/*
   (c) Copyright 2012-2013  DirectFB integrated media GmbH
   (c) Copyright 2001-2013  The world wide DirectFB Open Source Community (directfb.org)
   (c) Copyright 2000-2004  Convergence (integrated media) GmbH

   All rights reserved.

   Written by Denis Oliver Kropp <dok@directfb.org>,
              Andreas Shimokawa <andi@directfb.org>,
              Marek Pikarski <mass@directfb.org>,
              Sven Neumann <neo@directfb.org>,
              Ville Syrjälä <syrjala@sci.fi> and
              Claudio Ciccani <klan@users.sf.net>.

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

   This library 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
   Lesser General Public License for more details.

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



#include <config.h>

#include <asm/types.h>    /* Needs to be included before dfb_types.h */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/vt.h>
#include <sys/kd.h>
#include <errno.h>
#include <pthread.h>

#include <directfb.h>

#include <misc/conf.h>
#include <misc/util.h>

#include <direct/debug.h>
#include <direct/mem.h>
#include <direct/messages.h>
#include <direct/thread.h>
#include <direct/util.h>

#include <core/core.h>
#include <core/coredefs.h>
#include <core/coretypes.h>
#include <core/gfxcard.h>

#include "fbdev.h"
#include "fb.h"
#include "vt.h"

D_DEBUG_DOMAIN( VT, "FBDev/VT", "FBDev System Module VT Handling" );

/*
 *  FIXME: the following looks like a bad hack.
 *
 *  SIGUNUSED is no longer unused, but is defined for backwards compatibility.
 *  sparc, mips and alpha signal.h however do not define SIGUNUSED.
 */

#ifdef SIGUNUSED
     #define SIG_SWITCH_FROM  (SIGUNUSED + 10)
     #define SIG_SWITCH_TO    (SIGUNUSED + 11)
#else
     #define SIG_SWITCH_FROM  (31 + 10)
     #define SIG_SWITCH_TO    (31 + 11)
#endif

#ifndef SI_KERNEL
/* glibc 2.1.x doesn't have this in /usr/include/bits/siginfo.h */
     #define SI_KERNEL 0x80
#endif


extern FBDev *dfb_fbdev;

static VirtualTerminal *dfb_vt = NULL;

static DFBResult vt_init_switching( void );
static int       vt_get_fb( int vt );
static void      vt_set_fb( int vt, int fb );
static void     *vt_thread( DirectThread *thread, void *arg );

static void      vt_start_flushing( void );
static void      vt_stop_flushing( void );
static void     *vt_flush_thread( DirectThread *thread, void *arg );

DFBResult
dfb_vt_initialize( void )
{
     DFBResult ret;
     struct vt_stat vs;

     D_DEBUG_AT( VT, "%s()\n", __FUNCTION__ );

     dfb_vt = D_CALLOC( 1, sizeof(VirtualTerminal) );
     if (!dfb_vt)
          return D_OOM();

     setsid();
     dfb_vt->fd0 = open( "/dev/tty0", O_RDONLY | O_NOCTTY );
     if (dfb_vt->fd0 < 0) {
          if (errno == ENOENT) {
               dfb_vt->fd0 = open( "/dev/vc/0", O_RDONLY | O_NOCTTY );
               if (dfb_vt->fd0 < 0) {
                    if (errno == ENOENT) {
                         D_PERROR( "DirectFB/core/vt: Couldn't open "
                                    "neither `/dev/tty0' nor `/dev/vc/0'!\n" );
                    }
                    else {
                         D_PERROR( "DirectFB/core/vt: "
                                    "Error opening `/dev/vc/0'!\n" );
                    }

                    D_FREE( dfb_vt );
                    dfb_vt = NULL;

                    return DFB_INIT;
               }
          }
          else {
               D_PERROR( "DirectFB/core/vt: Error opening `/dev/tty0'!\n");

               D_FREE( dfb_vt );
               dfb_vt = NULL;

               return DFB_INIT;
          }
     }

     if (ioctl( dfb_vt->fd0, VT_GETSTATE, &vs ) < 0) {
          D_PERROR( "DirectFB/core/vt: VT_GETSTATE failed!\n" );
          close( dfb_vt->fd0 );
          D_FREE( dfb_vt );
          dfb_vt = NULL;
          return DFB_INIT;
     }

     dfb_vt->prev = vs.v_active;


     if (!dfb_config->vt_switch) {
          if (dfb_config->vt_num != -1)
               dfb_vt->num = dfb_config->vt_num;
          else
               dfb_vt->num = dfb_vt->prev;

          /* move vt to framebuffer */
          dfb_vt->old_fb = vt_get_fb( dfb_vt->num );
          vt_set_fb( dfb_vt->num, -1 );
     }
     else {
          if (dfb_config->vt_num == -1) {
               int n;

               n = ioctl( dfb_vt->fd0, VT_OPENQRY, &dfb_vt->num );
               if (n < 0 || dfb_vt->num == -1) {
                    D_PERROR( "DirectFB/core/vt: Cannot allocate VT!\n" );
                    close( dfb_vt->fd0 );
                    D_FREE( dfb_vt );
                    dfb_vt = NULL;
                    return DFB_INIT;
               }
          }
          else {
               dfb_vt->num = dfb_config->vt_num;
          }

          /* move vt to framebuffer */
          dfb_vt->old_fb = vt_get_fb( dfb_vt->num );
          vt_set_fb( dfb_vt->num, -1 );

          /* switch to vt */
          while (ioctl( dfb_vt->fd0, VT_ACTIVATE, dfb_vt->num ) < 0) {
               if (errno == EINTR)
                    continue;
               D_PERROR( "DirectFB/core/vt: VT_ACTIVATE failed!\n" );
               close( dfb_vt->fd0 );
               D_FREE( dfb_vt );
               dfb_vt = NULL;
               return DFB_INIT;
          }

          while (ioctl( dfb_vt->fd0, VT_WAITACTIVE, dfb_vt->num ) < 0) {
               if (errno == EINTR)
                    continue;
               D_PERROR( "DirectFB/core/vt: VT_WAITACTIVE failed!\n" );
               close( dfb_vt->fd0 );
               D_FREE( dfb_vt );
               dfb_vt = NULL;
               return DFB_INIT;
          }

          usleep( 40000 );
     }

     ret = vt_init_switching();
     if (ret) {
          if (dfb_config->vt_switch) {
               D_DEBUG_AT( VT, "  -> switching back...\n" );
               ioctl( dfb_vt->fd0, VT_ACTIVATE, dfb_vt->prev );
               ioctl( dfb_vt->fd0, VT_WAITACTIVE, dfb_vt->prev );
               D_DEBUG_AT( VT, "  -> ...switched back\n" );
               ioctl( dfb_vt->fd0, VT_DISALLOCATE, dfb_vt->num );
          }

          close( dfb_vt->fd0 );
          D_FREE( dfb_vt );
          dfb_vt = NULL;
          return ret;
     }

     vt_start_flushing();

     dfb_fbdev->vt = dfb_vt;

     return DFB_OK;
}

DFBResult
dfb_vt_join( void )
{
     D_DEBUG_AT( VT, "%s()\n", __FUNCTION__ );

     dfb_vt_detach( true );

     return DFB_OK;
}

DFBResult
dfb_vt_shutdown( bool emergency )
{
     int res;
     const char cursoron_str[] = "\033[?0;0;0c";
     const char blankon_str[] = "\033[9;10]";

     (void)res;

     D_DEBUG_AT( VT, "%s()\n", __FUNCTION__ );

     if (!dfb_vt)
          return DFB_OK;

     vt_stop_flushing();

     if (dfb_config->vt_switching) {
          if (ioctl( dfb_vt->fd, VT_SETMODE, &dfb_vt->vt_mode ) < 0)
               D_PERROR( "DirectFB/fbdev/vt: Unable to restore VT mode!!!\n" );

          sigaction( SIG_SWITCH_FROM, &dfb_vt->sig_usr1, NULL );
          sigaction( SIG_SWITCH_TO, &dfb_vt->sig_usr2, NULL );

          direct_thread_cancel( dfb_vt->thread );
          direct_thread_join( dfb_vt->thread );
          direct_thread_destroy( dfb_vt->thread );

          pthread_mutex_destroy( &dfb_vt->lock );
          pthread_cond_destroy( &dfb_vt->wait );
     }

     if (dfb_config->kd_graphics) {
          if (ioctl( dfb_vt->fd, KDSETMODE, KD_TEXT ) < 0)
               D_PERROR( "DirectFB/fbdev/vt: KD_TEXT failed!\n" );
     }
     else {
          res = write( dfb_vt->fd, blankon_str, sizeof(blankon_str) );
     }
     res = write( dfb_vt->fd, cursoron_str, sizeof(cursoron_str) );

     if (tcsetattr( dfb_vt->fd, TCSAFLUSH, &dfb_vt->old_ts ) < 0)
          D_PERROR("DirectFB/fbdev/vt: tcsetattr for original values failed!\n");

     if (ioctl( dfb_vt->fd, KDSKBMODE, K_XLATE ) < 0)
          D_PERROR( "DirectFB/fbdev/vt: K_XLATE failed!\n" );

     if (dfb_config->vt_switch) {
          D_DEBUG_AT( VT, "  -> switching back...\n" );

          if (ioctl( dfb_vt->fd0, VT_ACTIVATE, dfb_vt->prev ) < 0)
               D_PERROR( "DirectFB/core/vt: VT_ACTIVATE" );

          if (ioctl( dfb_vt->fd0, VT_WAITACTIVE, dfb_vt->prev ) < 0)
               D_PERROR( "DirectFB/core/vt: VT_WAITACTIVE" );

          D_DEBUG_AT( VT, "  -> switched back...\n" );

          usleep( 40000 );

          /* restore con2fbmap */
          vt_set_fb( dfb_vt->num, dfb_vt->old_fb );

          if (close( dfb_vt->fd ) < 0)
               D_PERROR( "DirectFB/core/vt: Unable to "
                          "close file descriptor of allocated VT!\n" );

          if (ioctl( dfb_vt->fd0, VT_DISALLOCATE, dfb_vt->num ) < 0)
               D_PERROR( "DirectFB/core/vt: Unable to disallocate VT!\n" );
     }
     else {
          /* restore con2fbmap */
          vt_set_fb( dfb_vt->num, dfb_vt->old_fb );

          if (close( dfb_vt->fd ) < 0)
               D_PERROR( "DirectFB/core/vt: Unable to "
                          "close file descriptor of current VT!\n" );
     }

     if (close( dfb_vt->fd0 ) < 0)
          D_PERROR( "DirectFB/core/vt: Unable to "
                     "close file descriptor of tty0!\n" );

     D_FREE( dfb_vt );
     dfb_vt = dfb_fbdev->vt = NULL;

     return DFB_OK;
}

DFBResult
dfb_vt_leave( bool emergency )
{
     D_DEBUG_AT( VT, "%s()\n", __FUNCTION__ );

     return DFB_OK;
}

DFBResult
dfb_vt_detach( bool force )
{
     D_DEBUG_AT( VT, "%s()\n", __FUNCTION__ );

     if (dfb_config->vt_switch || force) {
          int            fd;
          struct vt_stat vt_state;

          fd = open( "/dev/tty", O_RDONLY | O_NOCTTY );
          if (fd < 0) {
               if (errno == ENXIO)
                    return DFB_OK;

               D_PERROR( "DirectFB/VT: Opening /dev/tty failed!\n" );
               return errno2result( errno );
          }

          if (ioctl( fd, VT_GETSTATE, &vt_state )) {
               close( fd );
               return DFB_OK;
          }

          if (ioctl( fd, TIOCNOTTY )) {
               D_PERROR( "DirectFB/VT: TIOCNOTTY on /dev/tty failed\n" );
               close( fd );
               return errno2result( errno );
          }

          close( fd );
     }

     return DFB_OK;
}

bool
dfb_vt_switch( int num )
{
     D_DEBUG_AT( VT, "%s( %d )\n", __FUNCTION__, num );

     if (!dfb_config->vt_switching)
          return false;

     D_DEBUG_AT( VT, "  -> switching to vt %d...\n", num );

     if (ioctl( dfb_vt->fd0, VT_ACTIVATE, num ) < 0)
          D_PERROR( "DirectFB/fbdev/vt: VT_ACTIVATE failed\n" );

     return true;
}

static void *
vt_thread( DirectThread *thread, void *arg )
{
     D_DEBUG_AT( VT, "%s( %p, %p )\n", __FUNCTION__, thread, arg );

     pthread_mutex_lock( &dfb_vt->lock );

     while (true) {
          direct_thread_testcancel( thread );

          D_DEBUG_AT( VT, "...%s (signal %d)\n", __FUNCTION__, dfb_vt->vt_sig);

          switch (dfb_vt->vt_sig) {
               default:
                    D_BUG( "unexpected vt_sig" );
                    /* fall through */

               case -1:
                    pthread_cond_wait( &dfb_vt->wait, &dfb_vt->lock );
                    continue;

               case SIG_SWITCH_FROM:
                    if (dfb_core_suspend( dfb_fbdev->core ) == DFB_OK) {
                         if (ioctl( dfb_vt->fd, VT_RELDISP, VT_ACKACQ ) < 0)
                              D_PERROR( "DirectFB/fbdev/vt: VT_RELDISP failed\n" );
                    }

                    break;

               case SIG_SWITCH_TO:
                    if (dfb_core_resume( dfb_fbdev->core ) == DFB_OK) {
                         if (ioctl( dfb_vt->fd, VT_RELDISP, VT_ACKACQ ) < 0)
                              D_PERROR( "DirectFB/fbdev/vt: VT_RELDISP failed\n" );

                         if (dfb_config->kd_graphics) {
                              if (ioctl( dfb_vt->fd, KDSETMODE, KD_GRAPHICS ) < 0)
                                   D_PERROR( "DirectFB/fbdev/vt: KD_GRAPHICS failed!\n" );
                         }
                    }

                    break;
          }

          dfb_vt->vt_sig = -1;

          pthread_cond_signal( &dfb_vt->wait );
     }

     return NULL;
}

static void
vt_switch_handler( int signum )
{
     D_DEBUG_AT( VT, "%s( %d )\n", __FUNCTION__, signum );

     pthread_mutex_lock( &dfb_vt->lock );

     while (dfb_vt->vt_sig != -1)
          pthread_cond_wait( &dfb_vt->wait, &dfb_vt->lock );

     dfb_vt->vt_sig = signum;

     pthread_cond_signal( &dfb_vt->wait );

     pthread_mutex_unlock( &dfb_vt->lock );
}

static DFBResult
vt_init_switching( void )
{
     struct termios ts;
     const char cursoroff_str[] = "\033[?1;0;0c";
     const char blankoff_str[] = "\033[9;0]";
     char buf[32];

     int res;
     (void)res;

     D_DEBUG_AT( VT, "%s()\n", __FUNCTION__ );

     /* FIXME: Opening the device should be moved out of this function. */

     snprintf(buf, 32, "/dev/tty%d", dfb_vt->num);
     dfb_vt->fd = open( buf, O_RDWR | O_NOCTTY );
     if (dfb_vt->fd < 0) {
          if (errno == ENOENT) {
               snprintf(buf, 32, "/dev/vc/%d", dfb_vt->num);
               dfb_vt->fd = open( buf, O_RDWR | O_NOCTTY );
               if (dfb_vt->fd < 0) {
                    if (errno == ENOENT) {
                         D_PERROR( "DirectFB/core/vt: Couldn't open "
                                    "neither `/dev/tty%d' nor `/dev/vc/%d'!\n",
                                    dfb_vt->num, dfb_vt->num );
                    }
                    else {
                         D_PERROR( "DirectFB/core/vt: "
                                    "Error opening `%s'!\n", buf );
                    }

                    return errno2result( errno );
               }
          }
          else {
               D_PERROR( "DirectFB/core/vt: Error opening `%s'!\n", buf );
               return errno2result( errno );
          }
     }

     /* attach to the new TTY before doing anything like KDSETMODE with it,
        otherwise we'd get access denied error: */
     ioctl( dfb_vt->fd, TIOCSCTTY, 0 );

     if (ioctl( dfb_vt->fd, KDSKBMODE, K_MEDIUMRAW ) < 0) {
          D_PERROR( "DirectFB/fbdev/vt: K_MEDIUMRAW failed!\n" );
          close( dfb_vt->fd );
          return DFB_INIT;
     }

     if (tcgetattr( dfb_vt->fd, &dfb_vt->old_ts ) < 0) {
          D_PERROR( "DirectFB/fbdev/vt: tcgetattr failed!\n" );
          ioctl( dfb_vt->fd, KDSKBMODE, K_XLATE );
          close( dfb_vt->fd );
          return DFB_INIT;
     }
     ts = dfb_vt->old_ts;
     ts.c_cc[VTIME] = 0;
     ts.c_cc[VMIN] = 1;
     ts.c_lflag &= ~(ICANON|ECHO|ISIG);
     ts.c_iflag = 0;
     if (tcsetattr( dfb_vt->fd, TCSAFLUSH, &ts ) < 0) {
          D_PERROR( "DirectFB/fbdev/vt: tcsetattr for new values failed!\n" );
          ioctl( dfb_vt->fd, KDSKBMODE, K_XLATE );
          close( dfb_vt->fd );
          return DFB_INIT;
     }

     res = write( dfb_vt->fd, cursoroff_str, sizeof(cursoroff_str) );
     if (dfb_config->kd_graphics) {
          if (ioctl( dfb_vt->fd, KDSETMODE, KD_GRAPHICS ) < 0) {
               D_PERROR( "DirectFB/fbdev/vt: KD_GRAPHICS failed!\n" );
               tcsetattr( dfb_vt->fd, TCSAFLUSH, &dfb_vt->old_ts );
               ioctl( dfb_vt->fd, KDSKBMODE, K_XLATE );
               close( dfb_vt->fd );
               return DFB_INIT;
          }
     }
     else {
          res = write( dfb_vt->fd, blankoff_str, sizeof(blankoff_str) );
     }

     if (dfb_config->vt_switching) {
          struct vt_mode vt;
          struct sigaction sig_tty;

          memset( &sig_tty, 0, sizeof( sig_tty ) );
          sig_tty.sa_handler = vt_switch_handler;
          sigfillset( &sig_tty.sa_mask );

          if (sigaction( SIG_SWITCH_FROM, &sig_tty, &dfb_vt->sig_usr1 ) ||
              sigaction( SIG_SWITCH_TO, &sig_tty, &dfb_vt->sig_usr2 )) {
               D_PERROR( "DirectFB/fbdev/vt: sigaction failed!\n" );
               tcsetattr( dfb_vt->fd, TCSAFLUSH, &dfb_vt->old_ts );
               ioctl( dfb_vt->fd, KDSKBMODE, K_XLATE );
               close( dfb_vt->fd );
               return DFB_INIT;
          }


          vt.mode   = VT_PROCESS;
          vt.waitv  = 0;
          vt.relsig = SIG_SWITCH_FROM;
          vt.acqsig = SIG_SWITCH_TO;

          if (ioctl( dfb_vt->fd, VT_SETMODE, &vt ) < 0) {
               D_PERROR( "DirectFB/fbdev/vt: VT_SETMODE failed!\n" );

               sigaction( SIG_SWITCH_FROM, &dfb_vt->sig_usr1, NULL );
               sigaction( SIG_SWITCH_TO, &dfb_vt->sig_usr2, NULL );

               tcsetattr( dfb_vt->fd, TCSAFLUSH, &dfb_vt->old_ts );
               ioctl( dfb_vt->fd, KDSKBMODE, K_XLATE );
               close( dfb_vt->fd );

               return DFB_INIT;
          }

          direct_util_recursive_pthread_mutex_init( &dfb_vt->lock );

          pthread_cond_init( &dfb_vt->wait, NULL );

          dfb_vt->vt_sig = -1;

          dfb_vt->thread = direct_thread_create( DTT_CRITICAL, vt_thread, NULL, "VT Switcher" );
     }

     return DFB_OK;
}

static int
vt_get_fb( int vt )
{
     struct fb_con2fbmap c2m;

     D_DEBUG_AT( VT, "%s( %d )\n", __FUNCTION__, vt );

     c2m.console = vt;

     if (ioctl( dfb_fbdev->fd, FBIOGET_CON2FBMAP, &c2m )) {
          D_PERROR( "DirectFB/FBDev/vt: "
                     "FBIOGET_CON2FBMAP failed!\n" );
          return 0;
     }

     D_DEBUG_AT( VT, "  -> %d\n", c2m.framebuffer );

     return c2m.framebuffer;
}

static void
vt_set_fb( int vt, int fb )
{
     struct fb_con2fbmap c2m;
     struct stat         sbf;

     D_DEBUG_AT( VT, "%s( %d, %d )\n", __FUNCTION__, vt, fb );

     if (fstat( dfb_fbdev->fd, &sbf )) {
          D_PERROR( "DirectFB/FBDev/vt: Could not fstat fb device!\n" );
          return;
     }

     if (fb >= 0)
          c2m.framebuffer = fb;
     else
          c2m.framebuffer = (sbf.st_rdev & 0xFF) >> 5;

     c2m.console = vt;

     if (ioctl( dfb_fbdev->fd, FBIOPUT_CON2FBMAP, &c2m ) < 0) {
          D_PERROR( "DirectFB/FBDev/vt: "
                     "FBIOPUT_CON2FBMAP failed!\n" );
     }
}

static void
vt_start_flushing( void )
{
     dfb_vt->flush = true;
     dfb_vt->flush_thread = direct_thread_create( DTT_DEFAULT, vt_flush_thread, NULL, "VT Flusher" );
}

static void
vt_stop_flushing( void )
{
     dfb_vt->flush = false;
     direct_thread_cancel( dfb_vt->flush_thread );
     direct_thread_join( dfb_vt->flush_thread );
     direct_thread_destroy( dfb_vt->flush_thread );
     dfb_vt->flush_thread = NULL;
}

/*
 * If the vt buffer in not kept clean the kernel may stop sleeping.
 */
static void *
vt_flush_thread( DirectThread *thread, void *arg )
{
     D_DEBUG_AT( VT, "%s( %p, %p )\n", __FUNCTION__, thread, arg );

     while (dfb_vt->flush) {
          fd_set set;
          int ret;

          FD_ZERO( &set );
          FD_SET( dfb_vt->fd, &set );

          ret = select( dfb_vt->fd + 1, &set, NULL, NULL, NULL );

          if (ret < 0 && errno == EINTR)
               continue;

          if (ret < 0 || !dfb_vt->flush)
               break;

          tcflush( dfb_vt->fd, TCIFLUSH );
     }

     return NULL;
}