const express = require('express');
const db = require('../db');
const { authenticate, requireAdmin } = require('../middleware/auth');

const router = express.Router();

// 获取项目收款记录
router.get('/', async (req, res) => {
  try {
    const { projectId } = req.query;
    if (!projectId) {
      return res.status(400).json({ success: false, message: '缺少项目ID' });
    }
    const result = await db.query(
      `SELECT r.*, m.milestone_name, m.percentage as milestone_percentage,
              u.name as creator_name
       FROM project_receipts r
       LEFT JOIN project_milestones m ON r.milestone_id = m.id
       LEFT JOIN users u ON r.created_by = u.id
       WHERE r.project_id = $1
       ORDER BY r.receipt_date DESC, r.created_at DESC`,
      [projectId]
    );
    res.json({ success: true, data: result.rows });
  } catch (error) {
    console.error('获取收款记录失败:', error);
    res.status(500).json({ success: false, message: '获取收款记录失败' });
  }
});

// 获取项目付款节点列表（用于收款时选择）
router.get('/milestones', async (req, res) => {
  try {
    const { projectId } = req.query;
    if (!projectId) {
      return res.status(400).json({ success: false, message: '缺少项目ID' });
    }
    const result = await db.query(
      `SELECT id, milestone_name, percentage, amount, status, completion_progress
       FROM project_milestones WHERE project_id = $1 ORDER BY id`,
      [projectId]
    );
    res.json({ success: true, data: result.rows });
  } 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' });
  }
});

// 新增收款记录（同时写入 financial_records 统一记账）
router.post('/', authenticate, async (req, res) => {
  const client = await db.pool.connect();
  try {
    await client.query('BEGIN');
    const { project_id, receipt_type, milestone_id, amount, currency, exchange_rate, receipt_date, payer_name, description, voucher_url, counterparty_id } = req.body;
    const userId = req.user?.id || req.user?.userId;

    if (!project_id) {
      await client.query('ROLLBACK');
      return res.status(400).json({ success: false, message: '缺少项目ID' });
    }

    const amt = parseFloat(amount) || 0;
    const rate = parseFloat(exchange_rate) || 1;
    const amountCny = parseFloat((amt * rate).toFixed(2));

    // 1. 写入 financial_records（统一记账）
    const today = new Date();
    const dateStr = today.toISOString().slice(0, 10).replace(/-/g, '');
    const codeResult = await client.query(
      "SELECT COUNT(*) as cnt FROM financial_records WHERE record_code LIKE $1",
      [`FIN-${dateStr}%`]
    );
    const seq = String(parseInt(codeResult.rows[0].cnt) + 1).padStart(4, '0');
    const recordCode = `FIN-${dateStr}-${seq}`;

    // 确定分类
    let categoryLevel2 = 'contract_payment';
    if (receipt_type === 'advance') {
      categoryLevel2 = 'customer_advance';
    } else if (receipt_type === 'other') {
      categoryLevel2 = 'other_income';
    }

    const frResult = await client.query(
      `INSERT INTO financial_records 
        (record_code, txn_type, category_level1, category_level2, project_id, user_id, user_name,
         amount_original, currency, exchange_rate, amount_cny, record_date, 
         counterparty_name, counterparty_type, counterparty_id, source, source_code, description, status)
       VALUES ($1, 'income', $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, 'customer', $13, 'receipt', $14, $15, 'confirmed')
       RETURNING id`,
      [
        recordCode, 'income', categoryLevel2, project_id,
        userId, req.user?.name || req.user?.username || '',
        amt, currency || 'CNY', rate, amountCny,
        receipt_date, payer_name || '',
        counterparty_id || null,
        recordCode, description || ''
      ]
    );
    const financialRecordId = frResult.rows[0].id;

    // 2. 写入 project_receipts
    const receiptResult = await client.query(
      `INSERT INTO project_receipts 
        (project_id, receipt_type, milestone_id, amount, currency, exchange_rate, amount_cny,
         receipt_date, payer_name, description, voucher_url, financial_record_id, created_by)
       VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13)
       RETURNING *`,
      [project_id, receipt_type || 'node', milestone_id || null, amt, currency || 'CNY', rate, amountCny,
       receipt_date, payer_name || '', description || '', voucher_url || '', financialRecordId, userId]
    );

    // 3. 如果是节点收款，更新里程碑完成进度
    if (receipt_type === 'node' && milestone_id) {
      const msResult = await client.query('SELECT amount FROM project_milestones WHERE id = $1', [milestone_id]);
      if (msResult.rows.length > 0 && parseFloat(msResult.rows[0].amount) > 0) {
        const totalReceived = await client.query(
          `SELECT COALESCE(SUM(amount), 0) as total FROM project_receipts 
           WHERE milestone_id = $1 AND receipt_type = 'node'`,
          [milestone_id]
        );
        const progress = Math.min(100, Math.round((parseFloat(totalReceived.rows[0].total) / parseFloat(msResult.rows[0].amount)) * 100));
        await client.query(
          `UPDATE project_milestones SET completion_progress = $1::numeric, status = CASE WHEN $1::numeric >= 100 THEN 'completed' ELSE 'in_progress' END, actual_date = CASE WHEN $1::numeric >= 100 THEN $2 ELSE actual_date END WHERE id = $3`,
          [progress, receipt_date, milestone_id]
        );
      }
    }

    await client.query('COMMIT');

    // 返回带里程碑名称的完整记录
    const fullResult = await db.query(
      `SELECT r.*, m.milestone_name FROM project_receipts r LEFT JOIN project_milestones m ON r.milestone_id = m.id WHERE r.id = $1`,
      [receiptResult.rows[0].id]
    );

    res.json({ success: true, data: fullResult.rows[0] });
  } catch (error) {
    await client.query('ROLLBACK');
    console.error('新增收款记录失败:', error);
    res.status(500).json({ success: false, message: '新增收款记录失败' });
  } finally {
    client.release();
  }
});

// 删除收款记录（同时删除 financial_records）
router.delete('/:receiptId', authenticate, async (req, res) => {
  const client = await db.pool.connect();
  try {
    await client.query('BEGIN');
    const { receiptId } = req.params;

    const receiptResult = await client.query(
      'SELECT * FROM project_receipts WHERE id = $1',
      [receiptId]
    );
    if (receiptResult.rowCount === 0) {
      await client.query('ROLLBACK');
      return res.status(404).json({ success: false, message: '收款记录不存在' });
    }

    const receipt = receiptResult.rows[0];
    const financialRecordId = receipt.financial_record_id;

    // 先删除 project_receipts（引用方），再删除 financial_records（被引用方）
    await client.query('DELETE FROM project_receipts WHERE id = $1', [receiptId]);

    if (financialRecordId) {
      await client.query('DELETE FROM financial_records WHERE id = $1', [financialRecordId]);
    }

    // 如果是节点收款，重新计算里程碑进度
    if (receipt.receipt_type === 'node' && receipt.milestone_id) {
      const msResult = await client.query('SELECT amount FROM project_milestones WHERE id = $1', [receipt.milestone_id]);
      if (msResult.rows.length > 0 && parseFloat(msResult.rows[0].amount) > 0) {
        const totalReceived = await client.query(
          `SELECT COALESCE(SUM(amount), 0) as total FROM project_receipts 
           WHERE milestone_id = $1 AND receipt_type = 'node'`,
          [receipt.milestone_id]
        );
        const progress = Math.min(100, Math.round((parseFloat(totalReceived.rows[0].total) / parseFloat(msResult.rows[0].amount)) * 100));
        await client.query(
          `UPDATE project_milestones SET completion_progress = $1::numeric, status = CASE WHEN $1::numeric >= 100 THEN 'completed' WHEN $1::numeric > 0 THEN 'in_progress' ELSE 'pending' END WHERE id = $2`,
          [progress, receipt.milestone_id]
        );
      }
    }

    await client.query('COMMIT');
    res.json({ success: true, message: '删除成功' });
  } catch (error) {
    await client.query('ROLLBACK');
    console.error('删除收款记录失败:', error);
    res.status(500).json({ success: false, message: '删除收款记录失败' });
  } finally {
    client.release();
  }
});

module.exports = router;