/*
 *   GRacer
 *
 *   Copyright (C) 1999 Takashi Matsuda <matsu@users.sourceforge.net>
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */

#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/fcntl.h>
#include <sys/ioctl.h>
#include "joystick.h"
#include <GL/glut.h>
#include <config.h>

#define JOYSTICK_INTERVAL	10

static int js_fd = -1;
static Tcl_Interp *js_interp;
static Tcl_Obj *js_obj;

static Tcl_Obj *obj_time;
static Tcl_Obj *obj_value;
static Tcl_Obj *obj_type;
static Tcl_Obj *obj_number;

#ifdef ENABLE_LINUX_JOYSTICK

#include <linux/joystick.h>

static void
joystick_timer_func (int value)
{
  struct js_event event[256];
  int res, num, i;
  Tcl_Obj *obj;
  Tcl_Interp *interp;
  double lf;
  double sign;
  const double margin = 0.1;

  if (!js_obj)
    return;

  while ((res = read (js_fd, event, sizeof (event))) > 0) {
    num = res / sizeof (struct js_event);

    for (i=0; i<num; i++) {
      interp = js_interp;
      obj = js_obj;

      Tcl_ObjSetVar2 (interp, obj_time, NULL,
		      Tcl_NewIntObj (event[i].time), 0);
      if (event[i].type & JS_EVENT_BUTTON) {
	Tcl_ObjSetVar2 (interp, obj_value, NULL,
			Tcl_NewIntObj (event[i].value), 0);
      } else if (event[i].type & JS_EVENT_AXIS) {
	lf = (double)(event[i].value)/32767;
	if (lf < 0) {
	  sign = -1.0;
	  lf = -lf;
	} else {
	  sign = 1.0;
	}
	if (lf > margin) {
	  lf = sign * (lf - margin) / (1.0 - margin);
	} else {
	  lf = 0.0;
	}
	Tcl_ObjSetVar2 (interp, obj_value, NULL, Tcl_NewDoubleObj (lf), 0);
      }
      Tcl_ObjSetVar2 (interp, obj_type, NULL,
		      Tcl_NewIntObj (event[i].type & ~JS_EVENT_INIT), 0);
      Tcl_ObjSetVar2 (interp, obj_number, NULL,
		      Tcl_NewIntObj (event[i].number), 0);

      Tcl_IncrRefCount (obj);
      if ((res = Tcl_EvalObj (interp, obj)) == TCL_ERROR)
	fputs (Tcl_GetVar (interp, "errorInfo", TCL_GLOBAL_ONLY), stderr);
      Tcl_DecrRefCount (obj);

      if (!js_obj)
	return;
    }


  }
  if (errno != EAGAIN) {
    perror (NULL);
  }

  glutTimerFunc (JOYSTICK_INTERVAL, joystick_timer_func, -1);
}

#endif /* ENABLE_LINUX_JOYSTICK */

static int
joystick_cmd (ClientData data,
	      Tcl_Interp *interp,
	      int objc,
	      Tcl_Obj *CONST objv[]) {

#ifdef ENABLE_LINUX_JOYSTICK

  int length;
  char *str;
  char *filename;


  if (objc < 2) {
    return TCL_ERROR;
  }

  str = Tcl_GetStringFromObj (objv[1], NULL);
  if (!strcmp (str, "open")) {
    if (objc < 3) {
      return TCL_ERROR;
    }
    filename = Tcl_GetStringFromObj (objv[2], NULL);
    js_fd = open (filename, O_RDONLY | O_NONBLOCK);
    if (js_fd == -1) {
      Tcl_SetObjResult (interp, objv[0]);
      Tcl_AppendResult (interp, ": can not open joystick device (",
	  		sys_errlist[errno], ")", NULL);
      return TCL_ERROR;
    }
    return TCL_OK;

  } else if (!strcmp (str, "close")) {
    if (js_fd != 0)
      close (js_fd);

    if (js_obj) {
      Tcl_DecrRefCount (js_obj);
      js_obj = NULL;
    }
    return TCL_OK;

  } else if (!strcmp (str, "command")) {
    if (js_fd == -1) {
      return TCL_ERROR;
    }

    if (objc < 3) {
      return TCL_ERROR;
    }

    if (js_obj) {
      Tcl_DecrRefCount (js_obj);
      js_obj = NULL;
    }

    Tcl_ListObjLength (interp, objv[2], &length);
    if (length == 0) {
      return TCL_OK;
    }
    js_interp = interp;
    js_obj = objv[2];
    Tcl_IncrRefCount (js_obj);

    glutTimerFunc (JOYSTICK_INTERVAL, joystick_timer_func, -1);
    return TCL_OK;
  }

#endif /* ENABLE_LINUX_JOYSTICK */

  return TCL_ERROR;
}

int
Joystick_Init (Tcl_Interp *interp)
{
  obj_time = Tcl_NewStringObj ("TIME", 4);
  obj_value = Tcl_NewStringObj ("VALUE", 5);
  obj_type = Tcl_NewStringObj ("TYPE", 4);
  obj_number = Tcl_NewStringObj ("NUMBER", 6);

  Tcl_CreateObjCommand (interp, "joystick", joystick_cmd, NULL, NULL);

  return TCL_OK;
}