require('dotenv').config();
const express = require('express');
const cors = require('cors');
const Database = require('better-sqlite3');
const path = require('path');

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

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

// 初始化数据库
const dbPath = path.join(__dirname, '..', 'data', 'crm.db');
const db = new Database(dbPath);

// 创建客户表
db.exec(`
  CREATE TABLE IF NOT EXISTS customers (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    name TEXT NOT NULL,
    company TEXT,
    phone TEXT,
    email TEXT,
    source TEXT,
    status TEXT DEFAULT 'potential',
    notes TEXT,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
  )
`);

// 创建跟进记录表
db.exec(`
  CREATE TABLE IF NOT EXISTS follow_ups (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    customer_id INTEGER NOT NULL,
    type TEXT,
    content TEXT,
    next_followup DATE,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (customer_id) REFERENCES customers(id) ON DELETE CASCADE
  )
`);

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

// 获取客户列表
app.get('/api/customers', (req, res) => {
  try {
    const { status, keyword } = req.query;
    let sql = 'SELECT * FROM customers WHERE 1=1';
    const params = [];
    
    if (status) {
      sql += ' AND status = ?';
      params.push(status);
    }
    if (keyword) {
      sql += ' AND (name LIKE ? OR company LIKE ? OR phone LIKE ?)';
      params.push(`%${keyword}%`, `%${keyword}%`, `%${keyword}%`);
    }
    
    sql += ' ORDER BY created_at DESC';
    const customers = db.prepare(sql).all(...params);
    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.prepare('SELECT * FROM customers WHERE id = ?').get(req.params.id);
    if (!customer) {
      return res.status(404).json({ success: false, error: '客户不存在' });
    }
    
    const followUps = db.prepare('SELECT * FROM follow_ups WHERE customer_id = ? ORDER BY created_at DESC')
      .all(req.params.id);
    
    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 stmt = db.prepare(`
      INSERT INTO customers (name, company, phone, email, source, notes)
      VALUES (?, ?, ?, ?, ?, ?)
    `);
    
    const result = stmt.run(name, company || '', phone || '', email || '', source || '', notes || '');
    
    res.json({ 
      success: true, 
      data: { id: result.lastInsertRowid },
      message: '客户创建成功'
    });
  } catch (error) {
    res.status(500).json({ success: false, error: error.message });
  }
});

// 更新客户
app.put('/api/customers/:id', (req, res) => {
  try {
    const { name, company, phone, email, source, status, notes } = req.body;
    
    const stmt = db.prepare(`
      UPDATE customers 
      SET name = ?, company = ?, phone = ?, email = ?, source = ?, status = ?, notes = ?, updated_at = CURRENT_TIMESTAMP
      WHERE id = ?
    `);
    
    stmt.run(name, company, phone, email, source, status, notes, req.params.id);
    
    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 {
    db.prepare('DELETE FROM customers WHERE id = ?').run(req.params.id);
    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 stmt = db.prepare(`
      INSERT INTO follow_ups (customer_id, type, content, next_followup)
      VALUES (?, ?, ?, ?)
    `);
    
    const result = stmt.run(req.params.id, type || '', content || '', nextFollowup || null);
    
    // 更新客户状态
    if (type === '成交') {
      db.prepare("UPDATE customers SET status = 'customer' WHERE id = ?").run(req.params.id);
    }
    
    res.json({ 
      success: true, 
      data: { id: result.lastInsertRowid },
      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.prepare('SELECT COUNT(*) as count FROM customers').get().count;
    const potential = db.prepare("SELECT COUNT(*) as count FROM customers WHERE status = 'potential'").get().count;
    const contacting = db.prepare("SELECT COUNT(*) as count FROM customers WHERE status = 'contacting'").get().count;
    const customer = db.prepare("SELECT COUNT(*) as count FROM customers WHERE status = 'customer'").get().count;
    
    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:${PORT}`);
  console.log(`📊 数据库：${dbPath}`);
});