VERSION 1.0 CLASS
BEGIN
  MultiUse = -1  'True
END
Attribute VB_Name = "PowerEstimator"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
' ====== Estimate power level according to graph synthesis ====
Option Explicit

Private graph_ As CDS_Graph
Private powerLevels_ As Scripting.Dictionary
Private visiting_ As Scripting.Dictionary
Private reps_ As Scripting.Dictionary

Public Function Estimate(iGraph As CDS_Graph, iOrder As Collection, iReps As Scripting.Dictionary) As Scripting.Dictionary
  Set graph_ = iGraph
  Set reps_ = iReps
  Call Reset
  
  Dim vNode As Variant
  For Each vNode In iOrder
    Call GetPowerRecursive(vNode)
  Next vNode

  Set Estimate = powerLevels_
End Function

' ===========
Private Function Reset()
  Set powerLevels_ = New Scripting.Dictionary
  Set visiting_ = New Scripting.Dictionary
  Set reps_ = New Scripting.Dictionary
End Function

Private Function GetPowerRecursive(vNode As Variant) As Long
  If reps_.Exists(vNode) Then _
    vNode = reps_(vNode)
    
  If visiting_.Exists(vNode) Then
    Call MsgBox("Внимание! Граф синтеза содержит цикл!", vbExclamation) ' TODO: extract message and raise error instead
    GetPowerRecursive = 0
    Exit Function
  End If
    
  If powerLevels_.Exists(vNode) Then
    GetPowerRecursive = powerLevels_(vNode)
    Exit Function
  End If
  
  Call visiting_.Add(vNode, 0)
   
  Dim parentCount&: parentCount = graph_.nodes_(vNode).inputs_.Count
  Dim nLevel&
  If parentCount = 0 Then
    nLevel = 1
  Else
    nLevel = 0
    Dim vChild As Variant
    For Each vChild In graph_.nodes_(vNode).inputs_
      nLevel = nLevel + GetPowerRecursive(vChild)
    Next vChild
  End If
  
  Call visiting_.Remove(vNode)
  
  Call powerLevels_.Add(vNode, nLevel)
  GetPowerRecursive = nLevel
End Function