Add API calls

Author: limcaaarl

frontend/src/app/questions/question.model.ts

@@ -4,11 +4,24 @@ export interface QuestionResponse {
     data?: Question[] | null;
 }
 
+export interface SingleQuestionResponse {
+    status: string;
+    message: string;
+    data: Question;
+}
+
 export interface Question {
-    _id: string;
+    _id?: string;
     id: number;
     description: string;
     difficulty: string;
     title: string;
     topics?: string[];
 }
+
+export interface QuestionBody {
+    description?: string;
+    difficulty?: string;
+    title?: string;
+    topics?: string[];
+}

frontend/src/app/questions/question.service.ts

@@ -1,8 +1,8 @@
-import { HttpClient, HttpParams } from '@angular/common/http';
+import { HttpClient, HttpHeaders, HttpParams } from '@angular/common/http';
 import { Injectable } from '@angular/core';
 import { API_CONFIG } from '../api.config';
 import { Observable } from 'rxjs';
-import { QuestionResponse } from './question.model';
+import { SingleQuestionResponse, QuestionResponse, QuestionBody } from './question.model';
 import { TopicResponse } from './topic.model';
 
 @Injectable({
@@ -11,6 +11,12 @@ import { TopicResponse } from './topic.model';
 export class QuestionService {
     private baseUrl = API_CONFIG.baseUrl;
 
+    private httpOptions = {
+        headers: new HttpHeaders({
+            'Content-Type': 'application/json',
+        }),
+    };
+
     constructor(private http: HttpClient) {}
 
     getQuestions(
@@ -38,7 +44,34 @@ export class QuestionService {
         return this.http.get<QuestionResponse>(this.baseUrl + '/questions', { params });
     }
 
+    getQuestionByID(id: number): Observable<QuestionResponse> {
+        return this.http.get<QuestionResponse>(this.baseUrl + '/questions/' + id);
+    }
+
+    getQuestionByParam(topics: string[], difficulty: string, limit?: number): Observable<QuestionResponse> {
+        let params = new HttpParams();
+
+        if (limit) {
+            params = params.append('limit', limit);
+        }
+        params = params.append('topics', topics.join(',')).append('difficulty', difficulty);
+
+        return this.http.get<QuestionResponse>(this.baseUrl + '/questions/search', { params });
+    }
+
     getTopics(): Observable<TopicResponse> {
         return this.http.get<TopicResponse>(this.baseUrl + '/questions/topics');
     }
+
+    addQuestion(question: QuestionBody): Observable<SingleQuestionResponse> {
+        return this.http.post<SingleQuestionResponse>(this.baseUrl + '/questions', question, this.httpOptions);
+    }
+
+    updateQuestion(id: number, question: QuestionBody): Observable<SingleQuestionResponse> {
+        return this.http.put<SingleQuestionResponse>(this.baseUrl + '/questions/' + id, question, this.httpOptions);
+    }
+
+    deleteQuestion(id: number): Observable<SingleQuestionResponse> {
+        return this.http.delete<SingleQuestionResponse>(this.baseUrl + '/questions/' + id);
+    }
 }