import { Router, Response } from 'express'
import { authMiddleware, AuthRequest } from '../middleware/auth'
import prisma from '../lib/prisma'
import { decrypt } from '../lib/crypto'
import ExcelJS from 'exceljs'
import { createGzip } from 'zlib'
import { Writable } from 'stream'

const router = Router()

// 敏感字段脱敏
function maskIdCard(idCard: string | null): string | null {
  if (!idCard) return null
  if (idCard.length >= 11) return idCard.slice(0, 3) + '*'.repeat(idCard.length - 7) + idCard.slice(-4)
  return idCard
}
function maskBankAccount(account: string | null): string | null {
  if (!account) return null
  if (account.length > 4) return '*'.repeat(account.length - 4) + account.slice(-4)
  return account
}

// 导出全部数据（支持模块选择、格式选择、脱敏）
router.get('/all', authMiddleware, async (req: AuthRequest, res: Response, next) => {
  try {
    const orgId = req.user!.orgId
    const format = (req.query.format as string) || 'json'
    const mask = req.query.mask === 'true' || req.user!.role !== 'ADMIN'
    const modules = (req.query.modules as string || 'employees,contracts,terminations,payrollBatches,payslips,socialRecords,housingRecords,riskItems').split(',')

    const fetchMap: Record<string, () => Promise<any>> = {
      employees: () => prisma.employee.findMany({ where: { orgId } }),
      contracts: () => prisma.laborContract.findMany({ where: { orgId } }),
      terminations: () => prisma.terminationRecord.findMany({ where: { orgId } }),
      payrollBatches: () => prisma.payrollBatch.findMany({ where: { orgId } }),
      payslips: () => prisma.payslip.findMany({ where: { orgId } }),
      socialRecords: () => prisma.employeeSocialInsRecord.findMany({ where: { orgId } }),
      housingRecords: () => prisma.employeeHousingFundRecord.findMany({ where: { orgId } }),
      riskItems: () => prisma.riskItem.findMany({ where: { orgId } }),
    }

    const useGzip = req.query.gzip !== 'false'
    const batchSize = 500

    if (format === 'excel') {
      const data: any = { exportedAt: new Date().toISOString(), orgId }

      if (modules.includes('employees')) {
        const employees = await fetchMap.employees()
        data.employees = employees.map((e: any) => {
          let salary = 0
          try { salary = Number(decrypt(e.monthlySalary)) || 0 } catch { salary = Number(e.monthlySalary) || 0 }
          let idCard: string | null = null
          try { if (e.idCardNumber) idCard = decrypt(e.idCardNumber) } catch { idCard = e.idCardNumber }
          let bankAccount: string | null = null
          try { if (e.bankAccount) bankAccount = decrypt(e.bankAccount) } catch { bankAccount = e.bankAccount }
          if (mask) {
            idCard = maskIdCard(idCard)
            bankAccount = maskBankAccount(bankAccount)
            if (salary) salary = 0
          }
          return { ...e, monthlySalary: salary, idCardNumber: idCard, bankAccount }
        })
      }

      for (const mod of modules) {
        if (mod === 'employees') continue
        if (fetchMap[mod]) {
          data[mod] = await fetchMap[mod]()
        }
      }

      const workbook = new ExcelJS.Workbook()
      for (const mod of modules) {
        if (!data[mod] || !data[mod].length) continue
        const ws = workbook.addWorksheet(mod.slice(0, 31))
        const rows = data[mod]
        const keys = Object.keys(rows[0]).filter(k => typeof rows[0][k] !== 'object')
        ws.columns = keys.map(k => ({ header: k, key: k, width: 18 }))
        ws.getRow(1).font = { bold: true }
        for (const row of rows) {
          const flat: any = {}
          for (const k of keys) flat[k] = typeof row[k] === 'object' ? JSON.stringify(row[k]) : row[k]
          ws.addRow(flat)
        }
      }
      res.setHeader('Content-Type', 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet')
      res.setHeader('Content-Disposition', `attachment; filename="export-${new Date().toISOString().slice(0, 10)}.xlsx"`)
      await workbook.xlsx.write(res)
      res.end()
    } else {
      // JSON 流式导出 + gzip 压缩
      if (useGzip) {
        res.setHeader('Content-Encoding', 'gzip')
        res.setHeader('Content-Type', 'application/json')
        res.setHeader('Content-Disposition', `attachment; filename="export-${new Date().toISOString().slice(0, 10)}.json.gz"`)
      } else {
        res.setHeader('Content-Type', 'application/json')
        res.setHeader('Content-Disposition', `attachment; filename="export-${new Date().toISOString().slice(0, 10)}.json"`)
      }

      const gzip = useGzip ? createGzip() : null
      const output: Writable = gzip || res
      if (gzip) { gzip.pipe(res) }

      const write = (chunk: string) => {
        output.write(Buffer.from(chunk))
      }

      write('{"exportedAt":"' + new Date().toISOString() + '","orgId":"' + orgId + '"')

      for (const mod of modules) {
        write(',"' + mod + '":[')

        if (mod === 'employees') {
          // 员工数据分批查询，避免内存溢出
          let skip = 0
          let first = true
          while (true) {
            const batch = await prisma.employee.findMany({ where: { orgId }, skip, take: batchSize })
            if (batch.length === 0) break
            for (const e of batch) {
              let salary = 0
              try { salary = Number(decrypt(e.monthlySalary)) || 0 } catch { salary = Number(e.monthlySalary) || 0 }
              let idCard: string | null = null
              try { if (e.idCardNumber) idCard = decrypt(e.idCardNumber) } catch { idCard = e.idCardNumber }
              let bankAccount: string | null = null
              try { if (e.bankAccount) bankAccount = decrypt(e.bankAccount) } catch { bankAccount = e.bankAccount }
              if (mask) {
                idCard = maskIdCard(idCard)
                bankAccount = maskBankAccount(bankAccount)
                if (salary) salary = 0
              }
              const row = { ...e, monthlySalary: salary, idCardNumber: idCard, bankAccount }
              write((first ? '' : ',') + JSON.stringify(row))
              first = false
            }
            skip += batchSize
            if (batch.length < batchSize) break
          }
        } else if (fetchMap[mod]) {
          const rows = await fetchMap[mod]()
          for (let i = 0; i < rows.length; i++) {
            write((i === 0 ? '' : ',') + JSON.stringify(rows[i]))
          }
        }

        write(']')
      }

      write('}')
      if (gzip) gzip.end()
      else res.end()
    }
  } catch (err) {
    next(err)
  }
})

// 导出本月薪税汇总 Excel
router.get('/payroll', authMiddleware, async (req: AuthRequest, res: Response, next) => {
  try {
    const orgId = req.user!.orgId
    const month = (req.query.month as string) || new Date().toISOString().slice(0, 7)

    const entries = await prisma.batchEntry.findMany({
      where: { orgId, batch: { month, status: 'ARCHIVED' } },
      include: { employee: true, batch: true },
      orderBy: { employee: { name: 'asc' } },
    })

    const workbook = new ExcelJS.Workbook()
    const ws = workbook.addWorksheet('薪税汇总')

    ws.columns = [
      { header: '员工姓名', key: 'name', width: 12 },
      { header: '部门', key: 'department', width: 15 },
      { header: '基本工资', key: 'baseSalary', width: 12 },
      { header: '加班费', key: 'overtimePay', width: 12 },
      { header: '津贴补贴', key: 'allowance', width: 12 },
      { header: '奖金', key: 'bonus', width: 12 },
      { header: '扣款', key: 'deduction', width: 12 },
      { header: '应发合计', key: 'totalPay', width: 12 },
      { header: '个人社保', key: 'socialEmp', width: 12 },
      { header: '个人公积金', key: 'housingEmp', width: 12 },
      { header: '个人所得税', key: 'tax', width: 12 },
      { header: '实发工资', key: 'netPay', width: 12 },
      { header: '企业社保', key: 'socialOrg', width: 12 },
      { header: '企业公积金', key: 'housingOrg', width: 12 },
      { header: '企业总成本', key: 'orgCost', width: 12 },
    ]

    ws.getRow(1).font = { bold: true }

    for (const e of entries) {
      ws.addRow({
        name: e.employee.name,
        department: e.employee.department,
        baseSalary: e.baseSalary,
        overtimePay: e.overtimePay,
        allowance: e.allowance,
        bonus: e.bonus,
        deduction: e.deduction,
        totalPay: e.totalPay,
        socialEmp: e.socialEmp,
        housingEmp: e.housingEmp,
        tax: e.tax,
        netPay: e.netPay,
        socialOrg: e.socialOrg,
        housingOrg: e.housingOrg,
        orgCost: e.totalPay + e.socialOrg + e.housingOrg,
      })
    }

    // 汇总行
    const totalRow = ws.addRow({
      name: '合计',
      baseSalary: { formula: `SUM(C2:C${entries.length + 1})` },
      overtimePay: { formula: `SUM(D2:D${entries.length + 1})` },
      allowance: { formula: `SUM(E2:E${entries.length + 1})` },
      bonus: { formula: `SUM(F2:F${entries.length + 1})` },
      deduction: { formula: `SUM(G2:G${entries.length + 1})` },
      totalPay: { formula: `SUM(H2:H${entries.length + 1})` },
      socialEmp: { formula: `SUM(I2:I${entries.length + 1})` },
      housingEmp: { formula: `SUM(J2:J${entries.length + 1})` },
      tax: { formula: `SUM(K2:K${entries.length + 1})` },
      netPay: { formula: `SUM(L2:L${entries.length + 1})` },
      socialOrg: { formula: `SUM(M2:M${entries.length + 1})` },
      housingOrg: { formula: `SUM(N2:N${entries.length + 1})` },
      orgCost: { formula: `SUM(O2:O${entries.length + 1})` },
    })
    totalRow.font = { bold: true }

    res.setHeader('Content-Type', 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet')
    res.setHeader('Content-Disposition', `attachment; filename="payroll-${month}.xlsx"`)
    await workbook.xlsx.write(res)
    res.end()
  } catch (err) {
    next(err)
  }
})

export default router