import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:mileograph_flutter/objects/objects.dart';
import 'package:mileograph_flutter/services/authservice.dart';
import 'package:mileograph_flutter/services/data_service.dart';

class ProfilePage extends StatefulWidget {
  const ProfilePage({super.key});

  @override
  State<ProfilePage> createState() => _ProfilePageState();
}

class _ProfilePageState extends State<ProfilePage> {
  final TextEditingController _searchController = TextEditingController();
  List<UserSummary> _searchResults = [];
  bool _searching = false;
  String? _searchError;
  bool _fetched = false;

  UserSummary? _selectedUser;
  Friendship? _status;
  bool _statusLoading = false;
  bool _actionLoading = false;

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (!mounted || _fetched) return;
      _fetched = true;
      final data = context.read<DataService>();
      data.fetchFriendships();
      data.fetchPendingFriendships();
    });
  }

  @override
  void dispose() {
    _searchController.dispose();
    super.dispose();
  }

  Future<void> _searchUsers() async {
    final query = _searchController.text.trim();
    if (query.isEmpty) {
      setState(() {
        _searchResults = [];
        _searchError = null;
      });
      return;
    }
    setState(() {
      _searching = true;
      _searchError = null;
    });
    try {
      final results = await context.read<DataService>().searchUsers(query);
      if (!mounted) return;
      setState(() {
        _searchResults = results;
      });
    } catch (e) {
      if (!mounted) return;
      setState(() {
        _searchError = 'Search failed';
      });
    } finally {
      if (mounted) setState(() => _searching = false);
    }
  }

  Future<void> _loadStatus(UserSummary user) async {
    setState(() {
      _selectedUser = user;
      _statusLoading = true;
    });
    try {
      final status =
          await context.read<DataService>().fetchFriendshipStatus(user.userId);
      if (!mounted) return;
      setState(() => _status = status);
    } catch (_) {
      if (!mounted) return;
      setState(() => _status = null);
    } finally {
      if (mounted) setState(() => _statusLoading = false);
    }
  }

  Future<void> _sendRequest(UserSummary user) async {
    setState(() => _actionLoading = true);
    try {
      final status = await context.read<DataService>().requestFriendship(
            user.userId,
            targetUser: user,
          );
      if (!mounted) return;
      setState(() => _status = status);
      _showSnack('Friend request sent');
    } catch (e) {
      _showSnack('Failed to send request: $e');
    } finally {
      if (mounted) setState(() => _actionLoading = false);
    }
  }

  Future<void> _cancelRequest(Friendship status) async {
    final id = status.id;
    if (id == null || id.isEmpty) return;
    setState(() => _actionLoading = true);
    try {
      await context.read<DataService>().cancelFriendship(id);
      if (!mounted) return;
      setState(() => _status = status.copyWith(status: 'none'));
      _showSnack('Request cancelled');
    } catch (e) {
      _showSnack('Failed to cancel: $e');
    } finally {
      if (mounted) setState(() => _actionLoading = false);
    }
  }

  Future<void> _accept(Friendship status) async {
    final id = status.id;
    if (id == null || id.isEmpty) return;
    setState(() => _actionLoading = true);
    try {
      final updated = await context.read<DataService>().acceptFriendship(id);
      if (!mounted) return;
      setState(() => _status = updated);
      _showSnack('Friend request accepted');
    } catch (e) {
      _showSnack('Failed to accept: $e');
    } finally {
      if (mounted) setState(() => _actionLoading = false);
    }
  }

  Future<void> _reject(Friendship status) async {
    final id = status.id;
    if (id == null || id.isEmpty) return;
    setState(() => _actionLoading = true);
    try {
      final updated = await context.read<DataService>().rejectFriendship(id);
      if (!mounted) return;
      setState(() => _status = updated);
      _showSnack('Friend request rejected');
    } catch (e) {
      _showSnack('Failed to reject: $e');
    } finally {
      if (mounted) setState(() => _actionLoading = false);
    }
  }

  Future<void> _unfriend(Friendship status) async {
    final id = status.id;
    if (id == null || id.isEmpty) return;
    final confirm = await showDialog<bool>(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('Remove friend'),
        content: const Text('Are you sure you want to remove this friend?'),
        actions: [
          TextButton(
            onPressed: () => Navigator.of(ctx).pop(false),
            child: const Text('Cancel'),
          ),
          TextButton(
            onPressed: () => Navigator.of(ctx).pop(true),
            child: const Text('Remove'),
          ),
        ],
      ),
    );
    if (confirm != true) return;
    if (!mounted) return;
    setState(() => _actionLoading = true);
    try {
      await context.read<DataService>().deleteFriendship(id);
      if (!mounted) return;
      setState(() => _status = status.copyWith(status: 'none'));
      _showSnack('Friend removed');
    } catch (e) {
      _showSnack('Failed to remove friend: $e');
    } finally {
      if (mounted) setState(() => _actionLoading = false);
    }
  }

  void _showSnack(String message) {
    ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text(message)));
  }

  @override
  Widget build(BuildContext context) {
    final auth = context.watch<AuthService>();
    final data = context.watch<DataService>();
    final statsUser = data.homepageStats?.user;
    final name = auth.fullName?.isNotEmpty == true
        ? auth.fullName!
        : (statsUser?.fullName ?? '');
    final username = auth.username ?? statsUser?.username ?? '';
    final email = statsUser?.email ?? '';

    return Scaffold(
      appBar: AppBar(
        title: const Text('Profile'),
      ),
      body: RefreshIndicator(
        onRefresh: () async {
          await data.fetchFriendships();
          await data.fetchPendingFriendships();
          if (_selectedUser != null) {
            await _loadStatus(_selectedUser!);
          }
        },
        child: ListView(
          padding: const EdgeInsets.all(16),
          children: [
            _buildUserCard(name: name, username: username, email: email),
            const SizedBox(height: 16),
            _buildSearchSection(),
            const SizedBox(height: 16),
            _buildSelectedUserSection(auth),
            const SizedBox(height: 16),
            _buildFriendsList(auth),
          ],
        ),
      ),
    );
  }

  Widget _buildUserCard({
    required String name,
    required String username,
    required String email,
  }) {
    return Card(
      child: ListTile(
        leading: const CircleAvatar(child: Icon(Icons.person)),
        title: Text(name.isNotEmpty ? name : 'You'),
        subtitle: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            if (username.isNotEmpty) Text('@$username'),
            if (email.isNotEmpty) Text(email),
          ],
        ),
      ),
    );
  }

  Widget _buildSearchSection() {
    return Card(
      child: Padding(
        padding: const EdgeInsets.all(12.0),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text(
              'Find a user',
              style: Theme.of(context).textTheme.titleMedium,
            ),
            const SizedBox(height: 8),
            Row(
              children: [
                Expanded(
                  child: TextField(
                    controller: _searchController,
                    decoration: const InputDecoration(
                      labelText: 'Search by username, email, or name',
                      border: OutlineInputBorder(),
                    ),
                    onSubmitted: (_) => _searchUsers(),
                  ),
                ),
                const SizedBox(width: 8),
                ElevatedButton(
                  onPressed: _searching ? null : _searchUsers,
                  child:
                      _searching ? const SizedBox(
                        width: 16,
                        height: 16,
                        child: CircularProgressIndicator(strokeWidth: 2),
                      ) : const Text('Search'),
                ),
              ],
            ),
            if (_searchError != null)
              Padding(
                padding: const EdgeInsets.only(top: 8.0),
                child: Text(
                  _searchError!,
                  style: TextStyle(color: Theme.of(context).colorScheme.error),
                ),
              ),
            if (_searchResults.isNotEmpty) const SizedBox(height: 12),
            if (_searchResults.isNotEmpty)
              ..._searchResults.map(
                (user) => ListTile(
                  leading: const Icon(Icons.person),
                  title: Text(user.displayName),
                  subtitle:
                      user.username.isNotEmpty ? Text('@${user.username}') : null,
                  trailing: TextButton(
                    onPressed: () => _loadStatus(user),
                    child: const Text('View'),
                  ),
                ),
              ),
          ],
        ),
      ),
    );
  }

  Widget _buildSelectedUserSection(AuthService auth) {
    final user = _selectedUser;
    if (user == null) return const SizedBox.shrink();
    final status = _status;
    final loading = _statusLoading;
    final isSelf = auth.userId == user.userId;

    return Card(
      child: Padding(
        padding: const EdgeInsets.all(12.0),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Row(
              children: [
                Text(
                  user.displayName,
                  style: Theme.of(context).textTheme.titleMedium,
                ),
                const SizedBox(width: 8),
                if (loading)
                  const SizedBox(
                    width: 16,
                    height: 16,
                    child: CircularProgressIndicator(strokeWidth: 2),
                  ),
                if (!loading && status != null) _buildStatusChip(status, auth),
              ],
            ),
            if (user.username.isNotEmpty) Text('@${user.username}'),
            const SizedBox(height: 8),
            if (!isSelf) _buildActions(status, user, auth),
            if (isSelf)
              const Text('This is you.', style: TextStyle(fontStyle: FontStyle.italic)),
          ],
        ),
      ),
    );
  }

  Widget _buildStatusChip(Friendship status, AuthService auth) {
    String label = status.status;
    Color color = Colors.grey;
    switch (status.status.toLowerCase()) {
      case 'accepted':
        label = 'Friends';
        color = Colors.green;
        break;
      case 'pending':
        final isRequester = status.requesterId == auth.userId;
        label = isRequester ? 'Pending (you sent)' : 'Pending (waiting on you)';
        color = Colors.orange;
        break;
      case 'blocked':
        color = Colors.red;
        label = 'Blocked';
        break;
      case 'declined':
      case 'rejected':
        label = 'Declined';
        break;
      default:
        label = 'Not friends';
    }
    final bg = Color.alphaBlend(
      color.withValues(alpha: 0.15),
      Theme.of(context).colorScheme.surface,
    );
    return Container(
      margin: const EdgeInsets.only(left: 6),
      padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 6),
      decoration: BoxDecoration(
        color: bg,
        borderRadius: BorderRadius.circular(20),
      ),
      child: Text(label),
    );
  }

  Widget _buildActions(
    Friendship? status,
    UserSummary user,
    AuthService auth,
  ) {
    if (status == null) {
      return const SizedBox.shrink();
    }
    final isRequester = status.requesterId == auth.userId;
    final id = status.id;
    final buttons = <Widget>[];

    if (status.isNone || status.isDeclined) {
      buttons.add(
        ElevatedButton.icon(
          onPressed: _actionLoading ? null : () => _sendRequest(user),
          icon: const Icon(Icons.person_add),
          label: const Text('Send friend request'),
        ),
      );
    } else if (status.isPending) {
      if (isRequester) {
        buttons.add(
          OutlinedButton(
            onPressed: _actionLoading || id == null || id.isEmpty
                ? null
                : () => _cancelRequest(status),
            child: const Text('Cancel request'),
          ),
        );
      } else {
        buttons.add(
          ElevatedButton(
            onPressed: _actionLoading || id == null || id.isEmpty
                ? null
                : () => _accept(status),
            child: const Text('Accept'),
          ),
        );
        buttons.add(
          OutlinedButton(
            onPressed: _actionLoading || id == null || id.isEmpty
                ? null
                : () => _reject(status),
            child: const Text('Reject'),
          ),
        );
      }
    } else if (status.isAccepted) {
      buttons.add(
        ElevatedButton.icon(
          onPressed: _actionLoading || id == null || id.isEmpty
              ? null
              : () => _unfriend(status),
          icon: const Icon(Icons.person_remove),
          label: const Text('Unfriend'),
        ),
      );
      // Block action temporarily removed until backend support exists.
    } else if (status.isBlocked) {
      buttons.add(const Text('User is blocked.'));
    }

    if (buttons.isEmpty) return const SizedBox.shrink();

    return Wrap(
      spacing: 8,
      runSpacing: 8,
      children: buttons,
    );
  }

  Widget _buildFriendsList(AuthService auth) {
    final data = context.watch<DataService>();
    final friends = data.friendships;
    final incoming = data.pendingIncoming;
    final outgoing = data.pendingOutgoing;
    final loading = data.isFriendshipsLoading;
    final pendingLoading = data.isPendingFriendshipsLoading;
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        if (pendingLoading && incoming.isEmpty && outgoing.isEmpty)
          const Padding(
            padding: EdgeInsets.symmetric(vertical: 12.0),
            child: Center(child: CircularProgressIndicator()),
          ),
        if (incoming.isNotEmpty || outgoing.isNotEmpty)
          Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Text(
                'Pending requests',
                style: Theme.of(context).textTheme.titleMedium,
              ),
              const SizedBox(height: 8),
              if (outgoing.isNotEmpty)
                ...outgoing.map((f) {
                  final otherUser = _otherUser(f, auth.userId);
                  return Card(
                    child: ListTile(
                      leading: const Icon(Icons.person),
                      title: Text(otherUser?.displayName ?? 'User'),
                      subtitle: otherUser?.username.isNotEmpty == true
                          ? Text('@${otherUser!.username}')
                          : null,
                  trailing: Row(
                    mainAxisSize: MainAxisSize.min,
                    children: [
                      const Icon(Icons.north_east, size: 18),
                      const SizedBox(width: 6),
                      TextButton(
                        onPressed: f.id == null || _actionLoading
                            ? null
                            : () => _cancelRequest(f),
                        child: const Text('Cancel'),
                      ),
                    ],
                  ),
                    ),
                  );
                }),
              if (incoming.isNotEmpty && outgoing.isNotEmpty)
                const SizedBox(height: 8),
              if (incoming.isNotEmpty)
                ...incoming.map((f) {
                  final otherUser = _otherUser(f, auth.userId);
                  return Card(
                    child: ListTile(
                      leading: const Icon(Icons.person),
                      title: Text(otherUser?.displayName ?? 'User'),
                      subtitle: otherUser?.username.isNotEmpty == true
                          ? Text('@${otherUser!.username}')
                          : null,
                      trailing: Row(
                        mainAxisSize: MainAxisSize.min,
                        children: [
                          const Icon(Icons.south_west, size: 18),
                          const SizedBox(width: 6),
                          Wrap(
                            spacing: 8,
                            children: [
                              TextButton(
                                onPressed: f.id == null || _actionLoading
                                    ? null
                                    : () => _accept(f),
                                child: const Text('Accept'),
                              ),
                              TextButton(
                                onPressed: f.id == null || _actionLoading
                                    ? null
                                    : () => _reject(f),
                                child: const Text('Reject'),
                              ),
                            ],
                          ),
                        ],
                      ),
                    ),
                  );
                }),
              const SizedBox(height: 12),
            ],
          ),
        Text(
          'Friends',
          style: Theme.of(context).textTheme.titleMedium,
        ),
        const SizedBox(height: 8),
        if (loading && friends.isEmpty)
          const Padding(
            padding: EdgeInsets.symmetric(vertical: 12.0),
            child: Center(child: CircularProgressIndicator()),
          )
        else if (friends.isEmpty)
          const Text('No friends yet.')
        else
          ...friends.map((f) {
            final otherUser = _otherUser(f, auth.userId);
            return Card(
              child: ListTile(
                leading: const Icon(Icons.person),
                title: Text(otherUser?.displayName ?? 'User'),
                subtitle: otherUser?.username.isNotEmpty == true
                    ? Text('@${otherUser!.username}')
                    : null,
                trailing: TextButton(
                  onPressed: () {
                    final user = otherUser;
                    if (user != null) {
                      _loadStatus(user);
                    }
                  },
                  child: const Text('Manage'),
                ),
              ),
            );
          }),
      ],
    );
  }

  UserSummary? _otherUser(Friendship friendship, String? currentUserId) {
    final selfId = currentUserId ?? '';
    if (friendship.requester?.userId == selfId) return friendship.addressee;
    if (friendship.addressee?.userId == selfId) return friendship.requester;
    if (friendship.addresseeId == selfId && friendship.requester != null) {
      return friendship.requester;
    }
    if (friendship.requesterId == selfId && friendship.addressee != null) {
      return friendship.addressee;
    }
    if (friendship.addressee != null) return friendship.addressee;
    if (friendship.requester != null) return friendship.requester;
    return null;
  }
}