/*
  Copyright 2003 Rikard Björklind, Arsenij Vodjanov, Mikael Gransell

  This file is part of dc-qt.

  dc-qt is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  dc-qt is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with dc-qt; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include "chatedit.h"


ChatEdit::ChatEdit( QWidget *parent, const char *name ) : QLineEdit(parent, name) 
{
  completions = StrStrVec ( 256 );
  lastindex = 0;
  tabs = 0;
}


ChatEdit::~ ChatEdit()
{
  clearCompletions();
}



void ChatEdit::keyPressEvent( QKeyEvent *e )
{
  // keypress behaviour:
  // reset tab counter
  tabs = 0;
  QLineEdit::keyPressEvent( e );    
}


void ChatEdit::focusOutEvent( QFocusEvent *e )
{
  // exit if this event is not a TAB-focus change
  if (e->reason() != QFocusEvent::Tab) {
/*    if (e->reason() == QFocusEvent::Other) 
      tabs = 0; */
    QLineEdit::focusOutEvent(e);
    return;
  }
  
  tabs++;
  
  // behaviour on first tab press: 
  //   if one match exists, then autocomplete
  //   if several matches exist, then display list of all matches
  // behaviour on following tab presses (tab counter >= 2):
  //   if any matches exist, then autocomplete 1st match 
  //   if no matches exist, then execute default behaviour and reset tab counter
  
  int fromPos;
  
  // a stringlist of all matching strings
  QStringList matches;
  
  if (cursorPosition() > 0) {  
    QChar lastchar = text().at( cursorPosition()-1 );
    
    // proceed if last entered character is NOT some sort of separator
    if ( ! ( lastchar.isSpace() || lastchar.isNull() ) ) {
    
      // starting from last character, search backwards until a separator character is found
      for ( fromPos = cursorPosition()-1; fromPos>=0; fromPos--) {
        QChar c = text().at(fromPos);
        if ( c.isSpace() || c.isNull() ) 
          break;
      }
      
      fromPos++;
      
      QString str = text().mid(fromPos, cursorPosition() - fromPos);
      if (!str.isEmpty()) {
        
        QChar c = str.at(0).lower();
        if (cindex[c] < lastindex) {
  
          StrVec &ssv = completions[ cindex[c] ];

          for ( unsigned int k = 0; k<ssv.count(); k++ ) {
            if ( ssv[k].startsWith( str, false ) ) {
              matches += ssv[k];
            }
          }          
                  
        }
      }
    }     
  }

  // default TAB-behaviour on second press
  if (matches.count() == 0 && tabs >= 2) {
#ifdef _DEBUG
    printf("Gave up focus!\n");
#endif
    tabs = 0;
    QLineEdit::focusOutEvent(e);
    return;    
  }
  
  // here we have found one or more matches
  
  if ((matches.count()==1) || (matches.count() > 0 && tabs>=2)) {
    
    // if only one match exists, 
    // or several matches exist and tab has been pressed more than once, 
    // then complete with first match
    tabs = 0;
    setText( text().left( fromPos ) + matches[0] + ": " ); // replace incomplete string with full completion
    moveCompletionToFront(matches[0]);  // relocate this completion in list
  
  } else {
    
    // else if we have any matches, and tab has only been pressed once, display list of matches 
    if (matches.count()>0 && tabs < 2) {
      if (matches.count()<8)
        emit messageStr( QString("<-----> ") + matches.join(" ") + " ");
      else
        emit messageStr( QString("<-----> ") + matches[0] + " " + matches[1] + " " + matches[2] + " " + matches[3] 
                        + QString(" ... %1 possible completions").arg(matches.count()) );
    }
  }
  
  matches.clear();
  setFocus();
  end(false); // move cursor to end and deselect all
}


void ChatEdit::addCompletion( const QString &str )
{
  if (str.isEmpty()) 
    return;
  
  QChar c = str.at(0).lower();  
  if (cindex.find(c) == cindex.end())
    cindex[c] = lastindex++;

  if (lastindex>=completions.count())
    completions.resize(lastindex * 2);
  
  completions[ cindex[c] ].push_back( str );
  
#ifdef _DEBUG
  printf("addCompletion:  \"%s\" -> \'%c\' (%u)\n", str.ascii(), c.latin1(), cindex[c]);
#endif
}


void ChatEdit::removeCompletion( const QString &str )
{
  if (str.isEmpty()) 
    return;
    
  QChar c = str.at(0).lower();
  
  if (cindex[c] >= lastindex) 
    return;

#ifdef _DEBUG
  printf("removeCompletion:  \"%s\" -> \'%c\' (%u)\n", str.ascii(), c.latin1(), cindex[c]);
#endif
    
  StrVec &ssv = completions[ cindex[c] ];
  StrVec::iterator i = ssv.begin();
  while( i != ssv.end() ) {
    if (*i == str) {
      ssv.erase(i);
      return;
    } else
      i++;
  }
}

void ChatEdit::clearCompletions()
{
  completions.clear();
  cindex.clear();
  completions = StrStrVec ( 256 );
  lastindex = 0;
  tabs = 0;
}

void ChatEdit::moveCompletionToFront( const QString &str )
{
  if (str.isEmpty()) 
    return;

  QChar c = str.at(0).lower();
  
  if (cindex[c] >= lastindex) 
    return;
    
  StrVec &ssv = completions[ cindex[c] ];
  
  for ( unsigned int i = 0; i<ssv.count(); i++ ) {
    if (ssv[i] == str) {
      QString tmp = ssv[0];
      ssv[0] = ssv[i];
      ssv[i] = tmp;
      break;
    }
  }
}