1 files changed, 53 insertions, 0 deletions
diff --git a/packages/backend/src/server/web/url-preview.ts b/packages/backend/src/server/web/url-preview.ts
new file mode 100644
index 0000000000..1375420c0a
--- /dev/null
+++ b/packages/backend/src/server/web/url-preview.ts
@@ -0,0 +1,53 @@
+import * as Koa from 'koa';
+import summaly from 'summaly';
+import { fetchMeta } from '@/misc/fetch-meta';
+import Logger from '@/services/logger';
+import config from '@/config/index';
+import { query } from '@/prelude/url';
+import { getJson } from '@/misc/fetch';
+
+const logger = new Logger('url-preview');
+
+module.exports = async (ctx: Koa.Context) => {
+	const meta = await fetchMeta();
+
+	logger.info(meta.summalyProxy
+		? `(Proxy) Getting preview of ${ctx.query.url}@${ctx.query.lang} ...`
+		: `Getting preview of ${ctx.query.url}@${ctx.query.lang} ...`);
+
+	try {
+		const summary = meta.summalyProxy ? await getJson(`${meta.summalyProxy}?${query({
+			url: ctx.query.url,
+			lang: ctx.query.lang || 'ja-JP'
+		})}`) : await summaly(ctx.query.url, {
+			followRedirects: false,
+			lang: ctx.query.lang || 'ja-JP'
+		});
+
+		logger.succ(`Got preview of ${ctx.query.url}: ${summary.title}`);
+
+		summary.icon = wrap(summary.icon);
+		summary.thumbnail = wrap(summary.thumbnail);
+
+		// Cache 7days
+		ctx.set('Cache-Control', 'max-age=604800, immutable');
+
+		ctx.body = summary;
+	} catch (e) {
+		logger.warn(`Failed to get preview of ${ctx.query.url}: ${e}`);
+		ctx.status = 200;
+		ctx.set('Cache-Control', 'max-age=86400, immutable');
+		ctx.body = '{}';
+	}
+};
+
+function wrap(url?: string): string | null {
+	return url != null
+		? url.match(/^https?:\/\//)
+			? `${config.url}/proxy/preview.jpg?${query({
+				url,
+				preview: '1'
+			})}`
+			: url
+		: null;
+}