type PerformanceSurveyTargetPolicyInput = {
  requestedEmployeeIds: unknown
  currentEmployeeId?: string | null
  surveyKind: string
}

function normalizeEmployeeIds(value: unknown): string[] {
  if (!Array.isArray(value)) return []
  return Array.from(new Set(
    value
      .map((item) => String(item || '').trim())
      .filter(Boolean),
  ))
}

export function getPerformanceSurveyTargetEmployeeIds({
  requestedEmployeeIds,
  currentEmployeeId,
  surveyKind,
}: PerformanceSurveyTargetPolicyInput): string[] {
  const requested = normalizeEmployeeIds(requestedEmployeeIds)
  if (surveyKind === 'item_course') return requested
  return normalizeEmployeeIds([currentEmployeeId, ...requested])
}