// routes/employees.js —— 员工管理 CRUD（纯数据库操作，权限由中间件层控制）
const { pool } = require('../db')
const bcrypt = require('bcryptjs')

// 格式化日期为 YYYY-MM-DD
function formatDate(dateStr) {
  if (!dateStr) return null
  if (typeof dateStr === 'string' && /^\d{4}-\d{2}-\d{2}$/.test(dateStr)) {
    return dateStr // 已经是正确格式
  }
  try {
    const date = new Date(dateStr)
    if (isNaN(date.getTime())) return null
    const year = date.getFullYear()
    const month = String(date.getMonth() + 1).padStart(2, '0')
    const day = String(date.getDate()).padStart(2, '0')
    return `${year}-${month}-${day}`
  } catch {
    return null
  }
}

function pagination(query) {
  const page = Math.max(Number(query.page) || 1, 1)
  const pageSize = Math.min(Math.max(Number(query.pageSize) || 10, 1), 100)
  const offset = (page - 1) * pageSize
  return { page, pageSize, offset }
}

// GET /api/employees —— 列表
async function list(req, res) {
  try {
    const { page, pageSize, offset } = pagination(req.query)
    const { id, name, status, department } = req.query

    let where = 'WHERE 1=1'
    const params = []

    // 数据范围过滤（由中间件注入 req.scope）
    if (req.scope && req.scope.sql) {
      where += ' ' + req.scope.sql
      params.push(...req.scope.params)
    }

    if (id) {
      where += ' AND id = ?'
      params.push(Number(id))
    }
    if (name) {
      where += ' AND name LIKE ?'
      params.push(`%${name}%`)
    }
    if (status !== undefined && status !== '') {
      where += ' AND status = ?'
      params.push(Number(status))
    }
    if (department) {
      where += ' AND department LIKE ?'
      params.push(`%${department}%`)
    }

    const [[{ total }]] = await pool.query(
      `SELECT COUNT(*) AS total FROM employees ${where}`,
      params
    )

    const [rows] = await pool.query(
      `SELECT * FROM employees ${where} ORDER BY id ASC LIMIT ? OFFSET ?`,
      [...params, pageSize, offset]
    )

    res.json({
      code: 0,
      message: 'ok',
      data: {
        list: rows,
        total,
        page,
        pageSize,
        totalPages: Math.ceil(total / pageSize),
      },
    })
  } catch (e) {
    console.error('[employees list] error:', e)
    res.status(500).json({ code: 500, message: e.message })
  }
}

// GET /api/employees/:id —— 详情
async function detail(req, res) {
  try {
    let sql = 'SELECT * FROM employees WHERE id = ?'
    const params = [req.params.id]

    // 数据范围过滤（由中间件注入 req.scope）
    if (req.scope && req.scope.sql) {
      sql += ' ' + req.scope.sql
      params.push(...req.scope.params)
    }

    const [rows] = await pool.query(sql, params)
    if (rows.length === 0) {
      return res.status(404).json({ code: 404, message: '员工不存在' })
    }
    res.json({ code: 0, message: 'ok', data: rows[0] })
  } catch (e) {
    console.error('[employees detail] error:', e)
    res.status(500).json({ code: 500, message: e.message })
  }
}

// POST /api/employees —— 新增
async function create(req, res) {
  const {
    name, gender, age, education, department,
    entry_date, position, salary, phone, email, status, remark,
  } = req.body || {}

  if (!name) {
    return res.status(400).json({ code: 400, message: '员工姓名必填' })
  }

  try {
    const [result] = await pool.query(
      `INSERT INTO employees (name, gender, age, education, department, entry_date, position, salary, phone, email, status, remark)
       VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
      [name,
        gender || null,
        age !== undefined ? age : null,
        education || null,
        department || null,
        formatDate(entry_date),
        position || null,
        salary !== undefined ? salary : null,
        phone || null,
        email || null,
        status !== undefined ? status : 1,
        remark || null]
    )
    const [rows] = await pool.query('SELECT * FROM employees WHERE id = ?', [result.insertId])

    // 如果中间件 allowUserCreation 要求同步创建用户账号
    if (req._createUser) {
      const { username, password, department_id } = req._createUser
      const hash = await bcrypt.hash(password, 10)
      await pool.query(
        'INSERT INTO users (username, password, is_active, department_id, employee_id) VALUES (?, ?, 1, ?, ?)',
        [username, hash, department_id, result.insertId]
      )
      delete req._createUser // 清理，避免影响后续中间件
    }

    res.json({ code: 0, message: 'ok', data: rows[0] })
  } catch (e) {
    console.error('[employees create] error:', e)
    res.status(500).json({ code: 500, message: e.message })
  }
}

// PUT /api/employees/:id —— 更新
async function update(req, res) {
  const { id } = req.params
  const fields = [
    'name', 'gender', 'age', 'education', 'department',
    'entry_date', 'position', 'salary', 'phone', 'email', 'status', 'remark',
  ]

  try {
    // 确认记录存在且在数据范围内
    let checkSql = 'SELECT id FROM employees WHERE id = ?'
    let checkParams = [id]
    if (req.scope && req.scope.sql) {
      checkSql += ' ' + req.scope.sql
      checkParams.push(...req.scope.params)
    }
    const [existing] = await pool.query(checkSql, checkParams)
    if (existing.length === 0) {
      return res.status(404).json({ code: 404, message: '员工不存在或无权操作' })
    }

    const sets = []
    const params = []
    for (const f of fields) {
      if (req.body[f] !== undefined) {
        sets.push(`${f} = ?`)
        // 日期字段需要格式化
        if (f === 'entry_date') {
          params.push(formatDate(req.body[f]))
        } else {
          params.push(req.body[f])
        }
      }
    }
    if (sets.length === 0) {
      return res.status(400).json({ code: 400, message: '没有需要更新的字段' })
    }

    params.push(id)
    await pool.query(`UPDATE employees SET ${sets.join(', ')} WHERE id = ?`, params)

    // 部门联动：员工部门变更时同步更新关联用户的部门
    if (req.body.department !== undefined) {
      const [[dept]] = await pool.query('SELECT id FROM departments WHERE description = ?', [req.body.department])
      if (dept) {
        await pool.query('UPDATE users SET department_id = ? WHERE employee_id = ?', [dept.id, id])
      }
    }

    // 状态联动：员工离职时同步禁用关联用户，复职时同步启用
    if (req.body.status !== undefined) {
      const isActive = req.body.status === 1 ? 1 : 0
      await pool.query('UPDATE users SET is_active = ? WHERE employee_id = ?', [isActive, id])
    }

    const [rows] = await pool.query('SELECT * FROM employees WHERE id = ?', [id])
    res.json({ code: 0, message: 'ok', data: rows[0] })
  } catch (e) {
    console.error('[employees update] error:', e)
    res.status(500).json({ code: 500, message: e.message })
  }
}

// DELETE /api/employees/:id —— 删除
async function remove(req, res) {
  const { id } = req.params
  try {
    let checkSql = 'SELECT id FROM employees WHERE id = ?'
    let checkParams = [id]
    if (req.scope && req.scope.sql) {
      checkSql += ' ' + req.scope.sql
      checkParams.push(...req.scope.params)
    }
    const [existing] = await pool.query(checkSql, checkParams)
    if (existing.length === 0) {
      return res.status(404).json({ code: 404, message: '员工不存在或无权操作' })
    }
    // 禁止删除自己关联的员工
    const [selfCheck] = await pool.query('SELECT id FROM users WHERE employee_id = ? AND id = ?', [id, req.user.id])
    if (selfCheck.length > 0) {
      return res.status(400).json({ code: 400, message: '不能删除自己的员工账号' })
    }
    // 同步删除关联的用户账号
    await pool.query('DELETE FROM users WHERE employee_id = ?', [id])
    await pool.query('DELETE FROM employees WHERE id = ?', [id])
    res.json({ code: 0, message: 'ok' })
  } catch (e) {
    console.error('[employees delete] error:', e)
    if (e.code === 'ER_ROW_IS_REFERENCED_2') {
      return res.status(400).json({ code: 400, message: '该员工被合同或售后记录引用，无法删除' })
    }
    res.status(500).json({ code: 500, message: e.message })
  }
}

// GET /api/employees/simple —— 简易员工列表（无数据范围限制，用于下拉选择）
async function simpleList(req, res) {
  try {
    const { department } = req.query
    let sql = 'SELECT id, name, department, position FROM employees WHERE status = 1'
    const params = []
    if (department) {
      sql += ' AND department = ?'
      params.push(department)
    }
    sql += ' ORDER BY id'
    const [rows] = await pool.query(sql, params)
    res.json({ code: 0, message: 'ok', data: rows })
  } catch (e) {
    console.error('[employees simpleList] error:', e)
    res.status(500).json({ code: 500, message: e.message })
  }
}

module.exports = { list, detail, create, update, remove, simpleList }