import { firstHeaderValue } from '@admin/actions/audit/first-header-value'
import { MAX_IP_LENGTH } from '@admin/actions/audit/max-ip-length'
import { MAX_USER_AGENT_LENGTH } from '@admin/actions/audit/max-user-agent-length'
import { headers } from 'next/headers'

function truncate(value: string | null, maxLength: number): string | null {
  if (!value) return null
  return value.length > maxLength ? value.slice(0, maxLength) : value
}

export async function getAuditRequestMetadata(): Promise<{
  ipAddress: string | null
  userAgent: string | null
}> {
  try {
    const requestHeaders = await headers()
    const ipAddress =
      firstHeaderValue(requestHeaders.get('x-forwarded-for')) ??
      firstHeaderValue(requestHeaders.get('x-real-ip')) ??
      firstHeaderValue(requestHeaders.get('cf-connecting-ip'))
    const userAgent = requestHeaders.get('user-agent')?.trim() || null

    return {
      ipAddress: truncate(ipAddress, MAX_IP_LENGTH),
      userAgent: truncate(userAgent, MAX_USER_AGENT_LENGTH)
    }
  } catch {
    return {
      ipAddress: null,
      userAgent: null
    }
  }
}