76 lines
2.8 KiB
TypeScript
76 lines
2.8 KiB
TypeScript
|
import { toSeverity } from "../describe";
|
||
|
|
import { fetchJson } from "../http";
|
||
|
|
import type { WeatherAlert } from "../types";
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Active US weather alerts from the National Weather Service (free, no key).
|
||
|
|
* Docs: https://www.weather.gov/documentation/services-web-api
|
||
|
|
*
|
||
|
|
* NWS asks every app to identify itself with a User-Agent containing contact
|
||
|
|
* info, so set NWS_CONTACT in .env.local (an email or website).
|
||
|
|
* Outside the US this returns nothing, which is fine.
|
||
|
|
*/
|
||
|
|
|
||
|
|
interface NwsResponse {
|
||
|
|
features: {
|
||
|
|
properties: {
|
||
|
|
event: string;
|
||
|
|
headline: string | null;
|
||
|
|
severity: string;
|
||
|
|
senderName: string;
|
||
|
|
onset: string | null;
|
||
|
|
effective: string;
|
||
|
|
ends: string | null;
|
||
|
|
expires: string;
|
||
|
|
description: string;
|
||
|
|
instruction: string | null;
|
||
|
|
};
|
||
|
|
}[];
|
||
|
|
}
|
||
|
|
|
||
|
|
/** Rough boxes around US states and territories — skips pointless calls elsewhere. */
|
||
|
|
function mightBeInUS(lat: number, lon: number): boolean {
|
||
|
|
const mainland = lat > 24 && lat < 50 && lon > -125 && lon < -66;
|
||
|
|
const alaska = lat > 51 && lat < 72 && (lon < -129 || lon > 172);
|
||
|
|
const hawaii = lat > 18 && lat < 23 && lon > -161 && lon < -154;
|
||
|
|
const caribbean = lat > 17 && lat < 19 && lon > -68 && lon < -64; // Puerto Rico, USVI
|
||
|
|
const pacific = lat > 13 && lat < 21 && lon > 144 && lon < 146; // Guam, Northern Marianas
|
||
|
|
return mainland || alaska || hawaii || caribbean || pacific;
|
||
|
|
}
|
||
|
|
|
||
|
|
let warnedMissingContact = false;
|
||
|
|
|
||
|
|
function buildNwsUserAgent(): string {
|
||
|
|
const explicit = process.env.NWS_CONTACT?.trim();
|
||
|
|
if (explicit) return `WayfarerWeather/1.0 (${explicit})`;
|
||
|
|
|
||
|
|
const deployedHost = process.env.VERCEL_PROJECT_PRODUCTION_URL?.trim() || process.env.VERCEL_URL?.trim();
|
||
|
|
if (deployedHost) return `WayfarerWeather/1.0 (https://${deployedHost})`;
|
||
|
|
|
||
|
|
if (process.env.NODE_ENV === "production" && !warnedMissingContact) {
|
||
|
|
warnedMissingContact = true;
|
||
|
|
console.warn("[Wayfarer] Set NWS_CONTACT (email or site URL) so api.weather.gov requests include contact details.");
|
||
|
|
}
|
||
|
|
return "WayfarerWeather/1.0 (local-dev)";
|
||
|
|
}
|
||
|
|
|
||
|
|
export async function getNwsAlerts(lat: number, lon: number): Promise<WeatherAlert[]> {
|
||
|
|
if (!mightBeInUS(lat, lon)) return [];
|
||
|
|
|
||
|
|
const point = `${lat.toFixed(4)},${lon.toFixed(4)}`;
|
||
|
|
const data = await fetchJson<NwsResponse>(`https://api.weather.gov/alerts/active?point=${point}`, "National Weather Service", {
|
||
|
|
cacheSeconds: 300, // alerts matter; refresh more often
|
||
|
|
headers: { "User-Agent": buildNwsUserAgent(), Accept: "application/geo+json" },
|
||
|
|
});
|
||
|
|
|
||
|
|
return data.features.map(({ properties: p }) => ({
|
||
|
|
title: p.headline ?? p.event,
|
||
|
|
severity: toSeverity(p.severity),
|
||
|
|
source: p.senderName,
|
||
|
|
starts: p.onset ?? p.effective,
|
||
|
|
ends: p.ends ?? p.expires,
|
||
|
|
description: p.description,
|
||
|
|
instruction: p.instruction,
|
||
|
|
}));
|
||
|
|
}
|