getUSAStateFromZipOrIp.ts

import { WebServiceClient } from "@maxmind/geoip2-node";
import zipState from "zip-state";

const { MAXMIND_APP_ID, MAXMIND_APP_KEY } = process.env;

const DEFAULT_REGION = "NY";

export async function getUSAStateFromZipOrIp({
  ip,
  zip,
}: {
  ip: string;
  zip?: string;
}) {
  const normalizedIp = ip.split(" ")[0];

  let region = DEFAULT_REGION;
  let postal: string | null = zip || null;
  let country = "US";
  let city = "empty";

  if (!zip) {
    const client = new WebServiceClient(MAXMIND_APP_ID!, MAXMIND_APP_KEY!);

    try {
      const response = await client.city(normalizedIp);
      const state = response?.subdivisions?.[0].isoCode;
      const countryFromResponse = response?.country?.isoCode;

      if (countryFromResponse === "US" && state) {
        country = "US";
        region = state || DEFAULT_REGION;
        postal = response?.postal?.code || null;
        city = response?.city?.names.en || "empty";
      }
    } catch (rejectedValue) {
      console.warn("getUSAStateFromZipOrIp MAXMIND error: ", rejectedValue);
    }
  } else {
      region = zipState(zip) ? zipState(zip) as string : DEFAULT_REGION;
  }

  return {
    region,
    postal,
    country,
    city,
  };
}