DataProvider.vb

Imports Microsoft.VisualBasic
Imports System.Collections
Imports System.Collections.Generic
Imports System.Linq
Imports System.Web
Imports System.Web.SessionState

Public NotInheritable Class DataProvider

	Private Sub New()
	End Sub
	Private Shared ReadOnly Property Session() As HttpSessionState
		Get
			Return HttpContext.Current.Session
		End Get
	End Property

	Private Shared ReadOnly Property DemoData() As DemoDataObject
		Get
			Const key As String = "FB1EB35F-86F5-4FFE-BB23-CBAAF1514C49"
			If Session(key) Is Nothing Then
				Dim obj = New DemoDataObject()
				obj.FillObj()
				Session(key) = obj
			End If
			Return CType(Session(key), DemoDataObject)
		End Get
	End Property

	Public Shared Function GetCustomers() As IEnumerable
		Return DemoData.Customers
	End Function

	Public Shared Sub InsertCustomer(ByVal customerName As String, ByVal countryID As Integer, ByVal cityID As Integer)
		Dim c = New Customer() With {.CustomerID = DemoData.Customers.Count, .CustomerName = customerName, .CountryID = countryID, .CityID = cityID}

		DemoData.Customers.Add(c)
	End Sub

	Public Shared Sub UpdateCustomer(ByVal customerID As Integer, ByVal customerName As String, ByVal countryID As Integer, ByVal cityID As Integer)
		Dim c = DemoData.Customers.First(Function(i) i.CustomerID = customerID)

		c.CustomerName = customerName
		c.CountryID = countryID
		c.CityID = cityID
	End Sub

	Public Shared Function GetCountries() As IEnumerable
		Return DemoData.Countries
	End Function

	Public Shared Function GetCities() As IEnumerable
		Return DemoData.Cities
	End Function

	Public Shared Function GetCities(ByVal countryID As Integer) As IEnumerable
		Return _
			From c In DemoData.Cities _
			Where c.CountryID = countryID _
			Select c
	End Function
End Class

Public Class DemoDataObject
	Private privateCustomers As List(Of Customer)
	Public Property Customers() As List(Of Customer)
		Get
			Return privateCustomers
		End Get
		Set(ByVal value As List(Of Customer))
			privateCustomers = value
		End Set
	End Property
	Private privateCountries As List(Of Country)
	Public Property Countries() As List(Of Country)
		Get
			Return privateCountries
		End Get
		Set(ByVal value As List(Of Country))
			privateCountries = value
		End Set
	End Property
	Private privateCities As List(Of City)
	Public Property Cities() As List(Of City)
		Get
			Return privateCities
		End Get
		Set(ByVal value As List(Of City))
			privateCities = value
		End Set
	End Property

	Public Sub FillObj()
		Customers = New List(Of Customer)()
		Countries = New List(Of Country)()
		Cities = New List(Of City)()

		Dim uk = CreateCountry("UK")
		Dim usa = CreateCountry("USA")

		CreateCustomer("Jacob", CreateCity("Brighton", uk.CountryID))
		CreateCustomer("Michael", CreateCity("Glasgow", uk.CountryID))
		CreateCustomer("Emily", CreateCity("London", uk.CountryID))
		CreateCustomer("Joshua", CreateCity("Bath", uk.CountryID))
		CreateCustomer("Emma", CreateCity("Manchester", uk.CountryID))
		CreateCustomer("Madison", CreateCity("Wells", uk.CountryID))
		CreateCustomer("Matthew", CreateCity("York", uk.CountryID))
		CreateCustomer("Olivia", CreateCity("Dallas", usa.CountryID))
		CreateCustomer("Ethan", CreateCity("Las Vegas", usa.CountryID))
		CreateCustomer("Hannah", CreateCity("Los Angeles", usa.CountryID))
		CreateCustomer("Abigail", CreateCity("New York City", usa.CountryID))
		CreateCustomer("Isabella", CreateCity("San Francisco", usa.CountryID))
		CreateCustomer("Andrew", CreateCity("Washington D.C.", usa.CountryID))
		CreateCustomer("Daniel", CreateCity("Miami", usa.CountryID))

		CreateCity("Cardiff", uk.CountryID)
		CreateCity("Liverpool", uk.CountryID)
		CreateCity("Oxford", uk.CountryID)
		CreateCity("Atlanta", usa.CountryID)
		CreateCity("Houston", usa.CountryID)
		CreateCity("Phoenix", usa.CountryID)
	End Sub

	Private Function CreateCustomer(ByVal name As String, ByVal city As City) As Customer
		Dim c = New Customer() With {.CustomerName = name, .CityID = city.CityID, .CountryID = city.CountryID, .CustomerID = Customers.Count}

		Customers.Add(c)

		Return c
	End Function

	Private Function CreateCountry(ByVal name As String) As Country
		Dim c = New Country() With {.CountryName = name}
		c.CountryID = Countries.Count
		Countries.Add(c)
		Return c
	End Function

	Private Function CreateCity(ByVal name As String, ByVal countryID As Integer) As City
		Dim c = New City() With {.CityName = name, .CountryID = countryID, .CityID = Cities.Count}

		Cities.Add(c)

		Return c
	End Function
End Class

Public Class Customer
	Private privateCustomerID As Integer
	Public Property CustomerID() As Integer
		Get
			Return privateCustomerID
		End Get
		Set(ByVal value As Integer)
			privateCustomerID = value
		End Set
	End Property
	Private privateCustomerName As String
	Public Property CustomerName() As String
		Get
			Return privateCustomerName
		End Get
		Set(ByVal value As String)
			privateCustomerName = value
		End Set
	End Property
	Private privateCountryID As Integer
	Public Property CountryID() As Integer
		Get
			Return privateCountryID
		End Get
		Set(ByVal value As Integer)
			privateCountryID = value
		End Set
	End Property
	Private privateCityID As Integer
	Public Property CityID() As Integer
		Get
			Return privateCityID
		End Get
		Set(ByVal value As Integer)
			privateCityID = value
		End Set
	End Property
End Class

Public Class Country
	Private privateCountryID As Integer
	Public Property CountryID() As Integer
		Get
			Return privateCountryID
		End Get
		Set(ByVal value As Integer)
			privateCountryID = value
		End Set
	End Property
	Private privateCountryName As String
	Public Property CountryName() As String
		Get
			Return privateCountryName
		End Get
		Set(ByVal value As String)
			privateCountryName = value
		End Set
	End Property
End Class

Public Class City
	Private privateCityID As Integer
	Public Property CityID() As Integer
		Get
			Return privateCityID
		End Get
		Set(ByVal value As Integer)
			privateCityID = value
		End Set
	End Property
	Private privateCityName As String
	Public Property CityName() As String
		Get
			Return privateCityName
		End Get
		Set(ByVal value As String)
			privateCityName = value
		End Set
	End Property
	Private privateCountryID As Integer
	Public Property CountryID() As Integer
		Get
			Return privateCountryID
		End Get
		Set(ByVal value As Integer)
			privateCountryID = value
		End Set
	End Property
End Class