feat: answer routes en put question

backend/src/services/answers.ts

@@ -0,0 +1,68 @@
+import {getAnswerRepository} from "../data/repositories";
+import {Answer} from "../entities/questions/answer.entity";
+import {mapToAnswerDTO, mapToAnswerDTOId} from "../interfaces/answer";
+import {fetchTeacher} from "./teachers";
+import {fetchQuestion} from "./questions";
+import {QuestionId} from "@dwengo-1/common/interfaces/question";
+import {AnswerData, AnswerDTO, AnswerId} from "@dwengo-1/common/interfaces/answer";
+import {NotFoundException} from "../exceptions/not-found-exception";
+
+export async function getAnswersByQuestion(questionId: QuestionId, full: boolean): Promise<AnswerDTO[] | AnswerId[]> {
+    const answerRepository = getAnswerRepository();
+    const question = await fetchQuestion(questionId);
+
+    const answers: Answer[] = await answerRepository.findAllAnswersToQuestion(question);
+
+    if (full) {
+        return answers.map(mapToAnswerDTO);
+    }
+
+    return answers.map(mapToAnswerDTOId);
+}
+
+export async function createAnswer(questionId: QuestionId, answerData: AnswerData): Promise<AnswerDTO> {
+    const answerRepository = getAnswerRepository();
+    const toQuestion = await fetchQuestion(questionId);
+    const author = await fetchTeacher(answerData.author);
+    const content = answerData.content;
+
+    const answer = await answerRepository.createAnswer({
+        toQuestion, author, content
+    });
+    return mapToAnswerDTO(answer);
+}
+
+async function fetchAnswer(questionId: QuestionId, sequenceNumber: number): Promise<Answer> {
+    const answerRepository = getAnswerRepository();
+    const question = await fetchQuestion(questionId);
+    const answer = await answerRepository.findAnswer(question, sequenceNumber);
+
+    if (!answer){
+        throw new NotFoundException('Answer with questionID and sequence number not found');
+    }
+
+    return answer;
+}
+
+export async function getAnswer(questionId: QuestionId, sequenceNumber: number): Promise<AnswerDTO> {
+    const answer = await fetchAnswer(questionId, sequenceNumber);
+    return mapToAnswerDTO(answer);
+}
+
+export async function deleteAnswer(questionId: QuestionId, sequenceNumber: number): Promise<AnswerDTO> {
+    const answerRepository = getAnswerRepository();
+
+    const question = await fetchQuestion(questionId);
+    const answer = await fetchAnswer(questionId, sequenceNumber);
+
+    await answerRepository.removeAnswerByQuestionAndSequenceNumber(question, sequenceNumber);
+    return mapToAnswerDTO(answer);
+}
+
+export async function updateAnswer(questionId: QuestionId, sequenceNumber: number, answerData: AnswerData){
+    const answerRepository = getAnswerRepository();
+    const answer = await fetchAnswer(questionId, sequenceNumber);
+
+    const newAnswer = await answerRepository.updateContent(answer, answerData.content);
+    return mapToAnswerDTO(newAnswer);
+}