Add host detection

This re-implements the posting that was achieved in v3.

api/share.js

@@ -1,102 +0,0 @@
-/*!
-	share2fedi - Instance-agnostic share page for the Fediverse.
-	Copyright (C) 2020-2023  Nikita Karamov <me@kytta.dev>
-
-	This program is free software: you can redistribute it and/or modify
-	it under the terms of the GNU Affero General Public License as published
-	by the Free Software Foundation, either version 3 of the License, or
-	(at your option) any later version.
-
-	This program is distributed in the hope that it will be useful,
-	but WITHOUT ANY WARRANTY; without even the implied warranty of
-	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-	GNU Affero General Public License for more details.
-
-	You should have received a copy of the GNU Affero General Public License
-	along with this program.  If not, see <https://www.gnu.org/licenses/>.
-
-	SPDX-License-Identifier: AGPL-3.0-or-later
-*/
-
-import http from "http";
-import https from "https";
-
-const pathsMap = {
-	mastodon: {
-		checkUrl: "/api/v1/instance/rules",
-		postUrl: "share",
-		textParam: "text",
-	},
-	gnuSocial: {
-		checkUrl: "/api/statusnet/version.xml",
-		postUrl: "/notice/new",
-		textParam: "status_textarea",
-	},
-	pleroma: {
-		checkUrl: "/api/v1/pleroma/federation_status",
-		postUrl: "share",
-		textParam: "message",
-	},
-};
-
-const queryUrl = (url, service) => {
-	return new Promise((resolve, reject) => {
-		const get = url.protocol === "https:" ? https.get : http.get;
-		get(url, ({ statusCode }) => {
-			if (statusCode === 200) {
-				console.debug(url.href, "is", service);
-				resolve(service);
-			} else {
-				reject(url);
-			}
-		}).on("error", (error) => {
-			reject(error);
-		});
-	});
-};
-
-const detectService = async (instanceURL) => {
-	const checkPromises = Object.entries(pathsMap).map(
-		([service, { checkUrl }]) =>
-			queryUrl(new URL(checkUrl, instanceURL), service),
-	);
-
-	return await Promise.any(checkPromises);
-};
-
-const requestListener = async (request, response) => {
-	if (request.method !== "POST") {
-		response.writeHead(405).end();
-		return;
-	}
-
-	let data = "";
-	request.on("data", (chunk) => {
-		data += chunk.toString();
-	});
-
-	request.on("end", () => {
-		const requestBody = new URLSearchParams(data);
-		const postText = requestBody.get("text") || "";
-		const instanceURL =
-			requestBody.get("instance") || "https://mastodon.social/";
-
-		detectService(instanceURL)
-			.then((service) => {
-				const publishUrl = new URL(pathsMap[service].postUrl, instanceURL);
-				publishUrl.search = new URLSearchParams([
-					[pathsMap[service].textParam, postText],
-				]);
-				response.writeHead(303, { Location: publishUrl.toString() }).end();
-			})
-			.catch((error) => {
-				response.writeHead(400).end(error);
-			});
-	});
-};
-
-if (!import.meta.env || import.meta.env.PROD) {
-	http.createServer(requestListener).listen(8080);
-}
-
-export const viteNodeApp = requestListener;

src/pages/api/detect/[host].ts

@@ -0,0 +1,78 @@
+import { APIRoute } from "astro";
+import { normalizeURL } from "../../../util";
+
+const PROJECTS = {
+	mastodon: {
+		checkUrl: "/api/v1/instance/rules",
+		publishEndpoint: "share",
+		params: {
+			text: "text",
+		},
+	},
+	gnuSocial: {
+		checkUrl: "/api/statusnet/version.xml",
+		publishEndpoint: "/notice/new",
+		params: {
+			text: "status_textarea",
+		},
+	},
+	pleroma: {
+		checkUrl: "/api/v1/pleroma/federation_status",
+		publishEndpoint: "share",
+		params: {
+			text: "message",
+		},
+	},
+};
+
+const checkProjectUrl = (
+	urlToCheck: URL,
+	projectId: string,
+): Promise<string> => {
+	return new Promise((resolve, reject) => {
+		fetch(urlToCheck)
+			.then((response) => {
+				if (response.ok) {
+					resolve(projectId);
+				} else {
+					reject(urlToCheck);
+				}
+			})
+			.catch((error) => {
+				reject(error.toString());
+			});
+	});
+};
+
+export const get: APIRoute = async ({ params }) => {
+	const host = params.host;
+
+	const promises = Object.entries(PROJECTS).map(([service, { checkUrl }]) =>
+		checkProjectUrl(new URL(checkUrl, normalizeURL(host)), service),
+	);
+	try {
+		const project = await Promise.any(promises);
+		return new Response(
+			JSON.stringify({
+				host,
+				project,
+				publishEndpoint: PROJECTS[project].publishEndpoint,
+				params: PROJECTS[project].params,
+			}),
+			{
+				status: 200,
+				headers: {
+					"Cache-Control": "s-maxage=86400, max-age=86400, public",
+					"Content-Type": "application/json",
+				},
+			},
+		);
+	} catch {
+		return new Response(JSON.stringify({ error: "Couldn't detect instance" }), {
+			status: 400,
+			headers: {
+				"Content-Type": "application/json",
+			},
+		});
+	}
+};

src/pages/api/share.ts

@@ -1,16 +1,24 @@
 import { APIRoute } from "astro";
 
-export const post: APIRoute = async ({ redirect, request }) => {
+export const post: APIRoute = async ({ redirect, request, url }) => {
 	const formData = await request.formData();
 
 	const text = (formData.get("text") as string) || "";
-	const instanceDomain =
+	const instanceHost =
 		(formData.get("instance") as string) || "mastodon.social";
 
-	const publishUrl = new URL("/share", `https://${instanceDomain}/`);
+	try {
-	publishUrl.search = new URLSearchParams({
+		const response = await fetch(new URL(`/api/detect/${instanceHost}`, url));
-		text,
+		const { host, publishEndpoint, params } = await response.json();
-	}).toString();
+		const publishUrl = new URL(publishEndpoint, `https://${host}/`);
-
+		publishUrl.search = new URLSearchParams([[params.text, text]]).toString();
 		return redirect(publishUrl.toString(), 303);
+	} catch {
+		return new Response(JSON.stringify({ error: "Couldn't detect instance" }), {
+			status: 400,
+			headers: {
+				"Content-Type": "application/json",
+			},
+		});
+	}
 };