/*
   Copyright (C) 2007 Dirk Huenniger
   
   This library is free software; syou 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 2.1 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
   */
  package org.indi.examples;
  
  import java.io.IOException;
  import java.util.Date;
  
  import org.indi.clientmessages.GetProperties;
  import org.indi.objects.Number;
  import org.indi.objects.NumberVector;
  import org.indi.objects.Permission;
  import org.indi.objects.State;
  import org.indi.objects.Switch;
  import org.indi.objects.SwitchRule;
  import org.indi.objects.SwitchVector;
  import org.indi.reactor.TimerCallback;
  import org.indi.server.BasicDevice;
  import org.indi.server.IndiServer;
  
  /**
   * A simple telescope simulator. The telescope can be connected as well as
   * dsiconnected. It can be asked to move to a specified position and keeps
   * tracking when it reaches its target
   * 
   * @author Dirk Hünniger
   * 
   */
  public class SimpleTelescopeSimulator extends BasicDevice implements
  	TimerCallback {
      /**
       * the switchvector hosting the switch to connect/disconnect the device
       */
      private final SwitchVector powerswitch;
      /**
       * the name of the switchvector hosting the switch to connect/disconnect the
       * device
       */
      private final String powervectorname = "CONNECTION";
      /**
       * the name of the device
       */
      private final String name = "Simple Telescope Simulator";
      /**
       * the name of the only group in the device
       */
      private final String groupname = "Main Control";
      /**
       * the name of the vector hosting the position the telescope is pointing to
       */
      private final String coordvectorname = "EQUATORIAL_EOD_COORD";
      /**
       * the name of the indiobjects.Number to host the declination
       */
      private final String decname = "DEC";
      /**
       * the name of the indiobjects.Number to host the right ascension
       */
      private final String raname = "RA";
      /**
       * the Switch to connect/ disconnect the device
       */
      private Switch connectswitch = null;
      /**
       * the Number vector to keep the coordinates of the telescope
       */
      private NumberVector coordinates = null;
      /**
       * the time between the calls of the onTimer method in milliseconds
       */
      private final long timeout = 250;
      /**
       * the siderial movement of the stars in degrees per second
       */
      private final double sidrate = 0.004178;
      /**
       * the slew rate a which the motor can move the telescope in degrees per
       * second
       */
      private final double slewrate = 1.0;
      /**
       * the last time when on timer was called in milliseconds since epoch
       */
      private Double lastTime = null;
      /**
      * the indiobjects.Number representing the right ascentsion the telescope is
      * poiting to
      */
     private Number ra = null;
     /**
      * the indiobjects.Number representing the declination the telescope is
      * pointing to
      */
     private Number dec = null;
     /**
      * the right ascension to point to as requested by the user
      */
     private double targetRA;
     /**
      * the declination to point to as requested by the user
      */
     private double targetDEC;
 
     /**
      * class constructor
      * 
      * @param server
      *                the server to host this device
      */
     public SimpleTelescopeSimulator(IndiServer server) {
 	super(server);
 	this.powerswitch = new SwitchVector(this.name, this.powervectorname,
 		"Connection", this.groupname, State.Idle, Permission.ReadWrite,
 		SwitchRule.OneOfMany, 0);
 	this.connectswitch = new Switch("CONNECT", "Connect", Switch.State.Off);
 	this.powerswitch.add(this.connectswitch);
 	this.powerswitch.add(new Switch("DISCONNECT", "Disconnect",
 		Switch.State.On));
 	this.coordinates = new NumberVector(this.name, this.coordvectorname,
 		"Equatorial JNow", this.groupname, State.Idle,
 		Permission.ReadWrite, 0);
 	this.ra = new Number(this.raname, /* 1st Number name */
 	"RA  H:M:S", /* Number label */
 	"%f", /* Format. Refer to the Indi WhitePaper for number formats */
 	0., /* Minimum value */
 	24., /* Maximum value */
 	0., /* Steps */
 	0. /* Initial value */);
 	this.coordinates.add(this.ra);
 	this.dec = new Number(this.decname, "Dec D:M:S", "%f", -90., 90., 0.,
 		0.);
 	this.coordinates.add(this.dec);
 	def(this.powerswitch);
 	def(this.coordinates);
 	timer(this.timeout);
     }
 
     @Override
     public void onNew(SwitchVector vector) {
 	if (!((this.powervectorname.equals(vector.getName())) && (this.name
 		.equals(vector.getDevice())))) {
 	    return;
 	}
 	this.powerswitch.update(vector);
 	switch (this.connectswitch.getState()) {
 	case On:
 	    this.powerswitch.setState(State.Ok);
 	    set(this.powerswitch, "Connection to Simple Telescope Simulator"
 		    + " is successful.");
 	    break;
 	case Off:
 	    this.powerswitch.setState(State.Idle);
 	    set(this.powerswitch,
 		    "Simple Telescope Simulator has been disconneced.");
 	    this.coordinates.setState(State.Idle);
 	    set(this.coordinates);
 	    break;
 	}
     }
 
     @Override
     public void onNew(NumberVector vector) {
 	if (!((this.coordvectorname.equals(vector.getName())) && (this.name
 		.equals(vector.getDevice())))) {
 	    return;
 	}
 	if (this.connectswitch.getState() == Switch.State.Off) {
 	    msg("Position discaded because Telescope is disconnected");
 	    return;
 	}
 	if (this.powerswitch.getState() == State.Idle) {
 	    this.coordinates.setState(State.Idle);
 	    set(this.coordinates, "Telescope is offline");
 	}
 	double newra = 0, newdec = 0;
 	int nset = 0;
 	for (Number n : vector.getChlidren()) {
 	    String name = n.getName();
 	    if (name.equals(this.raname)) {
 		newra = n.getDouble();
 		nset += ((newra >= 0.) && (newra <= 24.)) ? 1 : 0;
 	    }
 	    if (name.equals(this.decname)) {
 		newdec = n.getDouble();
 		nset += ((newdec >= -90.) && (newdec <= 90.)) ? 1 : 0;
 	    }
 	    if (nset == 2) {
 		this.targetRA = newra;
 		this.targetDEC = newdec;
 		this.coordinates.setState(State.Busy);
 		set(this.coordinates, "Moving to RA Dec"
 			+ Double.toString(newra) + " "
 			+ Double.toString(newdec));
 	    } else {
 		this.coordinates.setState(State.Idle);
 		set(this.coordinates, "RA or Dec absent or bogus");
 	    }
 	}
     }
 
     @Override
     public void onGetProperties(GetProperties o) {
 	def(this.powerswitch);
 	def(this.coordinates);
     }
 
     /**
      * Create an Indiserver hosting a SimpleTelescope simultor an wait for
      * events.
      * 
      * @param args
      *                command line arguments (ignored)
      * @throws IOException
      */
     public static void main(String[] args) throws IOException {
 	IndiServer s = new IndiServer();
 	new SimpleTelescopeSimulator(s);
 	while (true) {
 	    s.reactor.handleEvents(10);
 	}
     }
 
     @Override
     public void onTimer() {
 	double time = new Date().getTime();
 	if (this.lastTime == null) {
 	    this.lastTime = time;
 	}
 	double dt = (time - this.lastTime) / 1000.0;
 	this.lastTime = time;
 	switch (this.coordinates.getState()) {
 	case Idle:
 	    this.ra.addDouble((this.sidrate * dt / 15.));
 	    set(this.coordinates);
 	    break;
 	case Busy:
 	    double da = this.slewrate * dt;
 	    int nlocked = 0;
 	    double dx = this.targetRA - this.ra.getDouble();
 	    if (Math.abs(dx) <= da / 15.) {
 		this.ra.setDouble(this.targetRA);
 		nlocked++;
 	    } else if (dx > 0) {
 		this.ra.addDouble(da / 15.);
 	    } else {
 		this.ra.subtractDouble(da / 15.);
 	    }
 
 	    dx = this.targetDEC - this.dec.getDouble();
 	    if (Math.abs(dx) <= da) {
 		this.dec.setDouble(this.targetDEC);
 		nlocked++;
 	    } else if (dx > 0) {
 		this.dec.addDouble(da);
 	    } else {
 		this.dec.subtractDouble(da);
 	    }
 	    if (nlocked == 2) {
 		this.coordinates.setState(State.Ok);
 		msg("Now tracking");
 	    }
 	    set(this.coordinates);
 	    break;
 	case Ok:
 	    set(this.coordinates);
 	    break;
 	case Alert:
 	    set(this.coordinates);
 	    break;
 	}
 	timer(this.timeout);
     }
 }