VEventDecoder.h

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/*!
 * \file   VEventDecoder.h
 * \brief  Virtual base class for event decoders to encode and decode CODA data
 */
 
#pragma once
 
#include <vector>
 
 
#include "Rtypes.h"
#include "QwTypes.h"
#include "MQwCodaControlEvent.h"
#include "QwOptions.h"
 
 
/**
 * \class VEventDecoder
 * \ingroup QwAnalysis
 * \brief Abstract base for CODA event encoding and decoding
 *
 * Provides the interface for encoding mock CODA events and decoding
 * real CODA event streams. Concrete implementations handle version-specific
 * differences (CODA 2 vs CODA 3) while exposing a common API for event
 * type detection, bank decoding, and header processing.
 */
class VEventDecoder : public MQwCodaControlEvent {
public:
    VEventDecoder() : 
        fWordsSoFar(0),
        fEvtLength(0),
        fEvtNumber(0),
        fFragLength(0),
        fEvtType(0),
        fEvtTag(0),
        fBankDataType(0),
        fSubbankTag(0),
        fSubbankType(0),
        fSubbankNum(0),
        fROC(0),
        fPhysicsEventFlag(kFALSE),
        fControlEventFlag(kFALSE),
        fAllowLowSubbankIDs(kFALSE) { }
 
    virtual ~VEventDecoder()  { }
 
public:
    // Encoding Functions
    /**
     * \brief Create a physics-event (PHYS) header bank for the given ROCs.
     *
     * Encodes a minimal CODA-compliant PHYS event header for one trigger,
     * suitable for mock-data generation and unit tests.
     *
     * @param ROCList List of ROC IDs to include in the header/banks.
     * @return A vector of 32-bit words containing the encoded header.
     */
    virtual std::vector<UInt_t> EncodePHYSEventHeader(std::vector<ROCID_t> &ROCList) = 0;
    /**
     * \brief Encode a PRESTART control-event header.
     * @param buffer Output buffer (size >= 5 words) to receive the header.
     * @param runnumber Run number to store in the header.
     * @param runtype   Run type identifier.
     * @param localtime Wall-clock time (seconds) for the header timestamp.
     */
    virtual void EncodePrestartEventHeader(int* buffer, int runnumber, int runtype, int localtime) = 0;
    /**
     * \brief Encode a GO control-event header.
     * @param buffer Output buffer (size >= 5 words) to receive the header.
     * @param eventcount Current event count.
     * @param localtime  Wall-clock time (seconds) for the header timestamp.
     */
    virtual void EncodeGoEventHeader(int* buffer, int eventcount, int localtime)     = 0;
    /**
     * \brief Encode a PAUSE control-event header.
     * @param buffer Output buffer (size >= 5 words) to receive the header.
     * @param eventcount Current event count.
     * @param localtime  Wall-clock time (seconds) for the header timestamp.
     */
    virtual void EncodePauseEventHeader(int* buffer, int eventcount, int localtime)  = 0;
    /**
     * \brief Encode an END control-event header.
     * @param buffer Output buffer (size >= 5 words) to receive the header.
     * @param eventcount Final event count.
     * @param localtime  Wall-clock time (seconds) for the header timestamp.
     */
    virtual void EncodeEndEventHeader(int* buffer, int eventcount, int localtime)    = 0;
 
public:
    // Decoding Functions
    /**
     * \brief Decode the event ID bank and classify the event type.
     * @param buffer Pointer to the start of the event buffer.
     * @return Non-negative on success (implementation-specific), negative on error.
     */
    virtual Int_t DecodeEventIDBank(UInt_t *buffer) = 0;
    /**
     * \brief Decode the subbank header for the current event/bank context.
     *
     * Updates internal fields (subbank tag/type/num, ROC, fragment length)
     * and advances the internal word counter to the first subbank data word.
     *
     * @param buffer Pointer to the current position in the event buffer.
     * @return kTRUE if a valid header was decoded; kFALSE at end-of-event or on error.
     */
    virtual Bool_t DecodeSubbankHeader(UInt_t *buffer);
    /**
     * \brief Print internal decoder state for diagnostics.
     * @param out Logging stream to receive the formatted state (QwMessage/QwWarning/etc.).
     */
    virtual void PrintDecoderInfo(QwLog& out);
 
public:
    // Boolean Functions
    virtual Bool_t IsPhysicsEvent(){
        return fPhysicsEventFlag;
    }
 
    virtual Bool_t IsROCConfigurationEvent(){
        return (fEvtType>=0x90 && fEvtType<=0x18f);
    }
 
    virtual Bool_t IsEPICSEvent(){
        return (fEvtType==EPICS_EVTYPE); // Defined in CodaDecoder.h
    }
// Accessor Functions
    // Generic Information
    UInt_t GetWordsSoFar()const  { return fWordsSoFar;  }
    UInt_t GetEvtNumber()const   { return fEvtNumber;   }
    UInt_t GetEvtLength()const   { return fEvtLength;   }
    UInt_t GetFragLength()const  { return fFragLength;  }
    // Event Information
    UInt_t GetEvtType()const     { return fEvtType;     }
    UInt_t GetBankDataType()const{ return fBankDataType;}
    UInt_t GetSubbankTag()const  { return fSubbankTag;  }
    UInt_t GetSubbankType()const { return fSubbankType; }
    ROCID_t GetROC()const        { return fROC;         }
 
// Mutator Functions
    void SetWordsSoFar(UInt_t val)                  { fWordsSoFar = val;         }
    void AddWordsSoFarAndFragLength()               { fWordsSoFar += fFragLength;}
    void SetFragLength(UInt_t val)                 { fFragLength = val;      }
    void SetAllowLowSubbankIDs(Bool_t val = kFALSE) { fAllowLowSubbankIDs = val; }
    
 
protected:
    // Generic Information
    UInt_t fWordsSoFar;
    UInt_t fEvtLength;    
    UInt_t fEvtNumber;   ///< CODA event number; only defined for physics events
    UInt_t fFragLength;
 
    // Event Information
    UInt_t fEvtType;
    UInt_t fEvtTag;
    UInt_t fBankDataType;
    BankID_t fSubbankTag;
    UInt_t fSubbankType;
    UInt_t fSubbankNum;
    ROCID_t fROC;
 
    // Booleans
    Bool_t fPhysicsEventFlag;
    Bool_t fControlEventFlag;
    Bool_t fAllowLowSubbankIDs;
 
protected:
    enum KEYWORDS {
        EPICS_EVTYPE = 131
    };
 
};