feat(server): Fetch icon url of an instance (#6591)

* feat(server): Fetch icon url of an instance

Resolve #6589

* chore: Rename the function

src/services/fetch-instance-metadata.ts

@@ -0,0 +1,135 @@
+import { JSDOM } from 'jsdom';
+import fetch from 'node-fetch';
+import { getJson, getHtml, getAgentByUrl } from '../misc/fetch';
+import { Instance } from '../models/entities/instance';
+import { Instances } from '../models';
+import { getFetchInstanceMetadataLock } from '../misc/app-lock';
+import Logger from './logger';
+import { URL } from 'url';
+
+const logger = new Logger('metadata', 'cyan');
+
+export async function fetchInstanceMetadata(instance: Instance): Promise<void> {
+	const unlock = await getFetchInstanceMetadataLock(instance.host);
+
+	const _instance = await Instances.findOne({ host: instance.host });
+	const now = Date.now();
+	if (_instance && _instance.infoUpdatedAt && (now - _instance.infoUpdatedAt.getTime() < 1000 * 60 * 60 * 24)) {
+		unlock();
+		return;
+	}
+
+	logger.info(`Fetching metadata of ${instance.host} ...`);
+
+	try {
+		const [info, icon] = await Promise.all([
+			fetchNodeinfo(instance).catch(() => null),
+			fetchIconUrl(instance).catch(() => null),
+		]);
+
+		logger.succ(`Successfuly fetched metadata of ${instance.host}`);
+
+		const updates = {
+			infoUpdatedAt: new Date(),
+		} as Record<string, any>;
+
+		if (info) {
+			updates.softwareName = info.software.name.toLowerCase();
+			updates.softwareVersion = info.software.version;
+			updates.openRegistrations = info.openRegistrations;
+			updates.name = info.metadata ? (info.metadata.nodeName || info.metadata.name || null) : null;
+			updates.description = info.metadata ? (info.metadata.nodeDescription || info.metadata.description || null) : null;
+			updates.maintainerName = info.metadata ? info.metadata.maintainer ? (info.metadata.maintainer.name || null) : null : null;
+			updates.maintainerEmail = info.metadata ? info.metadata.maintainer ? (info.metadata.maintainer.email || null) : null : null;
+		}
+
+		if (icon) {
+			updates.iconUrl = icon;
+		}
+
+		await Instances.update(instance.id, updates);
+
+		logger.succ(`Successfuly updated metadata of ${instance.host}`);
+	} catch (e) {
+		logger.error(`Failed to update metadata of ${instance.host}: ${e}`);
+	} finally {
+		unlock();
+	}
+}
+
+async function fetchNodeinfo(instance: Instance): Promise<Record<string, any>> {
+	logger.info(`Fetching nodeinfo of ${instance.host} ...`);
+
+	try {
+		const wellknown = await getJson('https://' + instance.host + '/.well-known/nodeinfo')
+			.catch(e => {
+				if (e.statusCode === 404) {
+					throw 'No nodeinfo provided';
+				} else {
+					throw e.statusCode || e.message;
+				}
+			});
+
+		if (wellknown.links == null || !Array.isArray(wellknown.links)) {
+			throw 'No wellknown links';
+		}
+
+		const links = wellknown.links as any[];
+
+		const lnik1_0 = links.find(link => link.rel === 'http://nodeinfo.diaspora.software/ns/schema/1.0');
+		const lnik2_0 = links.find(link => link.rel === 'http://nodeinfo.diaspora.software/ns/schema/2.0');
+		const lnik2_1 = links.find(link => link.rel === 'http://nodeinfo.diaspora.software/ns/schema/2.1');
+		const link = lnik2_1 || lnik2_0 || lnik1_0;
+
+		if (link == null) {
+			throw 'No nodeinfo link provided';
+		}
+
+		const info = await getJson(link.href)
+			.catch(e => {
+				throw e.statusCode || e.message;
+			});
+
+		logger.succ(`Successfuly fetched nodeinfo of ${instance.host}`);
+
+		return info;
+	} catch (e) {
+		logger.error(`Failed to fetch nodeinfo of ${instance.host}: ${e}`);
+
+		throw e;
+	}
+}
+
+async function fetchIconUrl(instance: Instance): Promise<string | null> {
+	logger.info(`Fetching icon URL of ${instance.host} ...`);
+
+	const url = 'https://' + instance.host;
+
+	const html = await getHtml(url);
+
+	const { window } = new JSDOM(html);
+	const doc = window.document;
+
+	const hrefAppleTouchIconPrecomposed = doc.querySelector('link[rel="apple-touch-icon-precomposed"]')?.getAttribute('href');
+	const hrefAppleTouchIcon = doc.querySelector('link[rel="apple-touch-icon"]')?.getAttribute('href');
+	const hrefIcon = doc.querySelector('link[rel="icon"]')?.getAttribute('href');
+
+	const href = hrefAppleTouchIconPrecomposed || hrefAppleTouchIcon || hrefIcon;
+
+	if (href) {
+		return (new URL(href, url)).href;
+	}
+
+	const faviconUrl = url + '/favicon.ico';
+
+	const favicon = await fetch(faviconUrl, {
+		timeout: 10000,
+		agent: getAgentByUrl,
+	});
+
+	if (favicon.ok) {
+		return faviconUrl;
+	}
+
+	return null;
+}