package tsp.pacman;

import java.util.HashMap;

public class PacmanMCTS implements Pacman {

    private MCTSNode tree;
    private HashMap<PacmanState, MCTSNode> stateToNode;
    private double C;

    private int maxTimeMilli;

    private int maxDepth;

    public PacmanMCTS(int maxTimeMilli, int maxDepth, double C){
        this.C = C;
        this.maxTimeMilli = maxTimeMilli;
        this.maxDepth = maxDepth;
        stateToNode = new HashMap<>();
    }


    @Override
    public Position chooseAction(PacmanState state) {
        // Mécanisme de mémorisation des simulations précédentes.
        if (tree == null) {
            tree = new MCTSNode(state);
            stateToNode.put(state, tree);
        }
        long startTime = System.currentTimeMillis();
        MCTSNode currentNode = stateToNode.get(state);
        tree = currentNode;
        if (currentNode == null){
            tree = new MCTSNode(state);
            stateToNode.put(state, tree);
            currentNode = stateToNode.get(state);
        }
        tree.deleteParent();
        stateToNode = new HashMap<>();
        stateToNode.put(state, tree);
        int counter = 0;
        while(System.currentTimeMillis() - startTime < maxTimeMilli){
            counter += 1;
            MCTSNode leaf = currentNode.selectLeaf(C);
            leaf.generateSons();
            for (MCTSNode node: leaf.getSons()){
                this.stateToNode.put(node.getState(), node);
            }
            leaf.selectSon(C).runSimulation(maxDepth);
        }
        System.out.println("Number of nodes explored: " + counter);
        //tree.printTree();
        return currentNode.selectSonFinal().getState().findPacman();
    }
}