// $Id: TESSerializer.cpp,v 1.2 2008/11/12 23:39:47 marcocle Exp $

// 23 May 2009 : changes to dumpBuffer, loadBuffer.
//
// TESSerializer.loadBuffer : Instead of accepting a const buffer, then copying to a new local buffer
// and then rebuilding the TES, the argument is now non-const, and the TES is reconstructed directly
// from the incoming buffer.
//
// TESSerializer.dumpBuffer : dumpBuffer now accepts an argument; a TBufferFile created externally
// in python.  Sometimes, creating the buffer internally was causing errors when using TMessages and
// TSockets.  Creating the empty buffer in python and passing as an argument fixes this.

#include "GaudiMP/TESSerializer.h"

// Framework include files
#include "GaudiKernel/IRegistry.h"
#include "GaudiKernel/IDataManagerSvc.h"
#include "GaudiKernel/IDataProviderSvc.h"
#include "GaudiKernel/LinkManager.h"
#include "GaudiKernel/DataObject.h"
#include "GaudiKernel/DataStoreItem.h"
#include "GaudiKernel/System.h"
#include "GaudiKernel/GaudiException.h"


#include "GaudiKernel/IOpaqueAddress.h"
#include "GaudiKernel/GenericAddress.h"
#include "GaudiKernel/ClassID.h"
#include "GaudiKernel/KeyedContainer.h"

#include "GaudiKernel/MsgStream.h"

// ROOT include files
#include "TROOT.h"
#include "TClass.h"
#include "TInterpreter.h"
#include "TBufferFile.h"

#include <map>

// a constant to guard against seg-faults in loadBuffer
#define SERIALIZER_END "EOF"

namespace {
  struct DataObjectPush {
    DataObjectPush(DataObject*& p) {
      Gaudi::pushCurrentDataObject(&p);
    }
    ~DataObjectPush() {
      Gaudi::popCurrentDataObject();
    }
  };
}

using namespace std;

bool GaudiMP::TESSerializer::analyse(IRegistry* dir, int level)   {
  if ( level < m_currentItem->depth() )   {
    if ( dir->object() != 0 )   {
      m_objects.push_back(dir->object());
      return true;
    }
  }
  return false;
}

/// Constructor
GaudiMP::TESSerializer::TESSerializer( IDataProviderSvc* svc, IAddressCreator* ac )
  : m_TES(svc)
{
  m_TESMgr = dynamic_cast<IDataManagerSvc*>(svc);
  m_addressCreator = ac;
  m_verifyItems = false;
  m_strict      = false;
}

/// Serialize contents of TES to a TBufferFile
void GaudiMP::TESSerializer::dumpBuffer(TBufferFile& buffer) {
  //
  //  Write all valid objects to the TBufferFile provided in the argument
  //  As objects are collected, the member variable m_classMap is filled
  //  with ROOT Class data, and is kept by the Serializer for future
  //  reference
  //
  //  @paramTBufferFile& buffer : TBufferFile passed by reference
  //          Cannot be declared inside the method, as repeated calls
  //          can cause confusion and buffer wiping.
  //
  StatusCode status;
  DataObject* obj;

  // Clear current selection
  m_objects.erase(m_objects.begin(), m_objects.end());

  // Traverse the tree and collect the requested objects
  for ( Items::iterator i = m_itemList.begin(); i != m_itemList.end(); i++ )    {
    m_currentItem = (*i);
    // cout << "Retrieving Mandatory Object : " << m_currentItem->path() << endl;
    status = m_TES->retrieveObject(m_currentItem->path(), obj);
    if ( status.isSuccess() )  {
      m_TESMgr->traverseSubTree(obj, this);
    }
    else  {
      string text("WARNING: Cannot retrieve TES object(s) for serialisation: ");
      text += m_currentItem->path();
      if ( m_strict ) {
        throw GaudiException(text + m_currentItem->path(), "", status);
      } else {
        cout << text << endl;
        // return StatusCode::FAILURE;
      }
    }
  }
  // Traverse the tree and collect the requested objects (tolerate missing items here)
  for ( Items::iterator i = m_optItemList.begin(); i != m_optItemList.end(); i++ )    {
    m_currentItem = (*i);
    // cout << "Retrieving Optional Object : " << m_currentItem->path() << endl;
    status= m_TES->retrieveObject(m_currentItem->path(), obj);
    if ( status.isSuccess() )  {
      m_TESMgr->traverseSubTree(obj, this);
    }
  }

  // cout << "TESSerializer : Beginning loop to write to TBufferFile for nObjects : " << m_objects.size() << endl;
  buffer.WriteInt(m_objects.size());

  for(Objects::iterator i = m_objects.begin(); i != m_objects.end(); ++i) {
    DataObject* pObj = (*i);	/* define pointer !pObj! to a data object */
    DataObjectPush p(pObj);		/* add the data object to the list... */

    // We build a map so gROOT has to access the whole class database as little as possible
    TClass* cl;						        /* announce a TClass */
    const type_info& objClass = typeid(*pObj);		        /* get the type of the data object */
    // cout << "TES Object : " << pObj->registry()->identifier() << endl;
    string objClassName = System::typeinfoName(objClass);	/* and then get the descriptive string from System */

    /* First go   : populate the class map
       Subsequent : refer to class map     */
    if (m_classMap[objClassName])   {
      cl=m_classMap[objClassName];
    } else {
      /* Map new object : pull the class name from the objects c_str() method */
      const char* clName = objClassName.c_str();
      /* Find the relevant Tclass (cl) in gROOT, and fill the map entry */
      cl = gROOT->GetClass(clName);
      m_classMap[objClassName]=cl;
    }

    /* Now, check if clname was valid... */
    if (cl==0){
      if ( m_strict ) {
        throw GaudiException("gROOT->GetClass cannot find clName", objClassName, StatusCode::FAILURE);
      } else  {
        cout << "WARNING: gROOT->GetClass fails for clname : "
            << objClassName.c_str() << endl;
        cout << "WARNING: Disregarding " << objClassName.c_str()
            << "erasing from object list" << endl;
        m_objects.erase( i );
        continue;
      }
    }

    // write object to buffer in order location-name-object
    std::string loc=pObj->registry()->identifier();
    buffer.WriteString(loc.c_str());
    buffer.WriteString(cl->GetName());
    cl->Streamer(pObj,buffer);

    /* take care of links */
    LinkManager* linkMgr = pObj->linkMgr();
    int numLinks = linkMgr->size();
    buffer.WriteInt(numLinks);
    // now write each link
    for (int it = 0; it != numLinks; it++)        {
      const string& link = linkMgr->link(it)->path();
      buffer.WriteString(link.c_str());
    }

    // now do the thing with the opaqueAddress
    // to go from string->object when recovering, will need svc_type, and clid, aswell as the string version
    IOpaqueAddress* iop = pObj->registry()->address();
    if (iop) {
      buffer.WriteInt(1);
      const string * par = iop->par();
      long svcType       = iop->svcType();
      long clid          = iop->clID();
      buffer.WriteLong(svcType);
      buffer.WriteLong(clid);
      buffer.WriteString(par->c_str());
    } else {
      buffer.WriteInt(0);
    }
    // object complete, continue in for-loop
  }

  // Final Actions
  // Write the End Flag, to avoid potential SegFaults on loadBuffer
  buffer.WriteString(SERIALIZER_END);
  // return StatusCode::SUCCESS;
}

/// Reconstruct the TES from a given TBufferFile
void GaudiMP::TESSerializer::loadBuffer(TBufferFile& buffer) {

  // reverse mechanism of dumps
  // buffer is: length of DataObjects vector
  //            location string
  //            type name string
  //            the object itself
  //            count of links
  //            list of links (conditional on count)
  //            flag indicating Opaque Address presence
  //            Opaque Address svcType (conditional on flag)
  //            Opaque Address clID    (conditional on flag)
  //            Opaque Address par     (conditional on flag)

  int nObjects;
  // 3 StatusCodes... for :
  //   general use : registering objects : creating OpaqueAddresses
  StatusCode sc, registerStat, createAddressStat;

  // Prepare for Reading
  buffer.SetReadMode();
  buffer.SetBufferOffset();

  buffer.ReadInt(nObjects);
  for (int i=0; i<nObjects; ++i) {
    char text[4096];
    buffer.ReadString(text,sizeof(text));
    string location(text);
    if (!location.compare("EOF")) {
      /* There was an error in serialization, but the EOF
         flag marks the endpoint in any case */
      break;
    }
    buffer.ReadString(text,sizeof(text));
    TClass* cl = gROOT->GetClass(text);
    if (cl==0){
      if ( m_strict ) {
        throw GaudiException("gROOT->GetClass cannot find clName", text, StatusCode::FAILURE);
      } else {
        cout << "TESSerializer WARNING : gROOT->GetClass fails for clname : " << location.c_str() << endl;
        continue;
      }
    }

    /// The next is equivalent to ReadObjectAny(cl) except of the 'magic!!'
    DataObject* obj = (DataObject*)cl->New();
    DataObjectPush push(obj); // This is magic!
    cl->Streamer(obj, buffer);


    // now restore links
    if ( obj ) {
      int nlink = 0;
      LinkManager* lnkMgr = obj->linkMgr();
      buffer.ReadInt(nlink);

      for (int j = 0; j < nlink; ++j) {
        buffer.ReadString(text,sizeof(text));
        lnkMgr->addLink(text,0);
      }
    }

    // Re-register...
    registerStat = m_TES->registerObject(location, obj);
    if (registerStat.isFailure()) {
      if ( location == "/Event" ) {
        sc = m_TESMgr->setRoot(location, obj);
        if(sc.isFailure()) {
          throw GaudiException("Cannot set root at location " + location, "", sc);
        }
      }
      else {
        const char* msg = "Cannot register object at location ";
        if ( m_strict ) {
          throw GaudiException(msg + location, "", registerStat);
        } else {
          cout << "WARNING : " << msg << location << endl;
          continue;
        }
      }
    }

    // next is the opaque address information
    // create Generic Address using the info from the TBufferFile,
    // then create an IOpaqueAddress object using the Persistency Svc
    // IOpaque Address pointer (blank... pass the ref to the createAddress Fn)

    int flag(0);
    buffer.ReadInt(flag);
    // flag will be 0 or 1 to indicate OpaqueAddress Info
    if (flag==1) {
      // will need an IOpaqueAddress and its ref
      IOpaqueAddress* iop;
      IOpaqueAddress*& iopref = iop;
      // Read svcType, clID and par from buffer
      long svcType;
      buffer.ReadLong(svcType);

      long clid;
      buffer.ReadLong(clid);
      const CLID classid(clid);

      char * cp;
      cp = buffer.ReadString(text, sizeof(text));
      const string opaque(cp);
      // create Generic address
      // already have svcType, clID, par1.. just make dummy variables for par2, and ipar1 and 2
      const string& p2="";
      unsigned long ip1(0);
      unsigned long ip2(0);
      GenericAddress gadd(svcType, classid, opaque, p2, ip1, ip2);

      // now create the address
      createAddressStat = m_addressCreator->createAddress( gadd.svcType(), gadd.clID(), gadd.par(), gadd.ipar(), iopref );
      if (createAddressStat.isFailure()) {
        throw GaudiException("Failure in creating OpaqueAddress for reconstructed registry", "", createAddressStat);
      }
      // And finally, set this address
      obj->registry()->setAddress(iop);
    }
    // all done
  }
}

// Protected
/// Add item to output streamer list (protected)
void GaudiMP::TESSerializer::addItem(Items& itms, const std::string& descriptor)   {
  // supports # notation
  int level = 0;

  std::string slevel;
  std::string obj_path;

  // Process the incoming string
  size_t sep = descriptor.rfind("#");
  if (sep > descriptor.length()) {
    // invalid sep case (# not found in string)
    obj_path = descriptor;
    slevel   = "1";
  } else {
    // valid sep case
    obj_path = descriptor.substr(0,sep);
    slevel   = descriptor.substr(sep+1);
  }

  // Convert the level string to an integer
  if ( slevel == "*" )  {
    level = 9999999;
  }
  else   {
    level = atoi(slevel.c_str());
  }

  // Are we verifying?
  if ( m_verifyItems )  {
    size_t idx = obj_path.find("/",1);
    while(idx != std::string::npos)  {
      std::string sub_item = obj_path.substr(0,idx);
      if ( 0 == findItem(sub_item) )   {
        cout << "... calling addItem with arg : " << sub_item << endl;
        addItem(itms, sub_item);
      }
      idx = obj_path.find("/",idx+1);
    }
  }
  DataStoreItem* item = new DataStoreItem(obj_path, level);
  //cout << "Adding TESSerializer item " << item->path()
  //   << " with " << item->depth()
  //   << " level(s)." << endl;
  itms.push_back( item );
}

/// Add item to serialization list; ie append to std::vector of DataStoreItems
void GaudiMP::TESSerializer::addItem(const std::string& path)   {
  // #notation supported
  addItem( m_itemList, path );
}

/// Add optional item to output streamer list
void GaudiMP::TESSerializer::addOptItem(const std::string& path)   {
  // #notation supported
  addItem( m_optItemList, path);
}

/// Uses cout to print the contents of the mandatory and optional item lists
void GaudiMP::TESSerializer::checkItems( )  {
  cout << "TESSerializer m_itemList : " << m_itemList.size() << " Items"<< endl;
  for(Items::const_iterator i=m_itemList.begin(); i != m_itemList.end(); ++i)  {
    cout << "\tItem : " << (*i)->path() << endl;
  }
  cout << "TESSerializer m_optItemList : " << m_optItemList.size() << " Items" << endl;
  for(Items::const_iterator i=m_optItemList.begin(); i != m_optItemList.end(); ++i)  {
    cout << "\tItem : " << (*i)->path() << endl;
  }
}

/// Find single item identified by its path (exact match)
DataStoreItem*
GaudiMP::TESSerializer::findItem(const std::string& path)  {
  for(Items::const_iterator i=m_itemList.begin(); i != m_itemList.end(); ++i)  {
    if ( (*i)->path() == path )  return (*i);
  }
  for(Items::const_iterator j=m_optItemList.begin(); j != m_optItemList.end(); ++j)  {
    if ( (*j)->path() == path )  return (*j);
  }
  return 0;
}