#ifndef __JTRIGGER__JTRIGGERINTERFACE__
#define __JTRIGGER__JTRIGGERINTERFACE__

#include "JLang/JConversion.hh"

#include "JTrigger/JTriggerException.hh"
#include "JTrigger/JTriggerInput.hh"
#include "JTrigger/JMatch.hh"
#include "JTrigger/JModuleCounter.hh"
#include "km3net-dataformat/online/JDAQTriggerMask.hh"


/**
 * \author mdejong
 */

namespace JTRIGGER {}
namespace JPP { using namespace JTRIGGER; }

namespace JTRIGGER {

  using JLANG::JAssertConversion;
  using KM3NETDAQ::NUMBER_OF_TRIGGER_BITS;


  /**
   * Type definition of trigger bit.
   */
  typedef unsigned int  JTriggerbit_t; 


  /**
   * Trigger interface.
   * This interface is used to define a unique bit for each trigger.
   */
  class JTriggerInterface
  {
  protected:
    /**
     * Default constructor.
     */
    JTriggerInterface()
    {}


    /**
     * Virtual destructor.
     */
    virtual ~JTriggerInterface() 
    {} 


    /**
     * Auxiliary class for type definition of specific trigger bit.
     */
    template<JTriggerbit_t N>
    struct JBit
    {
      static const JTriggerbit_t value = N;
    };


    /**
     * Test whether specific trigger bit correponds to derived trigger class.
     *
     * This method will be specialised using the marco setTriggerBit() so that
     * it will return true if this triggered event corresponds to bit N.
     *
     * This method will be repeatedly called by method find_trigger_bit()
     * which in turn is called by the member method JTriggerInterface::getTriggerBit() 
     * so that it returns the correct trigger bit. 
     *
     * \return            false
     */
    template<JTriggerbit_t N>
    inline bool checkTriggerBit() const
    {
      return false;
    }

    
    /**
     * Recursive method to find the trigger bit of the given trigger data.
     *
     * \param   bit       trigger bit
     * \return            trigger bit
     */
    template<JTriggerbit_t N>
    inline JTriggerbit_t find_trigger_bit(JBit<N> bit) const
    {
      if (checkTriggerBit<N>())
	return N;
      else
	return find_trigger_bit(JBit<N+1>());
    }
    
    
    /**
     * Termination method of recursive method to find the trigger bit of the given trigger data.
     * This method throws an error.
     *
     * \param   bit       trigger bit
     * \return            trigger bit
     */
    inline JTriggerbit_t find_trigger_bit(JBit<NUMBER_OF_TRIGGER_BITS> bit) const
    {
      throw JTriggerException("Method find_trigger_bit<>(): no corresponding trigger bit found.");
    }


    /**
     * Get trigger name.
     *
     * This method will be specialised using the marco setTriggerBit() so that
     * it will return name of trigger for bit N.
     *
     * This method will be repeatedly called by method get_trigger_name()
     * which in turn is called by the method JTriggerInterface::getTriggerName() 
     * so that it returns the correct trigger name. 
     *  
     * \return            NULL
     */
    template<JTriggerbit_t N>
    static const char* getTriggerName()
    {
      return NULL;
    }

    
    /**
     * Recursive method to get trigger name for given trigger bit.
     *  
     * \param   bit       trigger bit
     * \param   value     trigger bit
     * \return            trigger name
     */
    template<JTriggerbit_t N>
    static const char* get_trigger_name(JBit<N> bit, JTriggerbit_t value)
    {
      if (bit.value == value)
	return getTriggerName<N>();
      else
	return get_trigger_name(JBit<N+1>(), value);
    }

    
    /**
     * Termination method of recursive method to get trigger name.
     *  
     * \param   bit       trigger bit
     * \param   value     trigger bit
     * \return            NULL
     */
    static const char* get_trigger_name(JBit<NUMBER_OF_TRIGGER_BITS> bit, JTriggerbit_t value)
    {
      return NULL;
    }
    
  public:

    typedef JTriggerInput::value_type                    value_type;
    typedef JMatch<value_type>                           match_type;


    /**
     * Get the trigger bit.
     *
     * \return                trigger bit
     */
    inline JTriggerbit_t getTriggerBit() const
    {
      return find_trigger_bit(JBit<0>());
    }


    /**
     * Get trigger name.
     *  
     * param   bit        trigger bit
     * \return            trigger name
     */
    static const char* getTriggerName(JTriggerbit_t bit)
    {
      return get_trigger_name(JBit<0>(), bit);
    }
  };
  

  /**
   * This class is used to map trigger class to trigger bit.
   * It will be specialised using the marco setTriggerBit().
   *
   * The specialiation of this class will ensure unique use of a trigger class.
   * The trigger bit of a valid trigger class (i.e.\ one defined using
   * macro setTriggerBit()) is accessible using method getTriggerBit().
   */
  template<class JTrigger_t> struct JTriggerBit {};


  /**
   * Get the trigger bit.
   *
   * \return                trigger bit
   */
  template<class JTrigger_t>
  inline JTriggerbit_t getTriggerBit() 
  {
    return JTriggerBit<JTrigger_t>::value;
  }


  /**
   * Get the trigger bit.
   *
   * \param  event          triggered event
   * \return                trigger bit
   */
  template<class JTrigger_t>
  inline JTriggerbit_t getTriggerBit(const JTrigger_t& event) 
  {
    return JTriggerBit<JTrigger_t>::value;
  }

  
  /**
   * Get trigger name.
   *  
   * param   bit        trigger bit
   * \return            trigger name
   */
  inline const char* getTriggerName(JTriggerbit_t bit)
  {
    return JTriggerInterface::getTriggerName(bit);
  }
  
  
  /**
   * This class will generate a compiler error if trigger bit is out of range.
   */
  template<JTriggerbit_t N, bool is_valid = (N < NUMBER_OF_TRIGGER_BITS)> 
  struct JAssertBit;

  /**
   * Implementation of a valid trigger bit.
   */
  template<JTriggerbit_t N> 
  struct JAssertBit<N, true> {};
}


/**
 * Macro to set trigger bit of a given trigger class.
 *
 * This macro should be called for each trigger class.
 * As a result, the trigger class is mapped to a unique bit.
 * This mapping is then avaiable in the following ways:
 *
 *  -# The member method JTriggerInterface::getTriggerBit() 
 *     will return the specified trigger bit of the derived class; and
 *  -# The trigger bit is stored as a static data member value of
 *     the template class JTRIGGER::JTriggerBit.
 *
 * By using this macro, it is verified -at compile time- that:
 *  -# The trigger bit is unique;
 *  -# The trigger class derives from JTRIGGER::JTriggerInterface; and 
 *  -# The trigger class has not been associated to another trigger bit;
 *
 * \param JTrigger_t     trigger class
 * \param N              trigger bit
 */
#define setTriggerBit(JTrigger_t, N)					\
									\
  									\
  template<>								\
  struct JTriggerBit<JTrigger_t> :					\
    JAssertConversion<JTrigger_t, JTriggerInterface>,			\
    JAssertBit<N>							\
  {									\
    static const JTriggerbit_t value = N;				\
  };									\
									\
									\
  template<>								\
  inline bool JTriggerInterface::checkTriggerBit<N>() const		\
  {									\
    return dynamic_cast<const JTrigger_t*>(this) != NULL;		\
  }									\
									\
									\
  template<>								\
  const char* JTriggerInterface::getTriggerName<N>()			\
  {									\
    return #JTrigger_t;							\
  }

#endif