Function getPreferredProxy

site/src/contexts/ProxyContext.tsx:218–243

(
	proxies: readonly Region[],
	selectedProxy?: Region,
	latencies?: Record<string, ProxyLatencyReport>,
	autoSelectBasedOnLatency = true,
)

 *                  If not, `primary` is always the best default.
 */
export const getPreferredProxy = (
	proxies: readonly Region[],
	selectedProxy?: Region,
	latencies?: Record<string, ProxyLatencyReport>,
	autoSelectBasedOnLatency = true,
): PreferredProxy => {
	// If a proxy is selected, make sure it is in the list of proxies. If it is not
	// we should default to the primary.
	selectedProxy = proxies.find(
		(proxy) => selectedProxy && proxy.id === selectedProxy.id,
	);

	// If no proxy is selected, or the selected proxy is unhealthy default to the primary proxy.
	if (!selectedProxy?.healthy) {
		// Default to the primary proxy
		selectedProxy = proxies.find((proxy) => proxy.name === "primary");

		// If we have latencies, then attempt to use the best proxy by latency instead.
		const best = selectByLatency(proxies, latencies);
		if (autoSelectBasedOnLatency && best !== undefined) {
			selectedProxy = best;
		}
	}

	return computeUsableURLS(selectedProxy);
};

const selectByLatency = (
	proxies: readonly Region[],