alpha release

update v0.8.0

src/middlewares/queryHandler/metadataHandler.ts

@@ -0,0 +1,92 @@
+import type { Request, Response } from 'express';
+import type { Metadata } from 'twtxt-lib';
+
+import { env } from '../../lib/env.js';
+import twtxtCache from '../../lib/twtxtCache.js';
+import {
+	generateEtag,
+	getQueryParameterArray,
+	getValueOrFirstEntry,
+} from '../../lib/utils.js';
+import NodeCache from '@cacheable/node-cache';
+import { QueryParameters } from '../../types.js';
+
+export interface MetadataHandler {
+	cache: NodeCache<unknown>;
+	metadataParameter: QueryParameters['metadata'];
+	req: Request;
+	res: Response;
+}
+
+/**
+ *
+ * @param req
+ * @param res
+ * @param cache
+ * @param metadataParameter
+ */
+export default function metadataHandler(
+	req: Request,
+	res: Response,
+	cache: NodeCache<unknown>,
+	metadataParameter: QueryParameters['metadata']
+) {
+	const metadataToMatch = getQueryParameterArray(req.query[metadataParameter]);
+
+	const searchTermsToMatch = [
+		...getQueryParameterArray(req.query.search),
+		...getQueryParameterArray(req.query.s),
+	];
+
+	const metadata = (cache.get('metadata') as Metadata) ?? {};
+
+	const wantsJson =
+		req.is('json') ||
+		getValueOrFirstEntry(getQueryParameterArray(req.query.format)) === 'json';
+	if (wantsJson) res.set('content-type', 'application/json');
+	else res.set('content-type', 'text/plain');
+
+	const matchedMetadata = Object.keys(metadata)
+		.filter(
+			(key) =>
+				(!metadataToMatch.length ||
+					(metadataToMatch.length === 1 && metadataToMatch[0] === '') ||
+					metadataToMatch.includes(key)) &&
+				(!searchTermsToMatch.length ||
+					searchTermsToMatch.some((term) =>
+						key.includes(term) || Array.isArray(metadata[key])
+							? (metadata[key] as string[]).some((val) => val.includes(term))
+							: metadata[key].includes(term)
+					))
+		)
+		.reduce(
+			(acc, key) => {
+				const value = metadata[key as keyof typeof metadata];
+				acc[key] = Array.isArray(value)
+					? value.filter(
+							(value) =>
+								!searchTermsToMatch.length ||
+								searchTermsToMatch.some(
+									(term) => key.includes(term) || value.includes(term)
+								)
+						)
+					: value;
+				return acc;
+			},
+			{} as Record<string, string | string[]>
+		);
+
+	const result = wantsJson
+		? JSON.stringify(matchedMetadata)
+		: Object.keys(matchedMetadata)
+				.map((key) => {
+					const value = matchedMetadata[key as keyof typeof matchedMetadata];
+
+					return Array.isArray(value)
+						? value.map((rowVal) => `${key}: ${rowVal}`).join('\n')
+						: `${key}: ${value}`;
+				})
+				.join('\n');
+
+	res.set('etag', generateEtag(result)).send(result);
+}