/*
 * Copyright (c) 2005-2010 KOM – Multimedia Communications Lab
 *
 * This file is part of PeerfactSim.KOM.
 * 
 * PeerfactSim.KOM 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
 * any later version.
 * 
 * PeerfactSim.KOM 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 PeerfactSim.KOM.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

package de.tud.kom.p2psim.impl.topology.movement.modularosm.transition;

import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

import de.tud.kom.p2psim.api.scenario.ConfigurationException;
import de.tud.kom.p2psim.api.topology.Topology;
import de.tud.kom.p2psim.api.topology.movement.SimLocationActuator;
import de.tud.kom.p2psim.impl.topology.movement.modularosm.attraction.BasicAttractionPoint;
import de.tud.kom.p2psim.impl.topology.util.PositionVector;
import de.tudarmstadt.maki.simonstrator.api.Binder;
import de.tudarmstadt.maki.simonstrator.api.Event;
import de.tudarmstadt.maki.simonstrator.api.EventHandler;
import de.tudarmstadt.maki.simonstrator.api.Monitor;
import de.tudarmstadt.maki.simonstrator.api.component.sensor.location.AttractionPoint;

public class InAreaRoamingTransitionStrategy extends AbstractAttractionBasedTransitionStrategy implements EventHandler {

	public static enum roamingTransitionState {
		ROAMING,
		TRANSITION
	}
	
	private final static int EVENT_ROAMING_ENDED = 1;
	
	protected Map<SimLocationActuator, roamingTransitionState> roamingStates = new LinkedHashMap<>();

	private long pauseTimeMin = 0;
	
	private long pauseTimeMax = 0;
	
	@Override
	public void addComponent(SimLocationActuator comp) {
		this.roamingStates.put(comp, roamingTransitionState.TRANSITION);
		AttractionPoint nextAP = getNewAttractionPoint(comp);
		updateTargetAttractionPoint(comp, nextAP);
	}

	@Override
	public void reachedAttractionPoint(SimLocationActuator comp) {
		
		// start roaming 
		if(roamingStates.get(comp) == roamingTransitionState.TRANSITION) {			
			// schedule the end of the roaming phase, which will make a new transition
			Event.scheduleWithDelay(getPauseTime(), this, comp, EVENT_ROAMING_ENDED);
			
			this.roamingStates.put(comp, roamingTransitionState.ROAMING);
		}
		
		// roam around the attraction point
		roamAroundAttractionPoint(comp);						
	}	

	
	private void roamAroundAttractionPoint(SimLocationActuator comp) {
		if(roamingStates.get(comp) == roamingTransitionState.ROAMING) {
			AttractionPoint currentAttractionPoint = this.assignments.get(comp);
			
			if(currentAttractionPoint == null) {
				System.err.println("AP roaming failed: no AP");
			}
			
			if(currentAttractionPoint.getRadius() > 0) 
			{
				notifyListenersOfAssignmentUpdate(comp, currentAttractionPoint);
			}
		}		
	}
	
	@Override
	public void eventOccurred(Object content, int type) {
		assert type == EVENT_ROAMING_ENDED;
		SimLocationActuator comp = (SimLocationActuator) content;
		
		this.addComponent(comp);
	}	
	
	private long getPauseTime() {
		return (long) (rnd.nextDouble() * (pauseTimeMax-pauseTimeMin)) + pauseTimeMin;
	}
		
	public void setMinPauseTime(long minPauseTime) {
		if (minPauseTime < 0) {
			throw new ConfigurationException(
					"MinPauseTime should be >= 0!");
		}
		this.pauseTimeMin = minPauseTime;
	}

	public void setMaxPauseTime(long maxPauseTime) {
		if (maxPauseTime < 0) {
			throw new ConfigurationException(
					"MaxPauseTime should be >= 0!");
		}
		this.pauseTimeMax = maxPauseTime;
	}
	
	private AttractionPoint getNewAttractionPoint(SimLocationActuator component) {
		double score = rnd.nextDouble();
		List<AttractionPoint> candidates = new LinkedList<>();
		for (AttractionPoint ap : attractionPoints) {
			if (ap.getWeight() >= score) {
				if(lastAssignments.get(component) == null || !ap.equals(lastAssignments.get(component))) {
					candidates.add(ap);
				}				
			}
		}
		if (candidates.isEmpty()) {
			candidates.addAll(attractionPoints);
		}
		AttractionPoint assignment = candidates.get(rnd.nextInt(candidates.size()));		
		return assignment;
	}
	

    private AttractionPoint getNewRoamingPosition(AttractionPoint roamingAP)
    {
    	double apRadius = roamingAP.getRadius();
    	
        double x = roamingAP.getLongitudeOrX();
        double y = roamingAP.getLatitudeOrY();

        double newX = -1;
        double newY = -1;
        
        PositionVector destination = null;
        int tries = 0;               
        do
        {
            double calcRadius = rnd.nextDouble() * apRadius;
            double calcAngle = rnd.nextDouble() * 360;

            newX = x + Math.sin(calcAngle) * calcRadius;
            newY = y + Math.cos(calcAngle) * calcRadius;
           
            destination = new PositionVector(newX, newY);
            
        	// Check constraints
 			if (destination.getX() < 0.0
 				|| destination.getX() > Binder.getComponentOrNull(Topology.class).getWorldDimensions().getX() 
 				|| destination.getY() < 0.0
 				|| destination.getY() > Binder.getComponentOrNull(Topology.class).getWorldDimensions().getY()) 
 			{
 				destination = null;
 				if (tries > 100) {
 					throw new AssertionError("Unable to find a valid target destination within <100 tries.");
 				}
 			}
 			tries++;
        } while (destination == null);

        Monitor.log(this.getClass(), Monitor.Level.DEBUG, "Next roaming position is " + newX + " / " + newY);

        return new BasicAttractionPoint("ROAMING", destination);

    }
}