feat: submission endpoint geimplementeerd (ongetest)

backend/src/services/submissions.ts

@@ -0,0 +1,22 @@
+import { getSubmissionRepository } from "../data/repositories";
+import { Language } from "../entities/content/language";
+import { LearningObjectIdentifier } from "../entities/content/learning-object-identifier";
+import { mapToSubmissionDTO, SubmissionDTO } from "../interfaces/submission";
+
+export async function getSubmission(
+    learningObjectHruid: string,
+    language: Language,
+    version: string,
+    submissionNumber: number, 
+): Promise<SubmissionDTO | null> {
+    const loId = new LearningObjectIdentifier(learningObjectHruid, language, version); 
+
+    const submissionRepository = getSubmissionRepository();
+    const submission = await submissionRepository.findSubmissionByLearningObjectAndSubmissionNumber(loId, submissionNumber);
+
+    if (!submission) {
+        return null;
+    }
+
+    return mapToSubmissionDTO(submission);
+}