linqpad/Understanding UNC PayPeriods.linq

<Query Kind="Program">
  <Connection>
    <ID>40766b24-ff74-431b-b387-6c221ede77cf</ID>
    <Persist>true</Persist>
    <Server>p3121-sql-02.sdt.local</Server>
    <Database>jazz prd UNC 20180206.1</Database>
    <ShowServer>true</ShowServer>
  </Connection>
  <Reference>&lt;ProgramFilesX64&gt;\Microsoft SDKs\Azure\.NET SDK\v2.9\bin\plugins\Diagnostics\Newtonsoft.Json.dll</Reference>
  <NuGetReference>Amazon.Lambda.S3Events</NuGetReference>
  <NuGetReference>AWSSDK.Core</NuGetReference>
  <NuGetReference>AWSSDK.S3</NuGetReference>
  <Namespace>Amazon</Namespace>
  <Namespace>Amazon.Auth.AccessControlPolicy</Namespace>
  <Namespace>Amazon.Auth.AccessControlPolicy.ActionIdentifiers</Namespace>
  <Namespace>Amazon.Internal</Namespace>
  <Namespace>Amazon.Lambda.S3Events</Namespace>
  <Namespace>Amazon.MissingTypes</Namespace>
  <Namespace>Amazon.Runtime</Namespace>
  <Namespace>Amazon.Runtime.CredentialManagement</Namespace>
  <Namespace>Amazon.Runtime.CredentialManagement.Internal</Namespace>
  <Namespace>Amazon.Runtime.EventStreams</Namespace>
  <Namespace>Amazon.Runtime.EventStreams.Internal</Namespace>
  <Namespace>Amazon.Runtime.Internal</Namespace>
  <Namespace>Amazon.Runtime.Internal.Auth</Namespace>
  <Namespace>Amazon.Runtime.Internal.Settings</Namespace>
  <Namespace>Amazon.Runtime.Internal.Transform</Namespace>
  <Namespace>Amazon.Runtime.Internal.Util</Namespace>
  <Namespace>Amazon.Runtime.SharedInterfaces</Namespace>
  <Namespace>Amazon.Runtime.SharedInterfaces.Internal</Namespace>
  <Namespace>Amazon.S3</Namespace>
  <Namespace>Amazon.S3.Encryption</Namespace>
  <Namespace>Amazon.S3.Encryption.Internal</Namespace>
  <Namespace>Amazon.S3.Internal</Namespace>
  <Namespace>Amazon.S3.IO</Namespace>
  <Namespace>Amazon.S3.Model</Namespace>
  <Namespace>Amazon.S3.Model.Internal.MarshallTransformations</Namespace>
  <Namespace>Amazon.S3.Transfer</Namespace>
  <Namespace>Amazon.S3.Util</Namespace>
  <Namespace>Amazon.Util</Namespace>
  <Namespace>Amazon.Util.Internal</Namespace>
  <Namespace>Amazon.Util.Internal.PlatformServices</Namespace>
  <Namespace>Newtonsoft.Json</Namespace>
  <Namespace>Newtonsoft.Json.Converters</Namespace>
  <Namespace>Newtonsoft.Json.Linq</Namespace>
  <Namespace>Newtonsoft.Json.Schema</Namespace>
  <Namespace>Newtonsoft.Json.Serialization</Namespace>
  <Namespace>System</Namespace>
  <Namespace>System.Diagnostics</Namespace>
  <Namespace>System.Diagnostics.Tracing</Namespace>
  <Namespace>System.IO.Compression</Namespace>
  <Namespace>ThirdParty.BouncyCastle.Asn1</Namespace>
  <Namespace>ThirdParty.BouncyCastle.Asn1.Utilities</Namespace>
  <Namespace>ThirdParty.BouncyCastle.Math</Namespace>
  <Namespace>ThirdParty.BouncyCastle.OpenSsl</Namespace>
  <Namespace>ThirdParty.BouncyCastle.Utilities.IO.Pem</Namespace>
  <Namespace>ThirdParty.Ionic.Zlib</Namespace>
  <Namespace>ThirdParty.Json.LitJson</Namespace>
  <Namespace>ThirdParty.MD5</Namespace>
</Query>

void Main()
{
	var validPayPeriods = PayPeriodCycles
	.GroupBy(g => new { g.PayCycleID, g.PayCycleName }, (g, pp) =>
	 new
	 {
		 g.PayCycleID,
		 g.PayCycleName,
		 PayPeriods = pp.Select(p =>
		 new payperiodtiming
		 {
			 PayPeriodID = p.PayPeriodID,
			 PeriodEndCalendarDate = p.PeriodEndCalendarDate,
			 PeriodStartCalendarDate = p.PeriodStartCalendarDate
		 }).OrderByDescending(p => p.PeriodEndCalendarDate).Take(6)
	 })
	 .SelectMany(g => g.PayPeriods);

	DeptPayPeriods
	.ToList()
	//	.OrderBy(dpp => dpp.DepartmentID)
	//	.ThenByDescending(dpp => dpp.PayPeriodID)
	.GroupBy(dpp => new { dpp.DepartmentID, dpp.Department }, (g, dpp) => new deptpayperiodtiming
	{
		DepartmentID = g.DepartmentID,
		Department = g.Department,
		PayPeriodTimings = dpp.Select(d => d.PayPeriodID).Distinct()
		.Join(validPayPeriods, x => x, vpp => vpp.PayPeriodID, (x, vpp) => vpp)
		.OrderByDescending(d => d.PayPeriodID)
	})
	.Where(dpp => dpp.PayPeriodTimings.Any())
	.Dump("Department PayPeriods");
}

public void ShowCycles()
{
	PayPeriodCycles
	.GroupBy(g => new { g.PayCycleID, g.PayCycleName }, (g, pp) =>
	 new
	 {
		 g.PayCycleID,
		 g.PayCycleName,
		 PayPeriods = pp.Select(p =>
		 new payperiodtiming
		 {
			 PayPeriodID = p.PayPeriodID,
			 PeriodEndCalendarDate = p.PeriodEndCalendarDate,
			 PeriodStartCalendarDate = p.PeriodStartCalendarDate
		 }).OrderByDescending(p => p.PeriodEndCalendarDate).Take(6)
	 })
	.Dump("Pay Period Cycles");
}

public IEnumerable<deptpayperiod> DeptPayPeriods => (from fact in FactPayrollSampledPayPeriods
													 join dept in DimDepartments on fact.DepartmentID equals dept.DepartmentID
													 select new deptpayperiod
													 {
														 PayPeriodID = fact.PayPeriodID,
														 DepartmentID = fact.DepartmentID,
														 Department = dept.Name
													 }).Union((from fact in ViewPrimaryStatisticsStaffingByPayPeriod
															   join dept in DimDepartments on fact.DepartmentID equals dept.DepartmentID
															   select new deptpayperiod
															   {
																   PayPeriodID = fact.PayPeriodID,
																   DepartmentID = fact.DepartmentID,
																   Department = dept.Name
															   })).Distinct();

public IEnumerable<payperiodcycle> PayPeriodCycles => from pp in DimPayPeriods
													  where pp.PeriodEndCalendarDate < DateTime.Now
													  select new payperiodcycle
													  {
														  PayPeriodID = pp.PayPeriodID,
														  PayCycleID = pp.PayCycleID,
														  PayCycleName = pp.PayCycleName,
														  PeriodEndCalendarDate = pp.PeriodEndCalendarDate,
														  PeriodStartCalendarDate = pp.PeriodStartCalendarDate
													  };

// Define other methods and classes here

public class deptpayperiod
{
	public short PayPeriodID { get; set; }
	public int DepartmentID { get; set; }
	public string Department { get; set; }
}

public class deptpayperiodtiming
{
	public int DepartmentID { get; set; }
	public string Department { get; set; }
	internal IEnumerable<payperiodtiming> PayPeriodTimings { get; set; }
	public IDictionary<short, payperioddate> PayPeriods =>
	PayPeriodTimings.ToDictionary(ppt => ppt.PayPeriodID,
	ppt => new payperioddate
	{
		PeriodStartCalendarDate = ppt.PeriodStartCalendarDate,
		PeriodEndCalendarDate = ppt.PeriodEndCalendarDate
	});
	public DateTime? PeriodStartDate => PayPeriodTimings.OrderByDescending(ppt => ppt.PayPeriodID).First().PeriodStartCalendarDate;
	public DateTime? PeriodEndDate => PayPeriodTimings.OrderByDescending(ppt => ppt.PayPeriodID).First().PeriodEndCalendarDate;
}

public class payperioddate
{
	public DateTime PeriodEndCalendarDate { get; set; }
	public DateTime? PeriodStartCalendarDate { get; set; }
	object ToDump() => new
	{
		PeriodStartDate = $"{PeriodStartCalendarDate:yyyy MM dd}",
		PeriodEndDate = $"{PeriodEndCalendarDate:yyyy MM dd}"
	};
}

public class payperiodtiming : payperioddate
{
	public short PayPeriodID { get; set; }
	object ToDump() => new
	{
		PayPeriodID = $"{PayPeriodID}",
		PeriodStartDate = $"{PeriodStartCalendarDate:yyyy MM dd}",
		PeriodEndDate = $"{PeriodEndCalendarDate:yyyy MM dd}"
	};
}

public class payperiodcycle : payperiodtiming
{
	public int PayCycleID { get; set; }
	public string PayCycleName { get; set; }
}