Shields

package.json

@@ -78,6 +78,7 @@
         "ajv": "^8.17.1",
         "ajv-formats": "^3.0.1",
         "amqplib": "^0.10.9",
+        "badge-maker": "^5.0.2",
         "bcrypt": "^6.0.0",
         "body-parser": "^2.2.1",
         "chalk": "^5.6.2",

src/api/middlewares/Authentication.ts

@@ -53,6 +53,7 @@ export const NO_AUTHORIZATION_ROUTES = [
     "/oauth2/callback",
     // Asset delivery
     /^(GET|HEAD) \/guilds\/\d+\/widget\.(json|png)/,
+    /^(GET|HEAD) \/guilds\/\d+\/shield\.svg/,
     // Connections
     /^(POST|HEAD) \/connections\/\w+\/callback/,
     // Image proxy

src/api/routes/guilds/#guild_id/shield.svg.ts

@@ -0,0 +1,100 @@
+/*
+	Spacebar: A FOSS re-implementation and extension of the Discord.com backend.
+	Copyright (C) 2023 Spacebar and Spacebar Contributors
+
+	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/>.
+*/
+
+import { route } from "@spacebar/api";
+import { DiscordApiErrors, Guild, Member } from "@spacebar/util";
+import { Request, Response, Router } from "express";
+import { makeBadge } from "badge-maker";
+import path from "path";
+import fs from "fs";
+
+const router: Router = Router({ mergeParams: true });
+
+// Undocumented API notes:
+// An invite is created for the widget_channel_id on request (only if an existing one created by the widget doesn't already exist)
+// This invite created doesn't include an inviter object like user created ones and has a default expiry of 24 hours
+// Missing user object information is intentional (https://github.com/discord/discord-api-docs/issues/1287)
+// channels returns voice channel objects where @everyone has the CONNECT permission
+// members (max 100 returned) is a sample of all members, and bots par invisible status, there exists some alphabetical distribution pattern between the members returned
+
+// https://discord.com/developers/docs/resources/guild#get-guild-widget
+const expiryTime = 1000 * 60 * 5; // 5 minutes
+const jsonDataCache = new Map<string, { data: Promise<string>; expiry: Date }>();
+
+const assetsPath = path.join(__dirname, "..", "..", "..", "..", "..", "assets");
+const whiteLogo = "data:image/png;base64," + Buffer.from(fs.readFileSync(path.join(assetsPath, "icon_white.png"))).toString("base64");
+const blueLogo = "data:image/png;base64," + Buffer.from(fs.readFileSync(path.join(assetsPath, "icon.png"))).toString("base64");
+
+router.get(
+    "/",
+    route({
+        responses: {
+            200: {},
+            404: {
+                body: "APIErrorResponse",
+            },
+        },
+    }),
+    async (req: Request, res: Response) => {
+        const { guild_id } = req.params;
+
+        let cacheEntry = jsonDataCache.get(guild_id);
+        if (!cacheEntry || cacheEntry.expiry.getTime() < Date.now()) {
+            // Create new cache entry
+            const dataPromise = getWidgetJsonData(guild_id);
+            cacheEntry = {
+                data: dataPromise,
+                expiry: new Date(Date.now() + expiryTime),
+            };
+            console.log("[Shield] Caching shield data for guild", guild_id);
+            jsonDataCache.set(guild_id, cacheEntry);
+        }
+
+        const cacheRemainingSeconds = Math.floor((cacheEntry.expiry.getTime() - Date.now()) / 1000);
+        res.set("Cache-Control", `public, max-age=${cacheRemainingSeconds}, s-maxage=${cacheRemainingSeconds}, immutable`);
+        res.set("Content-Type", "image/svg+xml;charset=utf-8");
+        return res.status(200).send(await cacheEntry.data);
+    },
+);
+
+async function getWidgetJsonData(guild_id: string, useWhiteLogo: boolean = true) {
+    const guild = await Guild.findOneOrFail({
+        where: { id: guild_id },
+        select: {
+            channel_ordering: true,
+            widget_channel_id: true,
+            widget_enabled: true,
+            presence_count: true,
+            name: true,
+        },
+    });
+    if (!guild.widget_enabled) throw DiscordApiErrors.EMBED_DISABLED;
+
+    const members = await Member.find({ where: { guild_id: guild_id }, relations: { user: { sessions: true } } });
+    const minLastSeen = Date.now() - 1000 * 60 * 5;
+    const onlineMembers = members.filter((m) => m.user.sessions.filter((s) => (s.last_seen?.getTime() ?? 0) > minLastSeen).length > 0);
+
+    return makeBadge({
+        label: "Spacebar",
+        message: `${onlineMembers.length} online`,
+        color: "#0185ff",
+        logoBase64: useWhiteLogo ? whiteLogo : blueLogo,
+    });
+}
+
+export default router;