import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:travel_mate/components/home/create_trip_content.dart';
import '../home/show_trip_details_content.dart';
import '../../blocs/user/user_bloc.dart';
import '../../blocs/user/user_state.dart';
import '../../blocs/trip/trip_bloc.dart';
import '../../blocs/trip/trip_state.dart';
import '../../blocs/trip/trip_event.dart';
import '../../models/trip.dart';

/// Home content widget for the main application dashboard.
/// 
/// This widget serves as the primary content area of the home screen,
/// displaying user trips and providing navigation to trip management
/// features. Key functionality includes:
/// - Loading and displaying user trips
/// - Creating new trips
/// - Viewing trip details
/// - Managing trip state with proper user authentication
/// 
/// The widget maintains state persistence using AutomaticKeepAliveClientMixin
/// to preserve content when switching between tabs.
class HomeContent extends StatefulWidget {
  /// Creates a home content widget.
  const HomeContent({super.key});

  @override
  State<HomeContent> createState() => _HomeContentState();
}

class _HomeContentState extends State<HomeContent> with AutomaticKeepAliveClientMixin {
  /// Preserves widget state when switching between tabs
  @override
  bool get wantKeepAlive => true;
  
  /// Flag to prevent duplicate trip loading operations
  bool _hasLoadedTrips = false;

  @override
  void initState() {
    super.initState();
    // Use addPostFrameCallback to wait for the widget tree to be ready
    WidgetsBinding.instance.addPostFrameCallback((_) {
      _loadTripsIfUserLoaded();
    });
  }

  /// Loads trips if a user is currently loaded and trips haven't been loaded yet.
  /// 
  /// Checks the current user state and initiates trip loading if the user is
  /// authenticated and trips haven't been loaded previously. This prevents
  /// duplicate loading operations.
  void _loadTripsIfUserLoaded() {
    if (!_hasLoadedTrips && mounted) {
      final userState = context.read<UserBloc>().state;
      if (userState is UserLoaded) {
        _hasLoadedTrips = true;
        context.read<TripBloc>().add(LoadTripsByUserId(userId: userState.user.id));
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    super.build(context); // Important pour AutomaticKeepAliveClientMixin
    
    return BlocBuilder<UserBloc, UserState>(
      builder: (context, userState) {
        if (userState is UserLoading) {
          return Scaffold(
            body: Center(
              child: CircularProgressIndicator(),
            ),
          );
        }

        if (userState is UserError) {
          return Scaffold(
            body: Center(
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  Icon(Icons.error, size: 64, color: Colors.red),
                  SizedBox(height: 16),
                  Text('Erreur: ${userState.message}'),
                ],
              ),
            ),
          );
        }

        if (userState is! UserLoaded) {
          return Scaffold(
            body: Center(
              child: Text('Veuillez vous connecter'),
            ),
          );
        }

        final user = userState.user;

        return BlocConsumer<TripBloc, TripState>(
          listener: (context, tripState) {
            if (tripState is TripOperationSuccess) {
              ScaffoldMessenger.of(context).showSnackBar(
                SnackBar(
                  content: Text(tripState.message),
                  backgroundColor: Colors.green,
                ),
              );
            } else if (tripState is TripError) {
              ScaffoldMessenger.of(context).showSnackBar(
                SnackBar(
                  content: Text(tripState.message),
                  backgroundColor: Colors.red,
                ),
              );
            } else if (tripState is TripCreated) {
              ScaffoldMessenger.of(context).showSnackBar(
                SnackBar(
                  content: Text('Voyage en cours de création...'),
                  backgroundColor: Colors.blue,
                  duration: Duration(seconds: 1),
                ),
              );
            }
          },
          builder: (context, tripState) {
            // AJOUTÉ : Si l'état est initial et qu'on n'a pas encore chargé, charger maintenant
            if (tripState is TripInitial && !_hasLoadedTrips) {
              WidgetsBinding.instance.addPostFrameCallback((_) {
                _loadTripsIfUserLoaded();
              });
            }

            return Scaffold(
              body: RefreshIndicator(
                onRefresh: () async {
                  context.read<TripBloc>().add(LoadTripsByUserId(userId: user.id));
                  await Future.delayed(Duration(milliseconds: 500));
                },
                child: SingleChildScrollView(
                  physics: const AlwaysScrollableScrollPhysics(),
                  padding: const EdgeInsets.all(16.0),
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Text(
                        'Bonjour ${user.prenom} !',
                        style: TextStyle(
                          fontSize: 28, 
                          fontWeight: FontWeight.bold,
                          color: Theme.of(context).brightness == Brightness.dark 
                            ? Colors.white 
                            : Colors.black,
                        ),
                      ),
                      const SizedBox(height: 8),
                      Text(
                        'Vos voyages',
                        style: TextStyle(
                          fontSize: 16, 
                          color: Theme.of(context).brightness == Brightness.dark 
                            ? Colors.white70 
                            : Colors.grey[600],
                        ),
                      ),
                      const SizedBox(height: 20),

                      if (tripState is TripLoading || tripState is TripCreated)
                        _buildLoadingState()
                      else if (tripState is TripError)
                        _buildErrorState(tripState.message, user.id)
                      else if (tripState is TripLoaded)
                        tripState.trips.isEmpty
                            ? _buildEmptyState()
                            : _buildTripsList(tripState.trips)
                      else if (tripState is TripInitial)
                        _buildLoadingState() // Afficher le loader pendant le premier chargement
                      else
                        _buildEmptyState(),

                      const SizedBox(height: 80),
                    ],
                  ),
                ),
              ),
              floatingActionButton: FloatingActionButton(
                onPressed: () async {
                  final tripBloc = context.read<TripBloc>();

                  final result = await Navigator.push(
                    context,
                    MaterialPageRoute(builder: (context) => const CreateTripContent()),
                  );

                  if (result == true && mounted) {
                    tripBloc.add(LoadTripsByUserId(userId: user.id));
                  }
                },
                backgroundColor: Theme.of(context).colorScheme.primary,
                foregroundColor: Colors.white,
                child: const Icon(Icons.add),
              ),
              floatingActionButtonLocation: FloatingActionButtonLocation.endFloat,
            );
          },
        );
      },
    );
  }

  Widget _buildLoadingState() {
    return Center(
      child: Padding(
        padding: EdgeInsets.all(32),
        child: CircularProgressIndicator(),
      ),
    );
  }

  Widget _buildErrorState(String error, String userId) {
    return Center(
      child: Padding(
        padding: EdgeInsets.all(32),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Icon(Icons.error, size: 64, color: Colors.red),
            SizedBox(height: 16),
            Text('Erreur lors du chargement des voyages'),
            SizedBox(height: 8),
            Text(
              error,
              textAlign: TextAlign.center,
              style: TextStyle(fontSize: 12, color: Colors.grey),
            ),
            SizedBox(height: 16),
            ElevatedButton(
              onPressed: () {
                context.read<TripBloc>().add(LoadTripsByUserId(userId: userId));
              },
              child: Text('Réessayer'),
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildEmptyState() {
    return Center(
      child: Padding(
        padding: EdgeInsets.all(32),
        child: Column(
          children: [
            Icon(Icons.travel_explore, size: 80, color: Colors.grey[400]),
            SizedBox(height: 16),
            Text(
              'Aucun voyage',
              style: TextStyle(fontSize: 20, fontWeight: FontWeight.bold),
            ),
            SizedBox(height: 8),
            Text(
              'Créez votre premier voyage en appuyant sur le bouton +',
              textAlign: TextAlign.center,
              style: TextStyle(fontSize: 14, color: Colors.grey[600]),
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildTripsList(List<Trip> trips) {
    return Column(
      children: trips.map((trip) => _buildTripCard(trip)).toList(),
    );
  }

  Widget _buildTripCard(Trip trip) {
    final isDarkMode = Theme.of(context).brightness == Brightness.dark;
    final textColor = isDarkMode ? Colors.white : Colors.black;
    final subtextColor = isDarkMode ? Colors.white70 : Colors.grey[600];

    return Card(
      margin: EdgeInsets.only(bottom: 12),
      elevation: 2,
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(12),
      ),
      child: InkWell(
        onTap: () async {
          final result = await Navigator.push(
            context,
            MaterialPageRoute(
              builder: (context) => ShowTripDetailsContent(trip: trip),
            ),
          );
          
          if (result == true && mounted) {
            final userState = context.read<UserBloc>().state;
            if (userState is UserLoaded) {
              context.read<TripBloc>().add(LoadTripsByUserId(userId: userState.user.id));
            }
          }
        },
        borderRadius: BorderRadius.circular(12),
        child: Padding(
          padding: EdgeInsets.all(16),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Row(
                children: [
                  Expanded(
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        Text(
                          trip.title,
                          style: TextStyle(
                            fontSize: 18,
                            fontWeight: FontWeight.bold,
                            color: textColor,
                          ),
                        ),
                        SizedBox(height: 4),
                        Row(
                          children: [
                            Icon(Icons.location_on, size: 16, color: subtextColor),
                            SizedBox(width: 4),
                            Text(
                              trip.location,
                              style: TextStyle(color: subtextColor),
                            ),
                          ],
                        ),
                      ],
                    ),
                  ),
                  Container(
                    padding: EdgeInsets.symmetric(horizontal: 12, vertical: 6),
                    decoration: BoxDecoration(
                      color: _getStatusColor(trip).withValues(alpha: 0.2),
                      borderRadius: BorderRadius.circular(12),
                    ),
                    child: Text(
                      _getStatusText(trip),
                      style: TextStyle(
                        color: _getStatusColor(trip),
                        fontWeight: FontWeight.bold,
                        fontSize: 12,
                      ),
                    ),
                  ),
                ],
              ),
              SizedBox(height: 12),
              Row(
                children: [
                  Icon(Icons.calendar_today, size: 16, color: subtextColor),
                  SizedBox(width: 4),
                  Text(
                    '${_formatDate(trip.startDate)} - ${_formatDate(trip.endDate)}',
                    style: TextStyle(fontSize: 14, color: subtextColor),
                  ),
                ],
              ),
              if (trip.budget != null) ...[
                SizedBox(height: 8),
                Row(
                  children: [
                    Icon(Icons.euro, size: 16, color: subtextColor),
                    SizedBox(width: 4),
                    Text(
                      '${trip.budget!.toStringAsFixed(2)} €',
                      style: TextStyle(fontSize: 14, color: subtextColor),
                    ),
                  ],
                ),
              ],
              SizedBox(height: 8),
              Row(
                children: [
                  Icon(Icons.people, size: 16, color: subtextColor),
                  SizedBox(width: 4),
                  Text(
                    '${trip.participants.length} participant${trip.participants.length > 1 ? 's' : ''}',
                    style: TextStyle(fontSize: 14, color: subtextColor),
                  ),
                ],
              ),
            ],
          ),
        ),
      ),
    );
  }

  Color _getStatusColor(Trip trip) {
    final now = DateTime.now();
    if (now.isBefore(trip.startDate)) {
      return Colors.blue;
    } else if (now.isAfter(trip.endDate)) {
      return Colors.grey;
    } else {
      return Colors.green;
    }
  }

  String _getStatusText(Trip trip) {
    final now = DateTime.now();
    if (now.isBefore(trip.startDate)) {
      return 'À venir';
    } else if (now.isAfter(trip.endDate)) {
      return 'Terminé';
    } else {
      return 'En cours';
    }
  }

  String _formatDate(DateTime date) {
    return '${date.day}/${date.month}/${date.year}';
  }
}