Added ffmpeg progress bar via fluent-ffmpeg and progress libs (#57)

* Add fluent-ffmpeg back and cross-platform progress bar

* Repo clean up

Move ts files to src, build and output js files to build folder

* Do not print messages when exit code is 0

this is triggered by signal events

Co-authored-by: kylon <kylonux@gmail.com>

src/TokenCache.ts

@@ -0,0 +1,56 @@
+import * as fs from 'fs';
+import { Session } from './Types';
+import { bgGreen, bgYellow, green } from 'colors';
+import jwtDecode from 'jwt-decode';
+
+export class TokenCache {
+    private tokenCacheFile: string = '.token_cache';
+
+    public Read(): Session | null {
+        let j = null;
+        if(!fs.existsSync(this.tokenCacheFile)) {
+            console.warn(bgYellow.black(`${this.tokenCacheFile} not found.\n`));
+
+            return null;
+        }
+        let f = fs.readFileSync(this.tokenCacheFile, 'utf8');
+        j = JSON.parse(f);
+
+        interface Jwt {
+            [key: string]: any
+        }
+
+        const decodedJwt: Jwt = jwtDecode(j.AccessToken);
+
+        let now = Math.floor(Date.now() / 1000);
+        let exp = decodedJwt['exp'];
+        let timeLeft = exp - now;
+
+        let timeLeftInMinutes = Math.floor(timeLeft / 60);
+        if (timeLeft < 120) {
+            console.warn(bgYellow.black('\nAccess token has expired.'));
+
+            return null;
+        }
+
+        console.info(bgGreen.black(`\nAccess token still good for ${timeLeftInMinutes} minutes.\n`));
+
+        let session: Session = {
+            AccessToken: j.AccessToken,
+            ApiGatewayUri: j.ApiGatewayUri,
+            ApiGatewayVersion: j.ApiGatewayVersion
+        };
+
+        return session;
+    }
+
+    public Write(session: Session): void {
+        let s = JSON.stringify(session, null, 4);
+        fs.writeFile('.token_cache', s, (err: any) => {
+            if (err) {
+                return console.error(err);
+            }
+            console.info(green('Fresh access token dropped into .token_cache'));
+        });
+    }
+}