mirror of
https://github.com/bilawalsidhu/gods-eye-view.git
synced 2026-11-04 18:34:02 +00:00
Sameh Khamis
129174c3ab
The card never appeared: the Weather panel only passed five fixed ids and only rendered lists and categorical legends for cyclones. Air quality now reaches the panel, the legend style comes from the layer's descriptor, and any layer with list items gets its list. Adds the voice manifest entry main now requires, reads ECCC through the shared capped JSON reader with a 15 s deadline and the row limit enforced, reports stale when every reading was too old, adds source tests, links the ECCC licence and moves the changelog entry into Unreleased.
105 lines
4.1 KiB
JavaScript
105 lines
4.1 KiB
JavaScript
import { readResponseJsonCapped } from '../../sources/httpBody.js';
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import { normalizeAqhiStations, normalizeAqhiObservations } from './model.js';
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const COLLECTIONS_ROOT = 'https://api.weather.gc.ca/collections';
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const STATIONS_URL = `${COLLECTIONS_ROOT}/aqhi-stations/items`;
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const OBSERVATIONS_URL = `${COLLECTIONS_ROOT}/aqhi-observations-realtime/items`;
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/** Comfortably above Canada's ~134 stations without inviting a huge page. */
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const STATION_LIMIT = 500;
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const OBSERVATION_LIMIT = 500;
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/** Station geometry is near-static — a few changes a year. Refetch twice a day. */
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const STATION_TTL_MS = 12 * 60 * 60 * 1000;
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/** A full 500-row GeoJSON page is a few hundred KB; anything past this is not a page. */
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const MAX_RESPONSE_BYTES = 4 * 1024 * 1024;
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/**
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* Request and validate a complete ECCC AQHI snapshot before it can replace
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* displayed readings. The first registered air-quality provider.
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*
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* Two collections are involved. `aqhi-stations` is the catalog — it supplies
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* every reading its coordinates and is cached for twelve hours because it
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* barely changes. `aqhi-observations-realtime` is the hourly reading feed,
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* requested with `latest=true` so the response is current values rather than
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* the full observation history, which is roughly 2,000 rows nationally.
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*
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* The station catalog is only replaced when a refresh actually returns
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* stations, so a transient empty response cannot blank the layer.
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*
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* @param {object} [options]
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* @param {Function} [options.fetchImpl] - Injected fetch, for tests.
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* @param {() => number} [options.now] - Clock seam, for tests.
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* @param {number} [options.timeoutMs=15000] - Deadline for each request.
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* @returns {{getSnapshot: Function}}
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*/
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export function createEcccAirQualitySource({
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fetchImpl = (...args) => globalThis.fetch(...args),
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now = () => Date.now(),
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timeoutMs = 15_000,
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} = {}) {
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/** @type {Map<string, object>} */
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let stations = new Map();
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let stationsFetchedAt = 0;
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/** One bounded GeoJSON page: deadline, caller abort, byte cap, row cap. */
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const getJson = async (url, limit, signal) => {
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const controller = new AbortController();
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const abort = () => controller.abort(signal.reason);
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signal?.addEventListener('abort', abort, { once: true });
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const timer = setTimeout(
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() => controller.abort(new Error('ECCC request timed out')),
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timeoutMs,
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);
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try {
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signal?.throwIfAborted();
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const response = await fetchImpl(url, {
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headers: { Accept: 'application/json' },
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signal: controller.signal,
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});
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if (!response.ok) throw new Error(`ECCC HTTP ${response.status}`);
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const payload = await readResponseJsonCapped(
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response,
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MAX_RESPONSE_BYTES,
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controller.signal,
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);
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// The server's `limit` is a request, not a guarantee.
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if (Array.isArray(payload?.features) && payload.features.length > limit)
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return { ...payload, features: payload.features.slice(0, limit) };
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return payload;
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} finally {
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clearTimeout(timer);
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signal?.removeEventListener('abort', abort);
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}
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};
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return {
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async getSnapshot({ signal } = {}) {
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const clock = now();
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if (stations.size === 0 || clock - stationsFetchedAt > STATION_TTL_MS) {
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const payload = await getJson(
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`${STATIONS_URL}?f=json&limit=${STATION_LIMIT}`,
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STATION_LIMIT,
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signal,
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);
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const next = normalizeAqhiStations(payload);
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if (!next) throw new Error('Malformed AQHI station response');
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// An empty refresh must not wipe a good catalog.
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if (next.size > 0) {
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stations = next;
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stationsFetchedAt = clock;
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}
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}
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if (stations.size === 0) throw new Error('No AQHI stations available');
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const payload = await getJson(
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`${OBSERVATIONS_URL}?f=json&latest=true&limit=${OBSERVATION_LIMIT}`,
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OBSERVATION_LIMIT,
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signal,
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);
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const readings = normalizeAqhiObservations(payload, stations, clock);
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if (!readings) throw new Error('Malformed AQHI observation response');
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return readings;
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},
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};
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}
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