public IActionResult GetTestByGroupId(int groupId)
        {
            TeacherDataAccess teacher = new TeacherDataAccess();
            Mapper            mapper  = new Mapper();
            List <TestDTO>    tests   = teacher.GetTestByGroupId(groupId);

            if (tests == null)
            {
                return(BadRequest("Группы не существет"));
            }
            return(Ok(mapper.ConvertTestDTOToTestModelList(teacher.GetTestByGroupId(groupId))));
        }
        public IActionResult GetGroupTestsAndResults(int userId, int groupId)
        {
            TeacherDataAccess teacher = new TeacherDataAccess();
            Mapper            mapper  = new Mapper();
            TeacherGroup      groups  = new TeacherGroup();
            var g = groups.GetAll();

            if (!g.Any(g => g.UserID == userId))
            {
                return(BadRequest("Такой преподаватель отсутствует"));
            }
            if (!g.Any(g => g.GroupID == groupId))
            {
                return(BadRequest("Группа отсутствует"));
            }
            if (!groups.GetAllByUserId(userId).Any(g => g.GroupID == groupId))
            {
                return(BadRequest("Группа относится к другому преподавателю"));
            }
            List <TestDTO>           tests     = teacher.GetTestByGroupId(groupId);
            GroupStatistics          gs        = new GroupStatistics(groupId);
            Dictionary <int, double> statistic = gs.GetAverageResultsOfAllTestsByGroupId(groupId);

            return(Ok(mapper.ConvertTestDTOToGroupTestsAndResultsOutputModel(tests, statistic)));
        }