' Copyright 2012 ESRI
' 
' All rights reserved under the copyright laws of the United States
' and applicable international laws, treaties, and conventions.
' 
' You may freely redistribute and use this sample code, with or
' without modification, provided you include the original copyright
' notice and use restrictions.
' 
' See the use restrictions.
' 

Imports Microsoft.VisualBasic
Imports System
Imports System.Collections.Generic
Imports System.Text
Imports System.Runtime.InteropServices
Imports ESRI.ArcGIS.esriSystem
Imports ESRI.ArcGIS.Geodatabase

Namespace SubsetNetworkEvaluators
  ''' <summary>
  ''' The scale subset network evaluator is a custom network evaluator for modeling slowdown polygons
  ''' where traffic speeds are slowed down in only a particular subset of the network.  In this
  ''' example the subset of network elements that are slowed down is determined based on the geometry
  ''' of graphic elements drawn in arc map, but it does not matter how the element subset is determined.
  ''' The elements that are not in the subset just return the non-scaled base attribute value.  This could
  ''' be useful, for example, if certain low lying areas had a flash flood, or other localized congestion that
  ''' does not affect the network as a whole.  The subset of elements to be scaled and the scale factor to
  ''' scale the base attribute by in the scale subset evaluator are network attribute parameters of the attribute
  ''' the evaluator is assigned to.
  ''' </summary>

  <ClassInterface(ClassInterfaceType.None), Guid("67cf8446-22a2-4baf-9c97-3c22a33cc0c7"), ProgId("SubsetNetworkEvaluators.ScaleSubsetEvaluator")> _
  Public Class ScaleSubsetEvaluator : Implements INetworkEvaluator2, INetworkEvaluatorSetup
#Region "Member Variables"

    Private m_networkDataset As INetworkDataset
    Private m_networkSource As INetworkSource
    Private m_networkAttribute As INetworkAttribute

    Private m_scaleFactor As Double = 1
    Private m_thisNetworkAttributeID As Integer = -1 ' the ID for this attribute
    Private m_baseNetworkAttributeID As Integer = -1 ' the ID for the other attribute that should be scale (determined based on attribute name)
    Private m_countSourceEIDs As Integer = 0 ' number of EIDs to override for this source
    Private m_sourceEIDHashTable As Dictionary(Of Integer, Integer)  ' the EIDs to override values for, by scaling, for this source

#End Region

#Region "INetworkEvaluator Members"

    Public ReadOnly Property CacheAttribute() As Boolean Implements INetworkEvaluator.CacheAttribute, INetworkEvaluator2.CacheAttribute
      ' CacheAttribute returns whether or not we want the network dataset to cache our evaluated attribute values during the network dataset build
      ' Since this is a dynamic evaluator, we will return false, so that our attribute values are dynamically queried at runtime
      Get
        Return False
      End Get
    End Property

    Public ReadOnly Property DisplayName() As String Implements INetworkEvaluator.DisplayName, INetworkEvaluator2.DisplayName
      Get
        Return "ScaleSubset"
      End Get
    End Property

    Public ReadOnly Property Name() As String Implements INetworkEvaluator.Name, INetworkEvaluator2.Name
      Get
        Return "SubsetNetworkEvaluators.ScaleSubset"
      End Get
    End Property

#End Region

#Region "INetworkEvaluator2 Members"

    Public Sub Refresh() Implements INetworkEvaluator2.Refresh
      ' This method is called internally during a solve operation immediately prior to performing the actual solve
      ' This gives us an opportunity to update our evaluator's internal state based on parameter values

      m_scaleFactor = 1
      m_countSourceEIDs = 0
      m_sourceEIDHashTable = New Dictionary(Of Integer, Integer)()

      Dim netAttribute2 As INetworkAttribute2 = TryCast(m_networkAttribute, INetworkAttribute2)
      Dim netAttributeParams As IArray = netAttribute2.Parameters

      ' Parameters: "ScaleSubset_Factor", "ScaleSubset_EIDs_<SourceName>"
      Dim prefix As String = BaseParameterName & "_"

      Dim paramScaleFactorName As String = prefix & "Factor"
      Dim paramEIDsName As String = prefix & "eids_" & m_networkSource.Name

      Dim nParamScaleFactor As Integer = SubsetHelper.FindParameter(netAttributeParams, paramScaleFactorName)
      Dim nParamEIDs As Integer = SubsetHelper.FindParameter(netAttributeParams, paramEIDsName)

      Dim value As Object

      Dim paramScaleFactor As INetworkAttributeParameter
      Dim paramEIDs As INetworkAttributeParameter

      If nParamScaleFactor >= 0 Then
        paramScaleFactor = TryCast(netAttributeParams.Element(nParamScaleFactor), INetworkAttributeParameter)
        value = paramScaleFactor.Value
        If Not value Is Nothing Then
          m_scaleFactor = CDbl(value)
        End If
      End If

      If nParamEIDs >= 0 Then
        paramEIDs = TryCast(netAttributeParams.Element(nParamEIDs), INetworkAttributeParameter)
        value = TryCast(paramEIDs.Value, Integer())
        If Not value Is Nothing Then
          Dim eid As Integer
          Dim rgEIDs As Integer()
          rgEIDs = CType(value, Integer())

          Dim lb As Integer = rgEIDs.GetLowerBound(0)
          Dim ub As Integer = rgEIDs.GetUpperBound(0)

          Dim i As Integer = lb
          Do While i <= ub
            m_countSourceEIDs += 1
            eid = rgEIDs(i)
            m_sourceEIDHashTable.Add(eid, eid)
            i += 1
          Loop
        End If
      End If
    End Sub

    Public ReadOnly Property RequiredFieldNames() As IStringArray Implements INetworkEvaluator2.RequiredFieldNames
      ' This custom evaluator does not require any field names
      Get
        Return Nothing
      End Get
    End Property

#End Region

#Region "INetworkEvaluatorSetup Members"

    Public ReadOnly Property CLSID() As UID Implements INetworkEvaluatorSetup.CLSID
      Get
        ' Create and return the GUID for this custom evaluator
        Dim uid As UID = New UIDClass()
        uid.Value = "{67cf8446-22a2-4baf-9c97-3c22a33cc0c7}"
        Return uid
      End Get
    End Property

    Public Property Data() As IPropertySet Implements INetworkEvaluatorSetup.Data
      ' The Data property is intended to make use of property sets to get/set the custom evaluator's properties using only one call to the evaluator object
      ' This custom evaluator does not make use of this property
      Get
        Return Nothing
      End Get
      Set(ByVal value As IPropertySet)
      End Set
    End Property

    Public ReadOnly Property DataHasEdits() As Boolean Implements INetworkEvaluatorSetup.DataHasEdits
      ' Since this custom evaluator does not make any data edits, return false
      Get
        Return False
      End Get
    End Property

    Public Sub Initialize(ByVal networkDataset As INetworkDataset, ByVal DataElement As IDENetworkDataset, ByVal netSource As INetworkSource, ByVal netAttribute As IEvaluatedNetworkAttribute) Implements INetworkEvaluatorSetup.Initialize
      ' Initialize is called once per session (ArcMap session, ArcCatalog session, etc.) to initialize the evaluator for an associated network dataset            
      m_networkDataset = networkDataset
      m_networkSource = netSource
      m_networkAttribute = netAttribute

      m_thisNetworkAttributeID = netAttribute.ID
      m_baseNetworkAttributeID = -1

      'The attribute name must begin with one or more non underscore characters followed by
      'an underscore character and then the name of the base cost attribute.
      'The underscore prior to the base attribute name should be the first underscore in the name.

      Dim thisAttributeName As String = netAttribute.Name
      Dim nPos As Integer = thisAttributeName.IndexOf("_"c)
      Dim nLastPos As Integer = thisAttributeName.Length - 1

      Dim baseNetAttributeName As String
      Dim baseNetAttribute As INetworkAttribute = Nothing

      If nPos > 0 AndAlso nPos < nLastPos Then
        baseNetAttributeName = thisAttributeName.Remove(0, nPos + 1)
        Try
          baseNetAttribute = networkDataset.AttributeByName(baseNetAttributeName)
        Catch ex As COMException
          baseNetAttribute = Nothing
          Dim msg As String = String.Format("Base Attribute ({0}) not found. {1}.", baseNetAttributeName, ex.Message)
          System.Diagnostics.Trace.WriteLine(msg, "Scale Subset Network Evaluator")
        End Try

        If Not baseNetAttribute Is Nothing Then
          If baseNetAttribute.ID <> m_thisNetworkAttributeID Then
            m_baseNetworkAttributeID = baseNetAttribute.ID
          End If
        End If
      End If

      Refresh()
    End Sub

    Public Function QueryValue(ByVal Element As INetworkElement, ByVal Row As IRow) As Object Implements INetworkEvaluatorSetup.QueryValue
      If m_baseNetworkAttributeID < 0 Then
        Return -1
      End If

      Dim value As Object = Element.AttributeValue(m_baseNetworkAttributeID)
      If value Is Nothing Then
        Return -1
      End If

      Dim baseValue As Double = CDbl(value)
      If baseValue <= 0 OrElse m_scaleFactor = 1 OrElse m_countSourceEIDs <= 0 Then
        Return baseValue
      End If

      Dim isScaled As Boolean = False

      Dim eid As Integer = -1
      If m_sourceEIDHashTable.TryGetValue(Element.EID, eid) Then
        isScaled = (eid > 0)
      End If

      Dim resultValue As Object = baseValue
      If isScaled Then
        If m_scaleFactor >= 0 Then
          resultValue = m_scaleFactor * baseValue
        Else
          resultValue = -1
        End If
      End If

      Return resultValue
    End Function

    Public Function SupportsDefault(ByVal ElementType As esriNetworkElementType, ByVal netAttribute As IEvaluatedNetworkAttribute) As Boolean Implements INetworkEvaluatorSetup.SupportsDefault
      Return False
    End Function

    Public Function SupportsSource(ByVal netSource As INetworkSource, ByVal netAttribute As IEvaluatedNetworkAttribute) As Boolean Implements INetworkEvaluatorSetup.SupportsSource
      ' This custom evaluator supports cost attributes for all sources
      Return netAttribute.UsageType = esriNetworkAttributeUsageType.esriNAUTCost
    End Function

    Public Function ValidateDefault(ByVal ElementType As esriNetworkElementType, ByVal netAttribute As IEvaluatedNetworkAttribute, ByRef ErrorCode As Integer, ByRef ErrorDescription As String, ByRef errorAppendInfo As String) As Boolean Implements INetworkEvaluatorSetup.ValidateDefault
      If SupportsDefault(ElementType, netAttribute) Then
        ErrorCode = 0
        ErrorDescription = String.Empty
        errorAppendInfo = String.Empty
        Return True
      Else
        ErrorCode = -1
        ErrorDescription = String.Empty
        errorAppendInfo = String.Empty
        Return False
      End If
    End Function

    Public Function ValidateSource(ByVal datasetContainer As IDatasetContainer2, ByVal netSource As INetworkSource, ByVal netAttribute As IEvaluatedNetworkAttribute, ByRef ErrorCode As Integer, ByRef ErrorDescription As String, ByRef errorAppendInfo As String) As Boolean Implements INetworkEvaluatorSetup.ValidateSource
      If SupportsSource(netSource, netAttribute) Then
        ErrorCode = 0
        ErrorDescription = String.Empty
        errorAppendInfo = String.Empty
        Return True
      Else
        ErrorCode = -1
        ErrorDescription = String.Empty
        errorAppendInfo = String.Empty
        Return False
      End If
    End Function

#End Region

#Region "Static Members"

    Public Shared ReadOnly Property BaseParameterName() As String
      Get
        Return "ScaleSubset"
      End Get
    End Property

    Public Shared Sub RemoveScaleSubsetAttributes(ByVal deNet As IDENetworkDataset)
      Dim netAttributes As IArray = SubsetHelper.RemoveAttributesByPrefix(deNet.Attributes, BaseParameterName)
      deNet.Attributes = netAttributes
    End Sub

    Public Shared Function AddScaleSubsetAttributes(ByVal deNet As IDENetworkDataset) As List(Of IEvaluatedNetworkAttribute)
      Dim scaleSubsetAttributes As List(Of IEvaluatedNetworkAttribute) = New List(Of IEvaluatedNetworkAttribute)()

      Dim netAttributesArray As IArray = deNet.Attributes
      Dim baseIndexes As List(Of Integer) = SubsetHelper.FindAttributeIndexes(netAttributesArray, esriNetworkAttributeUsageType.esriNAUTCost, esriNetworkAttributeDataType.esriNADTDouble, True, False)
      Dim baseNetAttributes As List(Of INetworkAttribute2) = SubsetHelper.FindAttributes(netAttributesArray, baseIndexes)
      For Each baseNetAttribute As INetworkAttribute2 In baseNetAttributes
        scaleSubsetAttributes.Add(AddScaleSubsetAttribute(deNet, baseNetAttribute))
      Next baseNetAttribute

      Return scaleSubsetAttributes
    End Function

    Public Shared Function AddScaleSubsetAttribute(ByVal deNet As IDENetworkDataset, ByVal baseNetAttribute As INetworkAttribute2) As IEvaluatedNetworkAttribute
      If baseNetAttribute Is Nothing Then
        Return Nothing
      End If

      If baseNetAttribute.UsageType <> esriNetworkAttributeUsageType.esriNAUTCost Then
        Return Nothing
      End If

      Dim netAttributes As IArray = deNet.Attributes
      Dim netAttribute As IEvaluatedNetworkAttribute = TryCast(New EvaluatedNetworkAttributeClass(), IEvaluatedNetworkAttribute)

      Dim netAttributeName As String = BaseParameterName
      netAttributeName &= "_"
      netAttributeName &= baseNetAttribute.Name

      netAttribute.Name = netAttributeName
      netAttribute.UsageType = baseNetAttribute.UsageType
      netAttribute.DataType = baseNetAttribute.DataType
      netAttribute.Units = baseNetAttribute.Units

      Dim allNetSources As List(Of INetworkSource) = SubsetHelper.GetSourceList(deNet.Sources)
      Dim netSources As List(Of INetworkSource) = SubsetHelper.GetSourceList(allNetSources, esriNetworkElementType.esriNETEdge)
      Dim netSourceNames As List(Of String) = SubsetHelper.GetSourceNames(netSources)

      ResetScaleSubsetParameters(CType(netAttribute, INetworkAttribute2), netSourceNames)

      Dim supportTurns As Boolean = deNet.SupportsTurns

      'default evaluators
      SubsetHelper.SetDefaultEvaluator(netAttribute, 0, esriNetworkElementType.esriNETEdge)
      SubsetHelper.SetDefaultEvaluator(netAttribute, 0, esriNetworkElementType.esriNETJunction)
      If supportTurns Then
        SubsetHelper.SetDefaultEvaluator(netAttribute, 0, esriNetworkElementType.esriNETTurn)
      End If

      'sourced evaluators
      For Each netSource As INetworkSource In netSources
        SubsetHelper.SetEvaluators(netAttribute, netSource, GetType(ScaleSubsetEvaluator))
      Next netSource

      netAttributes.Add(netAttribute)
      deNet.Attributes = netAttributes

      Return netAttribute
    End Function

    Public Shared Sub ResetScaleSubsetParameters(ByVal netAttribute As INetworkAttribute2, ByVal netSourceNames As List(Of String))
      Dim netParams As IArray = New ESRI.ArcGIS.esriSystem.ArrayClass()
      Dim netParam As INetworkAttributeParameter = Nothing
      Dim paramValue As Object = Nothing
      Dim paramName As String = ""

      netParam = New NetworkAttributeParameterClass()
      paramValue = 1

      paramName = BaseParameterName
      paramName &= "_Factor"

      netParam.Name = paramName
      netParam.VarType = CInt(VarType.Double)
      netParam.Value = paramValue
      netParam.DefaultValue = paramValue
      netParams.Add(netParam)

      For Each netSourceName As String In netSourceNames
        netParam = New NetworkAttributeParameterClass()
        paramValue = Nothing

        paramName = BaseParameterName
        paramName &= "_eids_"
        paramName &= netSourceName
        netParam.Name = paramName
        netParam.VarType = CInt(VarType.Array Or VarType.Integer)
        netParam.Value = paramValue
        netParam.DefaultValue = paramValue
        netParams.Add(netParam)
      Next netSourceName

      'does not preserve existing parameters if any
      netAttribute.Parameters = netParams
    End Sub

#End Region
  End Class
End Namespace