import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'theme/app_theme.dart';
import 'screens/dashboard_screen.dart';
import 'screens/budget_screen.dart';
import 'screens/accounts_screen.dart';
import 'screens/transactions_screen.dart';
import 'providers/db_provider.dart';
import 'data/db.dart';

final _selectedIndexProvider = StateProvider<int>((ref) => 0);

class YnabApp extends ConsumerStatefulWidget {
  const YnabApp({super.key});

  @override
  ConsumerState<YnabApp> createState() => _YnabAppState();
}

class _YnabAppState extends ConsumerState<YnabApp> {
  late final List<Widget> _screens;
  late final List<_NavItem> _navItems;
  final _searchController = TextEditingController();
  bool _searchActive = false;

  @override
  void initState() {
    super.initState();
    _screens = const [
      DashboardScreen(),
      BudgetScreen(),
      AccountsScreen(),
      TransactionsScreen(),
    ];
    _navItems = const [
      _NavItem(icon: Icons.dashboard_outlined, selectedIcon: Icons.dashboard, label: 'Tableau de bord'),
      _NavItem(icon: Icons.pie_chart_outline, selectedIcon: Icons.pie_chart, label: 'Budget'),
      _NavItem(icon: Icons.account_balance_outlined, selectedIcon: Icons.account_balance, label: 'Comptes'),
      _NavItem(icon: Icons.receipt_long_outlined, selectedIcon: Icons.receipt_long, label: 'Transactions'),
    ];
  }

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

  Future<void> _addTransaction() async {
    final accounts = ref.read(openAccountsProvider);
    final db = ref.read(dbProvider);
    if (accounts.isEmpty) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('Créez d\'abord un compte')),
      );
      return;
    }

    final payeeCtrl = TextEditingController();
    final amountCtrl = TextEditingController();
    int? accountId = accounts.first.id;
    DateTime date = DateTime.now();

    await showDialog(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('Nouvelle transaction'),
        content: SingleChildScrollView(
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              TextField(
                controller: payeeCtrl,
                decoration: const InputDecoration(labelText: 'Bénéficiaire', hintText: 'Ex: Supermarché'),
                autofocus: true,
              ),
              const SizedBox(height: 12),
              TextField(
                controller: amountCtrl,
                decoration: const InputDecoration(labelText: 'Montant', hintText: '0,00'),
                keyboardType: const TextInputType.numberWithOptions(decimal: true),
              ),
              const SizedBox(height: 12),
              DropdownButtonFormField<int>(
                value: accountId,
                decoration: const InputDecoration(labelText: 'Compte'),
                items: accounts
                    .map((a) => DropdownMenuItem(value: a.id, child: Text(a.name)))
                    .toList(),
                onChanged: (v) => accountId = v,
              ),
            ],
          ),
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(ctx),
            child: const Text('Annuler'),
          ),
          FilledButton(
            onPressed: () async {
              final payee = payeeCtrl.text.trim();
              final amountStr = amountCtrl.text.trim().replaceAll(',', '.');
              final amount = double.tryParse(amountStr);
              if (payee.isEmpty || amount == null || accountId == null) return;
              await db.into(db.transactions).insert(TransactionsCompanion.insert(
                accountId: accountId!,
                payee: payee,
                amount: amount,
                date: date,
              ));
              if (ctx.mounted) Navigator.pop(ctx);
            },
            child: const Text('Ajouter'),
          ),
        ],
      ),
    );
    payeeCtrl.dispose();
    amountCtrl.dispose();
  }

  void _toggleSearch() {
    setState(() {
      _searchActive = !_searchActive;
      if (!_searchActive) {
        _searchController.clear();
        ref.read(searchQueryProvider.notifier).state = '';
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    final selectedIndex = ref.watch(_selectedIndexProvider);
    final theme = Theme.of(context);
    final colorScheme = theme.colorScheme;

    return Scaffold(
      appBar: AppBar(
        title: _searchActive
            ? TextField(
                controller: _searchController,
                autofocus: true,
                decoration: const InputDecoration(
                  hintText: 'Rechercher…',
                  border: InputBorder.none,
                  isDense: true,
                ),
                onChanged: (v) => ref.read(searchQueryProvider.notifier).state = v,
              )
            : Text(_navItems[selectedIndex].label),
        actions: [
          if (_searchActive)
            IconButton(
              icon: const Icon(Icons.close),
              onPressed: _toggleSearch,
              tooltip: 'Fermer la recherche',
            )
          else ...[
            IconButton(
              icon: Icon(Icons.add, color: colorScheme.primary),
              onPressed: _addTransaction,
              tooltip: 'Ajouter une transaction',
            ),
            IconButton(
              icon: Icon(Icons.search, color: colorScheme.onSurfaceVariant),
              onPressed: _toggleSearch,
              tooltip: 'Rechercher',
            ),
          ],
        ],
      ),
      body: AnimatedSwitcher(
        duration: const Duration(milliseconds: 200),
        child: _screens[selectedIndex],
      ),
      bottomNavigationBar: NavigationBar(
        selectedIndex: selectedIndex,
        onDestinationSelected: (int index) {
          setState(() {
            _searchActive = false;
            _searchController.clear();
            ref.read(searchQueryProvider.notifier).state = '';
          });
          ref.read(_selectedIndexProvider.notifier).state = index;
        },
        destinations: _navItems.map((item) {
          return NavigationDestination(
            icon: Icon(item.icon),
            selectedIcon: Icon(item.selectedIcon),
            label: item.label,
          );
        }).toList(),
      ),
    );
  }
}

class _NavItem {
  final IconData icon;
  final IconData selectedIcon;
  final String label;
  const _NavItem({required this.icon, required this.selectedIcon, required this.label});
}