package ch.epfl.maze.physical.stragegies.reducer;

import ch.epfl.maze.physical.World;
import ch.epfl.maze.util.Direction;

import java.util.Set;
import java.util.stream.Collectors;

/**
 * A filter reducer filtering possibilities case by case.
 *
 * @author Pacien TRAN-GIRARD
 */
public interface CaseReducer extends ChoiceReducer {

    /**
     * Checks if the given choice should be kept or excluded by the filter.
     *
     * @param choice A Direction
     * @param world  The World
     * @return T(The filter should keep the given choice)
     */
    boolean keepChoice(Direction choice, World world);

    @Override
    default Set<Direction> reduce(Set<Direction> choices, World world) {
        return choices
                .stream()
                .filter(choice -> this.keepChoice(choice, world))
                .collect(Collectors.toSet());
    }

}