package ch.epfl.maze.physical.pacman;

import ch.epfl.maze.physical.Animal;
import ch.epfl.maze.physical.Daedalus;
import ch.epfl.maze.util.Vector2D;

import java.util.NoSuchElementException;

/**
 * Blue ghost from the Pac-Man game, targets the result of two times the vector
 * from Blinky to its target.
 *
 * @author EPFL
 * @author Pacien TRAN-GIRARD
 */
public class Inky extends Ghost {

    private Ghost companion;

    /**
     * Finds Inky's best friend (Blinky) in the Daedalus.
     *
     * @param daedalus The Daedalus
     * @return The companion if found, null otherwise
     */
    private static Ghost findCompanion(Daedalus daedalus) {
        try {
            return (Blinky) daedalus
                    .getPredatorSet()
                    .stream()
                    .filter(pred -> pred instanceof Blinky)
                    .findFirst()
                    .get();
        } catch (NoSuchElementException e) {
            return null;
        }
    }

    /**
     * Constructs a Inky with a starting position.
     *
     * @param position  Starting position of Inky in the labyrinth
     * @param companion Inky's accomplice
     */
    public Inky(Vector2D position, Ghost companion) {
        super(position);
        this.companion = companion;
    }

    /**
     * Constructs a Inky with a starting position.
     *
     * @param position Starting position of Inky in the labyrinth
     */
    public Inky(Vector2D position) {
        this(position, null);
    }

    /**
     * Returns Inky's companion.
     *
     * @param daedalus The Daedalus
     * @return Inky's companion if present, null otherwise
     */
    private Ghost getCompanion(Daedalus daedalus) {
        if (this.companion == null)
            this.companion = Inky.findCompanion(daedalus);

        return this.companion;
    }

    /**
     * Returns Inky's companion's position.
     *
     * @param daedalus The Daedalus
     * @return Inky's companion's position if present, null otherwise
     */
    private Vector2D getCompanionPosition(Daedalus daedalus) {
        Ghost companion = this.getCompanion(daedalus);
        if (companion == null) return new Vector2D();
        return companion.getPosition();
    }

    /**
     * Targets beyond his friend's scope.
     *
     * @param daedalus The Daedalus
     * @return The targeted position
     */
    @Override
    protected Vector2D getPreyTargetPosition(Daedalus daedalus) {
        return this
                .getPreyPosition(daedalus)
                .mul(2)
                .sub(this.getCompanionPosition(daedalus));
    }

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

}