// @(#) $Id$

#ifndef ALIHLTRECONSTRUCTOR_H
#define ALIHLTRECONSTRUCTOR_H
//* This file is property of and copyright by the ALICE HLT Project        * 
//* ALICE Experiment at CERN, All rights reserved.                         *
//* See cxx source for full Copyright notice                               *

/** @file   AliHLTReconstructor.h
    @author Matthias Richter
    @date   
    @brief  Binding class for HLT simulation in AliRoot
*/

#include "AliReconstructor.h"
#include "AliHLTReconstructorBase.h"

class AliHLTSystem;
class AliRawReader;
class AliESDEvent;
class AliHLTOUT;
class AliHLTEsdManager;

/**
 * @class AliHLTReconstructor
 * AliHLTReconstructor AliRoot event reconstruction plug-in for the HLT.
 * The AliHLTReconstructor holds an instance of the @ref AliHLTSystem
 * steering class. The actual reconstruction depends on the loaded component
 * libraries. Each library must implement a module agent (@ref AliHLTModuleAgent)
 * in order to provide information on the supported features and the
 * configurations to be run.
 *
 * The AliHLTReconstructor provides both the functionality to run customized
 * analysis chains and the treatment of the HLTOUT data.
 *
 * @section sec_alihltreconstructor_options Options
 * The default component libraries which are loaded through the initialization
 * are determined by the @ref AliHLTSystem::fgkHLTDefaultLibs array. The library
 * loading can be overridden by an option to the AliHLTReconstructor through the
 * <tt>SetOption</tt> method of <tt>AliReconstruction</tt>, e.g.
 * <pre>
 * AliReconstruction rec;
 * rec.SetOption("HLT", "libAliHLTSample.so");
 * </pre>
 * will only load <tt>libAliHLTSample.so</tt>
 * 
 * Optional arguments:<br>
 * <!-- NOTE: ignore the \li. <i> and </i>: it's just doxygen formatting -->
 * \li loglevel=<i>level</i><br>
 *     level can be a hex number encoding the @ref AliHLTComponentLogSeverity
 * \li alilog=off <br>
 *     disables the logging of HLT log messages through <tt>AliLog</tt> <br>
 *
 * For further information on the AliRoot reconstruction refer to the AliRoot
 * documentation, namely <tt>AliReconstruction</tt>.
 *
 * @section sec_alihltreconstructor_chains Custom reconstruction chains
 * In order to run an HLT chain during the AliRoot reconstruction, a chain
 * configuration must be defined. This can be done by
 * - specifying a configuration macro defining a configuration macro and
 *   the name of the chain as parameters
 *   <pre>
 *   rec.SetOption("HLT", "config=[macro.C] chains=[name]")
 *   </pre>
 * - providing the configuration and the name by the module agent.
 *   AliHLTModuleAgent and the functions AliHLTModuleAgent::CreateConfigurations
 *   and AliHLTModuleAgent::GetReconstructionChains
 *
 * @section sec_alihltreconstructor_hltout Treatment of HLTOUT data.
 * The HLTOUT data is a collation of output blocks produced by the various
 * components running in an HLT chain. Typically its the output of the last
 * component(s) in the chain, or components specifically connected to the HLT
 * output.
 *
 * The treatment of the HLTOUT data blocks is implemented in handlers of type
 * AliHLTOUTHandler. The AliHLTModuleAgent of the module  creates the appropriate
 * handler for a data block.
 * The data type of the individual blocks is set by the producer component and
 * specifies the nature of the data processing. There are 5 overall groups:
 * - output is in ESD format:
 *      @ref sec_alihltreconstructor_hltout_esd
 * - data describes DDL raw format:
 *      @ref sec_alihltreconstructor_hltout_rawreader
 * - pre-analyzed data to be fed into the normal reconstruction:
 *      @ref sec_alihltreconstructor_hltout_rawstream
 * - data is fed into an analysis chain:
 *      @ref sec_alihltreconstructor_hltout_chain
 * - detector specific handler:
 *      @ref sec_alihltreconstructor_hltout_proprietary
 *
 * @subsection sec_alihltreconstructor_hltout_esd ESD HLTOUT data
 * The frame work implements a standard handling of
 * ESD data blocks of type ::kAliHLTDataTypeESDTree {ESD_TREE:ANY}. ANY can be
 * any detector origin. Each ESD block contains the data of only one event,
 * the ESDs are merged by the AliHLTEsdManager and written to files of the
 * naming scheme AliHLT<DET>ESDs.root. The first ESD block is also copied
 * to the hltEsd provided by the AliReconstruction. This is a temporary
 * solution as the handling and merging of HLT ESDs is under discussion.
 * At the time of writing (May 08) only the TPC HLT components produce ESD
 * blocks.
 * The module agent can provide a handler for multiple ESD data blocks, e.g.
 * for merging within one event prior to the writing. Instead of the individual
 * ESDs the one provided by the handler is passed to the AliHLTEsdManager. The
 * handler is of type AliHLTModuleAgent::AliHLTOUTHandlerType::kEsd
 *
 * @subsection sec_alihltreconstructor_hltout_rawreader DDL raw HLTOUT data
 * The HLT can perform selective readout and produces a reduced amount of data
 * in the original raw ddl format. In order to feed this data from the HLTOUT
 * DDL links into the normal reconstruction, a handler of type 
 * @ref AliHLTModuleAgent::AliHLTOUTHandlerType::kRawReader must be implemented and provided by the
 * module agent. The handler has to derive the original equipment id from the
 * data type and specification of the block. The offline reconstruction does
 * not need to be changed or adapted at all.
 *
 * @subsection sec_alihltreconstructor_hltout_rawstream Preprocessed Raw HLTOUT data
 * Handlers type @ref AliHLTModuleAgent::AliHLTOUTHandlerType::kRawStream are foreseen though at the time of writing (May 08) the
 * concept is not fixed. Advanced data compression algorithms can produce a
 * raw data format which is not convertible into the raw DDL data, e.g. lossy
 * compression techniques storing clusters parametrized regarding to tracks. A
 * specific RawStream is needed here since the data is detector specific and the
 * first stage of the offline reconstruction might need some adaptions.
 *
 * @subsection sec_alihltreconstructor_hltout_chain HLTOUT data fed into a chain
 * At the time of writing (May 08), handler type @ref AliHLTModuleAgent::AliHLTOUTHandlerType::kChain
 * is foreseen but not yet implemented. Has to be discussed.
 *
 * @subsection sec_alihltreconstructor_hltout_proprietary Proprietary HLTOUT data
 * This is a handler of proprietary detector data, @ref AliHLTModuleAgent::AliHLTOUTHandlerType::kProprietary.
 * Handlers of this type do not have any standard output to the framework. Data
 * can be processed and stored to files.
 *
 * @ingroup alihlt_aliroot_reconstruction
 */
class AliHLTReconstructor: public AliReconstructor, public AliHLTReconstructorBase {
public:
  /** standard constructor */
  AliHLTReconstructor();
  /** constructor */
  AliHLTReconstructor(const char* options);
  /** destructor */
  virtual ~AliHLTReconstructor();

  /** init the reconstructor */
  void Init();

  /** init the reconstructor */
  void Init(const char* options);

  /**
   * This Reconstructor function is not applicable for the AliHLTReconstructor
   * as it gets a detector specific digits tree. But HLT processes all detectors.
   * Furthermore it's purely simulated data. <br>
   * The function forwards to the default bahavior of AliReconstructor but gives
   * a warning if there were options set, i.e. the user runs customized
   * reconstruction.
   *
   * @note HLT reconstruction on simulated data is processed at the end of
   * simulation. <br>
   */
  void Reconstruct(TTree* digitsTree, TTree* clustersTree) const;

  /**
   * Reconstruction from RAW data.
   * The rawReader holds data for all detectors and this version of Reconstruct
   * is thus applicable for the HLT. The clustersTree is just ignored.
   */
  void Reconstruct(AliRawReader* rawReader, TTree* clustersTree) const;

  /**
   * This function treats the simulated HLTOUT data.
   * Opens a handler for simulated HLTOUT data and forwards to ::ProcessHLTOUT.
   */
  void FillESD(TTree* digitsTree, TTree* clustersTree, AliESDEvent* esd) const;

  /**
   * Process the raw HLTOUT data and fill ESD.
   * Opens a handler for raw HLTOUT data and forwards to ::ProcessHLTOUT.
   */
  void FillESD(AliRawReader* rawReader, TTree* clustersTree, AliESDEvent* esd) const;

  /**
   * Process HLTOUT data and fill ESD.
   * This is the final treatment of the HLTOUT data, either simulated or real.
   * HLTOUT data is stored in HOMER format, the AliHLTOUT object provides the interface
   * to the individual data blocks.
   *
   * During reconstruction (::Reconstruct), module or user defined chains can be
   * processed and may add additional data to the HLTOUT object. This data is then
   * treated in the same way.
   */
  void ProcessHLTOUT(AliHLTOUT* pHLTOUT, AliESDEvent* esd) const;

  /**
   * Process HLTOUT data.
   * Open digit file and process the HLTOUT digit data.
   * This function is mostly intended for debugging purposes and stand-alone
   * processing of the output from the simulation. Loops over all events.
   * @param digitFile        path of the digit file
   * @param pEsd             optional ESD to be filled
   */
  void ProcessHLTOUT(const char* digitFile="HLT.Digits.root", AliESDEvent* pEsd=NULL) const;

  /**
   * Process HLTOUT data.
   * Process the HLTOUT from the raw reader.
   * This function is mostly intended for debugging purposes and stand-alone
   * processing of simulated or real raw data. 
   * \em Note: Loops over all events, i.e. the current event of the the raw
   * reader will change. Not to be called inside the normal AliRoot processsing.
   * @param pRawReader       raw reader instance
   * @param pEsd             optional ESD to be filled
   */
  void ProcessHLTOUT(AliRawReader* pRawReader, AliESDEvent* pEsd=NULL) const;

  /**
   * Print a short info about the HLTOUT content.
   */
  void PrintHLTOUTContent(AliHLTOUT* pHLTOUT) const;

private:
  /** copy constructor prohibited */
  AliHLTReconstructor(const AliHLTReconstructor& src);
  /** assignment operator prohibited */
  AliHLTReconstructor& operator=(const AliHLTReconstructor& src);

  /** function pointer: processing of HLTOUT data */
  void* fFctProcessHLTOUT; //!transient

  /** ESD manger instance for this reconstruction */
  AliHLTEsdManager* fpEsdManager; //!transient

  ClassDef(AliHLTReconstructor, 5)   // class for the HLT reconstruction

};

typedef AliHLTReconstructor AliL3Reconstructor; // for backward compatibility

#endif