// fg_commands.cxx - internal FGFS commands.

#include <string.h>		// strcmp()

#include <simgear/compiler.h>
#include <simgear/misc/exception.hxx>

#include STL_STRING
#include STL_FSTREAM

#include <simgear/sg_inlines.h>
#include <simgear/debug/logstream.hxx>
#include <simgear/math/sg_random.h>
#include <simgear/misc/commands.hxx>
#include <simgear/props/props.hxx>

#include <Cockpit/panel.hxx>
#include <Cockpit/panel_io.hxx>
#include <FDM/flight.hxx>
#include <GUI/gui.h>
#include <GUI/new_gui.hxx>
#include <GUI/dialog.hxx>
#include <Replay/replay.hxx>
#include <Scenery/tilemgr.hxx>
#if defined(HAVE_PLIB_PSL)
#  include <Scripting/scriptmgr.hxx>
#endif
#include <Time/sunsolver.hxx>
#include <Time/tmp.hxx>

#include "fg_init.hxx"
#include "fg_commands.hxx"
#include "fg_props.hxx"

SG_USING_STD(string);
SG_USING_STD(ifstream);
SG_USING_STD(ofstream);

#include "fg_props.hxx"
#include "fg_io.hxx"
#include "globals.hxx"
#include "util.hxx"
#include "viewmgr.hxx"



////////////////////////////////////////////////////////////////////////
// Static helper functions.
////////////////////////////////////////////////////////////////////////


static inline SGPropertyNode *
get_prop (const SGPropertyNode * arg)
{
    return fgGetNode(arg->getStringValue("property[0]", "/null"), true);
}

static inline SGPropertyNode *
get_prop2 (const SGPropertyNode * arg)
{
    return fgGetNode(arg->getStringValue("property[1]", "/null"), true);
}


/**
 * Get a double value and split it as required.
 */
static void
split_value (double full_value, const char * mask,
             double * unmodifiable, double * modifiable)
{
    if (!strcmp("integer", mask)) {
        *modifiable = (full_value < 0 ? ceil(full_value) : floor (full_value));
        *unmodifiable = full_value - *modifiable;
    } else if (!strcmp("decimal", mask)) {
        *unmodifiable = (full_value < 0 ? ceil(full_value) : floor(full_value));
        *modifiable = full_value - *unmodifiable;
    } else {
        if (strcmp("all", mask))
            SG_LOG(SG_GENERAL, SG_ALERT, "Bad value " << mask << " for mask;"
                   << " assuming 'all'");
        *unmodifiable = 0;
        *modifiable = full_value;
    }
}


/**
 * Clamp or wrap a value as specified.
 */
static void
limit_value (double * value, const SGPropertyNode * arg)
{
    const SGPropertyNode * min_node = arg->getChild("min");
    const SGPropertyNode * max_node = arg->getChild("max");

    bool wrap = arg->getBoolValue("wrap");

    if (min_node == 0 || max_node == 0)
        wrap = false;
  
    if (wrap) {                 // wrap such that min <= x < max
        double min_val = min_node->getDoubleValue();
        double max_val = max_node->getDoubleValue();
        double resolution = arg->getDoubleValue("resolution");
        if (resolution > 0.0) {
            // snap to (min + N*resolution), taking special care to handle imprecision
            int n = (int)floor((*value - min_val) / resolution + 0.5);
            int steps = (int)floor((max_val - min_val) / resolution + 0.5);
            SG_NORMALIZE_RANGE(n, 0, steps);
            *value = min_val + resolution * n;
        } else {
            // plain circular wrapping
            SG_NORMALIZE_RANGE(*value, min_val, max_val);
        }
    } else {                    // clamp such that min <= x <= max
        if ((min_node != 0) && (*value < min_node->getDoubleValue()))
            *value = min_node->getDoubleValue();
        else if ((max_node != 0) && (*value > max_node->getDoubleValue()))
            *value = max_node->getDoubleValue();
    }
}

static bool
compare_values (SGPropertyNode * value1, SGPropertyNode * value2)
{
    switch (value1->getType()) {
    case SGPropertyNode::BOOL:
        return (value1->getBoolValue() == value2->getBoolValue());
    case SGPropertyNode::INT:
        return (value1->getIntValue() == value2->getIntValue());
    case SGPropertyNode::LONG:
        return (value1->getLongValue() == value2->getLongValue());
    case SGPropertyNode::FLOAT:
        return (value1->getFloatValue() == value2->getFloatValue());
    case SGPropertyNode::DOUBLE:
        return (value1->getDoubleValue() == value2->getDoubleValue());
    default:
        return !strcmp(value1->getStringValue(), value2->getStringValue());
    }
}



////////////////////////////////////////////////////////////////////////
// Command implementations.
////////////////////////////////////////////////////////////////////////


/**
 * Built-in command: do nothing.
 */
static bool
do_null (const SGPropertyNode * arg)
{
  return true;
}

#if defined(HAVE_PLIB_PSL)
/**
 * Built-in command: run a PSL script.
 *
 * script: the PSL script to execute
 */
static bool
do_script (const SGPropertyNode * arg)
{
    FGScriptMgr * mgr = (FGScriptMgr *)globals->get_subsystem("scripting");
    return mgr->run(arg->getStringValue("script"));
}
#endif // HAVE_PLIB_PSL


/**
 * Built-in command: exit FlightGear.
 *
 * status: the exit status to return to the operating system (defaults to 0)
 */
static bool
do_exit (const SGPropertyNode * arg)
{
  SG_LOG(SG_INPUT, SG_INFO, "Program exit requested.");
  fgExit(arg->getIntValue("status", 0));
  return true;
}


/**
 * Built-in command: reinitialize one or more subsystems.
 *
 * subsystem[*]: the name(s) of the subsystem(s) to reinitialize; if
 * none is specified, reinitialize all of them.
 */
static bool
do_reinit (const SGPropertyNode * arg)
{
    bool result = true;

    vector<SGPropertyNode_ptr> subsystems = arg->getChildren("subsystem");
    if (subsystems.size() == 0) {
        globals->get_subsystem_mgr()->reinit();
    } else {
        for ( unsigned int i = 0; i < subsystems.size(); i++ ) {
            const char * name = subsystems[i]->getStringValue();
            FGSubsystem * subsystem = globals->get_subsystem(name);
            if (subsystem == 0) {
                result = false;
                SG_LOG( SG_GENERAL, SG_ALERT,
                        "Subsystem " << name << "not found" );
            } else {
                subsystem->reinit();
            }
        }
    }

    return result;
}

/**
 * Built-in command: suspend one or more subsystems.
 *
 * subsystem[*] - the name(s) of the subsystem(s) to suspend.
 */
static bool
do_suspend (const SGPropertyNode * arg)
{
    bool result = true;

    vector<SGPropertyNode_ptr> subsystems = arg->getChildren("subsystem");
    for ( unsigned int i = 0; i < subsystems.size(); i++ ) {
        const char * name = subsystems[i]->getStringValue();
        FGSubsystem * subsystem = globals->get_subsystem(name);
        if (subsystem == 0) {
            result = false;
            SG_LOG(SG_GENERAL, SG_ALERT, "Subsystem " << name << "not found");
        } else {
            subsystem->suspend();
        }
    }
    return result;
}

/**
 * Built-in command: suspend one or more subsystems.
 *
 * subsystem[*] - the name(s) of the subsystem(s) to suspend.
 */
static bool
do_resume (const SGPropertyNode * arg)
{
    bool result = true;

    vector<SGPropertyNode_ptr> subsystems = arg->getChildren("subsystem");
    for ( unsigned int i = 0; i < subsystems.size(); i++ ) {
        const char * name = subsystems[i]->getStringValue();
        FGSubsystem * subsystem = globals->get_subsystem(name);
        if (subsystem == 0) {
            result = false;
            SG_LOG(SG_GENERAL, SG_ALERT, "Subsystem " << name << "not found");
        } else {
            subsystem->resume();
        }
    }
    return result;
}


/**
 * Built-in command: load flight.
 *
 * file (optional): the name of the file to load (relative to current
 *   directory).  Defaults to "fgfs.sav"
 */
static bool
do_load (const SGPropertyNode * arg)
{
  const string &file = arg->getStringValue("file", "fgfs.sav");
  ifstream input(file.c_str());
  if (input.good() && fgLoadFlight(input)) {
    input.close();
    SG_LOG(SG_INPUT, SG_INFO, "Restored flight from " << file);
    return true;
  } else {
    SG_LOG(SG_INPUT, SG_ALERT, "Cannot load flight from " << file);
    return false;
  }
}


/**
 * Built-in command: save flight.
 *
 * file (optional): the name of the file to save (relative to the
 * current directory).  Defaults to "fgfs.sav".
 */
static bool
do_save (const SGPropertyNode * arg)
{
  const string &file = arg->getStringValue("file", "fgfs.sav");
  bool write_all = arg->getBoolValue("write-all", false);
  SG_LOG(SG_INPUT, SG_INFO, "Saving flight");
  ofstream output(file.c_str());
  if (output.good() && fgSaveFlight(output, write_all)) {
    output.close();
    SG_LOG(SG_INPUT, SG_INFO, "Saved flight to " << file);
    return true;
  } else {
    SG_LOG(SG_INPUT, SG_ALERT, "Cannot save flight to " << file);
    return false;
  }
}


/**
 * Built-in command: (re)load the panel.
 *
 * path (optional): the file name to load the panel from 
 * (relative to FG_ROOT).  Defaults to the value of /sim/panel/path,
 * and if that's unspecified, to "Panels/Default/default.xml".
 */
static bool
do_panel_load (const SGPropertyNode * arg)
{
  string panel_path =
    arg->getStringValue("path",
			fgGetString("/sim/panel/path",
				    "Panels/Default/default.xml"));
  FGPanel * new_panel = fgReadPanel(panel_path);
  if (new_panel == 0) {
    SG_LOG(SG_INPUT, SG_ALERT,
	   "Error reading new panel from " << panel_path);
    return false;
  }
  SG_LOG(SG_INPUT, SG_INFO, "Loaded new panel from " << panel_path);
  globals->get_current_panel()->unbind();
  delete globals->get_current_panel();
  globals->set_current_panel( new_panel );
  globals->get_current_panel()->bind();
  return true;
}


/**
 * Built-in command: pass a mouse click to the panel.
 *
 * button: the mouse button number, zero-based.
 * is-down: true if the button is down, false if it is up.
 * x-pos: the x position of the mouse click.
 * y-pos: the y position of the mouse click.
 */
static bool
do_panel_mouse_click (const SGPropertyNode * arg)
{
  if (globals->get_current_panel() != 0)
    return globals->get_current_panel()
      ->doMouseAction(arg->getIntValue("button"),
		      arg->getBoolValue("is-down") ? PU_DOWN : PU_UP,
		      arg->getIntValue("x-pos"),
		      arg->getIntValue("y-pos"));
  else
    return false;
}


/**
 * Built-in command: (re)load preferences.
 *
 * path (optional): the file name to load the panel from (relative
 * to FG_ROOT). Defaults to "preferences.xml".
 */
static bool
do_preferences_load (const SGPropertyNode * arg)
{
  try {
    fgLoadProps(arg->getStringValue("path", "preferences.xml"),
                globals->get_props());
  } catch (const sg_exception &e) {
    guiErrorMessage("Error reading global preferences: ", e);
    return false;
  }
  SG_LOG(SG_INPUT, SG_INFO, "Successfully read global preferences.");
  return true;
}


static void
fix_hud_visibility()
{
  if ( !strcmp(fgGetString("/sim/flight-model"), "ada") ) {
      globals->get_props()->setBoolValue( "/sim/hud/visibility", true );
      if ( globals->get_viewmgr()->get_current() == 1 ) {
          globals->get_props()->setBoolValue( "/sim/hud/visibility", false );
      }
  }
}

static void
do_view_next( bool )
{
    globals->get_current_view()->setHeadingOffset_deg(0.0);
    globals->get_viewmgr()->next_view();
    fix_hud_visibility();
    globals->get_tile_mgr()->refresh_view_timestamps();
}

static void
do_view_prev( bool )
{
    globals->get_current_view()->setHeadingOffset_deg(0.0);
    globals->get_viewmgr()->prev_view();
    fix_hud_visibility();
    globals->get_tile_mgr()->refresh_view_timestamps();
}

/**
 * Built-in command: cycle view.
 */
static bool
do_view_cycle (const SGPropertyNode * arg)
{
  globals->get_current_view()->setHeadingOffset_deg(0.0);
  globals->get_viewmgr()->next_view();
  fix_hud_visibility();
  globals->get_tile_mgr()->refresh_view_timestamps();
//   fgReshape(fgGetInt("/sim/startup/xsize"), fgGetInt("/sim/startup/ysize"));
  return true;
}

/**
 * Built-in command: capture screen.
 */
static bool
do_screen_capture (const SGPropertyNode * arg)
{
  fgDumpSnapShot();
  return true;
}


/**
 * Reload the tile cache.
 */
static bool
do_tile_cache_reload (const SGPropertyNode * arg)
{
    static const SGPropertyNode *master_freeze
	= fgGetNode("/sim/freeze/master");
    bool freeze = master_freeze->getBoolValue();
    SG_LOG(SG_INPUT, SG_INFO, "ReIniting TileCache");
    if ( !freeze ) {
	fgSetBool("/sim/freeze/master", true);
    }
    // BusyCursor(0);
    if ( globals->get_tile_mgr()->init() ) {
	// Load the local scenery data
        double visibility_meters = fgGetDouble("/environment/visibility-m");
	globals->get_tile_mgr()->update( visibility_meters );
    } else {
	SG_LOG( SG_GENERAL, SG_ALERT, 
		"Error in Tile Manager initialization!" );
	exit(-1);
    }
    // BusyCursor(1);
    if ( !freeze ) {
	fgSetBool("/sim/freeze/master", false);
    }
    return true;
}


/**
 * Update the lighting manually.
 */
static bool
do_lighting_update (const SGPropertyNode * arg)
{
  fgUpdateSkyAndLightingParams();
  return true;
}


/**
 * Update the lighting manually.
 */
static bool
do_timeofday (const SGPropertyNode * arg)
{
    const string &offset_type = arg->getStringValue("timeofday", "noon");

    static const SGPropertyNode *longitude
        = fgGetNode("/position/longitude-deg");
    static const SGPropertyNode *latitude
        = fgGetNode("/position/latitude-deg");
    static const SGPropertyNode *cur_time_override
        = fgGetNode("/sim/time/cur-time-override", true);

    SGTime *t = globals->get_time_params();
    int orig_warp = globals->get_warp();
    time_t cur_time = t->get_cur_time();
    cout << "cur_time = " << cur_time << endl;
    cout << "orig_warp = " << orig_warp << endl;

    int warp = 0;
    if ( offset_type == "noon" ) {
        warp = fgTimeSecondsUntilNoon( cur_time,
                                       longitude->getDoubleValue()
                                         * SGD_DEGREES_TO_RADIANS,
                                       latitude->getDoubleValue()
                                         * SGD_DEGREES_TO_RADIANS ); 
    } else if ( offset_type == "midnight" ) {
        warp = fgTimeSecondsUntilMidnight( cur_time,
                                           longitude->getDoubleValue()
                                             * SGD_DEGREES_TO_RADIANS,
                                           latitude->getDoubleValue()
                                             * SGD_DEGREES_TO_RADIANS ); 
    } else if ( offset_type == "dawn" ) {
        warp = fgTimeSecondsUntilDawn( cur_time,
                                       longitude->getDoubleValue()
                                         * SGD_DEGREES_TO_RADIANS,
                                       latitude->getDoubleValue()
                                         * SGD_DEGREES_TO_RADIANS ); 
     } else if ( offset_type == "dusk" ) {
        warp = fgTimeSecondsUntilDusk( cur_time,
                                       longitude->getDoubleValue()
                                         * SGD_DEGREES_TO_RADIANS,
                                       latitude->getDoubleValue()
                                         * SGD_DEGREES_TO_RADIANS ); 
    }
    cout << "warp = " << warp << endl;
    globals->set_warp( orig_warp + warp );

    t->update( longitude->getDoubleValue() * SGD_DEGREES_TO_RADIANS,
               latitude->getDoubleValue() * SGD_DEGREES_TO_RADIANS,
               cur_time_override->getLongValue(),
               globals->get_warp() );

    fgUpdateSkyAndLightingParams();

    return true;
}


/**
 * Built-in command: toggle a bool property value.
 *
 * property: The name of the property to toggle.
 */
static bool
do_property_toggle (const SGPropertyNode * arg)
{
  SGPropertyNode * prop = get_prop(arg);
  return prop->setBoolValue(!prop->getBoolValue());
}


/**
 * Built-in command: assign a value to a property.
 *
 * property: the name of the property to assign.
 * value: the value to assign; or
 * property[1]: the property to copy from.
 */
static bool
do_property_assign (const SGPropertyNode * arg)
{
  SGPropertyNode * prop = get_prop(arg);
  const SGPropertyNode * prop2 = get_prop2(arg);
  const SGPropertyNode * value = arg->getNode("value");

  if (value != 0)
      return prop->setUnspecifiedValue(value->getStringValue());
  else if (prop2)
      return prop->setUnspecifiedValue(prop2->getStringValue());
  else
      return false;
}


/**
 * Built-in command: increment or decrement a property value.
 *
 * If the 'step' argument is present, it will be used; otherwise,
 * the command uses 'offset' and 'factor', usually from the mouse.
 *
 * property: the name of the property to increment or decrement.
 * step: the amount of the increment or decrement (default: 0).
 * offset: offset from the current setting (used for the mouse; multiplied 
 *         by factor)
 * factor: scaling amount for the offset (defaults to 1).
 * min: the minimum allowed value (default: no minimum).
 * max: the maximum allowed value (default: no maximum).
 * mask: 'integer' to apply only to the left of the decimal point, 
 *       'decimal' to apply only to the right of the decimal point,
 *       or 'all' to apply to the whole number (the default).
 * wrap: true if the value should be wrapped when it passes min or max;
 *       both min and max must be present for this to work (default:
 *       false).
 */
static bool
do_property_adjust (const SGPropertyNode * arg)
{
  SGPropertyNode * prop = get_prop(arg);

  double amount = 0;
  if (arg->hasValue("step"))
      amount = arg->getDoubleValue("step");
  else
      amount = (arg->getDoubleValue("factor", 1)
                * arg->getDoubleValue("offset"));
          
  double unmodifiable, modifiable;
  split_value(prop->getDoubleValue(), arg->getStringValue("mask", "all"),
              &unmodifiable, &modifiable);
  modifiable += amount;
  limit_value(&modifiable, arg);

  prop->setDoubleValue(unmodifiable + modifiable);

  return true;
}


/**
 * Built-in command: multiply a property value.
 *
 * property: the name of the property to multiply.
 * factor: the amount by which to multiply.
 * min: the minimum allowed value (default: no minimum).
 * max: the maximum allowed value (default: no maximum).
 * mask: 'integer' to apply only to the left of the decimal point, 
 *       'decimal' to apply only to the right of the decimal point,
 *       or 'all' to apply to the whole number (the default).
 * wrap: true if the value should be wrapped when it passes min or max;
 *       both min and max must be present for this to work (default:
 *       false).
 */
static bool
do_property_multiply (const SGPropertyNode * arg)
{
  SGPropertyNode * prop = get_prop(arg);
  double factor = arg->getDoubleValue("factor", 1);

  double unmodifiable, modifiable;
  split_value(prop->getDoubleValue(), arg->getStringValue("mask", "all"),
              &unmodifiable, &modifiable);
  modifiable *= factor;
  limit_value(&modifiable, arg);

  prop->setDoubleValue(unmodifiable + modifiable);

  return true;
}


/**
 * Built-in command: swap two property values.
 *
 * property[0]: the name of the first property.
 * property[1]: the name of the second property.
 */
static bool
do_property_swap (const SGPropertyNode * arg)
{
  SGPropertyNode * prop1 = get_prop(arg);
  SGPropertyNode * prop2 = get_prop2(arg);

				// FIXME: inefficient
  const string & tmp = prop1->getStringValue();
  return (prop1->setUnspecifiedValue(prop2->getStringValue()) &&
	  prop2->setUnspecifiedValue(tmp.c_str()));
}


/**
 * Built-in command: Set a property to an axis or other moving input.
 *
 * property: the name of the property to set.
 * setting: the current input setting, usually between -1.0 and 1.0.
 * offset: the offset to shift by, before applying the factor.
 * factor: the factor to multiply by (use negative to reverse).
 */
static bool
do_property_scale (const SGPropertyNode * arg)
{
  SGPropertyNode * prop = get_prop(arg);
  double setting = arg->getDoubleValue("setting");
  double offset = arg->getDoubleValue("offset", 0.0);
  double factor = arg->getDoubleValue("factor", 1.0);
  bool squared = arg->getBoolValue("squared", false);
  int power = arg->getIntValue("power", (squared ? 2 : 1));

  int sign = (setting < 0 ? -1 : 1);

  switch (power) {
  case 1:
      break;
  case 2:
      setting = setting * setting * sign;
      break;
  case 3:
      setting = setting * setting * setting;
      break;
  case 4:
      setting = setting * setting * setting * setting * sign;
      break;
  default:
      setting =  pow(setting, power);
      if ((power % 2) == 0)
          setting *= sign;
      break;
  }

  return prop->setDoubleValue((setting + offset) * factor);
}


/**
 * Built-in command: cycle a property through a set of values.
 *
 * If the current value isn't in the list, the cycle will
 * (re)start from the beginning.
 *
 * property: the name of the property to cycle.
 * value[*]: the list of values to cycle through.
 */
static bool
do_property_cycle (const SGPropertyNode * arg)
{
    SGPropertyNode * prop = get_prop(arg);
    vector<SGPropertyNode_ptr> values = arg->getChildren("value");
    int selection = -1;
    int nSelections = values.size();

    if (nSelections < 1) {
        SG_LOG(SG_GENERAL, SG_ALERT, "No values for property-cycle");
        return false;
    }

                                // Try to find the current selection
    for (int i = 0; i < nSelections; i++) {
        if (compare_values(prop, values[i])) {
            selection = i + 1;
            break;
        }
    }

                                // Default or wrap to the first selection
    if (selection < 0 || selection >= nSelections)
        selection = 0;

    prop->setUnspecifiedValue(values[selection]->getStringValue());
    return true;
}


/**
 * Built-in command: randomize a numeric property value.
 *
 * property: the name of the property value to randomize.
 * min: the minimum allowed value.
 * max: the maximum allowed value.
 */
static bool
do_property_randomize (const SGPropertyNode * arg)
{
    SGPropertyNode * prop = get_prop(arg);
    double min = arg->getDoubleValue("min", DBL_MIN);
    double max = arg->getDoubleValue("max", DBL_MAX);
    prop->setDoubleValue(sg_random() * (max - min) + min);
    return true;
}


/**
 * Built-in command: Show an XML-configured dialog.
 *
 * dialog-name: the name of the GUI dialog to display.
 */
static bool
do_dialog_show (const SGPropertyNode * arg)
{
    NewGUI * gui = (NewGUI *)globals->get_subsystem("gui");
    gui->showDialog(arg->getStringValue("dialog-name"));
    return true;
}


/**
 * Built-in Command: Hide the active XML-configured dialog.
 */
static bool
do_dialog_close (const SGPropertyNode * arg)
{
    NewGUI * gui = (NewGUI *)globals->get_subsystem("gui");
    return gui->closeActiveDialog();
}


/**
 * Update a value in the active XML-configured dialog.
 *
 * object-name: The name of the GUI object(s) (all GUI objects if omitted).
 */
static bool
do_dialog_update (const SGPropertyNode * arg)
{
    NewGUI * gui = (NewGUI *)globals->get_subsystem("gui");
    FGDialog * dialog = gui->getActiveDialog();
    if (dialog != 0) {
        if (arg->hasValue("object-name")) {
            dialog->updateValue(arg->getStringValue("object-name"));
        } else {
            dialog->updateValues();
        }
        return true;
    } else {
        return false;
    }
}


/**
 * Apply a value in the active XML-configured dialog.
 *
 * object-name: The name of the GUI object(s) (all GUI objects if omitted).
 */
static bool
do_dialog_apply (const SGPropertyNode * arg)
{
    NewGUI * gui = (NewGUI *)globals->get_subsystem("gui");
    FGDialog * dialog = gui->getActiveDialog();
    if (dialog != 0) {
        if (arg->hasValue("object-name")) {
            const char * name = arg->getStringValue("object-name");
            dialog->applyValue(name);
            dialog->updateValue(name);
        } else {
            dialog->applyValues();
            dialog->updateValues();
        }
        return true;
    } else {
        return false;
    }
}


/**
 * Built-in command: commit presets (read from in /sim/presets/)
 */
static bool
do_presets_commit (const SGPropertyNode * arg)
{
    // unbind the current fdm state so property changes
    // don't get lost when we subsequently delete this fdm
    // and create a new one.
    cur_fdm_state->unbind();
        
    // set position from presets
    fgInitPosition();

    // BusyCursor(0);
    fgReInitSubsystems();

    globals->get_tile_mgr()->update( fgGetDouble("/environment/visibility-m") );

#if 0
    if ( ! fgGetBool("/sim/presets/onground") ) {
        fgSetBool( "/sim/freeze/master", true );
        fgSetBool( "/sim/freeze/clock", true );
    }
#endif

    return true;
}

/**
 * Built-in command: set log level (0 ... 7)
 */
static bool
do_log_level (const SGPropertyNode * arg)
{
   sglog().setLogLevels( SG_ALL, (sgDebugPriority)arg->getIntValue() );

   return true;
}

/**
 * Built-in command: replay the FDR buffer
 */
static bool
do_replay (const SGPropertyNode * arg)
{
    // freeze the master fdm
    fgSetBool( "/sim/freeze/replay", true );

    FGReplay *r = (FGReplay *)(globals->get_subsystem( "replay" ));

    fgSetDouble( "/sim/replay/start-time", r->get_start_time() );
    fgSetDouble( "/sim/replay/end-time", r->get_end_time() );
    double duration = fgGetDouble( "/sim/replay/duration" );
    if( duration && duration < (r->get_end_time() - r->get_start_time()) ) {
        fgSetDouble( "/sim/replay/time", r->get_end_time() - duration );
    } else {
        fgSetDouble( "/sim/replay/time", r->get_start_time() );
    }

    cout << "start = " << r->get_start_time()
         << "  end = " << r->get_end_time() << endl;

    return true;
}



static bool
do_decrease_visibility (const SGPropertyNode * arg)
{
    double new_value = fgGetDouble("/environment/visibility-m") * 0.9;
    fgSetDouble("/environment/visibility-m", new_value);
    fgDefaultWeatherValue("visibility-m", new_value);
    globals->get_subsystem("environment")->reinit();

    return true;
}
 
static bool
do_increase_visibility (const SGPropertyNode * arg)
{
    double new_value = fgGetDouble("/environment/visibility-m") * 1.1;
    fgSetDouble("/environment/visibility-m", new_value);
    fgDefaultWeatherValue("visibility-m", new_value);
    globals->get_subsystem("environment")->reinit();

    return true;
}


////////////////////////////////////////////////////////////////////////
// Command setup.
////////////////////////////////////////////////////////////////////////


/**
 * Table of built-in commands.
 *
 * New commands do not have to be added here; any module in the application
 * can add a new command using globals->get_commands()->addCommand(...).
 */
static struct {
  const char * name;
  SGCommandMgr::command_t command;
} built_ins [] = {
    { "null", do_null },
#if defined(HAVE_PLIB_PSL)
    { "script", do_script },
#endif // HAVE_PLIB_PSL
    { "exit", do_exit },
    { "reinit", do_reinit },
    { "suspend", do_reinit },
    { "resume", do_reinit },
    { "load", do_load },
    { "save", do_save },
    { "panel-load", do_panel_load },
    { "panel-mouse-click", do_panel_mouse_click },
    { "preferences-load", do_preferences_load },
    { "view-cycle", do_view_cycle },
    { "screen-capture", do_screen_capture },
    { "tile-cache-reload", do_tile_cache_reload },
    { "lighting-update", do_lighting_update },
    { "timeofday", do_timeofday },
    { "property-toggle", do_property_toggle },
    { "property-assign", do_property_assign },
    { "property-adjust", do_property_adjust },
    { "property-multiply", do_property_multiply },
    { "property-swap", do_property_swap },
    { "property-scale", do_property_scale },
    { "property-cycle", do_property_cycle },
    { "property-randomize", do_property_randomize },
    { "dialog-show", do_dialog_show },
    { "dialog-close", do_dialog_close },
    { "dialog-show", do_dialog_show },
    { "dialog-update", do_dialog_update },
    { "dialog-apply", do_dialog_apply },
    { "presets-commit", do_presets_commit },
    { "log-level", do_log_level },
    { "replay", do_replay },
    { "decrease-visibility", do_decrease_visibility },
    { "increase-visibility", do_increase_visibility },
    { 0, 0 }			// zero-terminated
};


/**
 * Initialize the default built-in commands.
 *
 * Other commands may be added by other parts of the application.
 */
void
fgInitCommands ()
{
  SG_LOG(SG_GENERAL, SG_INFO, "Initializing basic built-in commands:");
  for (int i = 0; built_ins[i].name != 0; i++) {
    SG_LOG(SG_GENERAL, SG_INFO, "  " << built_ins[i].name);
    globals->get_commands()->addCommand(built_ins[i].name,
					built_ins[i].command);
  }

  typedef bool (*dummy)();
  fgTie( "/command/view/next", dummy(0), do_view_next );
  fgTie( "/command/view/prev", dummy(0), do_view_prev );
}

// end of fg_commands.cxx