/*
 * 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.groups.groupforming;

import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Random;
import java.util.Set;

import de.tud.kom.p2psim.api.scenario.ConfigurationException;
import de.tud.kom.p2psim.api.topology.movement.SimLocationActuator;
import de.tud.kom.p2psim.impl.topology.movement.modularosm.SocialGroupMovementModel;
import de.tud.kom.p2psim.impl.topology.movement.modularosm.attraction.BasicAttractionPoint;
import de.tud.kom.p2psim.impl.topology.movement.modularosm.attraction.IAttractionGenerator;
import de.tud.kom.p2psim.impl.topology.movement.modularosm.attraction.hostcount.IAttractionPointHostCounter;
import de.tud.kom.p2psim.impl.topology.movement.modularosm.groups.SocialMovementGroup;
import de.tud.kom.p2psim.impl.topology.movement.modularosm.groups.MovementGroupContainer;
import de.tud.kom.p2psim.impl.topology.util.PositionVector;
import de.tud.kom.p2psim.impl.util.Tuple;
import de.tudarmstadt.maki.simonstrator.api.Event;
import de.tudarmstadt.maki.simonstrator.api.EventHandler;
import de.tudarmstadt.maki.simonstrator.api.Randoms;
import de.tudarmstadt.maki.simonstrator.api.Time;
import de.tudarmstadt.maki.simonstrator.api.common.graph.INodeID;
import de.tudarmstadt.maki.simonstrator.api.component.sensor.location.AttractionPoint;
import de.tudarmstadt.maki.simonstrator.api.util.XMLConfigurableConstructor;

/**
 * Abstract class implementation for implementing GroupFormingStrategies.
 * 
 * @author Marcel Verst, Julian Zobel
 * @version 1.1, 30.01.2020
 */
public abstract class AbstractGroupForming implements IGroupFormingBehavior {
	protected Random rand = Randoms.getRandom(AbstractGroupForming.class);	
	
	protected SocialGroupMovementModel movementModel;	
	protected MovementGroupContainer groupCon;	
	
	// Holds time information of nodes for the groups (stay duration, last update)
	protected Map<INodeID, Tuple<Long,Long>> stayDuration;
	
	// GROUP VARIABLES FROM CONFIGS
	protected boolean enableGroups;
	protected int minGroupSize;
	protected int maxGroupSize;
	protected double probabilityToJoin;
	protected int maxNumberOfGroups;	
	
	protected long groupRejoinWaitTime;
	protected long groupFormationSetupDelay;
	private long groupFormationDelay;

	protected IAttractionPointHostCounter hostCounter;

	@XMLConfigurableConstructor({"enableGroups", "maxNumberOfGroups", "minGroupSize", "maxGroupSize", "probabilityToJoin", "groupFormationSetupDelay", "groupFormationDelay","groupRejoinWaitTime"})
	public AbstractGroupForming(boolean enableGroups, int maxNumberOfGroups, int minGroupSize, int maxGroupSize, double probabilityToJoin, long groupFormationSetupDelay, long groupFormationDelay, long groupRejoinWaitTime) {
		
		this.enableGroups = enableGroups;
		
		if(enableGroups) {
			if (probabilityToJoin < 0 || probabilityToJoin > 1.0) {
				throw new ConfigurationException(
						"GroupForming: probabilityToJoin must be between 0.0 and 1.0!");
			}
			
			if (maxNumberOfGroups <= 0) {
				throw new ConfigurationException(
						"GroupForming: maxNumberOfGroups must be >= 1!");
			}
			
			if (minGroupSize < 0) {
				throw new ConfigurationException(
						"GroupForming: minGroupSize must be >= 1!");
			}
			
			if (maxGroupSize < minGroupSize) {
				throw new ConfigurationException(
						"GroupForming: maxGroupSize cannot be bigger than minGroupSize!");
			}
			
			if (groupFormationSetupDelay <= 0) {
				throw new ConfigurationException(
						"GroupForming: groupFormationSetupDelay must be > 0!");
			}
			
			if (groupFormationDelay < 0) {
				throw new ConfigurationException(
						"GroupForming: groupFormationDelay must be >= 1!");
			}
			
			if (groupRejoinWaitTime < 0) {
				throw new ConfigurationException(
						"GroupForming: groupRejoinWaitTime must be >= 1!");
			}
		}
		
		this.maxNumberOfGroups = maxNumberOfGroups;
		this.minGroupSize = minGroupSize;
		this.maxGroupSize = maxGroupSize;
		this.probabilityToJoin = probabilityToJoin;		
		this.groupFormationSetupDelay = groupFormationSetupDelay;
		this.groupFormationDelay = groupFormationDelay;
		this.groupRejoinWaitTime = groupRejoinWaitTime;
	}
	
	@Override
	public void initialize(SocialGroupMovementModel movementModel) {
		this.movementModel = movementModel;
		
		groupCon = MovementGroupContainer.getInstance();		

		// Initialize instances of other classes		
		this.hostCounter = movementModel.getAttractionPointHostCounter();
		
		stayDuration = new LinkedHashMap<INodeID, Tuple<Long,Long>>();

		for(SimLocationActuator host : movementModel.getAllLocationActuators()) {
			stayDuration.put(host.getHost().getId(), new Tuple<Long, Long>(0L, Time.getCurrentTime()));			
		}
		
		Event.scheduleWithDelay(groupFormationSetupDelay, new EventHandler() {			
			@Override
			public void eventOccurred(Object content, int type) {
				triggerGroupFormation();				
			}
		}, null, 0);
	}
	
	/**
	 * Returns a time delay between removal and creation of a group. A random part of up to half of the 
	 * stated formation delay is added to/substracted from the formation delay.
	 * 
	 * @return
	 */
	protected long rndGroupFormationDelay() {		
		return (long) ((rand.nextDouble() + 0.5) * groupFormationDelay);		
	}
	
	/**
	 * Returns a random integer value between the minimum and maximumn group size boundaries 
	 * with an additional upper boundary. 
	 *  
	 * @return
	 */
	protected int rndGroupSize(int max) {			
		return Math.min(rndGroupSize(), max);
	}
	
	/**
	 * Returns a random integer value between the minimum and maximumn group size boundaries.
	 *  
	 * @return
	 */
	protected int rndGroupSize() {
		return rand.nextInt(maxGroupSize - minGroupSize) + minGroupSize;
	}
	
	protected abstract void triggerGroupFormation();
	
	/**
	 * Creates a group with the given set of members.
	 * 
	 * @param Set<SimLocationActuator> The members which want to form a group.
	 */
	protected void createGroup(Set<SimLocationActuator> members) {		
		SocialMovementGroup group = new SocialMovementGroup(members);
	
		movementModel.getAttractionAssignmentStrategy().addComponent(group.getLeader());
		
		AttractionPoint nextDestination =  movementModel.getAttractionAssignmentStrategy().getAssignment(group.getLeader());
					
		// Add Offset to group destination
		PositionVector destination = movementModel.addGaussianOffsetToPosition(new PositionVector(nextDestination),
				nextDestination.getRadius() / 3);
				
		group.setDestination(destination);
		setGroupMeetingPoint(group);

		for(SimLocationActuator member : group.getMembers()) {
			member.setTargetAttractionPoint(nextDestination);			
			if(groupCon.hostWasGroupMember(member)) {
				groupCon.removeLeftGroupAtTimeEntry(member);
			}
		}
		
		groupCon.addGroup(group);
	}

	/**
	 * Removes a group.
	 * 
	 * @param SocialMovementGroup The group to be removed.
	 * 
	 */
	@Override
	public void removeGroup(SocialMovementGroup group) {
		groupCon.removeGroup(group);
		
		Event.scheduleWithDelay(rndGroupFormationDelay(), new EventHandler() {			
			@Override
			public void eventOccurred(Object content, int type) {
				triggerGroupFormation();				
			}
		}, null, 0);
	}

	/**
	 * Returns the first AttractionPoint which contains the host with the greatest stayDuration of all hosts located in AttractionPoints.
	 * 
	 * @return AttractionPoint
	 * 
	 */
	protected AttractionPoint getAttractionPointWithOldestHost() {
		AttractionPoint result = null;
		long maxDuration = 0;
		
		for(AttractionPoint ap : IAttractionGenerator.attractionPoints) {
			for(SimLocationActuator host :  hostCounter.getHostsOfAttractionPoint(ap)) {
				INodeID id = host.getHost().getId();
				long duration = stayDuration.get(id).getA();
				
				if(duration > maxDuration) {					
					result = ap;
					maxDuration = duration;
				}
			}
		}
		
		return result;
	}
		
	protected AttractionPoint getAttractionPointWithMostHosts() {
		AttractionPoint apCandidate = null;
		int size = 0;
		for(AttractionPoint ap : IAttractionGenerator.attractionPoints) {
			int numberOfHostsInAP = hostCounter.getHostCountOfAttractionPoint(ap);
			if(numberOfHostsInAP > size) {
				apCandidate = ap;
				size = numberOfHostsInAP;
			}
		}
		return apCandidate;
	}
	
	/**
	 * Checks if a host wants to join a group or not based on a given probability.
	 * Returns true if willing to join, false else.
	 * 
	 * @return boolean
	 */
	protected boolean wantsToJoin() {
		return (rand.nextDouble() <= probabilityToJoin);
	}

	/**
	 * Checks if a host has waited long enough before he is allowed to join groups again.
	 * Returns true, if the host has waited long enough, false otherwise.
	 * 
	 * @param SimLocationActuator The host to be checked.
	 * @return boolean
	 */
	protected boolean groupRejoinTimerExpired(SimLocationActuator host) {		
		return groupCon.getTimeSinceHostLeftLastGroup(host) >= groupRejoinWaitTime;		
	}

	/**
	 * Returns true, if a host has been in a group before at least once. False else.
	 * 
	 * @param SimLocacationActuator The host to be checked.
	 * @return Boolean
	 */
	protected boolean beenInGroup(SimLocationActuator host) {
		return groupCon.hostWasGroupMember(host);
	}

	/* 
	 * =====================================================================================================
	 * === MEETING POINT FUNCTIONS
	 * =====================================================================================================
	 */
	/**
	 * Sets the meeting point of a group after the group has been created. Before walking towards the destination,
	 * the group members first have to meet at the meeting point.
	 * 
	 * @param SocialMovementGroup The group to set the meeting point.
	 */
	protected void setGroupMeetingPoint(SocialMovementGroup group) {
		PositionVector leaderPos = group.getLeader().getRealPosition();
		
		BasicAttractionPoint meetingPoint = 
				new BasicAttractionPoint("Group Movement Meeting Point of Leader #"+group.getLeader().getHost().getId(), leaderPos);
	
		group.setMeetingPoint(meetingPoint);

		// Update target for all group members to meeting point
		for(SimLocationActuator participant : group.getMembers()) {
			movementModel.getAttractionAssignmentStrategy().updateTargetAttractionPoint(participant, meetingPoint);
		}
	}	
	
	@Override
	public int getMinGroupSize() {
		return minGroupSize;
	}

	@Override
	public int getMaxGroupSize() {
		return maxGroupSize;
	}

}