/**************************************************************************
 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
 *                                                                        *
 * Author: The ALICE Off-line Project.                                    *
 * Contributors are mentioned in the code where appropriate.              *
 *                                                                        *
 * Permission to use, copy, modify and distribute this software and its   *
 * documentation strictly for non-commercial purposes is hereby granted   *
 * without fee, provided that the above copyright notice appears in all   *
 * copies and that both the copyright notice and this permission notice   *
 * appear in the supporting documentation. The authors make no claims     *
 * about the suitability of this software for any purpose. It is          *
 * provided "as is" without express or implied warranty.                  *
 **************************************************************************/

/* $Id$ */
// Author: Andrei Gheata, 31/05/2006

//==============================================================================
//   AliAnalysysDataSlot - Class representing a data slot of an analysis task.
//      An analysis slot enforces a certain data type required by the Exec()
//      method of the analysis task. The slot must be connected to a data 
//      container with data of the same type.
//
// The class should not be directly created by users - it is created by
// each AliAnalysisTask when defining its input/output slots using:
//
//    AliAnalysisTask::SetInput(Int_t index, TClass *type);
//    AliAnalysisTask::SetOutput(TClass *type);
//
// An existing data contaner (AliAnalysisDataContainer) can be connected to the
// input/output slots of an analysis task using:
//
//   AliAnalysisModule::ConnectInput(AliAnalysisTask *task, Int_t islot,
//                                   AliAnalysisDataContainer *cont)
//   AliAnalysisModule::ConnectOutput(AliAnalysisTask *task,
//                                    AliAnalysisDataContainer *cont)
// To connect a slot to a data container, the data types declared by both must
// match.
//==============================================================================

#include "Riostream.h"

#include "TClass.h"
#include "TTree.h"
//#include "AliLog.h"

#include "AliAnalysisDataSlot.h"
#include "AliAnalysisTask.h"
#include "AliAnalysisDataContainer.h"

ClassImp(AliAnalysisDataSlot)

//______________________________________________________________________________
AliAnalysisDataSlot& AliAnalysisDataSlot::operator=(const AliAnalysisDataSlot &slot)
{
// Assignment
   if (&slot == this) return *this;
   TObject::operator=(slot);
   fType = slot.fType;
   fParent = slot.fParent;
   fContainer = slot.fContainer;   
   return *this;
}

//______________________________________________________________________________
Bool_t AliAnalysisDataSlot::ConnectContainer(AliAnalysisDataContainer *cont)
{
// Connect the data slot with a given container. The operation will succeed only
// if the type defined by the slot inherits from the type enforced by the container.
// The error message in case of failure is posted by the caller.
   if (!cont || !fType) return kFALSE;
   if (!fType->InheritsFrom(cont->GetType())) {
     cout<<"Data slot of type "<<fType->GetName()<<" of task "<<fParent->GetName()<<" cannot be connected to data container "<<cont->GetName()<<" of type "<<cont->GetType()->GetName()<<endl;
     //AliError(Form("Data slot of type %s of task %s cannot be connected to data container %s of type %s", fType->GetName(), fParent->GetName(), cont->GetName(), cont->GetType()->GetName()));
      return kFALSE;
   }   
   fContainer = cont;
   return kTRUE;
}   

//______________________________________________________________________________
void *AliAnalysisDataSlot::GetBranchAddress(const char *branchname) const
{
// Retrieve the address for a given branch. One should always test this before
// using SetBranchAddress because the address gets set by the first caller.
// Call this in MyTask::Init()
   if (!fType->InheritsFrom(TTree::Class())) {
     cout<<"Cannot call GetBranchAddress() for data slot of task "<<fParent->GetName()<<" not pointing to tree-type data"<<endl;
     //AliFatal(Form("Cannot call GetBranchAddress() for data slot of task %s not pointing to tree-type data", fParent->GetName()));
      return NULL;
   }
   if (!IsDataReady()) {
     cout<<"Cannot call GetBranchAddress() for data slot of task "<<fParent->GetName()<<" while data is not ready"<<endl;
     //AliFatal(Form("Cannot call GetBranchAddress() for data slot of task %s while data is not ready", fParent->GetName()));
      return NULL;
   }
   TTree *tree = (TTree*)GetData();
   TBranch *br = tree->GetBranch(branchname);
   if (!br) {   
     cout<<"Branch "<<branchname<<" not found in tree "<<tree->GetName()<<" as input of task "<<fParent->GetName()<<"..."<<endl;
     //AliFatal(Form("Branch %s not found in tree %s as input of task %s...", branchname, tree->GetName(), fParent->GetName()));
      return NULL;
   }
   return br->GetAddress();
}   

//______________________________________________________________________________
Bool_t AliAnalysisDataSlot::SetBranchAddress(const char *branchname, void *address)
{
// Set a branch address for input tree. To be called during MyTask::Init()
// only if GetBranchAddress() returns a NULL pointer for a tree-type slot.
   if (GetBranchAddress(branchname)) {
     cout<<"Branch address for "<<branchname<<" already set by other task. Call first GetBranchAddress() in "<<fParent->GetName()<<"::Init()"<<endl;
     //AliError(Form("Branch address for %s already set by other task. Call first GetBranchAddress() in %s::Init()",branchname, fParent->GetName()));
      return kFALSE;
   }
   TTree *tree = (TTree*)GetData();
   tree->SetBranchAddress(branchname, address);
   return kTRUE;
}   
      
//______________________________________________________________________________
TObject *AliAnalysisDataSlot::GetData() const
{
// Retreives the data from the container if it is ready.
   if (!fContainer) {
     cout<<"Data slot of type "<<fType->GetName()<<" of task "<<fParent->GetName()<<" has no connected data container"<<endl;
     //AliError(Form("Data slot of type %s of task %s has no connected data container",fType->GetName(), fParent->GetName()));    
      return NULL;
   }
   if (!fContainer->IsDataReady()) return NULL;
   return fContainer->GetData();
}

//______________________________________________________________________________
Bool_t  AliAnalysisDataSlot::IsDataReady() const
{
// Check if data for this slot is ready in its container.
   if (!fContainer) {
     cout<<"Data slot of type "<<fType->GetName()<<" of task "<<fParent->GetName()<<" has no connected data container"<<endl;
     //AliError(Form("Data slot of type %s of task %s has no connected data container",fType->GetName(), fParent->GetName()));    
      return kFALSE;
   }
   return fContainer->IsDataReady();
}