export interface GeoInfo {
  ip: string | null;
  city: string | null;
  region: string | null;
  country: string | null;
}

/**
 * Extract geolocation info from request headers
 * Supports Cloudflare headers in production, falls back to standard headers
 * @param headers - Request headers
 * @returns Geolocation information extracted from headers
 */
export const getGeoInfo = (headers: Headers): GeoInfo => {
  // Try Cloudflare headers first (production)
  const cfIP = headers.get("CF-Connecting-IP");
  const cfCountry = headers.get("CF-IPCountry");
  const cfCity = headers.get("CF-IPCity");
  const cfRegion = headers.get("CF-Region");

  // Fallback to X-Forwarded-For or X-Real-IP
  const forwardedFor = headers.get("X-Forwarded-For");
  const realIP = headers.get("X-Real-IP");

  const ip = cfIP ?? realIP ?? forwardedFor?.split(",")[0]?.trim() ?? null;

  return {
    ip,
    city: cfCity ?? null,
    region: cfRegion ?? null,
    country: cfCountry ?? null,
  };
};

/**
 * Extract User-Agent from request headers
 * @param headers - Request headers
 * @returns User-Agent string or "Unknown" if not present
 */
export const getUserAgent = (headers: Headers): string => {
  return headers.get("User-Agent") ?? "Unknown";
};