful fallback to local cache
        },
      );
    }

    return controller.stream;
  }

  List<ClubWallPost> _sortPosts(List<ClubWallPost> posts) {
    final copy = List<ClubWallPost>.from(posts);
    copy.sort((a, b) {
      // Pinned posts always first
      if (a.isPinned && !b.isPinned) return -1;
      if (!a.isPinned && b.isPinned) return 1;
      return b.createdAt.compareTo(a.createdAt);
    });
    return copy;
  }

  /// Creates a new post on the Club Wall.
  Future<ClubWallPost> createPost({
    required String clubId,
    required String authorUid,
    required String authorDisplayName,
    String? authorHandle,
    String? authorAvatarUrl,
    String? authorDisplayRank,
    ClubRole authorRole = ClubRole.member,
    required String content,
    bool isPinned = false,
  }) async {
    final cleanContent = content.trim();
    if (cleanContent.isEmpty) {
      throw ArgumentError('Post content cannot be empty.');
    }

    final post = ClubWallPost(
      id: 'post_${DateTime.now().millisecondsSinceEpoch}_$authorUid',
      clubId: clubId,
      authorUid: authorUid,
      authorDisplayName: authorDisplayName,
      authorHandle: authorHandle,
      authorAvatarUrl: authorAvatarUrl,
      authorDisplayRank: authorDisplayRank,
      authorRole: authorRole,
      content: cleanContent,
      createdAt: DateTime.now(),
      isPinned: isPinned,
      fistBumpCount: 0,
      fistBumpUserIds: const [],
      comments: const [],
    );

    // Update local cache & notify stream
    final posts = _localPosts.putIfAbsent(clubId, () => _getSeedPosts(clubId));
    posts.insert(0, post);
    _localPosts[clubId] = posts;
    _getController(clubId).add(_sortPosts(posts));

    // Try persist to Firestore
    final firestore = _firestore;
    if (firestore != null) {
      try {
        await firestore
            .collection('clubs')
            .doc(clubId)
            .collection('wall_posts')
            .doc(post.id)
            .set(post.toFirestore());
      } catch (_) {
        // Silently preserve in local cache
      }
    }

    return post;
  }

  /// Toggles a Fist Bump (kudos) on a post.
  Future<void> toggleFistBump({
    required String clubId,
    required String postId,
    required String userUid,
  }) async {
    final posts = _localPosts[clubId] ?? [];
    final index = posts.indexWhere((p) => p.id == postId);
    if (index == -1) return;

    final target = posts[index];
    final alreadyBumped = target.fistBumpUserIds.contains(userUid);
    final updatedList = List<String>.from(target.fistBumpUserIds);

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

    final updatedPost = target.copyWith(
      fistBumpCount: updatedList.length,
      fistBumpUserIds: updatedList,
    );

    posts[index] = updatedPost;
    _localPosts[clubId] = posts;
    _getController(clubId).add(_sortPosts(posts));

    // Firestore sync if available
    final firestore = _firestore;
    if (firestore != null) {
      try {
        await firestore
            .collection('clubs')
            .doc(clubId)
            .collection('wall_posts')
            .doc(postId)
            .update({
          'fistBumpCount': updatedList.length,
          'fistBumpUserIds': updatedList,
        });
      } catch (_) {}
    }
  }

  /// Adds a comment to a Club Wall post.
  Future<void> addComment({
    required String clubId,
    required String postId,
    required String authorUid,
    required String authorDisplayName,
    String? authorHandle,
    String? authorAvatarUrl,
    String? authorDisplayRank,
    ClubRole authorRole = ClubRole.member,
    required String content,
  }) async {
    final cleanContent = content.trim();
    if (cleanContent.isEmpty) return;

    final posts = _localPosts[clubId] ?? [];
    final index = posts.indexWhere((p) => p.id == postId);
    if (index == -1) return;

    final comment = ClubWallComment(
      id: 'comment_${DateTime.now().millisecondsSinceEpoch}',
      postId: postId,
      authorUid: authorUid,
      authorDisplayName: authorDisplayName,
      authorHandle: authorHandle,
      authorAvatarUrl: authorAvatarUrl,
      authorDisplayRank: authorDisplayRank,
      authorRole: authorRole,
      content: cleanContent,
      createdAt: DateTime.now(),
    );

    final target = posts[index];
    final updatedComments = List<ClubWallComment>.from(target.comments)..add(comment);
    final updatedPost = target.copyWith(comments: updatedComments);

    posts[index] = updatedPost;
    _localPosts[clubId] = posts;
    _getController(clubId).add(_sortPosts(posts));

    // Firestore sync
    final firestore = _firestore;
    if (firestore != null) {
      try {
        await firestore
            .collection('clubs')
            .doc(clubId)
            .collection('wall_posts')
            .doc(postId)
            .update({
          'comments': updatedComments.map((c) => c.toJson()).toList(),
        });
      } catch (_) {}
    }
  }

  /// Deletes a post from the Club Wall.
  Future<void> deletePost({
    required String clubId,
    required String postId,
  }) async {
    final posts = _localPosts[clubId] ?? [];
    posts.removeWhere((p) => p.id == postId);
    _localPosts[clubId] = posts;
    _getController(clubId).add(_sortPosts(posts));

    final firestore = _firestore;
    if (firestore != null) {
      try {
        await firestore
            .collection('clubs')
            .doc(clubId)
            .collection('wall_posts')
            .doc(postId)
            .delete();
      } catch (_) {}
    }
  }
}