package ch.epfl.maze.physical;

import java.util.HashSet;
import java.util.Set;

/**
 * Maze in which an animal starts from a starting point and must find the exit.
 * Every animal added will have its position set to the starting point. The
 * animal is removed from the maze when it finds the exit.
 *
 * @author EPFL
 * @author Pacien TRAN-GIRARD
 */
public final class Maze extends World {

    private final Set<Animal> animals;
    private final Set<Animal> animalHistory;

    /**
     * Constructs a Maze with a labyrinth structure.
     *
     * @param labyrinth Structure of the labyrinth, an NxM array of tiles
     */
    public Maze(int[][] labyrinth) {
        super(labyrinth);

        this.animals = new HashSet<>();
        this.animalHistory = new HashSet<>();
    }

    @Override
    public boolean isSolved() {
        return this.animals.isEmpty();
    }

    @Override
    public Set<Animal> getAnimalSet() {
        return new HashSet<>(this.animals);
    }

    /**
     * Determines if the maze contains an animal.
     *
     * @param a The animal in question
     * @return <b>true</b> if the animal belongs to the world, <b>false</b>
     * otherwise.
     */
    public boolean hasAnimal(Animal a) {
        return this.animals.contains(a);
    }

    /**
     * Adds an animal to the maze at the start position.
     *
     * @param a The animal to add
     */
    public void addAnimal(Animal a) {
        a.setPosition(this.getStart());
        this.animals.add(a);
    }

    /**
     * Removes an animal from the maze.
     *
     * @param a The animal to remove
     */
    public void removeAnimal(Animal a) {
        boolean contained = this.animals.remove(a);
        if (contained) this.animalHistory.add(a);
    }

    @Override
    public void reset() {
        this.animalHistory.addAll(this.animals);
        this.animals.clear();
        this.animalHistory.forEach(a -> this.addAnimal(a.copy()));
        this.animalHistory.clear();
    }

}