package aco.ant;

import java.util.ArrayList;

import sys.Settings;

import util.PseudoRandom;

import aco.ACO;

public class Ant4ACS extends Ant4AS {

    /** 进行Exploitation的概率 */

    protected double Q0 = Settings.Q0;

    /** 信息素挥发的概率*/

    protected double P = Settings.P;

    public Ant4ACS(ACO aco) {

        super(aco);

    }

    /*实现了父类的explore操作的接口*/

    @Override

    public void explore() {

        while (!nodesToVisit.isEmpty()) {

            int nextNode = -1;

            if (PseudoRandom.randDouble(0, 1) <= Q0) {

                nextNode = doExploitation(currentNode);//Exploitation操作

            } else {

                nextNode = doExploration(currentNode);//Exploration操作

            }

            localUpdateRule(currentNode, nextNode);//挥发连接当前节点和下一个节点边的信息素

            // Save next node

            tour.add(new Integer(nextNode));//将下一个节点存入蚂蚁的路径列表

            path[currentNode][nextNode] = 1;//将当前节点与下一节点间的边标记为已访问过

            path[nextNode][currentNode] = 1;//将下一节点与当前节点间的边标记为已访问过

            aco.p.updateTheMandatoryNeighborhood(this);//更新邻域

            currentNode = nextNode;//将下一节点作为当前节点

        }

    }

/* 信息素挥发 */

    protected void localUpdateRule(int i, int j) {

        double evaporation = (1.0 - P) * aco.getTau(i, j);

        double deposition = P * aco.p.getT0();

        aco.setTau(i, j, evaporation + deposition);

        aco.setTau(j, i, evaporation + deposition);

    }

/*该操作选择和当前节点i相邻的所有未被访问过的节点中tij * nij值最高的节点作为下一个节点*/

    protected int doExploitation(int i) {

        int nextNode = -1;

        double maxValue = Double.MIN_VALUE;

        // Update the sum

        for (Integer j : nodesToVisit) {

            if (aco.getTau(i, j) == 0.0) {

                throw new RuntimeException("tau == 0.0");

            }

            double tij = aco.getTau(i, j);

            double nij = Math.pow(aco.p.getNij(i, j), BETA);

            double value = tij * nij;

            if(value > maxValue){

                maxValue = value;

                nextNode = j;

            }

        }

        if (nextNode == -1) {

            throw new RuntimeException("nextNode == -1");

        }

        nodesToVisit.remove(new Integer(nextNode));

        return nextNode;

    }

    @Override
   /*实现父类的clone接口，复制蚂蚁*/

    public Ant clone() {

        Ant ant = new Ant4ACS(aco);

        ant.id = id;

        ant.currentNode = currentNode;

        ant.tourLength = tourLength;

        ant.tour = new ArrayList<Integer>(tour);

        ant.path = path.clone();

        return ant;

    }

}