using SurveyBackend.DTOs.Question;
using SurveyLib.Core.Models;

namespace SurveyBackend.Mappers.QuestionDTOs;

public static class QuestionOutputMapper
{
    public static object ModelToQuestionDTO(QuestionBase question)
    {
        return question.Discriminator.ToLower() switch
        {
            "textquestion" => new OutputTextQuestionDto
            {
                Id = question.Id,
                Title = question.Title,
                SurveyId = question.SurveyId,
                QuestionType = question.Discriminator
            },
            "singleanswerquestion" => new OutputSingleAnswerQuestionDto
            {
                Id = question.Id,
                Title = question.Title,
                SurveyId = question.SurveyId,
                QuestionType = question.Discriminator,
                AnswerVariants = GetAnswerVariants(question.AnswerVariants ?? Array.Empty<AnswerVariant>())
            },
            "multipleanswerquestion" => new OutputMultipleAnswerQuestionDto
            {
                Id = question.Id,
                Title = question.Title,
                SurveyId = question.SurveyId,
                QuestionType = question.Discriminator,
                AnswerVariants = GetAnswerVariants(question.AnswerVariants ?? Array.Empty<AnswerVariant>())
            },
            _ => throw new Exception($"Unknown question type: {question.Discriminator}")
        };
    }

    private static List<OutputAnswerVariantDto> GetAnswerVariants(IEnumerable<AnswerVariant> answerVariants)
    {
        return answerVariants.Select(av => new OutputAnswerVariantDto
        {
            Id = av.Id,
            QuestionId = av.QuestionId,
            Text = av.Text,
        }).ToList();
    }
}