/**
 * 项目材料管理路由
 * 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：九、项目材料管理
 * 
 * 功能：
 * - 材料库存：显示项目当前材料库存
 * - 采购记录：显示项目关联的所有采购订单
 * - 退库记录：显示项目材料退库记录
 * - 材料价格历史：查询材料的历史采购价格
 */
const express = require('express');
const db = require('../db');

const router = express.Router();

/**
 * 获取项目材料库存列表
 */
router.get('/inventory/:projectId', async (req, res) => {
  try {
    const { projectId } = req.params;
    
    const result = await db.query(`
      SELECT pmi.*, p.name as product_name, p.specification
      FROM project_material_inventory pmi
      LEFT JOIN products p ON pmi.product_id = p.id
      WHERE pmi.project_id = ?
      ORDER BY p.name
    `, [projectId]);
    
    res.json({
      success: true,
      data: result.rows,
      count: result.rows.length
    });
  } catch (error) {
    console.error('获取项目材料库存失败:', error);
    res.status(500).json({
      success: false,
      message: '获取项目材料库存失败',
      error: error.message
    });
  }
});

/**
 * 获取项目材料库存汇总
 */
router.get('/inventory/:projectId/summary', async (req, res) => {
  try {
    const { projectId } = req.params;
    
    const result = await db.query(`
      SELECT 
        COUNT(*) as item_count,
        SUM(purchased_quantity) as total_purchased,
        SUM(received_quantity) as total_received,
        SUM(used_quantity) as total_used,
        SUM(returned_quantity) as total_returned,
        SUM(current_quantity) as total_current,
        SUM(total_amount) as total_value
      FROM project_material_inventory
      WHERE project_id = ?
    `, [projectId]);
    
    res.json({
      success: true,
      data: result.rows[0]
    });
  } catch (error) {
    console.error('获取项目材料库存汇总失败:', error);
    res.status(500).json({
      success: false,
      message: '获取项目材料库存汇总失败',
      error: error.message
    });
  }
});

/**
 * 获取项目采购记录
 */
router.get('/purchases/:projectId', async (req, res) => {
  try {
    const { projectId } = req.params;
    const { status } = req.query;
    
    let query = `
      SELECT po.*, s.name as supplier_name,
             (SELECT SUM(total_price) FROM purchase_order_items WHERE order_id = po.id) as total_amount,
             (SELECT SUM(CASE WHEN pp.status = 'paid' THEN COALESCE(pp.actual_amount, 0) ELSE 0 END) 
              FROM payment_plans pp WHERE pp.purchase_order_id = po.id) as paid_amount
      FROM purchase_orders po
      LEFT JOIN suppliers s ON po.supplier_id = s.id
      WHERE po.project_id = ?
    `;
    const params = [projectId];
    
    if (status) {
      query += ' AND po.status = $1';
      params.push(status);
    }
    
    query += ' ORDER BY po.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('获取项目采购记录失败:', error);
    res.status(500).json({
      success: false,
      message: '获取项目采购记录失败',
      error: error.message
    });
  }
});

/**
 * 获取项目退库记录
 */
router.get('/returns/:projectId', async (req, res) => {
  try {
    const { projectId } = req.params;
    const { status } = req.query;
    
    let query = `
      SELECT * FROM return_records
      WHERE project_id = ?
    `;
    const params = [projectId];
    
    if (status) {
      query += ' AND status = $1';
      params.push(status);
    }
    
    query += ' ORDER BY created_at DESC';
    
    const result = await db.query(query, params);
    
    const processedResults = result.rows.map(row => {
      if (row.items) {
        try {
          row.items = JSON.parse(row.items);
        } catch (e) {
          row.items = [];
        }
      }
      return row;
    });
    
    res.json({
      success: true,
      data: processedResults,
      count: processedResults.length
    });
  } catch (error) {
    console.error('获取项目退库记录失败:', error);
    res.status(500).json({
      success: false,
      message: '获取项目退库记录失败',
      error: error.message
    });
  }
});

/**
 * 获取材料价格历史
 * 遵循设计方案：每次订单确认时自动写入material_price_history表
 */
router.get('/price-history/:productId', async (req, res) => {
  try {
    const { productId } = req.params;
    const { supplier_id, limit } = req.query;
    
    let query = `
      SELECT mph.*, s.name as supplier_name, s.country as supplier_country,
             po.code as order_code
      FROM material_price_history mph
      LEFT JOIN suppliers s ON mph.supplier_id = s.id
      LEFT JOIN purchase_orders po ON mph.purchase_order_id = po.id
      WHERE mph.product_id = ?
    `;
    const params = [productId];
    
    if (supplier_id) {
      query += ' AND mph.supplier_id = $1';
      params.push(supplier_id);
    }
    
    query += ' ORDER BY mph.purchase_date DESC';
    
    if (limit) {
      query += ' LIMIT $1';
      params.push(parseInt(limit));
    }
    
    const result = await db.query(query, params);
    
    res.json({
      success: true,
      data: result.rows,
      count: result.rows.length
    });
  } catch (error) {
    console.error('获取材料价格历史失败:', error);
    res.status(500).json({
      success: false,
      message: '获取材料价格历史失败',
      error: error.message
    });
  }
});

/**
 * 获取材料平均采购价格
 */
router.get('/average-price/:productId', async (req, res) => {
  try {
    const { productId } = req.params;
    
    const result = await db.query(`
      SELECT 
        AVG(unit_price) as avg_price,
        MIN(unit_price) as min_price,
        MAX(unit_price) as max_price,
        COUNT(*) as purchase_count,
        SUM(quantity) as total_quantity
      FROM material_price_history
      WHERE product_id = ?
    `, [productId]);
    
    res.json({
      success: true,
      data: result.rows[0]
    });
  } catch (error) {
    console.error('获取材料平均价格失败:', error);
    res.status(500).json({
      success: false,
      message: '获取材料平均价格失败',
      error: error.message
    });
  }
});

/**
 * 获取材料近期价格趋势
 */
router.get('/price-trend/:productId', async (req, res) => {
  try {
    const { productId } = req.params;
    const { months } = req.query;
    const monthLimit = parseInt(months) || 6;
    
    const result = await db.query(`
      SELECT 
        strftime('%Y-%m', purchase_date) as month,
        AVG(unit_price) as avg_price,
        SUM(quantity) as total_quantity,
        COUNT(*) as purchase_count
      FROM material_price_history
      WHERE product_id = ?
        AND purchase_date >= date('now', '-' || ? || ' months')
      GROUP BY strftime('%Y-%m', purchase_date)
      ORDER BY month DESC
    `, [productId, monthLimit]);
    
    res.json({
      success: true,
      data: result.rows
    });
  } catch (error) {
    console.error('获取材料价格趋势失败:', error);
    res.status(500).json({
      success: false,
      message: '获取材料价格趋势失败',
      error: error.message
    });
  }
});

/**
 * 更新项目材料库存（手动调整）
 */
router.put('/inventory/:projectId/:productId', async (req, res) => {
  try {
    const { projectId, productId } = req.params;
    const { used_quantity, remark } = req.body;
    
    const existingResult = await db.query(`
      SELECT * FROM project_material_inventory 
      WHERE project_id = ? AND product_id = ?
    `, [projectId, productId]);
    
    if (existingResult.rows.length === 0) {
      return res.status(404).json({ success: false, message: '材料库存记录不存在' });
    }
    
    const existing = existingResult.rows[0];
    const newUsedQty = (existing.used_quantity || 0) + (used_quantity || 0);
    const newCurrentQty = Math.max(0, (existing.current_quantity || 0) - (used_quantity || 0));
    
    await db.query(`
      UPDATE project_material_inventory 
      SET used_quantity = ?, current_quantity = ?, updated_at = CURRENT_TIMESTAMP
      WHERE project_id = ? AND product_id = ?
    `, [newUsedQty, newCurrentQty, projectId, productId]);
    
    res.json({
      success: true,
      message: '库存更新成功',
      data: { used_quantity: newUsedQty, current_quantity: newCurrentQty }
    });
  } catch (error) {
    console.error('更新材料库存失败:', error);
    res.status(500).json({
      success: false,
      message: '更新材料库存失败',
      error: error.message
    });
  }
});

/**
 * 获取所有项目的材料库存汇总
 */
router.get('/all-projects-summary', async (req, res) => {
  try {
    const result = await db.query(`
      SELECT 
        p.id as project_id,
        p.name as project_name,
        COUNT(pmi.id) as item_count,
        SUM(pmi.current_quantity) as total_quantity,
        SUM(pmi.total_amount) as total_value
      FROM projects p
      LEFT JOIN project_material_inventory pmi ON p.id = pmi.project_id
      WHERE p.status = 'active'
      GROUP BY p.id
      ORDER BY p.name
    `);
    
    res.json({
      success: true,
      data: result.rows
    });
  } catch (error) {
    console.error('获取所有项目材料汇总失败:', error);
    res.status(500).json({
      success: false,
      message: '获取所有项目材料汇总失败',
      error: error.message
    });
  }
});

module.exports = router;