feat: add individual collection sheet (#1204)

Fixes: #255

src/app/collections/collections.service.ts

@@ -0,0 +1,54 @@
+/** Angular Imports */
+import { Injectable } from '@angular/core';
+import { HttpClient, HttpParams } from '@angular/common/http';
+
+/** rxjs Imports */
+import { Observable } from 'rxjs';
+
+/**
+ * Collections Service
+ */
+@Injectable({
+  providedIn: 'root'
+})
+export class CollectionsService {
+
+  constructor(private http: HttpClient) { }
+
+  /**
+   * Returns all the offices
+   */
+  getOffices(): Observable<any> {
+    return this.http.get(`/offices`);
+  }
+
+  /**
+   * Returns the loan officer(staffs) for the particular office
+   * @param {officeId} OfficeId any
+   */
+  getStaffs(officeId: any): Observable<any> {
+    const httpParams = new HttpParams()
+                      .set('officeId', officeId)
+                      .set('status', 'all');
+    return this.http.get(`/staff`, { params: httpParams });
+  }
+
+  /**
+   * Retrieves the Collection Sheet Data
+   * @param {data} data any
+   */
+  retrieveCollectionSheetData(data: any): Observable<any> {
+    const httpParams = new HttpParams().set('command', 'generateCollectionSheet');
+    return this.http.post(`/collectionsheet`, data, { params: httpParams });
+  }
+
+  /**
+   * Executes the Save Collection Sheet Data
+   * @param {data} data any
+   */
+  executeSaveCollectionSheet(data: any): Observable<any> {
+    const httpParams = new HttpParams().set('command', 'saveCollectionSheet');
+    return this.http.post(`/collectionsheet`, data, { params: httpParams });
+  }
+
+}