/**
 * 部门管理路由
 * 提供部门的增删改查（树形结构）
 */
import { Router } from 'express'
import { authMiddleware, AuthRequest } from '../middleware/auth'
import prisma from '../lib/prisma'
import { z } from 'zod'

const router = Router()

const createDeptSchema = z.object({
  name: z.string().min(1, '部门名称必填'),
  parentId: z.string().nullable().optional(),
  sortOrder: z.number().int().default(0),
  description: z.string().max(200).optional(),
})

const updateDeptSchema = createDeptSchema.partial()

/** 获取部门树 */
router.get('/', authMiddleware, async (req: AuthRequest, res, next) => {
  try {
    // 兼容历史组织：若无任何部门，自动创建根部门（公司名）
    const existing = await prisma.department.findFirst({ where: { orgId: req.user!.orgId! } })
    if (!existing) {
      const org = await prisma.organization.findUnique({ where: { id: req.user!.orgId! } })
      if (org) {
        await prisma.department.create({
          data: {
            orgId: org.id,
            name: org.name,
            parentId: null,
            level: 0,
            sortOrder: 0,
            description: '组织根节点',
            createdBy: req.user!.id,
          },
        })
      }
    }
    const departments = await prisma.department.findMany({
      where: { orgId: req.user!.orgId! },
      orderBy: [{ sortOrder: 'asc' }, { createdAt: 'asc' }],
      include: { _count: { select: { employees: true, positions: true } } },
    })
    res.json({ success: true, data: departments })
  } catch (err) {
    next(err)
  }
})

/** 创建部门 */
router.post('/', authMiddleware, async (req: AuthRequest, res, next) => {
  try {
    const data = createDeptSchema.parse(req.body)
    // 空字符串视为无父部门，统一转为 null
    let parentId = data.parentId && data.parentId.trim() !== '' ? data.parentId : null
    // 若未指定父部门，默认挂到根部门（level=0）下
    if (!parentId) {
      const root = await prisma.department.findFirst({ where: { orgId: req.user!.orgId!, parentId: null }, orderBy: { sortOrder: 'asc' } })
      if (root) parentId = root.id
    }
    let level = 0
    if (parentId) {
      const parent = await prisma.department.findFirst({ where: { id: parentId, orgId: req.user!.orgId! } })
      if (!parent) throw { code: 'NOT_FOUND', message: '父部门不存在' }
      level = parent.level + 1
    }
    const dept = await prisma.department.create({
      data: {
        name: data.name,
        parentId,
        level,
        sortOrder: data.sortOrder,
        description: data.description,
        orgId: req.user!.orgId!,
        createdBy: req.user!.id,
      },
    })
    res.json({ success: true, data: dept })
  } catch (err) {
    next(err)
  }
})

/** 更新部门 */
router.put('/:id', authMiddleware, async (req: AuthRequest, res, next) => {
  try {
    const { id } = req.params
    const data = updateDeptSchema.parse(req.body)
    // 空字符串视为无父部门，统一转为 null
    const parentId = data.parentId !== undefined && data.parentId !== null && data.parentId.trim() !== '' ? data.parentId : data.parentId === undefined ? undefined : null
    // 防止循环引用
    if (parentId === id) throw { code: 'VALIDATION_ERROR', message: '不能将自身设为父部门' }
    let level: number | undefined
    if (parentId) {
      const parent = await prisma.department.findFirst({ where: { id: parentId, orgId: req.user!.orgId! } })
      if (!parent) throw { code: 'NOT_FOUND', message: '父部门不存在' }
      level = parent.level + 1
    } else if (parentId === null) {
      level = 0
    }
    const dept = await prisma.department.update({
      where: { id },
      data: {
        ...(data.name !== undefined ? { name: data.name } : {}),
        ...(parentId !== undefined ? { parentId } : {}),
        ...(data.sortOrder !== undefined ? { sortOrder: data.sortOrder } : {}),
        ...(data.description !== undefined ? { description: data.description } : {}),
        ...(level !== undefined ? { level } : {}),
      },
    })
    res.json({ success: true, data: dept })
  } catch (err) {
    next(err)
  }
})

/** 删除部门 */
router.delete('/:id', authMiddleware, async (req: AuthRequest, res, next) => {
  try {
    const { id } = req.params
    // 检查是否有子部门
    const children = await prisma.department.findFirst({ where: { parentId: id, orgId: req.user!.orgId! } })
    if (children) throw { code: 'VALIDATION_ERROR', message: '请先删除子部门' }
    // 检查是否有关联员工
    const employees = await prisma.employee.findFirst({ where: { departmentId: id, orgId: req.user!.orgId! } })
    if (employees) throw { code: 'VALIDATION_ERROR', message: '该部门下仍有员工，无法删除' }
    await prisma.department.delete({ where: { id } })
    res.json({ success: true })
  } catch (err) {
    next(err)
  }
})

export default router