const express = require('express');
const router = express.Router();
const db = require('./db');

// 获取所有付款节点
router.get('/payment-nodes', async (req, res) => {
  try {
    const result = await db.query(`
      SELECT 
        pn.*,
        pr.project_name,
        pr.project_code
      FROM payment_nodes pn
      LEFT JOIN projects pr ON pn.project_id = pr.project_id
      ORDER BY pn.due_date ASC
    `);
    
    res.json({
      success: true,
      data: result.rows,
      count: result.rows.length
    });
  } catch (error) {
    console.error('获取付款节点失败:', error);
    res.status(500).json({
      success: false,
      message: '获取付款节点失败',
      error: error.message
    });
  }
});

// 获取单个付款节点
router.get('/payment-nodes/:id', async (req, res) => {
  try {
    const { id } = req.params;
    const result = await db.query(`
      SELECT 
        pn.*,
        pr.project_name,
        pr.project_code
      FROM payment_nodes pn
      LEFT JOIN projects pr ON pn.project_id = pr.project_id
      WHERE pn.node_id = $1
    `, [id]);
    
    if (result.rows.length === 0) {
      return res.status(404).json({
        success: false,
        message: '付款节点不存在'
      });
    }
    
    res.json({
      success: true,
      data: result.rows[0]
    });
  } catch (error) {
    console.error('获取付款节点失败:', error);
    res.status(500).json({
      success: false,
      message: '获取付款节点失败',
      error: error.message
    });
  }
});

// 创建付款节点
router.post('/payment-nodes', async (req, res) => {
  try {
    const {
      project_id,
      node_type,
      node_name,
      node_name_zh,
      node_name_th,
      node_name_en,
      amount,
      currency,
      due_date,
      status,
      notes
    } = req.body;
    
    const result = await db.query(`
      INSERT INTO payment_nodes (
        project_id, node_type, node_name, 
        node_name_zh, node_name_th, node_name_en,
        amount, currency, due_date, status, notes
      ) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11)
      RETURNING *
    `, [
      project_id, node_type, node_name,
      node_name_zh, node_name_th, node_name_en,
      amount, currency, due_date, status || 'pending', notes
    ]);
    
    res.status(201).json({
      success: true,
      message: '付款节点创建成功',
      data: result.rows[0]
    });
  } catch (error) {
    console.error('创建付款节点失败:', error);
    res.status(500).json({
      success: false,
      message: '创建付款节点失败',
      error: error.message
    });
  }
});

// 更新付款节点
router.put('/payment-nodes/:id', async (req, res) => {
  try {
    const { id } = req.params;
    const {
      node_type,
      node_name,
      node_name_zh,
      node_name_th,
      node_name_en,
      amount,
      currency,
      due_date,
      status,
      notes
    } = req.body;
    
    const result = await db.query(`
      UPDATE payment_nodes 
      SET 
        node_type = COALESCE($1, node_type),
        node_name = COALESCE($2, node_name),
        node_name_zh = COALESCE($3, node_name_zh),
        node_name_th = COALESCE($4, node_name_th),
        node_name_en = COALESCE($5, node_name_en),
        amount = COALESCE($6, amount),
        currency = COALESCE($7, currency),
        due_date = COALESCE($8, due_date),
        status = COALESCE($9, status),
        notes = COALESCE($10, notes),
        updated_at = CURRENT_TIMESTAMP
      WHERE node_id = $11
      RETURNING *
    `, [
      node_type, node_name, node_name_zh, node_name_th, node_name_en,
      amount, currency, due_date, status, notes, id
    ]);
    
    if (result.rows.length === 0) {
      return res.status(404).json({
        success: false,
        message: '付款节点不存在'
      });
    }
    
    res.json({
      success: true,
      message: '付款节点更新成功',
      data: result.rows[0]
    });
  } catch (error) {
    console.error('更新付款节点失败:', error);
    res.status(500).json({
      success: false,
      message: '更新付款节点失败',
      error: error.message
    });
  }
});

// 删除付款节点
router.delete('/payment-nodes/:id', async (req, res) => {
  try {
    const { id } = req.params;
    
    const result = await db.query(
      'DELETE FROM payment_nodes WHERE node_id = $1 RETURNING *',
      [id]
    );
    
    if (result.rows.length === 0) {
      return res.status(404).json({
        success: false,
        message: '付款节点不存在'
      });
    }
    
    res.json({
      success: true,
      message: '付款节点删除成功'
    });
  } catch (error) {
    console.error('删除付款节点失败:', error);
    res.status(500).json({
      success: false,
      message: '删除付款节点失败',
      error: error.message
    });
  }
});

// 获取付款记录
router.get('/payment-records', async (req, res) => {
  try {
    const { node_id, record_type, start_date, end_date } = req.query;
    
    let query = `
      SELECT 
        pr.*,
        pn.node_name,
        pn.project_id,
        proj.project_name
      FROM payment_records pr
      LEFT JOIN payment_nodes pn ON pr.node_id = pn.node_id
      LEFT JOIN projects proj ON pn.project_id = proj.project_id
      WHERE 1=1
    `;
    const params = [];
    let paramIndex = 1;
    
    if (node_id) {
      query += ` AND pr.node_id = $${paramIndex}`;
      params.push(node_id);
      paramIndex++;
    }
    
    if (record_type) {
      query += ` AND pr.record_type = $${paramIndex}`;
      params.push(record_type);
      paramIndex++;
    }
    
    if (start_date) {
      query += ` AND pr.payment_date >= $${paramIndex}`;
      params.push(start_date);
      paramIndex++;
    }
    
    if (end_date) {
      query += ` AND pr.payment_date <= $${paramIndex}`;
      params.push(end_date);
      paramIndex++;
    }
    
    query += ` ORDER BY pr.payment_date DESC, pr.created_at DESC`;
    
    const result = await db.query(query, params);
    
    res.json({
      success: true,
      data: result.rows,
      count: result.rows.length
    });
  } catch (error) {
    console.error('获取付款记录失败:', error);
    res.status(500).json({
      success: false,
      message: '获取付款记录失败',
      error: error.message
    });
  }
});

// 创建付款记录
router.post('/payment-records', async (req, res) => {
  try {
    const {
      node_id,
      record_type,
      amount,
      currency,
      exchange_rate,
      payment_date,
      payment_method,
      reference_number,
      status,
      notes
    } = req.body;
    
    const result = await db.query(`
      INSERT INTO payment_records (
        node_id, record_type, amount, currency, exchange_rate,
        payment_date, payment_method, reference_number, status, notes
      ) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10)
      RETURNING *
    `, [
      node_id, record_type, amount, currency, exchange_rate || 1.0,
      payment_date, payment_method, reference_number, status || 'completed', notes
    ]);
    
    // 如果是付款记录，更新付款节点状态
    if (record_type === 'payment') {
      await db.query(`
        UPDATE payment_nodes 
        SET status = 'paid', updated_at = CURRENT_TIMESTAMP
        WHERE node_id = $1
      `, [node_id]);
    }
    
    res.status(201).json({
      success: true,
      message: '付款记录创建成功',
      data: result.rows[0]
    });
  } catch (error) {
    console.error('创建付款记录失败:', error);
    res.status(500).json({
      success: false,
      message: '创建付款记录失败',
      error: error.message
    });
  }
});

// 获取汇率
router.get('/exchange-rates', async (req, res) => {
  try {
    const { from_currency, to_currency, effective_date } = req.query;
    
    let query = 'SELECT * FROM exchange_rates WHERE 1=1';
    const params = [];
    let paramIndex = 1;
    
    if (from_currency) {
      query += ` AND from_currency = $${paramIndex}`;
      params.push(from_currency);
      paramIndex++;
    }
    
    if (to_currency) {
      query += ` AND to_currency = $${paramIndex}`;
      params.push(to_currency);
      paramIndex++;
    }
    
    if (effective_date) {
      query += ` AND effective_date = $${paramIndex}`;
      params.push(effective_date);
      paramIndex++;
    }
    
    query += ` ORDER BY effective_date DESC, created_at DESC`;
    
    const result = await db.query(query, params);
    
    res.json({
      success: true,
      data: result.rows,
      count: result.rows.length
    });
  } catch (error) {
    console.error('获取汇率失败:', error);
    res.status(500).json({
      success: false,
      message: '获取汇率失败',
      error: error.message
    });
  }
});

// 创建/更新汇率
router.post('/exchange-rates', async (req, res) => {
  try {
    const { from_currency, to_currency, rate, effective_date } = req.body;
    
    // 检查是否已存在
    const checkResult = await db.query(`
      SELECT * FROM exchange_rates 
      WHERE from_currency = $1 AND to_currency = $2 AND effective_date = $3
    `, [from_currency, to_currency, effective_date]);
    
    let result;
    if (checkResult.rows.length > 0) {
      // 更新
      result = await db.query(`
        UPDATE exchange_rates 
        SET rate = $1, updated_at = CURRENT_TIMESTAMP
        WHERE from_currency = $2 AND to_currency = $3 AND effective_date = $4
        RETURNING *
      `, [rate, from_currency, to_currency, effective_date]);
    } else {
      // 创建
      result = await db.query(`
        INSERT INTO exchange_rates (from_currency, to_currency, rate, effective_date)
        VALUES ($1, $2, $3, $4)
        RETURNING *
      `, [from_currency, to_currency, rate, effective_date]);
    }
    
    res.status(201).json({
      success: true,
      message: '汇率保存成功',
      data: result.rows[0]
    });
  } catch (error) {
    console.error('保存汇率失败:', error);
    res.status(500).json({
      success: false,
      message: '保存汇率失败',
      error: error.message
    });
  }
});

// 财务统计
router.get('/finance-stats', async (req, res) => {
  try {
    // 付款节点统计
    const nodesStats = await db.query(`
      SELECT 
        COUNT(*) as total_nodes,
        COUNT(CASE WHEN status = 'pending' THEN 1 END) as pending_nodes,
        COUNT(CASE WHEN status = 'paid' THEN 1 END) as paid_nodes,
        COUNT(CASE WHEN status = 'overdue' THEN 1 END) as overdue_nodes,
        SUM(amount) as total_amount,
        SUM(CASE WHEN status = 'pending' THEN amount ELSE 0 END) as pending_amount,
        SUM(CASE WHEN status = 'paid' THEN amount ELSE 0 END) as paid_amount
      FROM payment_nodes
    `);
    
    // 付款记录统计
    const recordsStats = await db.query(`
      SELECT 
        COUNT(*) as total_records,
        COUNT(CASE WHEN record_type = 'payment' THEN 1 END) as payment_count,
        COUNT(CASE WHEN record_type = 'receipt' THEN 1 END) as receipt_count,
        SUM(CASE WHEN record_type = 'payment' THEN amount ELSE 0 END) as total_payments,
        SUM(CASE WHEN record_type = 'receipt' THEN amount ELSE 0 END) as total_receipts
      FROM payment_records
    `);
    
    // 货币分布
    const currencyStats = await db.query(`
      SELECT 
        currency,
        COUNT(*) as node_count,
        SUM(amount) as total_amount
      FROM payment_nodes
      GROUP BY currency
      ORDER BY total_amount DESC
    `);
    
    res.json({
      success: true,
      data: {
        nodes: nodesStats.rows[0],
        records: recordsStats.rows[0],
        currencies: currencyStats.rows,
        summary: {
          net_cash_flow: (recordsStats.rows[0]?.total_receipts || 0) - (recordsStats.rows[0]?.total_payments || 0),
          outstanding_amount: nodesStats.rows[0]?.pending_amount || 0
        }
      }
    });
  } catch (error) {
    console.error('获取财务统计失败:', error);
    res.status(500).json({
      success: false,
      message: '获取财务统计失败',
      error: error.message
    });
  }
});

module.exports = router;