import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import '../../blocs/expense/expense_bloc.dart';
import '../../blocs/expense/expense_event.dart';
import '../../blocs/expense/expense_state.dart';
import '../../blocs/balance/balance_bloc.dart';
import '../../blocs/balance/balance_event.dart';
import '../../blocs/balance/balance_state.dart';
import '../../blocs/user/user_bloc.dart';
import '../../blocs/user/user_state.dart' as user_state;
import '../../models/account.dart';
import '../../models/group.dart';
import 'add_expense_dialog.dart';
import 'balances_tab.dart';
import 'expenses_tab.dart';
import 'settlements_tab.dart';

class GroupExpensesPage extends StatefulWidget {
  final Account account;
  final Group group;

  const GroupExpensesPage({
    super.key,
    required this.account,
    required this.group,
  });

  @override
  State<GroupExpensesPage> createState() => _GroupExpensesPageState();
}

class _GroupExpensesPageState extends State<GroupExpensesPage>
    with SingleTickerProviderStateMixin {
  
  late TabController _tabController;
  
  @override
  void initState() {
    super.initState();
    _tabController = TabController(length: 3, vsync: this);
    _loadData();
  }

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

  void _loadData() {
    // Charger les dépenses du groupe
    context.read<ExpenseBloc>().add(LoadExpensesByGroup(widget.group.id));
    
    // Charger les balances du groupe
    context.read<BalanceBloc>().add(LoadGroupBalances(widget.group.id));
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.account.name),
        backgroundColor: Theme.of(context).primaryColor,
        foregroundColor: Colors.white,
        elevation: 0,
        bottom: TabBar(
          controller: _tabController,
          indicatorColor: Colors.white,
          labelColor: Colors.white,
          unselectedLabelColor: Colors.white70,
          tabs: const [
            Tab(
              icon: Icon(Icons.balance),
              text: 'Balances',
            ),
            Tab(
              icon: Icon(Icons.receipt_long),
              text: 'Dépenses',
            ),
            Tab(
              icon: Icon(Icons.payment),
              text: 'Règlements',
            ),
          ],
        ),
      ),
      body: MultiBlocListener(
        listeners: [
          BlocListener<ExpenseBloc, ExpenseState>(
            listener: (context, state) {
              if (state is ExpenseOperationSuccess) {
                ScaffoldMessenger.of(context).showSnackBar(
                  SnackBar(
                    content: Text(state.message),
                    backgroundColor: Colors.green,
                  ),
                );
                _loadData(); // Recharger les données après une opération
              } else if (state is ExpenseError) {
                ScaffoldMessenger.of(context).showSnackBar(
                  SnackBar(
                    content: Text(state.message),
                    backgroundColor: Colors.red,
                  ),
                );
              }
            },
          ),
        ],
        child: TabBarView(
          controller: _tabController,
          children: [
            // Onglet Balances
            BlocBuilder<BalanceBloc, BalanceState>(
              builder: (context, state) {
                if (state is BalanceLoading) {
                  return const Center(child: CircularProgressIndicator());
                } else if (state is GroupBalancesLoaded) {
                  return BalancesTab(balances: state.balances);
                } else if (state is BalanceError) {
                  return _buildErrorState('Erreur lors du chargement des balances: ${state.message}');
                }
                return _buildEmptyState('Aucune balance disponible');
              },
            ),
            
            // Onglet Dépenses
            BlocBuilder<ExpenseBloc, ExpenseState>(
              builder: (context, state) {
                if (state is ExpenseLoading) {
                  return const Center(child: CircularProgressIndicator());
                } else if (state is ExpensesLoaded) {
                  return ExpensesTab(
                    expenses: state.expenses,
                    group: widget.group,
                  );
                } else if (state is ExpenseError) {
                  return _buildErrorState('Erreur lors du chargement des dépenses: ${state.message}');
                }
                return _buildEmptyState('Aucune dépense trouvée');
              },
            ),
            
            // Onglet Règlements
            BlocBuilder<BalanceBloc, BalanceState>(
              builder: (context, state) {
                if (state is BalanceLoading) {
                  return const Center(child: CircularProgressIndicator());
                } else if (state is GroupBalancesLoaded) {
                  return SettlementsTab(settlements: state.settlements);
                } else if (state is BalanceError) {
                  return _buildErrorState('Erreur lors du chargement des règlements: ${state.message}');
                }
                return _buildEmptyState('Aucun règlement nécessaire');
              },
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _showAddExpenseDialog,
        heroTag: "add_expense_fab",
        tooltip: 'Ajouter une dépense',
        child: const Icon(Icons.add),
      ),
    );
  }

  Widget _buildErrorState(String message) {
    return Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Icon(
            Icons.error_outline,
            size: 80,
            color: Colors.red[300],
          ),
          const SizedBox(height: 16),
          Text(
            'Erreur',
            style: TextStyle(
              fontSize: 20,
              fontWeight: FontWeight.bold,
              color: Colors.red[600],
            ),
          ),
          const SizedBox(height: 8),
          Padding(
            padding: const EdgeInsets.symmetric(horizontal: 32),
            child: Text(
              message,
              style: TextStyle(
                fontSize: 16,
                color: Colors.grey[600],
              ),
              textAlign: TextAlign.center,
            ),
          ),
          const SizedBox(height: 32),
          ElevatedButton.icon(
            onPressed: _loadData,
            icon: const Icon(Icons.refresh),
            label: const Text('Réessayer'),
          ),
        ],
      ),
    );
  }

  Widget _buildEmptyState(String message) {
    return Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Icon(
            Icons.info_outline,
            size: 80,
            color: Colors.grey[400],
          ),
          const SizedBox(height: 16),
          Text(
            'Aucune donnée',
            style: TextStyle(
              fontSize: 20,
              fontWeight: FontWeight.bold,
              color: Colors.grey[600],
            ),
          ),
          const SizedBox(height: 8),
          Text(
            message,
            style: TextStyle(
              fontSize: 16,
              color: Colors.grey[500],
            ),
            textAlign: TextAlign.center,
          ),
        ],
      ),
    );
  }

  void _showAddExpenseDialog() {
    final userState = context.read<UserBloc>().state;
    
    if (userState is user_state.UserLoaded) {
      showDialog(
        context: context,
        builder: (context) => AddExpenseDialog(
          group: widget.group,
          currentUser: userState.user,
        ),
      );
    } else {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(
          content: Text('Erreur: utilisateur non connecté'),
          backgroundColor: Colors.red,
        ),
      );
    }
  }
}