//////////////////////////////////////////////////////////////////////////
////////////////////////////     ROOT API     ////////////////////////////
//////////////////////////////////////////////////////////////////////////


#include <cctype>
#include <cstdlib>
#include <list>
#include <sstream>
#include <string>

#include "TList.h"
#include "TString.h"
#include "TSystem.h"

#include "IDbi.hxx"
#include "IDbiAsciiDbImporter.hxx"
#include "IDbiConnection.hxx"
#include "IDbiExceptionLog.hxx"
#include "IDbiServices.hxx"
#include <ICOMETLog.hxx>
#include <IMsgFormat.h>
using std::endl;
#include <ICOMETLog.hxx>

ClassImp(COMET::IDbiConnection)


//   Definition of static data members
//   *********************************


//    Definition of all member functions (static or otherwise)
//    *******************************************************
//
//    -  ordered: ctors, dtor, operators then in alphabetical order.

//.....................................................................
//      Throws COMET::EBadConnection() if can not make connection
COMET::IDbiConnection::IDbiConnection(const std::string& url      /* = "" */,
                             const std::string& user     /* = "" */,
                             const std::string& password /* = "" */,
			     int maxConnects) :

fUrl(url.c_str()),
fUser(user),
fPassword(password),
fUrlValidated(false),
fNumConnectedStatements(0),
fIsTemporary(true),
fServer(0)
{
//
//
//  Purpose:  Default constructor

  fMaxConnectionAttempts = maxConnects;

  COMETTrace( "Creating COMET::IDbiConnection" << "  ");

  if ( this->Open() ) {
    COMETInfo(  "Successfully opened connection to: " << this->GetUrl() << "  ");
    fUrlValidated =  true;

    // Initialise the list existing supported tables.
    this->SetTableExists();

    //  If URL looks O.K., check that both client and server support prepared statements.
    if ( fUrlValidated ) {
#if ROOT_VERSION_CODE >= ROOT_VERSION(5,15,9)
      if ( ! fServer->HasStatement() ) {
#else
      if ( ! fServer->IsSupportStatement() ) {
#endif
        COMETSevere( "  This client does not support prepared statements." << "  ");
        fUrlValidated = false;
        #if ROOT_VERSION_CODE >= ROOT_VERSION(5,15,9)
      }
#else
     }
#endif
      
      std::string serverInfo(fServer->ServerInfo());
      if ( serverInfo < "4.1" ) {
        COMETSevere( "This MySQL server (" << serverInfo
  			     << ") does NOT support prepared statements." << "  ");
        fUrlValidated = false;
      }
      if ( fUrlValidated ) {
        COMETInfo( "This client, and MySQL server (" << serverInfo
  			     << ") supports prepared statements." << "  ");
      }
      else {

        COMETSevere( "\n"
           << "This version of MySQL does not support prepared statements.\n"
           << "\n"
           << "Please upgrade to MySQL (client and server) version 4.1 or greater \n"
           << "\n"
	   << "  ");
      }

    }
    }
    if ( ! fUrlValidated ) {
      COMETSevere( "FATAL: " << "Aborting due to above errors" << "  ");
      throw COMET::EBadConnection();
    }
   fDbName = fUrl.GetFile();
  

}

//.....................................................................

COMET::IDbiConnection::~IDbiConnection() {
//
//
//  Purpose: Destructor


  COMETTrace( "Destroying COMET::IDbiConnection" << "  ");
  this->Close(true);

}
//.....................................................................
///\verbatim
///
///  Purpose: Close server connection unless active (or always if forced) .
///
///  Return:  true if connection now closed.
///\endverbatim
Bool_t COMET::IDbiConnection::Close(Bool_t force /* = false */ ) {

  this->ClearExceptionLog();
  if ( this->IsClosed() ) return true;

  if ( fNumConnectedStatements ) {
    if ( ! force ) {
      COMETInfo( "Unable to close connection: " << this->GetUrl()
                            << "; it still has  "
			    << fNumConnectedStatements << "active statements. " << "  ");
      return false;
    }
    COMETInfo( "Closing connection: " << this->GetUrl()
                          << "; even though it still has "
			  << fNumConnectedStatements << " active statements. " << "  ");
  }

  delete fServer;
  fServer = 0;
  COMETDebug( "Closed connection: " << this->GetUrl() << "  ");
  return true;

}

//.....................................................................
///
///
///  Purpose:  Close idle connection. Idle means there are no active connections to this database.

void COMET::IDbiConnection::CloseIdleConnection() {

  if ( fIsTemporary &&  fNumConnectedStatements == 0 ) this->Close();

}


//.....................................................................
///\verbatim
///
///  Purpose:  Open if necessary and get a prepared statment.
///
///  Return:    Statement - Caller must take ownership.
///             will be 0 if failure.
///\endverbatim
TSQLStatement* COMET::IDbiConnection::CreatePreparedStatement(const std::string& sql) {

  TSQLStatement* stmt = 0;
  if ( ! this->Open() ) return stmt;
  stmt = fServer->Statement(sql.c_str());
  if ( ! stmt ) {
    fExceptionLog.AddEntry(*fServer);
  }
  else stmt->EnableErrorOutput(false);

  return stmt;
}
//.....................................................................
///\verbatim
///
///  Purpose:  Open if necessary and get a TSQLServer.
///
///  Return:    Server ( = 0 if connection not open).
///
///  WARNING:  The server returned remains is being borrowed from the
///            COMET::IDbiConnection and remains under its ownership and must
///            not be deleted.  However the caller must invoke the
///            Connect() method on this COMET::IDbiConnection before borrowing
///            it and must invoke the DisConnect() when it has finished
///            using it to ensure the COMET::IDbiConnection does not close it
///            prematurely i.e.:-
///
///            void Demo(COMET::IDbiConnection* con) {
///              con->Connect();
///              TSQLServer* server = con->GetServer();
///              // Do stuff
///              con->DisConnect();
///            }
///\endverbatim
TSQLServer* COMET::IDbiConnection::GetServer() {


  if ( ! this->Open() ) return 0;
  return fServer;
}

//.....................................................................
///\verbatim
/// Don't ask me why TUrl::GetUrl() is non-const, just accept that it is!
///
/// Note: This function returns a reference to a shared string; use the
///       value or make a copy of it before any subsequent call to this
///       function.
///\endverbatim
const std::string& COMET::IDbiConnection::GetUrl() const {

  

  static std::string url;
  url = const_cast<COMET::IDbiConnection*>(this)->fUrl.GetUrl();
  return url;

}

//.....................................................................
///
///  Purpose:  Open connection if necessary.
///

Bool_t COMET::IDbiConnection::Open() {

  this->ClearExceptionLog();
  if ( ! this->IsClosed() ) return true;

  if ( ! fUrl.IsValid() ) {
    ostringstream oss;
    oss << "Unable to open connection: URL '" << fUrl.GetUrl() << "' is invalid";
       COMETSevere( oss.str() << "  ");
    fExceptionLog.AddEntry(oss.str());
    return false;
  }

  // Make several attempts (or more if URL is known to be O.K.) to open connection.
  int maxAttempt = fUrlValidated ?  100: fMaxConnectionAttempts ;
  for (int attempt = 1; attempt <= maxAttempt; attempt++) {
    fServer = TSQLServer::Connect(fUrl.GetUrl(),fUser.c_str(),fPassword.c_str());
    if ( ! fServer ) {
      ostringstream oss;
      oss << "Failing to open: " << fUrl.GetUrl() << " for user " << fUser
	  << " and password " << fPassword << " (attempt " << attempt << ")";
      fExceptionLog.AddEntry(oss.str());
      if ( fMaxConnectionAttempts > attempt ){
         
         if ( attempt == 1 ) {
              COMETSevere( " retrying ... " << "  ");
         }
         COMETLog(" Waiting "<<attempt<<" seconds before trying again");
         gSystem->Sleep(attempt*1000);
      }
    }

    else {
      fServer->EnableErrorOutput(false);
      if ( attempt > 1 ) COMETWarn( "... Connection opened on attempt " << attempt << "  ");
      COMETDebug(  "Successfully opened connection to: " << fUrl.GetUrl() << "  ");

      // If this is an ASCII database, populate it and make the connection permanent
      // unless even ASCII DB connections are temporary.

      TString ascii_file = fUrl.GetAnchor();
      if ( ascii_file.IsNull() ) return true;
      gSystem->Setenv("DBI_CATALOGUE_PATH",gSystem->DirName(fUrl.GetAnchor()));
      COMET::IDbiAsciiDbImporter importer(ascii_file,fServer);
      const COMET::IDbiExceptionLog& el(importer.GetExceptionLog());
      if ( ! el.IsEmpty() ) {
        COMETSevere( "Failed to populate ASCII database from " << fUrl.GetUrl() << "\n"
			       << el << "  ");
        delete fServer;
        fServer = 0;
        return false;
      }
      fIsTemporary = COMET::IDbiServices::AsciiDBConectionsTemporary();
      // Add imported tables names.
      const std::list<std::string> tableNames(importer.GetImportedTableNames());
      std::list<std::string>::const_iterator itr(tableNames.begin()), itrEnd(tableNames.end());
      while ( itr != itrEnd ) {
        this->SetTableExists(*itr);
        ++itr;
      }
      return true;

    }
  }
     COMETSevere(  "... Failed to open a connection to: " << fUrl.GetUrl()
    << " for user " << fUser << " and pwd " << fPassword << "  ");

  return false;

}//
//  Purpose:  Record an exception that has occurred while a client was using its TSQLServer.


//.....................................................................
///\verbatim
///
///  Purpose:  Print all warning at supplied  Msg log level.
///
///  Return:    kTRUE if warnings have occurred
///\endverbatim
Bool_t COMET::IDbiConnection::PrintExceptionLog(Int_t level) const {

  switch(level)
  {
   case ICOMETLog::QuietLevel:
    break;
   case ICOMETLog::LogLevel:
    COMETInfo(fExceptionLog);
    break;
   case ICOMETLog::InfoLevel:
    COMETInfo(fExceptionLog);
    break;
   case ICOMETLog::VerboseLevel:
    COMETVerbose(fExceptionLog);
    break;
   }

  return fExceptionLog.Size() != 0;

}

//.....................................................................
///
///  Purpose:  Record an exception that has occurred while a client was using its TSQLServer.

void  COMET::IDbiConnection::RecordException() {

  fExceptionLog.AddEntry(*fServer);

}

//.....................................................................
///\verbatim
///  Purpose: Add name to list of existing tables (necessary when creating tables)
///
///  Note: If tableName is null refresh list from the database.
///\enbdverbatim
void  COMET::IDbiConnection::SetTableExists(const std::string& tableName) {

  if ( tableName == "" ) {
    TSQLStatement* stmt =  CreatePreparedStatement("show tables");
    if ( stmt ) {
      if (stmt->Process()) {
        stmt->StoreResult();
        while (stmt->NextResultRow()) {
	  std::string tn(stmt->GetString(0));
          this->SetTableExists(tn);
        }
      }
      delete stmt;
      stmt = 0;
    }
  }
  else {
    if ( ! this->TableExists(tableName) ) {
      fExistingTableList += ",'";
      fExistingTableList += tableName;
      fExistingTableList += "'";
    }
  }
}

//.....................................................................
///  Purpose: Check to see table exists in connected database.
Bool_t  COMET::IDbiConnection::TableExists(const std::string& tableName) const {
//

  std::string test("'");
  test += tableName;
  test += "'";
  return fExistingTableList.find(test) != std::string::npos;
}