feat(login): add login authentication and authorization (#122)

Add login basic authentication, oauth2 authentication, two factor
authentication and authorization and allow to reset password on expiry.

Fixes #117, #118, #119, #120

src/app/core/http/error-handler.interceptor.ts

@@ -1,11 +1,12 @@
 import { Injectable } from '@angular/core';
-import { HttpEvent, HttpInterceptor, HttpHandler, HttpRequest } from '@angular/common/http';
+import { HttpEvent, HttpInterceptor, HttpHandler, HttpRequest, HttpErrorResponse } from '@angular/common/http';
 
 import { Observable } from 'rxjs';
 import { catchError } from 'rxjs/operators';
 
 import { environment } from '../../../environments/environment';
 import { Logger } from '../logger.service';
+import { AlertService } from '../alert.service';
 
 const log = new Logger('ErrorHandlerInterceptor');
 
@@ -15,16 +16,42 @@ const log = new Logger('ErrorHandlerInterceptor');
 @Injectable()
 export class ErrorHandlerInterceptor implements HttpInterceptor {
 
+  constructor(private alertService: AlertService) {  }
+
   intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
-    return next.handle(request).pipe(catchError(error => this.errorHandler(error)));
+    return next.handle(request).pipe(catchError(error => this.handleError(error)));
   }
 
   // Customize the default error handler here if needed
-  private errorHandler(response: HttpEvent<any>): Observable<HttpEvent<any>> {
-    if (!environment.production) {
-      // Do something with the error
-      log.error('Request error', response);
+  private handleError(response: HttpErrorResponse): Observable<HttpEvent<any>> {
+    const status = response.status;
+    let errorMessage = (response.error.developerMessage || response.message);
+    if (response.error.errors) {
+      if (response.error.errors[0]) {
+        errorMessage = response.error.errors[0].developerMessage;
+      }
     }
+
+    if (!environment.production) {
+      log.error(`Request Error: ${errorMessage}`);
+    }
+
+    if (status === 401 || (environment.oauth.enabled && status === 400)) {
+      this.alertService.alert({ type: 'Authentication Error', message: 'Invalid User Details. Please try again!' });
+    } else if (status === 403 && errorMessage === 'The provided one time token is invalid') {
+      this.alertService.alert({ type: 'Invalid Token', message: 'Invalid Token. Please try again!' });
+    } else if (status === 400) {
+      this.alertService.alert({ type: 'Bad Request', message: 'Invalid parameters were passed in the request!' });
+    } else if (status === 403) {
+      this.alertService.alert({ type: 'Unauthorized Request', message: 'You are not authorized for this request!' });
+    } else if (status === 404) {
+      this.alertService.alert({ type: 'Resource does not exist', message: 'Resource does not exist!' });
+    }  else if (status === 500) {
+      this.alertService.alert({ type: 'Internal Server Error', message: 'Internal Server Error. Please try again later.' });
+    } else {
+      this.alertService.alert({ type: 'Unknown Error', message: 'Unknown Error. Please try again later.' });
+    }
+
     throw response;
   }