// FileEvent.cxx

#include "FileEvent.h"

using hes::EventId;
using hes::File;
using hes::FileEvent;

//**********************************************************************
// Private member functions.
//**********************************************************************

// Set the current event iterator.
// All changes to the current event come through here.

EventId FileEvent::set_event_iter(EventIdList::const_iterator ievid) {
  // Do nothing if the new event is the same as the old.
  if ( ievid == m_ievid ) {
    return *m_ievid;
  }
  // Notify subclasses that event is ending.
  if ( m_ievid != m_evids.end() ) {
    end_event();
  }
  // Do not allow a change if we are in the middle of writing an
  // event. This should not happen: end_event() should finish
  // writing the event.
  if ( is_writing() ) {
    return *m_ievid;
  }
  // Notify subclasses that a new event is has begun.
  m_ievid = ievid;
  if ( ievid != m_evids.end() ) {
    begin_event();
  }
  return *m_ievid;
}

//**********************************************************************
// Member functions.
//**********************************************************************

// Constructor.

FileEvent::FileEvent()
: m_ievid(m_evids.end()) { }

//**********************************************************************

// Add an event ID.

int FileEvent::add_event_id(EventId evid) {
  bool atend = m_ievid == m_evids.end();
  // Handle the first event.
  if ( ! m_min_evid.is_valid() ) {
    assert( ! m_max_evid.is_valid() );
    assert( m_evids.size() == 0 );
    m_evids.push_back(evid);
    m_min_evid = evid;
    m_max_evid = evid;
    m_ievid = m_evids.end();
    return m_evids.size();
  }
  assert( m_max_evid.is_valid() );
  assert( m_evids.size() != 0 );
  // If this ID is in the current range, check that it is not already
  // included in the list.
  if ( evid >= m_min_evid && evid <= m_max_evid ) {
    for ( EventIdList::const_iterator ievid=m_evids.begin();
          ievid!=m_evids.end(); ++ievid ) {
      if ( evid == *ievid ) {
        return 0;
      }
    }
  }
  m_evids.push_back(evid);
  if ( evid > m_max_evid ) {
    m_max_evid = evid;
  } else if ( evid < m_min_evid ) {
    m_min_evid = evid;
  }
  // Reset the current event if we are at the end.
  if ( atend ) {
    m_ievid = m_evids.end();
  }
  return m_evids.size();
}

//**********************************************************************

// Return the number of events.

int FileEvent::event_count() const {
  return m_evids.size();
}

//**********************************************************************

// Return the min event ID.

EventId FileEvent::min_event() const {
  return m_min_evid;
}

//**********************************************************************

// Return the max event ID.
 
EventId FileEvent::max_event() const {
  return m_max_evid;
}

//**********************************************************************

// Return the list of event ID's.

const File::EventIdList& FileEvent::event_ids() const {
  return m_evids;
}

//**********************************************************************

// Return the current event ID.

EventId FileEvent::event() const {
  if ( m_ievid == m_evids.end() ) {
    return EventId();
  }
  return *m_ievid;
}

//**********************************************************************

// Set the current event.

EventId FileEvent::set_event(EventId evid) {
  // Simple strategy for now.
  EventIdList::const_iterator ievid;
  for ( ievid=m_evids.begin(); ievid!=m_evids.end(); ++ievid ) {
    if ( *ievid == evid ) {
      break;
    }
  }
  return set_event_iter(ievid);
}

//**********************************************************************

// Set the current event to the first event.
 
EventId FileEvent::first_event() {
  return set_event_iter(m_evids.begin());
}

//**********************************************************************

// Set the current event to the last event;

EventId FileEvent::last_event() {
  EventIdList::const_iterator ievid = m_evids.end();
  --ievid;
  return set_event_iter(ievid);
}

//**********************************************************************

// Advance to the next event.

EventId FileEvent::next_event() {
  return set_event_iter(++m_ievid);
}

//**********************************************************************