/*
    Mosh: the mobile shell
    Copyright 2012 Keith Winstein

    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 3 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, see <http://www.gnu.org/licenses/>.
*/

#include <assert.h>
#include "terminaluserinput.h"

using namespace Terminal;
using namespace std;

string UserInput::input( const Parser::UserByte *act,
			 bool application_mode_cursor_keys )
{
  act->handled = true;

  /* The user will always be in application mode. If stm is not in
     application mode, convert user's cursor control function to an
     ANSI cursor control sequence */

  /* We need to look ahead one byte in the SS3 state to see if
     the next byte will be A, B, C, or D (cursor control keys). */

  switch ( state ) {
  case Ground:
    if ( act->c == 0x1b ) { /* ESC */
      state = ESC;
    }
    return string( &act->c, 1 );
    break;

  case ESC:
    if ( act->c == 'O' ) { /* ESC O = 7-bit SS3 */
      state = SS3;
      return string();
    } else {
      state = Ground;
      return string( &act->c, 1 );
    }
    break;

  case SS3:
    state = Ground;
    if ( (!application_mode_cursor_keys)
	 && (act->c >= 'A')
	 && (act->c <= 'D') ) {
      char translated_cursor[ 2 ] = { '[', act->c };
      return string( translated_cursor, 2 );
    } else {
      char original_cursor[ 2 ] = { 'O', act->c };
      return string( original_cursor, 2 );
    }
    break;
  }

  /* This doesn't handle the 8-bit SS3 C1 control, which would be
     two octets in UTF-8. Fortunately nobody seems to send this. */

  assert( false );
  return string();
}