require('dotenv').config();
const express = require('express');
const cors = require('cors');
const fs = require('fs');
const path = require('path');

const app = express();
const PORT = process.env.PORT || 3002;

app.use(cors());
app.use(express.json());

// 使用 JSON 文件存储数据 - 修复路径
const dbPath = path.join(__dirname, '..', '..', 'data', 'crm-data.json');

function loadDB() {
  try {
    if (fs.existsSync(dbPath)) {
      return JSON.parse(fs.readFileSync(dbPath, 'utf-8'));
    }
  } catch (e) {
    console.error('加载数据库失败:', e.message);
  }
  return { customers: [], followUps: [] };
}

function saveDB(data) {
  try {
    const dir = path.dirname(dbPath);
    if (!fs.existsSync(dir)) {
      fs.mkdirSync(dir, { recursive: true });
    }
    fs.writeFileSync(dbPath, JSON.stringify(data, null, 2), 'utf-8');
    console.log('💾 数据已保存:', dbPath);
  } catch (e) {
    console.error('保存数据库失败:', e.message);
  }
}

// 初始化
let db = loadDB();
console.log('📊 数据文件:', dbPath);
console.log('📝 当前客户数:', db.customers.length);

// 健康检查
app.get('/api/health', (req, res) => {
  res.json({ status: 'ok', service: 'CRM API', customers: db.customers.length });
});

// 获取客户列表
app.get('/api/customers', (req, res) => {
  try {
    const { status, keyword } = req.query;
    let customers = db.customers;
    
    if (status) {
      customers = customers.filter(c => c.status === status);
    }
    if (keyword) {
      const k = keyword.toLowerCase();
      customers = customers.filter(c => 
        c.name.toLowerCase().includes(k) || 
        (c.company && c.company.toLowerCase().includes(k)) ||
        (c.phone && c.phone.includes(k))
      );
    }
    
    customers.sort((a, b) => new Date(b.created_at) - new Date(a.created_at));
    res.json({ success: true, data: customers });
  } catch (error) {
    res.status(500).json({ success: false, error: error.message });
  }
});

// 获取客户详情
app.get('/api/customers/:id', (req, res) => {
  try {
    const customer = db.customers.find(c => c.id == req.params.id);
    if (!customer) {
      return res.status(404).json({ success: false, error: '客户不存在' });
    }
    
    const followUps = db.followUps.filter(f => f.customer_id == req.params.id)
      .sort((a, b) => new Date(b.created_at) - new Date(a.created_at));
    
    res.json({ success: true, data: { ...customer, followUps } });
  } catch (error) {
    res.status(500).json({ success: false, error: error.message });
  }
});

// 创建客户
app.post('/api/customers', (req, res) => {
  try {
    const { name, company, phone, email, source, notes } = req.body;
    
    if (!name) {
      return res.status(400).json({ success: false, error: '客户名称必填' });
    }
    
    const customer = {
      id: Date.now(),
      name,
      company: company || '',
      phone: phone || '',
      email: email || '',
      source: source || '',
      status: 'potential',
      notes: notes || '',
      created_at: new Date().toISOString(),
      updated_at: new Date().toISOString()
    };
    
    db.customers.push(customer);
    saveDB(db);
    
    res.json({ success: true, data: { id: customer.id }, message: '客户创建成功' });
  } catch (error) {
    console.error('创建客户失败:', error);
    res.status(500).json({ success: false, error: error.message });
  }
});

// 更新客户
app.put('/api/customers/:id', (req, res) => {
  try {
    const index = db.customers.findIndex(c => c.id == req.params.id);
    if (index === -1) {
      return res.status(404).json({ success: false, error: '客户不存在' });
    }
    
    const { name, company, phone, email, source, status, notes } = req.body;
    db.customers[index] = {
      ...db.customers[index],
      name, company, phone, email, source, status, notes,
      updated_at: new Date().toISOString()
    };
    
    saveDB(db);
    res.json({ success: true, message: '客户更新成功' });
  } catch (error) {
    res.status(500).json({ success: false, error: error.message });
  }
});

// 删除客户
app.delete('/api/customers/:id', (req, res) => {
  try {
    const index = db.customers.findIndex(c => c.id == req.params.id);
    if (index === -1) {
      return res.status(404).json({ success: false, error: '客户不存在' });
    }
    
    db.customers.splice(index, 1);
    db.followUps = db.followUps.filter(f => f.customer_id != req.params.id);
    saveDB(db);
    
    res.json({ success: true, message: '客户删除成功' });
  } catch (error) {
    res.status(500).json({ success: false, error: error.message });
  }
});

// 添加跟进记录
app.post('/api/customers/:id/followups', (req, res) => {
  try {
    const { type, content, nextFollowup } = req.body;
    
    const followUp = {
      id: Date.now(),
      customer_id: parseInt(req.params.id),
      type: type || '',
      content: content || '',
      next_followup: nextFollowup || null,
      created_at: new Date().toISOString()
    };
    
    db.followUps.push(followUp);
    
    // 更新客户状态
    if (type === '成交') {
      const index = db.customers.findIndex(c => c.id == req.params.id);
      if (index !== -1) {
        db.customers[index].status = 'customer';
        db.customers[index].updated_at = new Date().toISOString();
      }
    }
    
    saveDB(db);
    res.json({ success: true, data: { id: followUp.id }, message: '跟进记录添加成功' });
  } catch (error) {
    res.status(500).json({ success: false, error: error.message });
  }
});

// 获取统计数据
app.get('/api/stats', (req, res) => {
  try {
    const total = db.customers.length;
    const potential = db.customers.filter(c => c.status === 'potential').length;
    const contacting = db.customers.filter(c => c.status === 'contacting').length;
    const customer = db.customers.filter(c => c.status === 'customer').length;
    
    res.json({ success: true, data: { total, potential, contacting, customer } });
  } catch (error) {
    res.status(500).json({ success: false, error: error.message });
  }
});

app.listen(PORT, () => {
  console.log(`🚀 CRM API 服务已启动：http://localhost:${PORT}`);
});