// @(#)root/tmva $Id$    
// Author: Andreas Hoecker, Joerg Stelzer, Helge Voss, Kai Voss 

/**********************************************************************************
 * Project: TMVA - a Root-integrated toolkit for multivariate Data analysis       *
 * Package: TMVA                                                                  *
 * Classes: Node                                                                  *
 * Web    : http://tmva.sourceforge.net                                           *
 *                                                                                *
 * Description:                                                                   *
 *      Implementation (see header file for description)                          *
 *                                                                                *
 * Authors (alphabetical):                                                        *
 *      Andreas Hoecker <Andreas.Hocker@cern.ch> - CERN, Switzerland              *
 *      Helge Voss      <Helge.Voss@cern.ch>     - MPI-K Heidelberg, Germany      *
 *      Kai Voss        <Kai.Voss@cern.ch>       - U. of Victoria, Canada         *
 *                                                                                *
 * CopyRight (c) 2005:                                                            *
 *      CERN, Switzerland                                                         * 
 *      U. of Victoria, Canada                                                    * 
 *      MPI-K Heidelberg, Germany                                                 * 
 *                                                                                *
 * Redistribution and use in source and binary forms, with or without             *
 * modification, are permitted according to the terms listed in LICENSE           *
 * (http://tmva.sourceforge.net/LICENSE)                                          *
 **********************************************************************************/

//_______________________________________________________________________
/*
  Node for the BinarySearch or Decision Trees.
  
  For the binary search tree, it basically consists of the EVENT, and
  pointers to the parent and daughters

  In case of the Decision Tree, it specifies parent and daughters, as
  well as "which variable is used" in the selection of this node,
  including the respective cut value.
*/
//______________________________________________________________________

#include <stdexcept>
#include <iosfwd>
#include <iostream>

#include "TMVA/Node.h"
#include "TMVA/Tools.h"

ClassImp(TMVA::Node)

Int_t TMVA::Node::fgCount = 0;

TMVA::Node::Node() 
   : fParent( NULL ),
     fLeft  ( NULL),
     fRight ( NULL ),
     fPos   ( 'u' ),
     fDepth ( 0 ),
     fParentTree( NULL )
{
   // default constructor
   fgCount++;
}

//_______________________________________________________________________
TMVA::Node::Node( Node* p, char pos ) 
   : fParent ( p ), 
     fLeft ( NULL ), 
     fRight( NULL ),  
     fPos  ( pos ), 
     fDepth( p->GetDepth() + 1), 
     fParentTree(p->GetParentTree()) 
{
   // constructor of a daughter node as a daughter of 'p'

   fgCount++;
   if (fPos == 'l' ) p->SetLeft(this);
   else if (fPos == 'r' ) p->SetRight(this);
}

//_______________________________________________________________________
TMVA::Node::Node ( const Node &n ) 
   : fParent( NULL ), 
     fLeft  ( NULL), 
     fRight ( NULL ), 
     fPos   ( n.fPos ), 
     fDepth ( n.fDepth ), 
     fParentTree( NULL )
{
   // copy constructor, make sure you don't just copy the poiter to the node, but
   // that the parents/daugthers are initialized to 0 (and set by the copy 
   // constructors of the derived classes 
   fgCount++;
}

//_______________________________________________________________________
TMVA::Node::~Node()
{
   // node destructor
   fgCount--;
}

//_______________________________________________________________________
int TMVA::Node::GetCount()
{
   // retuns the global number of instantiated nodes
   return fgCount;
}

//_______________________________________________________________________
Int_t TMVA::Node::CountMeAndAllDaughters() const 
{
   //recursively go through the part of the tree below this node and count all daughters
   Int_t n=1;
   if (this->GetLeft() != NULL) 
      n+= this->GetLeft()->CountMeAndAllDaughters(); 
   if (this->GetRight() != NULL) 
      n+= this->GetRight()->CountMeAndAllDaughters(); 
  
   return n;
}

// print a node
//_______________________________________________________________________
std::ostream& TMVA::operator<<( std::ostream& os, const TMVA::Node& node )
{ 
   // output operator for a node  
   node.Print(os);
   return os;                // Return the output stream.
}

//_______________________________________________________________________
std::ostream& TMVA::operator<<( std::ostream& os, const TMVA::Node* node )
{ 
   // output operator with a pointer to the node (which still prints the node itself)
   if (node!=NULL) node->Print(os);
   return os;                // Return the output stream.
}

//_______________________________________________________________________
void* TMVA::Node::AddXMLTo( void* parent ) const
{
   // add attributes to XML
   std::stringstream s("");
   AddContentToNode(s);
   void* node = gTools().AddChild(parent, "Node", s.str().c_str());
   gTools().AddAttr( node, "pos",   fPos );
   gTools().AddAttr( node, "depth", fDepth );
   this->AddAttributesToNode(node);
   if (this->GetLeft())  this->GetLeft()->AddXMLTo(node);
   if (this->GetRight()) this->GetRight()->AddXMLTo(node);
   return node;
}

//_______________________________________________________________________
void TMVA::Node::ReadXML( void* node,  UInt_t tmva_Version_Code )
{
   // read attributes from XML
   ReadAttributes(node, tmva_Version_Code);
   const char* content = gTools().GetContent(node);
   if (content) {
      std::stringstream s(content);
      ReadContent(s);
   }
   gTools().ReadAttr( node, "pos",   fPos );
   gTools().ReadAttr( node, "depth", fDepth );

   void* ch = gTools().GetChild(node);
   while (ch) {
      Node* n = CreateNode();
      n->ReadXML(ch, tmva_Version_Code);
      if (n->GetPos()=='l')     { this->SetLeft(n);  }
      else if(n->GetPos()=='r') { this->SetRight(n); }
      else { 
	 std::cout << "neither left nor right" << std::endl;
      }
      ch = gTools().GetNextChild(ch);
   }
}