import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:intl/intl.dart';
import '../providers/expense_provider.dart';
import 'add_transaction_screen.dart';
import 'stats_screen.dart';
import 'category_management_screen.dart';

class HomeScreen extends StatelessWidget {
  const HomeScreen({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('我的记账本'),
        actions: [
          IconButton(
            icon: const Icon(Icons.bar_chart),
            tooltip: '统计',
            onPressed: () {
              Navigator.of(context).push(
                MaterialPageRoute(builder: (context) => const StatsScreen()),
              );
            },
          ),
        ],
      ),
      drawer: Drawer(
        child: ListView(
          padding: EdgeInsets.zero,
          children: [
            const UserAccountsDrawerHeader(
              accountName: Text('用户'),
              accountEmail: Text('本地用户'),
              currentAccountPicture: CircleAvatar(
                backgroundColor: Colors.white,
                child: Icon(Icons.person, color: Colors.deepPurple),
              ),
              decoration: BoxDecoration(
                color: Colors.deepPurple,
              ),
            ),
            ListTile(
              leading: const Icon(Icons.category),
              title: const Text('分类管理'),
              onTap: () {
                Navigator.pop(context); // Close drawer
                Navigator.of(context).push(
                  MaterialPageRoute(builder: (context) => const CategoryManagementScreen()),
                );
              },
            ),
            ListTile(
              leading: const Icon(Icons.settings),
              title: const Text('设置'),
              onTap: () {
                Navigator.pop(context);
                ScaffoldMessenger.of(context).showSnackBar(const SnackBar(content: Text('设置功能开发中...')));
              },
            ),
          ],
        ),
      ),
      body: Consumer<ExpenseProvider>(
        builder: (context, provider, child) {
          if (provider.isLoading) {
            return const Center(child: CircularProgressIndicator());
          }

          if (provider.transactions.isEmpty) {
            return const Center(
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  Icon(Icons.receipt_long, size: 64, color: Colors.grey),
                  SizedBox(height: 16),
                  Text('暂无账单，快去记一笔吧！', style: TextStyle(color: Colors.grey)),
                ],
              ),
            );
          }

          return Column(
            children: [
              _buildSummaryCard(provider),
              Expanded(
                child: ListView.builder(
                  itemCount: provider.transactions.length,
                  itemBuilder: (context, index) {
                    final transaction = provider.transactions[index];
                    final category = provider.getCategoryById(transaction.categoryId);
                    
                    return Dismissible(
                      key: Key(transaction.id),
                      background: Container(
                        color: Colors.red,
                        alignment: Alignment.centerRight,
                        padding: const EdgeInsets.only(right: 20),
                        child: const Icon(Icons.delete, color: Colors.white),
                      ),
                      direction: DismissDirection.endToStart,
                      confirmDismiss: (direction) async {
                        return await showDialog(
                          context: context,
                          builder: (ctx) => AlertDialog(
                            title: const Text('确认删除'),
                            content: const Text('确定要删除这条记录吗？'),
                            actions: [
                              TextButton(onPressed: () => Navigator.of(ctx).pop(false), child: const Text('取消')),
                              TextButton(onPressed: () => Navigator.of(ctx).pop(true), child: const Text('删除', style: TextStyle(color: Colors.red))),
                            ],
                          ),
                        );
                      },
                      onDismissed: (direction) {
                        provider.deleteTransaction(transaction.id);
                        ScaffoldMessenger.of(context).showSnackBar(const SnackBar(content: Text('已删除')));
                      },
                      child: Card(
                        margin: const EdgeInsets.symmetric(horizontal: 16, vertical: 4),
                        child: ListTile(
                          leading: CircleAvatar(
                            backgroundColor: Color(category.color),
                            child: Icon(_getIconData(category.icon), color: Colors.white),
                          ),
                          title: Text(category.name, style: const TextStyle(fontWeight: FontWeight.bold)),
                          subtitle: Column(
                            crossAxisAlignment: CrossAxisAlignment.start,
                            children: [
                              Text(DateFormat('yyyy-MM-dd HH:mm').format(transaction.date)),
                              if (transaction.note != null && transaction.note!.isNotEmpty)
                                Text(transaction.note!, style: const TextStyle(fontSize: 12, color: Colors.grey)),
                            ],
                          ),
                          trailing: Text(
                            '${transaction.type == 'income' ? '+' : '-'}${transaction.amount.toStringAsFixed(2)}',
                            style: TextStyle(
                              color: transaction.type == 'income' ? Colors.green : Colors.red,
                              fontWeight: FontWeight.bold,
                              fontSize: 16,
                            ),
                          ),
                        ),
                      ),
                    );
                  },
                ),
              ),
            ],
          );
        },
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          Navigator.of(context).push(
            MaterialPageRoute(builder: (context) => const AddTransactionScreen()),
          );
        },
        child: const Icon(Icons.add),
      ),
    );
  }

  Widget _buildSummaryCard(ExpenseProvider provider) {
    return Card(
      margin: const EdgeInsets.all(16),
      elevation: 4,
      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(16)),
      child: Container(
        decoration: BoxDecoration(
          borderRadius: BorderRadius.circular(16),
          gradient: LinearGradient(
            colors: [Colors.deepPurple.shade400, Colors.deepPurple.shade700],
            begin: Alignment.topLeft,
            end: Alignment.bottomRight,
          ),
        ),
        padding: const EdgeInsets.all(20),
        child: Column(
          children: [
            const Text('本月结余', style: TextStyle(color: Colors.white70, fontSize: 14)),
            const SizedBox(height: 8),
            Text(
              '¥${(provider.totalIncome - provider.totalExpense).toStringAsFixed(2)}',
              style: const TextStyle(color: Colors.white, fontSize: 32, fontWeight: FontWeight.bold),
            ),
            const SizedBox(height: 20),
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Row(
                      children: [
                        const Icon(Icons.arrow_downward, color: Colors.greenAccent, size: 16),
                        const SizedBox(width: 4),
                        const Text('收入', style: TextStyle(color: Colors.white70)),
                      ],
                    ),
                    Text('¥${provider.totalIncome.toStringAsFixed(2)}', style: const TextStyle(color: Colors.white, fontSize: 18, fontWeight: FontWeight.bold)),
                  ],
                ),
                Column(
                  crossAxisAlignment: CrossAxisAlignment.end,
                  children: [
                    Row(
                      children: [
                        const Icon(Icons.arrow_upward, color: Colors.redAccent, size: 16),
                        const SizedBox(width: 4),
                        const Text('支出', style: TextStyle(color: Colors.white70)),
                      ],
                    ),
                    Text('¥${provider.totalExpense.toStringAsFixed(2)}', style: const TextStyle(color: Colors.white, fontSize: 18, fontWeight: FontWeight.bold)),
                  ],
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }

  IconData _getIconData(String iconName) {
    switch (iconName) {
      case 'restaurant': return Icons.restaurant;
      case 'directions_bus': return Icons.directions_bus;
      case 'shopping_cart': return Icons.shopping_cart;
      case 'movie': return Icons.movie;
      case 'local_hospital': return Icons.local_hospital;
      case 'attach_money': return Icons.attach_money;
      case 'trending_up': return Icons.trending_up;
      case 'breakfast_dining': return Icons.breakfast_dining;
      case 'lunch_dining': return Icons.lunch_dining;
      case 'dinner_dining': return Icons.dinner_dining;
      case 'subway': return Icons.subway;
      case 'local_taxi': return Icons.local_taxi;
      default: return Icons.category;
    }
  }
}