Code smell - LINQ to SQL Datacontext usage and more…

I just came across some code where I needed to fix a couple of issues in. Since I am a strong proponent of continuous improvement and refactoring I thought I blog about this good example.

 

image
Figure: Webform that allows management of employee type history: "Assign" (Add), "Edit" (Modify) and "Delete"

The purpose of this class "EmployeePositionAssignment" is: helper functions for a webpage that lets you manage the depot history of an employee

Read this and find the code smell!
Keep in mind:

  • Single Responsibility Principle
  • Functions should be small and express intent
  • Purpose of commented code
  • Parameter of functions
using System;
using System.Linq;
using NorthWind.FOMS.Domain;
using NorthWind.FOMS.Domain.Rules;

namespace NorthWind.FOMS.WebUI.DynamicData.CustomPages.EmployeePositionHistoryAssignments
{
    public class EmployeePositionAssignment
    {
        private NorthWindDataContext db = new NorthWindDataContext();
        private static readonly TimeSpan defaultTimeSpan = new TimeSpan(1, 0, 0, 0);
        private static readonly DateTime defaultMaxDate = new DateTime(2100, 1, 1);

        public EmployeePositionAssignment()
        {
            db.Connection.Open();
        }

        //~EmployeePositionAssignment()
        //{
        //    if (db.Connection.State == ConnectionState.Open)
        //    {
        //        db.Connection.Close();
        //    }
        //    db.Dispose();
        //}

      
        public void UpdateEmployeePositionHistory(Guid EmployeeAssignmentID, Guid EmployeeTypeID, DateTime startDate)
        {
            var _positionAssignment = GetCurrentAssignment(EmployeeAssignmentID);
            var assignmentBefore = this.GetAssignStartDateBeforeEmployeePositionAssigment(_positionAssignment.EmployeeID, _positionAssignment.DateBegin);
            var assignmentAfter = this.GetAssignStartDateAfterEmployeePositionAssigment(_positionAssignment.EmployeeID, _positionAssignment.DateBegin);
            if (_positionAssignment != null)
            {
                _positionAssignment.EmployeeTypeID = EmployeeTypeID;
                _positionAssignment.DateBegin = startDate;
                if (assignmentBefore != null)
                {
                    assignmentBefore.DateEnd = startDate.AddDays(-1);
                }
                if (assignmentAfter == null)
                {
                    _positionAssignment.DateEnd = defaultMaxDate;
                }
                else
                {
                    _positionAssignment.DateEnd = assignmentAfter.DateBegin.AddDays(-1);
                }
            }
            db.SubmitChanges();
            this.ApplyPositionChangesToEmployee(_positionAssignment.EmployeeID);
            RuleManager.MarkEmployeeShiftAsDirty(_positionAssignment.EmployeeID, _positionAssignment.DateBegin, (DateTime)_positionAssignment.DateEnd);
        }
        public void DeleteEmployeePositionHistory(Guid EmployeeAssignmentID)
        {
            var employeePositionAssignment = GetCurrentAssignment(EmployeeAssignmentID);
            if (employeePositionAssignment != null)
            {
                Guid EmployeeID = employeePositionAssignment.EmployeeID;

                var assignmentAfter = this.GetAssignStartDateAfterEmployeePositionAssigment(employeePositionAssignment.EmployeeID, employeePositionAssignment.DateBegin);
                var assignmentBefore = this.GetAssignStartDateBeforeEmployeePositionAssigment(employeePositionAssignment.EmployeeID, employeePositionAssignment.DateBegin);
                if (assignmentBefore != null)
                {
                    assignmentBefore.DateEnd = employeePositionAssignment.DateEnd;
                }

                if (assignmentBefore != null && assignmentAfter != null)
                {
                    if (assignmentAfter.EmployeeTypeID == assignmentBefore.EmployeeTypeID)
                    {
                        assignmentBefore.DateEnd = assignmentAfter.DateEnd;
                        db.EmployeePositionHistoryAssignments.DeleteOnSubmit(assignmentAfter);
                    }
                }
                db.EmployeePositionHistoryAssignments.DeleteOnSubmit(employeePositionAssignment);
                db.SubmitChanges();
                this.ApplyPositionChangesToEmployee(EmployeeID);
                RuleManager.MarkEmployeeShiftAsDirty(EmployeeID, employeePositionAssignment.DateBegin, (employeePositionAssignment.DateEnd.HasValue ? employeePositionAssignment.DateEnd.Value : defaultMaxDate));
            }
        }
        public void AssignEmployeePositionHistory(Guid EmployeeID, Guid EmployeeTypeID, DateTime startDate)
        {
            if (!IsExistedEmployeePositionAssignment(EmployeeID, startDate))
            {
                var assignmentAfter = GetAssignStartDateAfterEmployeePositionAssigment(EmployeeID, startDate);
                var assignmentBefore = GetAssignStartDateBeforeEmployeePositionAssigment(EmployeeID, startDate);

                EmployeePositionHistoryAssignment epha = new EmployeePositionHistoryAssignment();
                epha.EmployeePositionHistoryAssignmentID = Guid.NewGuid();
                epha.EmployeeTypeID = EmployeeTypeID;
                epha.EmployeeID = EmployeeID;
                if (assignmentAfter != null && assignmentBefore != null)
                {
                    assignmentBefore.DateEnd = startDate.Subtract(defaultTimeSpan);
                    epha.DateBegin = assignmentBefore.DateEnd.Value.Add(defaultTimeSpan);
                    epha.DateEnd = assignmentAfter.DateBegin.Subtract(defaultTimeSpan);
                }
                else if (assignmentAfter != null && assignmentBefore == null)
                {
                    epha.DateEnd = assignmentAfter.DateBegin.Subtract(defaultTimeSpan);
                    epha.DateBegin = startDate;
                }
                else if (assignmentBefore != null & assignmentAfter == null)
                {
                    epha.DateBegin = startDate;
                    assignmentBefore.DateEnd = (DateTime?)startDate.Subtract(defaultTimeSpan);
                    epha.DateEnd = defaultMaxDate;
                }
                db.EmployeePositionHistoryAssignments.InsertOnSubmit(epha);
                db.SubmitChanges();
                ApplyPositionChangesToEmployee(EmployeeID);
                RuleManager.MarkEmployeeShiftAsDirty(EmployeeID, (DateTime)epha.DateBegin, (DateTime)epha.DateEnd);
            }

        }

        public void ApplyPositionChangesToEmployee(Guid EmployeeID)
        {
            var positionChange = (from positionAssignment in db.EmployeePositionHistoryAssignments
                                  where positionAssignment.EmployeeID == EmployeeID &&
                                        positionAssignment.DateBegin <= DateTime.Today && positionAssignment.DateEnd >= DateTime.Today
                                  select positionAssignment).FirstOrDefault();
            if (positionChange != null)
            {
                positionChange.Employee.EmployeeTypeID = positionChange.EmployeeTypeID;
                db.SubmitChanges();
            }
        }
        public bool IsExistedEmployeePositionAssignment(Guid EmployeeID, DateTime startDate)
        {
            var positionAssignment = (from assignment in db.EmployeePositionHistoryAssignments
                                      where assignment.DateBegin == startDate
                                      && assignment.EmployeeID == EmployeeID
                                      select assignment).FirstOrDefault();

            return positionAssignment == null ? false : true;
        }
        public bool ValidateStartDate(Guid EmployeeID, DateTime startDate)
        {
            //Dev1: Fixed. don't allow crossover date
            var assignmentAfter = GetAssignStartDateAfterEmployeePositionAssigment(EmployeeID, startDate);
            var assignmentBefore = GetAssignStartDateBeforeEmployeePositionAssigment(EmployeeID, startDate);
            if (assignmentAfter != null)
            {
                if (assignmentAfter.DateBegin <= startDate)
                {
                    return false;
                }
            }

            if (assignmentBefore != null)
            {
                if (assignmentBefore.DateBegin >= startDate)
                {
                    return false;
                }
            }
            return true;
        }
        public bool ValidateEmployeeType(Guid EmployeeID, Guid EmployeeTypeID, DateTime startDate)
        {
            var assignmentAfter = GetAssignStartDateAfterEmployeePositionAssigment(EmployeeID, startDate);
            var assignmentBefore = GetAssignStartDateBeforeEmployeePositionAssigment(EmployeeID, startDate);
            if ((assignmentAfter != null && assignmentAfter.EmployeeTypeID == EmployeeTypeID) || (assignmentBefore != null && assignmentBefore.EmployeeTypeID == EmployeeTypeID))
            {
                return false;
            }
            else
            {
                return true;
            }
        }
        public bool ValidationOnDeletedAssignment(Guid EmployeeID)
        {
            //Dev2: Fixed. Don't allow to delete the last record.
            int count = (from assignment in db.EmployeePositionHistoryAssignments
                         where assignment.EmployeeID == EmployeeID
                         select assignment).Count();
            if (count > 1)
            {
                return true;
            }
            else
            {
                return false;
            }

        }
        public bool VidationDateBeginOnUpdatedAssingment(Guid employeeAssingmentID, DateTime startDate)
        {
            //Dev1: the begin date of the first record should always be in the past
            var positionAssignment = (from assignment in db.EmployeePositionHistoryAssignments
                                      where assignment.EmployeePositionHistoryAssignmentID == employeeAssingmentID
                                      select assignment).FirstOrDefault();
            if (positionAssignment != null)
            {
                var firstAssignment = this.GetFirstPositionHistoryAssignment(positionAssignment.EmployeeID);
                if (firstAssignment.EmployeePositionHistoryAssignmentID == positionAssignment.EmployeePositionHistoryAssignmentID)
                {
                    if (startDate > DateTime.Today)
                    {
                        return false;
                    }
                }
                return true;
            }
            else
            {
                return false;
            }
        }


        // ---  SNIP SNIP SNIP  more of code godness


        private static int ApplyDepotChangesToShifts(NorthWindDataContext dataContext, EmployeeDepotHistoryAssignment assignment, bool isDelete, DateTime originalDateBegin)
        {

            var existingSameBeforeOne = dataContext.EmployeeDepotHistoryAssignments.Where(h => h.DateBegin < assignment.DateBegin
                                                                                            && h.EmployeeID == assignment.EmployeeID).OrderByDescending(h => h.DateBegin).FirstOrDefault();
            Guid depotid = assignment.DepotID;
            DateTime dateBegin = assignment.DateBegin;
            DateTime dateEnd = assignment.DateEnd.HasValue ? assignment.DateEnd.Value.AddDays(1) : DateTime.MaxValue;
            Guid employeeID = assignment.EmployeeID;
            Guid previouseDepotID = existingSameBeforeOne == null ? Guid.Empty : existingSameBeforeOne.DepotID;
            DateTime previouseDateEnd = existingSameBeforeOne == null ? originalDateBegin : (existingSameBeforeOne.DateEnd.HasValue ? existingSameBeforeOne.DateEnd.Value.AddDays(1) : DateTime.MaxValue);

            int affectedShifts = 0;
            //dataContext.MoveShifts(assignment.DepotID, previouseDepotID, dateBegin, dateEnd, employeeID);

            if (isDelete)
            {
                affectedShifts = MoveShifts(dataContext, assignment.DepotID, previouseDepotID, dateBegin, dateEnd, employeeID);

                if (existingSameBeforeOne != null)
                {
                    existingSameBeforeOne.DateEnd = assignment.DateEnd;
                }
                dataContext.EmployeeDepotHistoryAssignments.DeleteOnSubmit(assignment);

                dataContext.SubmitChanges();

                RuleManager.MarkEmployeeShiftAsDirty(employeeID, dateBegin, dateEnd);
            }
            else
            {
                if (existingSameBeforeOne != null)
                {
                    existingSameBeforeOne.DateEnd = assignment.DateBegin.AddDays(-1);
                }
                dataContext.SubmitChanges();

                if (assignment.DateBegin <= previouseDateEnd)
                {
                    //if (assignment.DateBegin < DateTime.Today.AddDays(1))
                    //{
                    affectedShifts = MoveShifts(dataContext, previouseDepotID, assignment.DepotID,
                            assignment.DateBegin, previouseDateEnd, employeeID);
                    //}

                    //if (assignment.DateBegin < DateTime.Today.AddDays(1))
                    //{
                    RuleManager.MarkEmployeeShiftAsDirty(employeeID, assignment.DateBegin, previouseDateEnd);
                    //}
                }
                else
                {
                    //if (assignment.DateBegin < DateTime.Today.AddDays(1))
                    //{
                    affectedShifts = MoveShifts(dataContext, assignment.DepotID, previouseDepotID,
                        previouseDateEnd, assignment.DateBegin, employeeID);
                    //}                    

                    //if (assignment.DateBegin < DateTime.Today.AddDays(1))
                    //{
                    RuleManager.MarkEmployeeShiftAsDirty(employeeID, previouseDateEnd.AddDays(-1), assignment.DateBegin.AddDays(1));
                    //}
                }

            }

            //Update employee's deopt
            var currentAssignment = dataContext.EmployeeDepotHistoryAssignments.Where(h => h.DateBegin <= DateTime.Today && (h.DateEnd.HasValue ? h.DateEnd.Value : DateTime.MaxValue) > DateTime.Today
                                                                                            && h.EmployeeID == employeeID).FirstOrDefault();
            if (currentAssignment != null)
            {
                Employee emp = dataContext.Employees.Where(e => e.EmployeeID == employeeID).FirstOrDefault();
                if (emp != null)
                {
                    emp.Depot = dataContext.Depots.Single(d => d.DepotID == currentAssignment.DepotID);
                    //emp.DepotID = currentAssignment.DepotID;
                    dataContext.SubmitChanges();
                }
            }

            return affectedShifts;
        }


        // SNIP SNIP SNIP  -> I spare you the rest

    }
}

 

I post the refactored code file in the next days. You can and should read the book: "Clean Code" from Uncle Bob in the meantime Winking smile

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