/*
    This file is part of Konsole, an X terminal.
    
    Copyright 2007-2008 by Robert Knight <robertknight@gmail.com>
    Copyright 1997,1998 by Lars Doelle <lars.doelle@on-line.de>

    This program 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.

    This program 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 this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
    02110-1301  USA.
*/

#ifndef VT102EMULATION_H
#define VT102EMULATION_H

// Standard Library
#include <stdio.h>

// Qt 
#include <QtGui/QKeyEvent>
#include <QtCore/QHash>
#include <QtCore/QTimer>

// Konsole
#include "Emulation.h"
#include "Screen.h"

#define MODE_AppScreen       (MODES_SCREEN+0)	// Mode #1
#define MODE_AppCuKeys       (MODES_SCREEN+1)	// Application cursor keys (DECCKM)
#define MODE_AppKeyPad       (MODES_SCREEN+2)	//
#define MODE_Mouse1000       (MODES_SCREEN+3)	// Send mouse X,Y position on press and release
#define MODE_Mouse1001       (MODES_SCREEN+4)	// Use Hilight mouse tracking
#define MODE_Mouse1002       (MODES_SCREEN+5)	// Use cell motion mouse tracking
#define MODE_Mouse1003       (MODES_SCREEN+6)	// Use all motion mouse tracking
#define MODE_Ansi            (MODES_SCREEN+7)	// Use US Ascii for character sets G0-G3 (DECANM)
#define MODE_132Columns      (MODES_SCREEN+8)	// 80 <-> 132 column mode switch (DECCOLM)
#define MODE_Allow132Columns (MODES_SCREEN+9)	// Allow DECCOLM mode
#define MODE_total           (MODES_SCREEN+10)

struct CharCodes
{
  // coding info
  char charset[4];		//
  int cu_cs;			// actual charset.
  bool graphic;			// Some VT100 tricks
  bool pound;			// Some VT100 tricks
  bool sa_graphic;		// saved graphic
  bool sa_pound;		// saved pound
};

/**
 * Provides an xterm compatible terminal emulation based on the DEC VT102 terminal.
 * A full description of this terminal can be found at
 * 
 * In addition, various additional xterm escape sequences are supported to provide 
 * features such as mouse input handling.
 * See http://rtfm.etla.org/xterm/ctlseq.html for a description of xterm's escape
 * sequences. 
 *
 */
class Vt102Emulation:public Emulation
{
Q_OBJECT public:
  /** Constructs a new emulation */
  Vt102Emulation ();
  ~Vt102Emulation ();

  // reimplemented from Emulation
  virtual void clearEntireScreen ();
  virtual void reset ();
  virtual char eraseChar () const;

  public slots:
    // reimplemented from Emulation 
    virtual void sendString (const char *, int length = -1);
  virtual void sendText (const QString & text);
  virtual void sendKeyEvent (QKeyEvent *);
  virtual void sendMouseEvent (int buttons, int column, int line,
			       int eventType);

protected:
  // reimplemented from Emulation
    virtual void setMode (int mode);
  virtual void resetMode (int mode);
  virtual void receiveChar (int cc);

  private slots:
    //causes changeTitle() to be emitted for each (int,QString) pair in pendingTitleUpdates
    //used to buffer multiple title updates
  void updateTitle ();

private:
  unsigned short applyCharset (unsigned short c);
  void setCharset (int n, int cs);
  void useCharset (int n);
  void setAndUseCharset (int n, int cs);
  void saveCursor ();
  void restoreCursor ();
  void resetCharset (int scrno);

  void setMargins (int top, int bottom);
  //set margins for all screens back to their defaults
  void setDefaultMargins ();

  // returns true if 'mode' is set or false otherwise
  bool getMode (int mode);
  // saves the current boolean value of 'mode'
  void saveMode (int mode);
  // restores the boolean value of 'mode' 
  void restoreMode (int mode);
  // resets all modes
  // (except MODE_Allow132Columns)
  void resetModes ();

  void resetTokenizer ();
#define MAX_TOKEN_LENGTH 80
  void addToCurrentToken (int cc);
  int tokenBuffer[MAX_TOKEN_LENGTH];	//FIXME: overflow?
  int tokenBufferPos;
#define MAXARGS 15
  void addDigit (int dig);
  void addArgument ();
  int argv[MAXARGS];
  int argc;
  void initTokenizer ();

  // Set of flags for each of the ASCII characters which indicates
  // what category they fall into (printable character, control, digit etc.)
  // for the purposes of decoding terminal output
  int charClass[256];

  void reportDecodingError ();

  void processToken (int code, int p, int q);
  void processWindowAttributeChange ();

  void reportTerminalType ();
  void reportSecondaryAttributes ();
  void reportStatus ();
  void reportAnswerBack ();
  void reportCursorPosition ();
  void reportTerminalParms (int p);

  void onScrollLock ();
  void scrollLock (const bool lock);

  // clears the screen and resizes it to the specified
  // number of columns
  void clearScreenAndSetColumns (int columnCount);

  CharCodes _charset[2];

  class TerminalState
  {
  public:
    // Initializes all modes to false
    TerminalState ()
    {
      memset (&mode, false, MODE_total * sizeof (bool));
    }

    bool mode[MODE_total];
  };

  TerminalState _currentModes;
  TerminalState _savedModes;

  //hash table and timer for buffering calls to the session instance 
  //to update the name of the session
  //or window title.
  //these calls occur when certain escape sequences are seen in the 
  //output from the terminal
  QHash < int, QString > _pendingTitleUpdates;
  QTimer *_titleUpdateTimer;
};

#endif // VT102EMULATION_H