add basic versions of retrieving answers by question or completion

SurveyBackend/SurveyBackend.Services/Services/AnswerService.cs

@@ -0,0 +1,40 @@
+using SurveyLib.Core.Models;
+using SurveyLib.Core.Repositories;
+using SurveyLib.Core.Services;
+
+namespace SurveyBackend.Services.Services;
+
+public class AnswerService : IAnswerService
+{
+    private readonly IAnswerRepository _answerRepository;
+
+    public AnswerService(IAnswerRepository answerRepository)
+    {
+        _answerRepository = answerRepository;
+    }
+
+    public async Task AddAnswerAsync(Answer answer)
+    {
+        await _answerRepository.AddAsync(answer);
+    }
+
+    public async Task UpdateAnswerAsync(Answer answer)
+    {
+        await _answerRepository.UpdateAsync(answer);
+    }
+
+    public async Task DeleteAnswerAsync(int id)
+    {
+        await _answerRepository.DeleteAsync(id);
+    }
+
+    public async Task<IEnumerable<Answer>> GetAnswersByCompletionIdAsync(int completionId)
+    {
+        return await _answerRepository.GetAnswersByCompletionIdAsync(completionId);
+    }
+
+    public async Task<IEnumerable<Answer>> GetAnswersByQuestionIdAsync(int questionId)
+    {
+        return await _answerRepository.GetAnswersByQuestionIdAsync(questionId);
+    }
+}