add basic gatewayt

package.json

@@ -11,13 +11,16 @@
     "express": "^4.17.3",
     "express-validator": "^6.14.0",
     "jsonwebtoken": "^8.5.1",
-    "pg": "^8.7.3"
+    "pg": "^8.7.3",
+    "ws": "^8.5.0"
   },
   "devDependencies": {
     "@types/bcrypt": "^5.0.0",
     "@types/express": "^4.17.13",
     "@types/jsonwebtoken": "^8.5.8",
+    "@types/node": "^17.0.23",
     "@types/pg": "^8.6.5",
+    "@types/ws": "^8.5.3",
     "typescript": "^4.6.3"
   }
 }

src/errors.ts

@@ -6,3 +6,10 @@ export const errors = {
     FORBIDDEN_DUE_TO_MISSING_PERMISSIONS: { code: 6005, message: "Forbidden due to missing permission(s)" },
     GOT_NO_DATABASE_DATA: { code: 7001, message: "Unexpectedly got no data from database" }
 };
+
+export const gatewayErrors = {
+    BAD_PAYLOAD: { code: 4001, message: "Bad payload" },
+    BAD_AUTH: { code: 4002, message: "Bad authentication" },
+    AUTHENTICATION_TIMEOUT: { code: 4003, message: "Authentication timeout" },
+    NO_PING: { code: 4004, message: "No ping" },
+};

src/gateway/gatewaypayloadtype.ts

@@ -0,0 +1,5 @@
+export enum GatewayPayloadType {
+    Hello = 0,
+    Authenticate,
+    Ready
+}

src/gateway/index.ts

@@ -0,0 +1,123 @@
+import { Server } from "node:http";
+import { performance } from "node:perf_hooks";
+import WebSocket, { WebSocketServer } from "ws";
+import { decodeTokenOrNull } from "../auth";
+import { gatewayErrors } from "../errors";
+import { GatewayPayload } from "../types/gatewaypayload";
+import { GatewayPayloadType } from "./gatewaypayloadtype";
+
+const GATEWAY_BATCH_INTERVAL = 25000 || process.env.GATEWAY_BATCH_INTERVAL;
+const GATEWAY_PING_INTERVAL = 20000 || process.env.GATEWAY_PING_INTERVAL;
+
+function closeWithError(ws: WebSocket, { code, message }: { code: number, message: string }) {
+    return ws.close(1000, `(${code}) ${message}`);
+}
+
+function closeWithBadPayload(ws: WebSocket, hint: string) {
+    return ws.close(gatewayErrors.BAD_PAYLOAD.code, `${gatewayErrors.BAD_PAYLOAD.message}: ${hint}`);
+}
+
+function parseJsonOrNull(payload: string): any {
+    try {
+        return JSON.parse(payload);
+    } catch (e) {
+        return null;
+    }
+}
+
+// The function below ensures `payload` is of the GatewayPayload
+// interface payload. If it does not match, null is returned.
+function ensureFormattedGatewayPayload(payload: any): GatewayPayload | null {
+    if (!payload) {
+        return null;
+    }
+
+    let foundT = false;
+    let foundD = false;
+    for (const [k, v] of Object.entries(payload)) {
+        if (k === "t" && typeof v === "number") {
+            foundT = true;
+        } else if (k === "d") {
+            foundD = true;
+        } else {
+            return null;
+        }
+    }
+    if (!foundT || !foundD) {
+        return null;
+    }
+    const asPayload = payload as GatewayPayload;
+    return asPayload;
+}
+
+function sendPayload(ws: WebSocket, payload: GatewayPayload) {
+    ws.send(JSON.stringify(payload));
+}
+
+export default function(server: Server) {
+    const wss = new WebSocketServer({ server });
+
+    setInterval(() => {
+        wss.clients.forEach((e) => {
+            const now = performance.now();
+            if (e.state && (now - e.state.lastAliveCheck) >= GATEWAY_PING_INTERVAL) {
+                if (!e.state.ready) {
+                    return closeWithError(e, gatewayErrors.AUTHENTICATION_TIMEOUT);
+                }
+            }
+        });
+    }, GATEWAY_BATCH_INTERVAL);
+
+    wss.on("connection", (ws) => {
+        ws.state = {
+            user: undefined,
+            alive: false,
+            ready: false,
+            lastAliveCheck: performance.now()
+        };
+
+        sendPayload(ws, {
+            t: GatewayPayloadType.Hello,
+            d: {
+                pingInterval: GATEWAY_PING_INTERVAL
+            }
+        });
+
+        ws.on("message", async (rawData, isBinary) => {
+            if (isBinary) {
+                return closeWithBadPayload(ws, "Binary messages are not supported");
+            }
+
+            const payload = ensureFormattedGatewayPayload(parseJsonOrNull(rawData.toString()));
+            if (!payload) {
+                return closeWithBadPayload(ws, "Invalid JSON or message does not match schema");
+            }
+
+            switch (payload.t) {
+                case GatewayPayloadType.Authenticate: {
+                    const token = payload.d;
+                    if (typeof token !== "string") {
+                        return closeWithBadPayload(ws, "d: expected string");
+                    }
+                    const user = await decodeTokenOrNull(token);
+                    if (!user) {
+                        return closeWithError(ws, gatewayErrors.BAD_AUTH);
+                    }
+                    ws.state.user = user;
+                    ws.state.ready = true;
+                    
+                    sendPayload(ws, {
+                        t: GatewayPayloadType.Ready,
+                        d: {
+                            user: ws.state.user,
+                        }
+                    })
+                    break;
+                }
+                default: {
+                    return closeWithBadPayload(ws, "t: unknown type");
+                }
+            }
+        });
+    });
+};

src/index.ts

@@ -1,15 +1,20 @@
 import "dotenv/config";
 import express from "express";
+import { createServer } from "node:http";
 import databaseInit from "./database/init";
+import gateway from "./gateway";
 import server from "./server";
 
 const port = process.env.PORT || 3000;
 
 const app = express();
 server(app);
+const httpServer = createServer(app);
+gateway(httpServer);
+
 
 function serve() {
-    app.listen(port, () => console.log(`listening on port ${port}`));
+    httpServer.listen(port, () => console.log(`listening on port ${port}`));
 }
 
 async function main() {

src/server.ts

@@ -3,6 +3,8 @@ import usersRouter from "./routes/api/v1/users";
 import channelsRouter from "./routes/api/v1/channels";
 
 export default function(app: Application) {
+    app.get("/", (req, res) => res.send("hello!"));
+
     app.use(json());
     app.use("/api/v1/users", usersRouter);
     app.use("/api/v1/channels", channelsRouter);

src/types/gatewayclientstate.d.ts

@@ -0,0 +1,6 @@
+interface GatewayClientState {
+    user?: User;
+    ready: boolean,
+    alive: boolean,
+    lastAliveCheck: number,
+}

src/types/gatewaypayload.d.ts

@@ -0,0 +1,6 @@
+import { GatewayPayloadType } from "../gateway/gatewaypayloadtype";
+
+declare interface GatewayPayload {
+    t: GatewayPayloadType;
+    d: any;
+}

src/types/ws.d.ts

@@ -0,0 +1,7 @@
+import ws from 'ws';
+
+declare module 'ws' {
+    export interface WebSocket extends ws {
+        state: GatewayClientState;
+    }
+}

test.rest

@@ -19,13 +19,13 @@ content-type: application/json
 ###
 
 GET http://localhost:3000/api/v1/users/self HTTP/1.1
-Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6MSwidHlwZSI6MSwiaWF0IjoxNjQ5MTg3MDc5LCJleHAiOjE2NDkzNTk4Nzl9.tVzJWnBP7IFhA88XRwByKGXQ4cihWdJSoxUkrWHkIVU
+Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6MiwidHlwZSI6MSwiaWF0IjoxNjQ5NTI0NDA1LCJleHAiOjE2NDk2OTcyMDV9.4nIDs0K8MCT18GsdlKdicT_GK2KbEqi_P7cND3_aZvE
 
 ###
 
 POST http://localhost:3000/api/v1/channels HTTP/1.1
 content-type: application/json
-Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6MSwidHlwZSI6MSwiaWF0IjoxNjQ5MTg3MDc5LCJleHAiOjE2NDkzNTk4Nzl9.tVzJWnBP7IFhA88XRwByKGXQ4cihWdJSoxUkrWHkIVU
+Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6MiwidHlwZSI6MSwiaWF0IjoxNjQ5NTI0NDA1LCJleHAiOjE2NDk2OTcyMDV9.4nIDs0K8MCT18GsdlKdicT_GK2KbEqi_P7cND3_aZvE
 
 {
     "name": "another channel"
@@ -35,7 +35,7 @@ Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6MSwidHlwZSI6M
 
 PUT http://localhost:3000/api/v1/channels/2 HTTP/1.1
 content-type: application/json
-Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6MSwidHlwZSI6MSwiaWF0IjoxNjQ5MTg3MDc5LCJleHAiOjE2NDkzNTk4Nzl9.tVzJWnBP7IFhA88XRwByKGXQ4cihWdJSoxUkrWHkIVU
+Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6MiwidHlwZSI6MSwiaWF0IjoxNjQ5NTI0NDA1LCJleHAiOjE2NDk2OTcyMDV9.4nIDs0K8MCT18GsdlKdicT_GK2KbEqi_P7cND3_aZvE
 #Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6MiwidHlwZSI6MSwiaWF0IjoxNjQ5MjU5NDUwLCJleHAiOjE2NDk0MzIyNTB9.JmF9NujFZnln7A-ynNpeyayGBqmR5poAyACYV6RnSQY
 
 {
@@ -45,15 +45,15 @@ Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6MSwidHlwZSI6M
 ###
 
 DELETE http://localhost:3000/api/v1/channels/1 HTTP/1.1
-Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6MSwidHlwZSI6MSwiaWF0IjoxNjQ5MTg3MDc5LCJleHAiOjE2NDkzNTk4Nzl9.tVzJWnBP7IFhA88XRwByKGXQ4cihWdJSoxUkrWHkIVU
+Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6MiwidHlwZSI6MSwiaWF0IjoxNjQ5NTI0NDA1LCJleHAiOjE2NDk2OTcyMDV9.4nIDs0K8MCT18GsdlKdicT_GK2KbEqi_P7cND3_aZvE
 #Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6MiwidHlwZSI6MSwiaWF0IjoxNjQ5MjU5NDUwLCJleHAiOjE2NDk0MzIyNTB9.JmF9NujFZnln7A-ynNpeyayGBqmR5poAyACYV6RnSQY
 
 ###
 
 GET http://localhost:3000/api/v1/channels/1 HTTP/1.1
-Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6MSwidHlwZSI6MSwiaWF0IjoxNjQ5MTg3MDc5LCJleHAiOjE2NDkzNTk4Nzl9.tVzJWnBP7IFhA88XRwByKGXQ4cihWdJSoxUkrWHkIVU
+Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6MiwidHlwZSI6MSwiaWF0IjoxNjQ5NTI0NDA1LCJleHAiOjE2NDk2OTcyMDV9.4nIDs0K8MCT18GsdlKdicT_GK2KbEqi_P7cND3_aZvE
 
 ###
 
 GET http://localhost:3000/api/v1/channels HTTP/1.1
-Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6MSwidHlwZSI6MSwiaWF0IjoxNjQ5MTg3MDc5LCJleHAiOjE2NDkzNTk4Nzl9.tVzJWnBP7IFhA88XRwByKGXQ4cihWdJSoxUkrWHkIVU
+Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6MiwidHlwZSI6MSwiaWF0IjoxNjQ5NTI0NDA1LCJleHAiOjE2NDk2OTcyMDV9.4nIDs0K8MCT18GsdlKdicT_GK2KbEqi_P7cND3_aZvE

yarn.lock

@@ -70,7 +70,7 @@
   resolved "https://registry.yarnpkg.com/@types/mime/-/mime-1.3.2.tgz#93e25bf9ee75fe0fd80b594bc4feb0e862111b5a"
   integrity sha512-YATxVxgRqNH6nHEIsvg6k2Boc1JHI9ZbH5iWFFv/MTkchz3b1ieGDa5T0a9RznNdI0KhVbdbWSN+KWWrQZRxTw==
 
-"@types/node@*":
+"@types/node@*", "@types/node@^17.0.23":
   version "17.0.23"
   resolved "https://registry.yarnpkg.com/@types/node/-/node-17.0.23.tgz#3b41a6e643589ac6442bdbd7a4a3ded62f33f7da"
   integrity sha512-UxDxWn7dl97rKVeVS61vErvw086aCYhDLyvRQZ5Rk65rZKepaFdm53GeqXaKBuOhED4e9uWq34IC3TdSdJJ2Gw==
@@ -102,6 +102,13 @@
     "@types/mime" "^1"
     "@types/node" "*"
 
+"@types/ws@^8.5.3":
+  version "8.5.3"
+  resolved "https://registry.yarnpkg.com/@types/ws/-/ws-8.5.3.tgz#7d25a1ffbecd3c4f2d35068d0b283c037003274d"
+  integrity sha512-6YOoWjruKj1uLf3INHH7D3qTXwFfEsg1kf3c0uDdSBJwfa/llkwIjrAGV7j7mVgGNbzTQ3HiHKKDXl6bJPD97w==
+  dependencies:
+    "@types/node" "*"
+
 abbrev@1:
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/abbrev/-/abbrev-1.1.1.tgz#f8f2c887ad10bf67f634f005b6987fed3179aac8"
@@ -1010,6 +1017,11 @@ wrappy@1:
   resolved "https://registry.yarnpkg.com/wrappy/-/wrappy-1.0.2.tgz#b5243d8f3ec1aa35f1364605bc0d1036e30ab69f"
   integrity sha1-tSQ9jz7BqjXxNkYFvA0QNuMKtp8=
 
+ws@^8.5.0:
+  version "8.5.0"
+  resolved "https://registry.yarnpkg.com/ws/-/ws-8.5.0.tgz#bfb4be96600757fe5382de12c670dab984a1ed4f"
+  integrity sha512-BWX0SWVgLPzYwF8lTzEy1egjhS4S4OEAHfsO8o65WOVsrnSRGaSiUaa9e0ggGlkMTtBlmOpEXiie9RUcBO86qg==
+
 xtend@^4.0.0:
   version "4.0.2"
   resolved "https://registry.yarnpkg.com/xtend/-/xtend-4.0.2.tgz#bb72779f5fa465186b1f438f674fa347fdb5db54"