foul-magics/Mage/src/main/java/mage/target/common/TargetTappedPermanentAsYouCast.java

package mage.target.common;

import mage.abilities.Ability;
import mage.filter.FilterPermanent;
import mage.game.Game;
import mage.game.permanent.Permanent;
import mage.target.TargetPermanent;

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

public class TargetTappedPermanentAsYouCast extends TargetPermanent {

    public TargetTappedPermanentAsYouCast() {}

    public TargetTappedPermanentAsYouCast(FilterPermanent filter) {
        this.filter = filter;
        this.targetName = filter.getMessage();
    }

    private TargetTappedPermanentAsYouCast(TargetTappedPermanentAsYouCast target) {
        super(target);
    }

    @Override
    public TargetTappedPermanentAsYouCast copy() {
        return new TargetTappedPermanentAsYouCast(this);
    }

    @Override
    public Set<UUID> possibleTargets(UUID sourceControllerId, Ability source, Game game) {
        return game.getBattlefield().getAllActivePermanents(getFilter(), game).stream()
                .filter(Permanent::isTapped)
                .map(Permanent::getId)
                .collect(Collectors.toSet());
    }

    @Override
    public boolean canChoose(UUID sourceControllerId, Ability source, Game game) {
        return game.getBattlefield().getAllActivePermanents(getFilter(), game).stream()
                .anyMatch(Permanent::isTapped);
    }

    @Override
    public boolean canTarget(UUID controllerId, UUID id, Ability source, Game game) {
        if (super.canTarget(controllerId, id, source, game)) {
            Permanent permanent = game.getPermanent(id);
            return permanent != null && permanent.isTapped();
        }
        return false;
    }

    // See ruling: https://www.mtgsalvation.com/forums/magic-fundamentals/magic-rulings/magic-rulings-archives/253345-dream-leash
    @Override
    public boolean stillLegalTarget(UUID id, Ability source, Game game) {
        Permanent permanent = game.getPermanent(id);
        return permanent != null 
                && getFilter().match(permanent, game)
                && super.canTarget(id, game);  // check everything but leave out the tapped requirement
    }
}