Add workload service

package.json

@@ -3,6 +3,7 @@
   "version": "0.1.0",
   "private": true,
   "dependencies": {
+    "moment": "^2.24.0",
     "react": "^16.7.0",
     "react-dom": "^16.7.0",
     "react-redux": "^6.0.0",

src/state/workloads/index.ts

@@ -1,2 +1,3 @@
 export * from './actions';
 export * from './reducers';
+export * from './services';

src/state/workloads/services.ts

@@ -0,0 +1,67 @@
+import moment from 'moment';
+
+import { Status } from './types';
+
+
+export class WorkloadService {  
+  
+  private workLoads: { [key in number]: Work } = {};
+  private counter = 0;
+  
+
+  private getWorkload(id: number): Work | undefined {
+    return this.workLoads[id]; 
+  }
+
+  private completeWorkload(work: Work) {
+    work.status = this.counter % 2 
+      ? 'SUCCESS'
+      : 'FAILURE';
+  }
+
+
+  public create({ complexity }: { complexity: number }) {
+    const id = this.counter++;
+    const status = 'WORKING';
+    
+    const seconds = complexity;
+    const completeDate = moment().add(complexity, 'second').toDate();
+    const timer = setTimeout(() => this.completeWorkload(work), seconds);
+
+    const work: Work = {
+      id,
+      complexity,
+      status,
+      completeDate,
+      timer,
+    }
+    this.workLoads[id] = work;
+
+    return Promise.resolve({ id, complexity, completeDate });
+  }
+
+  public checkStatus({ id }: { id: number }) {
+    const work = this.getWorkload(id);
+    if (!work) return Promise.reject('Workload not found');
+    return Promise.resolve(work);
+  }
+
+  public cancel({ id }: { id: number }) {
+    const work = this.getWorkload(id);
+    if (!work) return Promise.reject('Workload not found');
+    if (work.status !== 'WORKING') return Promise.reject('Workload cannot be canceled');
+    
+    clearTimeout(work.timer)
+    work.status = 'CANCELED';
+
+    return Promise.resolve(work);
+  }
+}
+
+interface Work {
+  id: number;
+  complexity: number;
+  completeDate: Date;
+  status: Status;
+  timer: NodeJS.Timeout;
+}

yarn.lock

@@ -6297,6 +6297,11 @@ mkdirp@0.5.1, mkdirp@0.5.x, mkdirp@^0.5.0, mkdirp@^0.5.1, mkdirp@~0.5.0, mkdirp@
   dependencies:
     minimist "0.0.8"
 
+moment@^2.24.0:
+  version "2.24.0"
+  resolved "https://npm.nutterlogic.com/moment/-/moment-2.24.0.tgz#0d055d53f5052aa653c9f6eb68bb5d12bf5c2b5b"
+  integrity sha512-bV7f+6l2QigeBBZSM/6yTNq4P2fNpSWj/0e7jQcy87A8e7o2nAfP/34/2ky5Vw4B9S446EtIhodAzkFCcR4dQg==
+
 move-concurrently@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/move-concurrently/-/move-concurrently-1.0.1.tgz#be2c005fda32e0b29af1f05d7c4b33214c701f92"