feat: question route als subroute van learning objects

backend/src/interfaces/answer.ts

@@ -0,0 +1,38 @@
+import {mapToUserDTO, UserDTO} from "./user.js";
+import {mapToQuestionDTO, mapToQuestionId, QuestionDTO, QuestionId} from "./question.js";
+import {Answer} from "../entities/questions/answer.entity.js";
+
+export interface AnswerDTO {
+    author: UserDTO;
+    toQuestion: QuestionDTO;
+    sequenceNumber: number;
+    timestamp: string;
+    content: string;
+}
+
+/**
+ * Convert a Question entity to a DTO format.
+ */
+export function mapToAnswerDTO(answer: Answer): AnswerDTO {
+    return {
+        author: mapToUserDTO(answer.author),
+        toQuestion: mapToQuestionDTO(answer.toQuestion),
+        sequenceNumber: answer.sequenceNumber,
+        timestamp: answer.timestamp.toISOString(),
+        content: answer.content,
+    };
+}
+
+export interface AnswerId {
+    author: string;
+    toQuestion: QuestionId;
+    sequenceNumber: number;
+}
+
+export function mapToAnswerId(answer: AnswerDTO): AnswerId {
+    return {
+        author: answer.author.username,
+        toQuestion: mapToQuestionId(answer.toQuestion),
+        sequenceNumber: answer.sequenceNumber
+    }
+}