life quality changes

- refactored SurveyController.cs
- added ProducesResponseType to every endpoint in every controller
- remade mappers

SurveyBackend/SurveyBackend.API/Mappers/QuestionMapper.cs

@@ -0,0 +1,57 @@
+using SurveyBackend.DTOs.Question;
+using SurveyBackend.Services.Exceptions;
+using SurveyLib.Core.Models;
+using SurveyLib.Core.Models.QuestionVariants;
+
+namespace SurveyBackend.Mappers;
+
+public static class QuestionMapper
+{
+    public static QuestionBase QuestionCreationToModel(CreateQuestionDto dto, int surveyId)
+    {
+        return dto.QuestionType.ToLower() switch
+        {
+            "textquestion" => new TextQuestion
+            {
+                Title = dto.Title,
+                SurveyId = surveyId,
+            },
+            "singleanswerquestion" => new SingleAnswerQuestion
+            {
+                Title = dto.Title,
+                SurveyId = surveyId,
+                AnswerVariants = dto.AnswerVariants?.Select(v => new AnswerVariant { Text = v }).ToList() ?? [],
+            },
+            "multipleanswerquestion" => new MultipleAnswerQuestion
+            {
+                Title = dto.Title,
+                SurveyId = surveyId,
+                AnswerVariants = dto.AnswerVariants?.Select(v => new AnswerVariant { Text = v }).ToList() ?? []
+            },
+            _ => throw new BadRequestException("Unknown question type")
+        };
+    }
+
+    public static OutputQuestionDto ModelToQuestionDto(QuestionBase question)
+    {
+        var withAnswerVariants = question.GetType() != typeof(TextQuestion);
+        return new OutputQuestionDto
+        {
+            Id = question.Id,
+            SurveyId = question.SurveyId,
+            Title = question.Title,
+            QuestionType = question.Discriminator,
+            AnswerVariants = withAnswerVariants ? AnswerVariantsToDto(question.AnswerVariants) : null,
+        };
+    }
+
+    private static List<OutputAnswerVariantDto> AnswerVariantsToDto(IEnumerable<AnswerVariant> answerVariants)
+    {
+        return answerVariants.Select(av => new OutputAnswerVariantDto
+        {
+            Id = av.Id,
+            QuestionId = av.QuestionId,
+            Text = av.Text,
+        }).ToList();
+    }
+}