Add workload service

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;
+}