YouGrade - Asp.NET MVC Multimedia Exam Suite

using System;
using System.ComponentModel;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.ServiceModel.Activation;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Text;
using YouGrade.Silverlight;
using model = YouGrade.Silverlight.Core.Model;
using service = YouGrade.Silverlight.Web.Model;
using System.Data;
using YouGrade.Silverlight.Web.Model;
using TOModel = YouGrade.Silverlight.Core.Model;
using YouGrade.Silverlight.Core.Model;
using YouGrade.Model;

namespace YouGrade.Silverlight.Web
{
    [ServiceContract(Namespace = "")]
    [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
    public class YouGradeService
    {
        static ExamDef examDef = new ExamDef();
        static User user;

        public YouGradeService()
        {
        }

        [OperationContract]
        public User GetUser(string login, string password)
        {
            using (YouGradeEntities1 db = new YouGradeEntities1())
            {
                var query = db.User
                    .Where(e => e.Login.Equals(login, StringComparison.InvariantCultureIgnoreCase))
                    .Where(e => e.Password.Equals(password, StringComparison.InvariantCultureIgnoreCase)
                    );

                if (query.Any())
                {
                    return query.AsQueryable<User>().First();
                }
                else
                {
                    return null;
                }
            }
        }

        [OperationContract]
        public ExamDef GetExamDef()
        {
            using (YouGradeEntities1 ctx = new YouGradeEntities1())
            {
                return ctx.ExamDef.Include("QuestionDef.Alternative").First();
            }
        }

        [OperationContract]
        public IQueryable<Alternative> GetAlternatives(int questionId)
        {
            using (YouGradeEntities1 ctx = new YouGradeEntities1())
            {
                return ctx.Alternative.Where(e => e.QuestionDef.Id == questionId);
            }
        }

        [OperationContract]
        public double SaveExamTake(ExamTakeTO examTakeTO)
        {
            double grade = 0;
            try
            {
                using (YouGradeEntities1 ctx = new YouGradeEntities1())
                {
                    User user = ctx.User.Where(e => e.Id == examTakeTO.UserId).First();
                    ExamDef examDef = ctx.ExamDef.Where(e => e.Id == examTakeTO.ExamId).First();

                    service.ExamTake newExamTake = service.ExamTake.CreateExamTake
                        (
                            0,
                            examTakeTO.StartDateTime,
                            examTakeTO.Duration,
                            examTakeTO.Grade,
                            examTakeTO.Status.ToString()
                        );

                    newExamTake.User = user;
                    newExamTake.ExamDef = examDef;

                    ctx.AddToExamTake(newExamTake);

                    ctx.SaveChanges();

                    foreach (AnswerTO a in examTakeTO.Answers)
                    {
                        ExamTake examTake = ctx.ExamTake.Where(e => e.Id == newExamTake.Id).First();
                        Alternative alternative = ctx.Alternative.Where(e => e.QuestionId == a.QuestionId).Where(e => e.Id == a.AlternativeId).First();
                        Answer newAnswer = Answer.CreateAnswer(newExamTake.Id, a.QuestionId, a.AlternativeId, a.IsChecked);
                        newAnswer.ExamTake = examTake;
                        newAnswer.Alternative = alternative;
                        ctx.AddToAnswer(newAnswer);
                    }

                    ctx.SaveChanges();

                    foreach (QuestionDef q in ctx.QuestionDef)
                    {
                        var query = from qd in ctx.QuestionDef
                                    join a in ctx.Answer on qd.Id equals a.QuestionId
                                    join alt in ctx.Alternative on new { qId = a.QuestionId, aId = a.AlternativeId } equals new { qId = alt.QuestionId, aId = alt.Id }
                                    where qd.Id == q.Id
                                    where a.ExamTakeId == newExamTake.Id
                                    select new { alt.Correct, a.IsChecked };

                        bool correct = true;
                        foreach (var v in query)
                        {
                            if (v.Correct != v.IsChecked)
                            {
                                correct = false;
                                break;
                            }
                        }
                        grade += correct ? 1 : 0;
                    }

                    int examTakeId = examTakeTO.Id;
                }

                using (YouGradeEntities1 ctx = new YouGradeEntities1())
                {
                    ExamTake et = ctx.ExamTake.First();
                    string s = et.Status;
                }
                
                return grade;
            }
            catch (Exception exc)
            {
                string s = exc.ToString();
                throw;
            }
        }
    }
}