some progress, interrupted because MusicKit bugs

backend/src/app.ts

@@ -0,0 +1,54 @@
+import express from 'express';
+import path from 'path';
+import fs from 'fs';
+import bodyParser from 'body-parser';
+import jwt from 'jsonwebtoken';
+import cors from 'cors';
+
+declare let __dirname: string | undefined
+if ( typeof( __dirname ) === 'undefined' ) {
+    __dirname = path.resolve( path.dirname( '' ) );
+}
+
+const run = () => {
+    let app = express();
+    app.use( cors( { 
+        credentials: true,
+        origin: true 
+    } ) );
+
+    app.get( '/', ( request, response ) => {
+        response.send( 'HELLO WORLD' );
+    } );
+
+
+    app.get( '/getAppleMusicDevToken', ( req, res ) => {
+        // sign dev token
+        const privateKey = fs.readFileSync( path.join( __dirname + '/config/apple_private_key.p8' ) ).toString();
+        // TODO: Remove secret
+        const config = JSON.parse( '' + fs.readFileSync( path.join( __dirname + '/config/apple-music-api.config.json' ) ) );
+        const jwtToken = jwt.sign( {}, privateKey, {
+            algorithm: "ES256",
+            expiresIn: "180d",
+            issuer: config.teamID,
+            header: {
+                alg: "ES256",
+                kid: config.keyID
+            }
+        } );
+        res.send( jwtToken );
+    } );
+
+    app.use( ( request: express.Request, response: express.Response, next: express.NextFunction ) => {
+        response.status( 404 ).send( 'ERR_NOT_FOUND' );
+        // response.sendFile( path.join( __dirname + '' ) ) 
+    } );
+
+
+    const PORT = process.env.PORT || 8081;
+    app.listen( PORT );
+}
+
+export default {
+    run
+}