const express = require('express');
const cors = require('cors');

const app = express();

// 中间件
app.use(cors());
app.use(express.json());

// 模拟认证中间件
const mockAuthMiddleware = (req, res, next) => {
  req.user = { id: 1, username: 'test' };
  next();
};

// 模拟仪表盘控制器
const mockDashboardController = {
  getStats: (req, res) => {
    res.json({
      success: true,
      message: '获取统计数据成功（模拟数据）',
      data: {
        overview: {
          totalUsers: 1250,
          totalAccounts: 3420,
          totalTransactions: 15680,
          totalBalance: 12500000.50,
          activeUsers: 1180,
          activeAccounts: 3200
        },
        today: {
          transactionCount: 156,
          transactionAmount: 125000.00
        },
        accountTypes: [
          { type: 'savings', count: 2100, totalBalance: 8500000.00 },
          { type: 'checking', count: 800, totalBalance: 3200000.00 },
          { type: 'credit', count: 400, totalBalance: 500000.00 },
          { type: 'loan', count: 120, totalBalance: 300000.00 }
        ],
        trends: [
          { date: '2024-01-15', count: 45, totalAmount: 12500.00 },
          { date: '2024-01-16', count: 52, totalAmount: 15200.00 },
          { date: '2024-01-17', count: 38, totalAmount: 9800.00 },
          { date: '2024-01-18', count: 61, totalAmount: 18500.00 },
          { date: '2024-01-19', count: 48, totalAmount: 13200.00 },
          { date: '2024-01-20', count: 55, totalAmount: 16800.00 },
          { date: '2024-01-21', count: 42, totalAmount: 11200.00 }
        ]
      }
    });
  },

  getRecentTransactions: (req, res) => {
    const { limit = 10 } = req.query;
    
    const mockTransactions = [
      {
        id: 1,
        type: 'deposit',
        amount: 1000.00,
        description: '存款',
        status: 'completed',
        created_at: new Date(),
        account: {
          account_number: '1234567890',
          user: {
            username: 'user1',
            real_name: '张三'
          }
        }
      },
      {
        id: 2,
        type: 'withdrawal',
        amount: 500.00,
        description: '取款',
        status: 'completed',
        created_at: new Date(Date.now() - 3600000),
        account: {
          account_number: '1234567891',
          user: {
            username: 'user2',
            real_name: '李四'
          }
        }
      },
      {
        id: 3,
        type: 'transfer',
        amount: 200.00,
        description: '转账',
        status: 'completed',
        created_at: new Date(Date.now() - 7200000),
        account: {
          account_number: '1234567892',
          user: {
            username: 'user3',
            real_name: '王五'
          }
        }
      }
    ].slice(0, parseInt(limit));

    res.json({
      success: true,
      message: '获取最近交易记录成功（模拟数据）',
      data: mockTransactions
    });
  }
};

// 路由
app.get('/health', (req, res) => {
  res.json({ message: '银行后端服务运行正常', timestamp: new Date().toISOString() });
});

app.get('/api/dashboard', mockAuthMiddleware, mockDashboardController.getStats);
app.get('/api/dashboard/recent-transactions', mockAuthMiddleware, mockDashboardController.getRecentTransactions);

// 启动服务器
const PORT = 5351;
app.listen(PORT, () => {
  console.log(`🚀 银行后端模拟服务已启动`);
  console.log(`📡 服务地址: http://localhost:${PORT}`);
  console.log(`🏥 健康检查: http://localhost:${PORT}/health`);
  console.log(`📊 仪表盘API: http://localhost:${PORT}/api/dashboard`);
  console.log(`💳 最近交易API: http://localhost:${PORT}/api/dashboard/recent-transactions`);
});