// -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: t; tab-width: 8; -*-

#ifndef MATACQTBRAWEVENT_H
#define MATACQTBRAWEVENT_H

#include <cinttypes>
#include <ctime>
#include <vector>
//replace 1 by 0 to remove XDAQ dependency. In this case it is assumed the machine is little endian.
#if 0
#include "i2o/utils/endian.h"  //from XDAQ
#define UINT32_FROM_LE i2odecodel
#define UINT16_FROM_LE i2odecodes
#define INT16_FROM_LE i2odecodes

#else  //assuming little endianness of the machine

#define UINT32_FROM_LE
#define UINT16_FROM_LE
#define INT16_FROM_LE

#endif

/** Wrapper for matacq raw event fragments. This class provides the
 * method to interpret the data. 
 */
class MatacqTBRawEvent {
  //typedefs, enums and static constants
public:
  enum matacqError_t {
    /** Event length is specified both in the data header and the trailer. This
     * flags indicates an inconsitency between the two indications.
     */
    errorLengthConsistency = 1 << 0,
    /** Error in data length.
     */
    errorLength = 1 << 1,
    /** Wrong Begin of eevent flag
     */
    errorWrongBoe = 1 << 2
  };

  /* The following types are little-endian encoded types. Use of these types
   * for the I20 data block should offer portability to big-endian platforms.
   */
  //@{
  struct uint32le_t {
    uint32_t littleEndianInt;
    operator uint32_t() const { return UINT32_FROM_LE(littleEndianInt); }
  };

  struct uint16le_t {
    uint16_t littleEndianInt;
    operator uint16_t() const { return UINT16_FROM_LE(littleEndianInt); }
  };

  struct int16le_t {
    int16_t littleEndianInt;
    operator int16_t() const { return INT16_FROM_LE(littleEndianInt); }
  };
  //@}

  struct ChannelData {
    /** Matacq channel number. From 0 to 3.
     */
    int chId;
    /** Number of samples in following array
     */
    int nSamples;
    /** ADC count of time samples. Array of size nSamples
     */
    const int16le_t* samples;
  };

private:
  /** Matacq header data structure
   */
  struct matacqHeader_t {
    uint16le_t version;
    unsigned char freqGHz;
    unsigned char channelCount;
    uint32_t timeStamp;
  };

  /** Specification of DAQ header field.
   */
  struct field32spec_t {
    int offset;
    unsigned int mask;
  };

  /** DAQ header field specifications.
   */
  static const field32spec_t fov32;
  static const field32spec_t fedId32;
  static const field32spec_t bxId32;
  static const field32spec_t lv132;
  static const field32spec_t triggerType32;
  static const field32spec_t boeType32;
  static const field32spec_t dccLen32;
  static const field32spec_t dccErrors32;
  static const field32spec_t runNum32;
  static const field32spec_t h1Marker32;

  //constructors
public:
  /** Constuctor.
   * @param dataBuffer pointer to the raw data. Beware the data are not copied,
   * therefore the data must be kept valid during the lifetime of the
   * constructed object. pData must be aligned at least on 32-bit words.
   * @param bufferSize size of the buffer pointed by dataBuffer and containing
   * the data. The data themselves are allowed to be smaller than the buffer.
   * @throw std::exception if the data cannot be decoded due to data corruption
   * or truncation.
   */
  MatacqTBRawEvent(const unsigned char* dataBuffer, std::size_t bufferSize) { setRawData(dataBuffer, bufferSize); }
  //methods
public:
  /** Gets the Fed event fragment data format (FOV) field content.
   * Currently the FOV is not used for MATACQ.
   * Note that matacq data format has its own internal version. See
   * #getMatacqDataFormatVersion()
   * @return FOV
   */
  int getFov() const { return read32(daqHeader, fov32); }

  /** Gets the FED ID field contents. Should be 43.
   * @return FED ID
   */
  int getFedId() const { return read32(daqHeader, fedId32); }

  /** Gets the bunch crossing id field contents.
   * @return BX id
   */
  int getBxId() const { return read32(daqHeader, bxId32); }

  /** Gets the LV1 field contents.
   * @return LV1 id
   */
  unsigned getEventId() const { return read32(daqHeader, lv132); }

  /** Gets the trigger type field contents.
   * @return trigger type
   */
  int getTriggerType() const { return read32(daqHeader, triggerType32); }

  /** Gets the beging of event field contents (BOE). Must be 0x5.
   * @return BOE
   */
  int getBoe() const { return read32(daqHeader, boeType32); }

  /** Gets the event length specifies in the "a la DCC" header.
   * @return event length
   */
  unsigned getDccLen() const { return read32(daqHeader, dccLen32); }

  /** Gets the event length specifies in the DAQ trailer
   * @return event length
   */
  unsigned getDaqLen() const { return fragLen; }

  /** Gets the contents of the DCC error field. Currently Not used for Matacq.
   * @return dcc error
   */
  int getDccErrors() const { return read32(daqHeader, dccErrors32); }

  /** Gets the run number field contents.
   * @return run number
   */
  unsigned getRunNum() const { return read32(daqHeader, runNum32); }

  /** Gets the header marker field contents. Must be 1
   * @return H1 header marker
   */
  int getH1Marker() const { return read32(daqHeader, h1Marker32); }

  /** Gets the matcq data format version
   * @return data version
   */
  int getMatacqDataFormatVersion() const { return matacqHeader->version; }

  /** Gets the raw data status. Bitwise OR of the error flags
   * defined by matcqError_t
   * @return status
   */
  int32_t getStatus() const { return error; }

  /** Gets the matacq sampling frequency field contents.
   * @return sampling frequency in GHz: 1 or 2
   */
  int getFreqGHz() const { return matacqHeader->freqGHz; }

  /** Gets the matacq channel count field contents.
   * @return number of channels
   */
  int getChannelCount() const { return matacqHeader->channelCount; }

  /** Gets the matacq channel data. Beware that no copy is done and that
   * the returned data will be invalidated if the data contains in the buffer
   * is modified (see constructor and #setRawData().
   * @return matacq channel data.
   */
  const std::vector<ChannelData>& getChannelData() const { return channelData; }

  /** Gets the data length in number of 64-bit words computed by the data
   * parser.
   * @return event length
   */
  int getParsedLen() { return parsedLen; }

  /** Gets the matacq data timestamp field contents: 
   * @return acquisition date of the data expressed in number of "elapsed"
   * second since the EPOCH as defined in POSIX.1. See time()  standard c
   * function.
   */
  time_t getTimeStamp() const { return matacqHeader->timeStamp; }

  /** Gets the Matacq trigger time.
   * @return (t_trig-t_0) in ps, with t_0 the time of the first sample and
   * t_trig the trigger time.
   */
  int getTTrigPs() const { return tTrigPs; }

private:
  /** Help function to decode header content.
   * @param data pointer
   * @param spec specification of the data field to read
   * @return content of data field specified by 'spec'
   */
  int read32(const uint32le_t* pData, field32spec_t spec) const;

  /** Changes the raw data pointer and updates accordingly this object. 
   * @param buffer new pointer to the data buffer. Must be aligned at least
   * on 32-bit words.
   * @param size of the data buffer.
   * @throw std::exception if the data cannot be decoded due to data corruption
   * or truncation.
   */
  void setRawData(const unsigned char* buffer, std::size_t bufferSize);

  //fields
private:
  /** Begin Of Event marker
   */
  int boe;

  /** Bunch crossing Id 
   */
  int bxId;

  /** Number of matacq channels in the data.
   */
  int channelCount;

  /** Channel samples
   */
  std::vector<ChannelData> channelData;

  /** Pointer to the standard CMS DAQ header
   */
  const uint32le_t* daqHeader;

  /** DCC error field content.
   */
  int dccErrors;

  /** Event length specified in 'DCC' header
   */
  unsigned dccLen;

  /** Event id. Actually LV1 ID.
   */
  unsigned eventId;

  /** Error code or 0 if no error.
   */
  int32_t error;

  /** FED ID
   */
  int fedId;

  /** FED data format version
   */
  int fov;

  /** event fragment length as read in the std DAQ trailer. In 64-bit words
   */
  int fragLen;

  /** MATACQ sampling frequency in GHz
   */
  int freqGHz;

  /** header marker
   */
  int h1Marker;

  /**Matacq header:
   */
  const matacqHeader_t* matacqHeader;

  /** MATACQ data format internal version
   */
  int matacqDataFormatVersion;

  /** event lenght computed by the raw data parser
   */
  int parsedLen;

  /** Pointer to MATACQ samples block
   */
  uint16le_t* pSamples;

  /** Run number
   */
  unsigned runNum;

  /** Matacq acquisition time stamp
   */
  time_t timeStamp;

  /** MATACQ trigger time position in ps
   */
  int tTrigPs;

  /** Trigger type
   */
  int triggerType;
};

#endif  //MATACQRAWEVENT_H not defined