Merge branch 'master' of https://github.com/browngraphicslab/Dash-Web

1 files changed, 151 insertions, 0 deletions

diff --git a/src/server/RouteManager.ts b/src/server/RouteManager.ts
new file mode 100644
index 000000000..7c49485f1
--- /dev/null
+++ b/src/server/RouteManager.ts
@@ -0,0 +1,151 @@
+import RouteSubscriber from "./RouteSubscriber";
+import { DashUserModel } from "./authentication/models/user_model";
+import * as express from 'express';
+import { ConsoleColors } from "./ActionUtilities";
+
+export enum Method {
+    GET,
+    POST
+}
+
+export interface CoreArguments {
+    req: express.Request;
+    res: express.Response;
+    isRelease: boolean;
+}
+
+export type OnValidation = (core: CoreArguments & { user: DashUserModel }) => any | Promise<any>;
+export type OnUnauthenticated = (core: CoreArguments) => any | Promise<any>;
+export type OnError = (core: CoreArguments & { error: any }) => any | Promise<any>;
+
+export interface RouteInitializer {
+    method: Method;
+    subscription: string | RouteSubscriber | (string | RouteSubscriber)[];
+    onValidation: OnValidation;
+    onUnauthenticated?: OnUnauthenticated;
+    onError?: OnError;
+}
+
+const registered = new Map<string, Set<Method>>();
+
+export default class RouteManager {
+    private server: express.Express;
+    private _isRelease: boolean;
+
+    public get isRelease() {
+        return this._isRelease;
+    }
+
+    constructor(server: express.Express, isRelease: boolean) {
+        this.server = server;
+        this._isRelease = isRelease;
+    }
+
+    /**
+     * 
+     * @param initializer 
+     */
+    addSupervisedRoute = (initializer: RouteInitializer): void => {
+        const { method, subscription, onValidation, onUnauthenticated, onError } = initializer;
+        const isRelease = this._isRelease;
+        let supervised = async (req: express.Request, res: express.Response) => {
+            const { user, originalUrl: target } = req;
+            const core = { req, res, isRelease };
+            const tryExecute = async (toExecute: (args: any) => any | Promise<any>, args: any) => {
+                try {
+                    await toExecute(args);
+                } catch (e) {
+                    console.log(ConsoleColors.Red, target, user?.email ?? "<user logged out>");
+                    if (onError) {
+                        onError({ ...core, error: e });
+                    } else {
+                        _error(res, `The server encountered an internal error when serving ${target}.`, e);
+                    }
+                }
+            };
+            if (user) {
+                await tryExecute(onValidation, { ...core, user });
+            } else {
+                req.session!.target = target;
+                if (onUnauthenticated) {
+                    await tryExecute(onUnauthenticated, core);
+                    if (!res.headersSent) {
+                        res.redirect("/login");
+                    }
+                } else {
+                    res.redirect("/login");
+                }
+            }
+            setTimeout(() => {
+                if (!res.headersSent) {
+                    console.log("Initiating fallback for ", target);
+                    const warning = `request to ${target} fell through - this is a fallback response`;
+                    res.send({ warning });
+                }
+            }, 1000);
+        };
+        const subscribe = (subscriber: RouteSubscriber | string) => {
+            let route: string;
+            if (typeof subscriber === "string") {
+                route = subscriber;
+            } else {
+                route = subscriber.build;
+            }
+            const existing = registered.get(route);
+            if (existing) {
+                if (existing.has(method)) {
+                    console.log(ConsoleColors.Red, `\nDuplicate registration error: already registered ${route} with Method[${method}]`);
+                    console.log('Please remove duplicate registrations before continuing...\n');
+                    process.exit(0);
+                }
+            } else {
+                const specific = new Set<Method>();
+                specific.add(method);
+                registered.set(route, specific);
+            }
+            switch (method) {
+                case Method.GET:
+                    this.server.get(route, supervised);
+                    break;
+                case Method.POST:
+                    this.server.post(route, supervised);
+                    break;
+            }
+        };
+        if (Array.isArray(subscription)) {
+            subscription.forEach(subscribe);
+        } else {
+            subscribe(subscription);
+        }
+    }
+
+}
+
+export const STATUS = {
+    OK: 200,
+    BAD_REQUEST: 400,
+    EXECUTION_ERROR: 500,
+    PERMISSION_DENIED: 403
+};
+
+export function _error(res: express.Response, message: string, error?: any) {
+    console.error(message);
+    res.statusMessage = message;
+    res.status(STATUS.EXECUTION_ERROR).send(error);
+}
+
+export function _success(res: express.Response, body: any) {
+    res.status(STATUS.OK).send(body);
+}
+
+export function _invalid(res: express.Response, message: string) {
+    res.statusMessage = message;
+    res.status(STATUS.BAD_REQUEST).send();
+}
+
+export function _permission_denied(res: express.Response, message?: string) {
+    if (message) {
+        res.statusMessage = message;
+    }
+    res.status(STATUS.BAD_REQUEST).send("Permission Denied!");
+}