/**
 * 付款执行统一路由
 * 遵循设计方案：采购-付款-物流-退库一体化流程设计方案.md
 * 章节：七、付款执行统一页面
 * 
 * 功能：
 * - 整合所有支付类型：材料采购、一次运费、二次运费、预支、报销等
 * - 执行付款时必须上传付款凭证
 * - 统一的付款执行列表和操作界面
 */
const express = require('express');
const db = require('../db');

const router = express.Router();

/**
 * 获取待执行付款列表
 * 整合所有支付类型
 */
router.get('/pending', async (req, res) => {
  try {
    const { payment_type } = req.query;
    const results = [];
    
    // 1. 材料采购付款（来自付款计划）
    if (!payment_type || payment_type === 'material') {
      const materialPayments = await db.query(`
        SELECT 
          'material' as payment_type,
          pp.id as source_id,
          pp.stage as description,
          pp.planned_amount as amount,
          po.currency,
          pp.planned_date as due_date,
          s.name as payee_name,
          po.code as order_code,
          pp.status,
          '付款计划' as source_type
        FROM payment_plans pp
        LEFT JOIN purchase_orders po ON pp.purchase_order_id = po.id
        LEFT JOIN suppliers s ON po.supplier_id = s.id
        WHERE pp.status IN ('pending', 'requested')
      `);
      results.push(...materialPayments.rows);
    }
    
    // 2. 一次运费付款
    if (!payment_type || payment_type === 'primary_freight') {
      const primaryFreight = await db.query(`
        SELECT 
          'primary_freight' as payment_type,
          lr.id as source_id,
          '一次运费' as description,
          lr.primary_freight as amount,
          lr.primary_freight_currency as currency,
          lr.ship_date as due_date,
          lc.name as payee_name,
          po.code as order_code,
          lr.primary_freight_status as status,
          '物流单' as source_type
        FROM logistics_records lr
        LEFT JOIN purchase_orders po ON lr.purchase_order_id = po.id
        LEFT JOIN logistics_companies lc ON lr.logistics_company_id = lc.id
        WHERE lr.primary_freight_status IN ('pending', 'requested')
          AND lr.primary_freight > 0
      `);
      results.push(...primaryFreight.rows);
    }
    
    // 3. 二次运费付款
    if (!payment_type || payment_type === 'secondary_freight') {
      const secondaryFreight = await db.query(`
        SELECT 
          'secondary_freight' as payment_type,
          lr.id as source_id,
          '二次运费' as description,
          lr.secondary_freight as amount,
          lr.secondary_freight_currency as currency,
          lr.second_ship_date as due_date,
          lr.driver_phone as payee_name,
          po.code as order_code,
          lr.secondary_freight_status as status,
          '物流单' as source_type
        FROM logistics_records lr
        LEFT JOIN purchase_orders po ON lr.purchase_order_id = po.id
        WHERE lr.secondary_freight_status IN ('pending', 'requested')
          AND lr.secondary_freight > 0
      `);
      results.push(...secondaryFreight.rows);
    }
    
    // 4. 预支款
    if (!payment_type || payment_type === 'advance') {
      const advances = await db.query(`
        SELECT 
          'advance' as payment_type,
          a.id as source_id,
          a.purpose as description,
          a.amount,
          a.currency,
          a.request_date as due_date,
          a.applicant as payee_name,
          NULL as order_code,
          a.status,
          '预支申请' as source_type
        FROM advances a
        WHERE a.status = 'approved'
      `);
      results.push(...advances.rows);
    }
    
    // 5. 报销
    if (!payment_type || payment_type === 'reimbursement') {
      const reimbursements = await db.query(`
        SELECT 
          'reimbursement' as payment_type,
          r.id as source_id,
          r.description,
          r.total_amount as amount,
          r.currency,
          r.request_date as due_date,
          r.applicant as payee_name,
          NULL as order_code,
          r.status,
          '报销申请' as source_type
        FROM reimbursements r
        WHERE r.status = 'approved'
      `);
      results.push(...reimbursements.rows);
    }
    
    // 按日期排序
    results.sort((a, b) => {
      if (!a.due_date) return 1;
      if (!b.due_date) return -1;
      return new Date(a.due_date) - new Date(b.due_date);
    });
    
    res.json({
      success: true,
      data: results,
      count: results.length
    });
  } catch (error) {
    console.error('获取待执行付款列表失败:', error);
    res.status(500).json({
      success: false,
      message: '获取待执行付款列表失败',
      error: error.message
    });
  }
});

/**
 * 获取已执行付款记录
 */
router.get('/executed', async (req, res) => {
  try {
    const results = [];
    
    // 1. 材料采购付款记录
    const materialPayments = await db.query(`
      SELECT 
        'material' as payment_type,
        pp.id as source_id,
        pp.stage as description,
        pp.actual_amount as amount,
        po.currency,
        pp.actual_date as payment_date,
        s.name as payee_name,
        po.code as order_code,
        '已支付' as status,
        '付款计划' as source_type
      FROM payment_plans pp
      LEFT JOIN purchase_orders po ON pp.purchase_order_id = po.id
      LEFT JOIN suppliers s ON po.supplier_id = s.id
      WHERE pp.status = 'paid'
    `);
    results.push(...materialPayments.rows);
    
    // 2. 一次运费付款记录
    const primaryFreight = await db.query(`
      SELECT 
        'primary_freight' as payment_type,
        lr.id as source_id,
        '一次运费' as description,
        lr.primary_freight as amount,
        lr.primary_freight_currency as currency,
        lr.final_arrival_date as payment_date,
        lc.name as payee_name,
        po.code as order_code,
        '已支付' as status,
        '物流单' as source_type
      FROM logistics_records lr
      LEFT JOIN purchase_orders po ON lr.purchase_order_id = po.id
      LEFT JOIN logistics_companies lc ON lr.logistics_company_id = lc.id
      WHERE lr.primary_freight_status = 'paid'
    `);
    results.push(...primaryFreight.rows);
    
    // 3. 二次运费付款记录
    const secondaryFreight = await db.query(`
      SELECT 
        'secondary_freight' as payment_type,
        lr.id as source_id,
        '二次运费' as description,
        lr.secondary_freight as amount,
        lr.secondary_freight_currency as currency,
        lr.final_arrival_date as payment_date,
        lr.driver_phone as payee_name,
        po.code as order_code,
        '已支付' as status,
        '物流单' as source_type
      FROM logistics_records lr
      LEFT JOIN purchase_orders po ON lr.purchase_order_id = po.id
      WHERE lr.secondary_freight_status = 'paid'
    `);
    results.push(...secondaryFreight.rows);
    
    // 按日期排序（最新的在前）
    results.sort((a, b) => {
      if (!a.payment_date) return 1;
      if (!b.payment_date) return -1;
      return new Date(b.payment_date) - new Date(a.payment_date);
    });
    
    res.json({
      success: true,
      data: results,
      count: results.length
    });
  } catch (error) {
    console.error('获取已执行付款记录失败:', error);
    res.status(500).json({
      success: false,
      message: '获取已执行付款记录失败',
      error: error.message
    });
  }
});

/**
 * 执行付款
 * 遵循设计方案：必须上传付款凭证
 */
router.post('/execute', async (req, res) => {
  try {
    const { payment_type, source_id, amount, payment_date, voucher_url, remark, payee_account } = req.body;
    
    if (!payment_type || !source_id) {
      return res.status(400).json({ success: false, message: '缺少付款类型或来源ID' });
    }
    
    if (!voucher_url) {
      return res.status(400).json({ success: false, message: '执行付款必须上传付款凭证' });
    }
    
    await db.query('BEGIN TRANSACTION');
    
    try {
      const paymentDate = payment_date || new Date().toISOString().slice(0, 10);
      
      switch (payment_type) {
        case 'material':
          await db.query(`
            UPDATE payment_plans 
            SET status = 'paid', actual_amount = ?, actual_date = ?, updated_at = CURRENT_TIMESTAMP
            WHERE id = ?
          `, [amount, paymentDate, source_id]);
          
          const planResult = await db.query('SELECT purchase_order_id FROM payment_plans WHERE id = $1', [source_id]);
          if (planResult.rows.length > 0) {
            const orderId = planResult.rows[0].purchase_order_id;
            const orderStats = await db.query(`
              SELECT 
                SUM(CASE WHEN status = 'paid' THEN COALESCE(actual_amount, 0) ELSE 0 END) as paid_amount,
                SUM(planned_amount) as total_amount
              FROM payment_plans WHERE purchase_order_id = ?
            `, [orderId]);
            
            const { paid_amount, total_amount } = orderStats.rows[0];
            let newStatus = 'confirmed';
            if (paid_amount >= total_amount) {
              newStatus = 'paid';
            } else if (paid_amount > 0) {
              newStatus = 'partial_paid';
            }
            
            await db.query(`
              UPDATE purchase_orders SET paid_amount = ?, status = ?, updated_at = CURRENT_TIMESTAMP WHERE id = ?
            `, [paid_amount, newStatus, orderId]);
          }
          break;
          
        case 'primary_freight':
          await db.query(`
            UPDATE logistics_records 
            SET primary_freight_status = 'paid', primary_freight_document = ?, updated_at = CURRENT_TIMESTAMP
            WHERE id = ?
          `, [voucher_url, source_id]);
          break;
          
        case 'secondary_freight':
          await db.query(`
            UPDATE logistics_records 
            SET secondary_freight_status = 'paid', updated_at = CURRENT_TIMESTAMP
            WHERE id = ?
          `, [source_id]);
          break;
          
        case 'advance':
          await db.query(`
            UPDATE advances SET status = 'paid', updated_at = CURRENT_TIMESTAMP WHERE id = ?
          `, [source_id]);
          break;
          
        case 'reimbursement':
          await db.query(`
            UPDATE reimbursements SET status = 'paid', updated_at = CURRENT_TIMESTAMP WHERE id = ?
          `, [source_id]);
          break;
          
        default:
          throw new Error('未知的付款类型');
      }
      
      const recordCode = 'PAY-REC-' + Date.now();
      await db.query(`
        INSERT INTO payment_records 
        (code, payment_type, source_id, amount, currency, payment_date, voucher_url, payee_account, remark, created_at)
        VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, CURRENT_TIMESTAMP)
      `, [recordCode, payment_type, source_id, amount, 'CNY', paymentDate, voucher_url, payee_account, remark]);
      
      await db.query('COMMIT');
      
      res.json({
        success: true,
        message: '付款执行成功',
        data: { record_code: recordCode }
      });
    } catch (innerError) {
      await db.query('ROLLBACK');
      throw innerError;
    }
  } catch (error) {
    console.error('执行付款失败:', error);
    res.status(500).json({
      success: false,
      message: '执行付款失败',
      error: error.message
    });
  }
});

/**
 * 获取付款详情
 */
router.get('/detail/:payment_type/:source_id', async (req, res) => {
  try {
    const { payment_type, source_id } = req.params;
    let result;
    
    switch (payment_type) {
      case 'material':
        result = await db.query(`
          SELECT pp.*, po.code as order_code, s.name as supplier_name, s.country as supplier_country
          FROM payment_plans pp
          LEFT JOIN purchase_orders po ON pp.purchase_order_id = po.id
          LEFT JOIN suppliers s ON po.supplier_id = s.id
          WHERE pp.id = ?
        `, [source_id]);
        break;
        
      case 'primary_freight':
      case 'secondary_freight':
        result = await db.query(`
          SELECT lr.*, po.code as order_code, lc.name as logistics_company_name
          FROM logistics_records lr
          LEFT JOIN purchase_orders po ON lr.purchase_order_id = po.id
          LEFT JOIN logistics_companies lc ON lr.logistics_company_id = lc.id
          WHERE lr.id = ?
        `, [source_id]);
        break;
        
      case 'advance':
        result = await db.query('SELECT * FROM advances WHERE id = $1', [source_id]);
        break;
        
      case 'reimbursement':
        result = await db.query('SELECT * FROM reimbursements WHERE id = $1', [source_id]);
        break;
        
      default:
        return res.status(400).json({ success: false, message: '未知的付款类型' });
    }
    
    if (result.rows.length === 0) {
      return res.status(404).json({ success: false, message: '付款记录不存在' });
    }
    
    res.json({
      success: true,
      data: result.rows[0]
    });
  } catch (error) {
    console.error('获取付款详情失败:', error);
    res.status(500).json({
      success: false,
      message: '获取付款详情失败',
      error: error.message
    });
  }
});

/**
 * 获取付款统计
 */
router.get('/statistics', async (req, res) => {
  try {
    const stats = {
      pending_count: 0,
      pending_amount: 0,
      executed_count: 0,
      executed_amount: 0,
      by_type: {}
    };
    
    // 统计待执行付款
    const pendingResult = await db.query(`
      SELECT payment_type, COUNT(*) as count, SUM(amount) as total_amount
      FROM (
        SELECT 'material' as payment_type, pp.planned_amount as amount
        FROM payment_plans pp WHERE pp.status IN ('pending', 'requested')
        UNION ALL
        SELECT 'primary_freight', lr.primary_freight
        FROM logistics_records lr WHERE lr.primary_freight_status IN ('pending', 'requested') AND lr.primary_freight > 0
        UNION ALL
        SELECT 'secondary_freight', lr.secondary_freight
        FROM logistics_records lr WHERE lr.secondary_freight_status IN ('pending', 'requested') AND lr.secondary_freight > 0
        UNION ALL
        SELECT 'advance', a.amount
        FROM advances a WHERE a.status = 'approved'
        UNION ALL
        SELECT 'reimbursement', r.total_amount
        FROM reimbursements r WHERE r.status = 'approved'
      )
      GROUP BY payment_type
    `);
    
    for (const row of pendingResult.rows) {
      stats.pending_count += row.count;
      stats.pending_amount += row.total_amount || 0;
      stats.by_type[row.payment_type] = {
        pending_count: row.count,
        pending_amount: row.total_amount || 0
      };
    }
    
    // 统计已执行付款
    const executedResult = await db.query(`
      SELECT payment_type, COUNT(*) as count, SUM(amount) as total_amount
      FROM (
        SELECT 'material' as payment_type, pp.actual_amount as amount
        FROM payment_plans pp WHERE pp.status = 'paid'
        UNION ALL
        SELECT 'primary_freight', lr.primary_freight
        FROM logistics_records lr WHERE lr.primary_freight_status = 'paid'
        UNION ALL
        SELECT 'secondary_freight', lr.secondary_freight
        FROM logistics_records lr WHERE lr.secondary_freight_status = 'paid'
      )
      GROUP BY payment_type
    `);
    
    for (const row of executedResult.rows) {
      stats.executed_count += row.count;
      stats.executed_amount += row.total_amount || 0;
      if (!stats.by_type[row.payment_type]) {
        stats.by_type[row.payment_type] = {};
      }
      stats.by_type[row.payment_type].executed_count = row.count;
      stats.by_type[row.payment_type].executed_amount = row.total_amount || 0;
    }
    
    res.json({
      success: true,
      data: stats
    });
  } catch (error) {
    console.error('获取付款统计失败:', error);
    res.status(500).json({
      success: false,
      message: '获取付款统计失败',
      error: error.message
    });
  }
});

module.exports = router;