import { headers } from "next/headers";

import { prisma } from "@/lib/prisma";

export type AuditTrailParams = {
  tenantId: string;
  actorUserId?: string | null;
  entityType: string;
  entityId: string;
  action: string;
  metadata?: unknown;
  ipAddress?: string | null;
  userAgent?: string | null;
};

function serializeMetadata(metadata: unknown) {
  if (typeof metadata === "undefined") {
    return null;
  }

  try {
    return JSON.stringify(metadata);
  } catch {
    return null;
  }
}

export async function writeAuditTrail(params: AuditTrailParams) {
  await prisma.auditLog.create({
    data: {
      tenantId: params.tenantId,
      actorUserId: params.actorUserId,
      entityType: params.entityType,
      entityId: params.entityId,
      action: params.action,
      metadataJson: serializeMetadata(params.metadata),
      ipAddress: params.ipAddress,
      userAgent: params.userAgent
    }
  });
}

export async function getRequestAuditContext() {
  const requestHeaders = await headers();
  const forwardedFor = requestHeaders.get("x-forwarded-for");
  const ipAddress = forwardedFor ? forwardedFor.split(",")[0]?.trim() : requestHeaders.get("x-real-ip");
  const userAgent = requestHeaders.get("user-agent");

  return { ipAddress, userAgent };
}