/**
 * Country-code suggestion for a country-routed Popcorn browser session, when
 * the caller doesn't name one explicitly. `attach_browser` returns this as the
 * suggestion to confirm with the developer — the calling machine's own
 * public-IP country, resolved the same way reclaim-portal's `ip-geolocation`
 * util does.
 */
import { LOGGER } from '../logger.ts'

export interface IpGeolocation {
	countryCode: string
	country?: string
	region?: string
	city?: string
}

const IPINFO_URL = 'https://ipinfo.io/json'
const FALLBACK_COUNTRY_CODE = 'US'

/** Resolve the calling machine's own public-IP country. Never throws — a
 *  lookup failure just loses the "best guess" convenience, falling back to
 *  {@link FALLBACK_COUNTRY_CODE} rather than blocking applying a proxy. */
export async function suggestCountryFromIp(
	fetchImpl: typeof fetch = fetch,
): Promise<IpGeolocation> {
	try {
		const res = await fetchImpl(IPINFO_URL)
		if(!res.ok) {
			throw new Error(`ipinfo.io ${res.status}`)
		}

		const data = await res.json() as {
			country?: string
			region?: string
			city?: string
		}
		const countryCode = data.country?.toUpperCase()
		if(!countryCode) {
			throw new Error('ipinfo.io response had no country')
		}

		return {
			countryCode,
			country: data.country,
			region: data.region,
			city: data.city,
		}
	} catch(err) {
		LOGGER.warn({ err }, 'suggestCountryFromIp failed; using fallback')
		return { countryCode: FALLBACK_COUNTRY_CODE }
	}
}