// @(#)root/sql:$Name:  $:$Id: TKeySQL.cxx,v 1.10 2006/06/22 08:21:22 brun Exp $
// Author: Sergey Linev  20/11/2005

/*************************************************************************
 * Copyright (C) 1995-2005, Rene Brun and Fons Rademakers.               *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *
 *************************************************************************/

//________________________________________________________________________
//
// TKeySQL is represents a metainforamtion about object, which was written to
// SQL database. It keeps object id, which used to locate object data
// from database tables.
//________________________________________________________________________


#include "TKeySQL.h"

#include "TROOT.h"
#include "TClass.h"
#include "TBrowser.h"
#include "TDirectory.h"
#include "Riostream.h"

#include "TSQLResult.h"
#include "TBufferSQL2.h"
#include "TSQLStructure.h"
#include "TSQLFile.h"

ClassImp(TKeySQL);

//______________________________________________________________________________
TKeySQL::TKeySQL() :
   TKey(),
   fKeyId(-1),
   fObjId(-1)
{
   // default constructor
}

//______________________________________________________________________________
TKeySQL::TKeySQL(TDirectory* mother, const TObject* obj, const char* name, const char* title) :
    TKey(mother),
    fKeyId(-1),
    fObjId(-1)
{
   // Creates TKeySQL and convert obj data to TSQLStructure via TBufferSQL2

   if (name) SetName(name); else
      if (obj!=0) {SetName(obj->GetName());  fClassName=obj->ClassName();}
      else SetName("Noname");

   if (title) SetTitle(title);

   StoreKeyObject((void*)obj, obj ? obj->IsA() : 0);
}

//______________________________________________________________________________
TKeySQL::TKeySQL(TDirectory* mother, const void* obj, const TClass* cl, const char* name, const char* title) :
    TKey(mother),
    fKeyId(-1),
    fObjId(-1)
{
   // Creates TKeySQL and convert obj data to TSQLStructure via TBufferSQL2

   if (name && *name) SetName(name);
   else SetName(cl ? cl->GetName() : "Noname");

   if (title) SetTitle(title);

   StoreKeyObject(obj, cl);
}

//______________________________________________________________________________
TKeySQL::TKeySQL(TDirectory* mother, Long64_t keyid, Long64_t objid, 
                 const char* name, const char* title,
                 const char* keydatetime, Int_t cycle, const char* classname) :
    TKey(mother),
    fKeyId(keyid),
    fObjId(objid)
{
   // Create TKeySQL object, which correponds to single entry in keys table

   SetName(name);
   if (title) SetTitle(title);
   TDatime dt(keydatetime);
   fDatime = dt;
   fCycle = cycle;
   fClassName = classname;
}

//______________________________________________________________________________
TKeySQL::~TKeySQL()
{
// TKeySQL destructor
}

//______________________________________________________________________________
Bool_t TKeySQL::IsKeyModified(const char* keyname, const char* keytitle, const char* keydatime, Int_t cycle, const char* classname)
{
// Compares keydata with provided and return kTRUE if key was modified
// Used in TFile::StreamKeysForDirectory() method to verify data for that keys
// should be updated

   Int_t len1 = (GetName()==0) ? 0 : strlen(GetName());
   Int_t len2 = (keyname==0) ? 0 : strlen(keyname);
   if (len1!=len2) return kTRUE;
   if ((len1>0) && (strcmp(GetName(), keyname)!=0)) return kTRUE;

   len1 = (GetTitle()==0) ? 0 : strlen(GetTitle());
   len2 = (keytitle==0) ? 0 : strlen(keytitle);
   if (len1!=len2) return kTRUE;
   if ((len1>0) && (strcmp(GetTitle(), keytitle)!=0)) return kTRUE;

   const char* tm = GetDatime().AsSQLString();
   len1 = (tm==0) ? 0 : strlen(tm);
   len2 = (keydatime==0) ? 0 : strlen(keydatime);
   if (len1!=len2) return kTRUE;
   if ((len1>0) && (strcmp(tm, keydatime)!=0)) return kTRUE;

   if (cycle!=GetCycle()) return kTRUE;

   len1 = (GetClassName()==0) ? 0 : strlen(GetClassName());
   len2 = (classname==0) ? 0 : strlen(classname);
   if (len1!=len2) return kTRUE;
   if ((len1>0) && (strcmp(GetClassName(), classname)!=0)) return kTRUE;

   return kFALSE;
}

//______________________________________________________________________________
void TKeySQL::Delete(Option_t * /*option*/)
{
// Removes key from current directory
// Note: TKeySQL object is not deleted. You still have to call "delete key"

   TSQLFile* f = (TSQLFile*) GetFile();

   if (f!=0)
      f->DeleteKeyFromDB(GetDBKeyId());

   fMotherDir->GetListOfKeys()->Remove(this);
}

//______________________________________________________________________________
Long64_t TKeySQL::GetDBDirId() const
{
   // return sql id of parent directory

   return GetMotherDir() ? GetMotherDir()->GetSeekDir() : 0;
}

//______________________________________________________________________________
void TKeySQL::StoreKeyObject(const void* obj, const TClass* cl)
{
   // Stores object, associated with key, into data tables

   TSQLFile* f = (TSQLFile*) GetFile();

   fCycle = GetMotherDir()->AppendKey(this);

   fKeyId = f->DefineNextKeyId();

   fObjId = f->StoreObjectInTables(fKeyId, obj, cl);

   if (cl) fClassName = cl->GetName();

   if (GetDBObjId()>=0) {
      fDatime.Set();
      if (!f->WriteKeyData(this)) {
         // cannot add entry to keys table                          
         Error("StoreKeyObject","Cannot write data to key tables");
         // delete everything relevant for that key
         f->DeleteKeyFromDB(GetDBKeyId());
         fObjId = -1;
      }
   }

   if (GetDBObjId()<0)
      GetMotherDir()->GetListOfKeys()->Remove(this);
   // fix me !!! One should delete object by other means
   // delete this;
}

//______________________________________________________________________________
Int_t TKeySQL::Read(TObject* tobj)
{
   // To read an object from the file.
   // The object associated to this key is read from the file into memory.
   // Before invoking this function, obj has been created via the
   // default constructor.

   if (tobj==0) return 0;

   void* res = ReadKeyObject(tobj, 0);

   return res==0 ? 0 : 1;
}

//______________________________________________________________________________
TObject* TKeySQL::ReadObj()
{
// Read object derived from TObject class
// If it is not TObject or in case of error, return 0

   TObject* tobj = (TObject*) ReadKeyObject(0, TObject::Class());

   if (tobj!=0) {
      if (gROOT->GetForceStyle()) tobj->UseCurrentStyle();
      if (tobj->IsA() == TDirectory::Class()) {
         TDirectory *dir = (TDirectory*) tobj;
         dir->SetName(GetName());
         dir->SetTitle(GetTitle());
         dir->SetSeekDir(GetDBKeyId());
         dir->SetMother(fMotherDir);
         dir->ReadKeys();
         fMotherDir->Append(dir);
      }
   }

   return tobj;
}

//______________________________________________________________________________
void* TKeySQL::ReadObjectAny(const TClass* expectedClass)
{
// read object of any type from SQL database

   return ReadKeyObject(0, expectedClass);
}

//______________________________________________________________________________
void* TKeySQL::ReadKeyObject(void* obj, const TClass* expectedClass)
{
   // Read object, associated with key, from database

   TSQLFile* f = (TSQLFile*) GetFile();

   if ((GetDBKeyId()<=0) || (f==0)) return obj;

   TBufferSQL2 buffer(TBuffer::kRead, f);

   TClass* cl = 0;

   void* res = buffer.SqlReadAny(GetDBKeyId(), GetDBObjId(), &cl, obj);

   if ((cl==0) || (res==0)) return 0;

   Int_t delta = 0;

   if (expectedClass!=0) {
      delta = cl->GetBaseClassOffset(expectedClass);
      if (delta<0) {
         if (obj==0) cl->Destructor(res);
         return 0;
      }
      if (cl->GetClassInfo() && !expectedClass->GetClassInfo()) {
         //we cannot mix a compiled class with an emulated class in the inheritance
         Warning("XmlReadAny",
                 "Trying to read an emulated class (%s) to store in a compiled pointer (%s)",
                 cl->GetName(),expectedClass->GetName());
      }
   }

   return ((char*)res) + delta;
}