/**
 * 审批流引擎
 * 支持最多 3 步审批（发起人 → 直属上级 → 部门负责人）
 */
import prisma from '../lib/prisma'

interface ApprovalStep {
  step: number
  approverType: 'SUPERVISOR' | 'DEPT_HEAD' | 'PERSON'
  approverId?: string
  name: string
}

interface ApprovalRecord {
  step: number
  approverId: string
  approverName: string
  result: 'APPROVED' | 'REJECTED'
  comment?: string
  timestamp: string
}

/**
 * 创建审批实例
 */
export async function createApprovalInstance(
  orgId: string,
  userId: string,
  type: string,
  bizId: string,
  bizType: string,
  employeeId: string,
): Promise<{ instance: any; firstApprover?: any }> {
  // 查找该类型的审批流配置
  const flow = await prisma.approvalFlow.findFirst({
    where: { orgId, type, enabled: true },
  })
  if (!flow) {
    // 无审批流配置，直接通过
    return { instance: null }
  }

  const steps = flow.steps as unknown as ApprovalStep[]
  if (!steps || steps.length === 0) {
    return { instance: null }
  }

  const instance = await prisma.approvalInstance.create({
    data: {
      orgId,
      flowId: flow.id,
      type,
      bizId,
      bizType,
      status: 'PENDING',
      currentStep: 1,
      approvals: [],
      employeeId,
      createdBy: userId,
    },
  })

  // 计算第一步审批人
  const firstApprover = await resolveApprover(orgId, employeeId, steps[0])
  return { instance, firstApprover }
}

/**
 * 根据步骤配置解析审批人
 */
async function resolveApprover(orgId: string, employeeId: string, step: ApprovalStep): Promise<any> {
  const employee = await prisma.employee.findFirst({
    where: { id: employeeId, orgId },
    include: { dept: true, supervisor: true },
  })
  if (!employee) return null

  if (step.approverType === 'SUPERVISOR') {
    return employee.supervisor ? { id: employee.supervisor.id, name: employee.supervisor.name } : null
  } else if (step.approverType === 'DEPT_HEAD') {
    // 部门负责人暂用部门创建人（简化实现）
    if (employee.dept) {
      return { id: employee.dept.createdBy, name: '部门负责人' }
    }
    return null
  } else if (step.approverType === 'PERSON' && step.approverId) {
    const approver = await prisma.employee.findFirst({ where: { id: step.approverId, orgId } })
    return approver ? { id: approver.id, name: approver.name } : null
  }
  return null
}

/**
 * 处理审批
 */
export async function processApproval(
  orgId: string,
  instanceId: string,
  approverId: string,
  approverName: string,
  result: 'APPROVED' | 'REJECTED',
  comment?: string,
): Promise<{ status: string; nextApprover?: any }> {
  const instance = await prisma.approvalInstance.findFirst({
    where: { id: instanceId, orgId },
    include: { flow: true },
  })
  if (!instance) throw { code: 'NOT_FOUND', message: '审批实例不存在' }
  if (instance.status !== 'PENDING') throw { code: 'VALIDATION_ERROR', message: '审批实例已处理' }

  const steps = instance.flow.steps as unknown as ApprovalStep[]
  const currentStepConfig = steps.find(s => s.step === instance.currentStep)
  if (!currentStepConfig) throw { code: 'VALIDATION_ERROR', message: '步骤配置错误' }

  // 记录审批结果
  const approvals = (instance.approvals as unknown as ApprovalRecord[]) || []
  approvals.push({
    step: instance.currentStep,
    approverId,
    approverName,
    result,
    comment,
    timestamp: new Date().toISOString(),
  })

  if (result === 'REJECTED') {
    await prisma.approvalInstance.update({
      where: { id: instanceId },
      data: { status: 'REJECTED', approvals: approvals as any },
    })
    return { status: 'REJECTED' }
  }

  // 查找下一步
  const nextStepConfig = steps.find(s => s.step === instance.currentStep + 1)
  if (!nextStepConfig) {
    // 全部通过
    await prisma.approvalInstance.update({
      where: { id: instanceId },
      data: { status: 'APPROVED', approvals: approvals as any },
    })
    return { status: 'APPROVED' }
  }

  // 进入下一步
  const nextApprover = await resolveApprover(orgId, instance.employeeId || '', nextStepConfig)
  await prisma.approvalInstance.update({
    where: { id: instanceId },
    data: { currentStep: instance.currentStep + 1, approvals: approvals as any },
  })
  return { status: 'PENDING', nextApprover }
}

/**
 * 取消审批
 */
export async function cancelApproval(orgId: string, instanceId: string): Promise<void> {
  await prisma.approvalInstance.update({
    where: { id: instanceId },
    data: { status: 'CANCELLED' },
  })
}