package ch.epfl.maze.physical.zoo;

import ch.epfl.maze.physical.Animal;
import ch.epfl.maze.physical.stragegies.picker.CyclePicker;
import ch.epfl.maze.physical.stragegies.picker.ForwardPicker;
import ch.epfl.maze.physical.stragegies.picker.SimplePicker;
import ch.epfl.maze.util.Direction;
import ch.epfl.maze.util.Vector2D;

import java.util.Set;

/**
 * Monkey A.I. that puts its hand on the left wall and follows it.
 *
 * @author EPFL
 * @author Pacien TRAN-GIRARD
 */
public class Monkey extends Animal implements SimplePicker, ForwardPicker, CyclePicker {

    public static final Direction SMART_PAW = Direction.LEFT;

    private boolean foundWall;

    /**
     * Constructs a monkey with a starting position.
     *
     * @param position Starting position of the monkey in the labyrinth
     */
    public Monkey(Vector2D position) {
        super(position);

        this.foundWall = false;
    }

    @Override
    public Direction getStartingDirection() {
        return this.getDirection().unRelativeDirection(Monkey.SMART_PAW);
    }

    @Override
    public Direction getRotationDirection() {
        return Monkey.SMART_PAW.reverse();
    }

    /**
     * Picks a Direction preferably following the "paw rule", or forward if no wall has been encountered,
     * or any available Direction if the Monkey has no current Direction.
     *
     * @param choices A set of Direction choices
     * @return The picked Direction
     */
    @Override
    public Direction pick(Set<Direction> choices) {
        if (this.getDirection() == Direction.NONE)
            return SimplePicker.super.pick(choices);
        else if (!this.foundWall)
            return ForwardPicker.super.pick(choices);
        else
            return CyclePicker.super.pick(choices);
    }

    /**
     * Moves according to the relative left wall that the monkey has to follow.
     */
    @Override
    public Direction move(Set<Direction> choices) {
        if (this.nextToWall(choices))
            this.foundWall = true;

        return this.pick(choices);
    }

    @Override
    public Animal copy() {
        return new Monkey(this.getPosition());
    }

    /**
     * Checks is the Monkey is next to a wall.
     *
     * @param choices The available Direction choices
     * @return T(The Direction choices set indicates the presence of a wall)
     */
    private boolean nextToWall(Set<Direction> choices) {
        return choices.size() < 4;
    }

}