foul-magics/Mage/src/main/java/mage/abilities/keyword/LevelerCardBuilder.java

package mage.abilities.keyword;

import mage.abilities.Abilities;
import mage.abilities.AbilitiesImpl;
import mage.abilities.Ability;
import mage.abilities.common.SimpleStaticAbility;
import mage.abilities.condition.Condition;
import mage.abilities.condition.common.SourceHasCounterCondition;
import mage.abilities.decorator.ConditionalContinuousEffect;
import mage.abilities.effects.ContinuousEffect;
import mage.abilities.effects.common.continuous.GainAbilitySourceEffect;
import mage.abilities.effects.common.continuous.SetBasePowerToughnessSourceEffect;
import mage.constants.Duration;
import mage.constants.SubLayer;
import mage.constants.Zone;
import mage.counters.CounterType;

import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

/**
 * The implementation by BetaSteward was discarded as requires special handling
 * in Mage.Core.
 * <p>
 * Instead it was replaced by conditional continuous effects and builder
 * pattern.
 *
 * @author BetaSteward_at_googlemail.com
 * @author noxx
 */
public class LevelerCardBuilder {

    private int level1;
    private int level2;
    private int power;
    private int toughness;
    private String rule = "";

    private Abilities<Ability> abilities = new AbilitiesImpl<>();

    /**
     * Main method constructing ability.
     *
     * @return
     */
    public List<Ability> build() {
        List<Ability> constructed = new ArrayList<>();

        Condition condition = new SourceHasCounterCondition(CounterType.LEVEL, level1, level2);
        for (Ability ability : abilities) {
            ContinuousEffect effect = new GainAbilitySourceEffect(ability);
            ConditionalContinuousEffect abEffect = new ConditionalContinuousEffect(effect, condition, "");
            Ability staticAbility = new SimpleStaticAbility(Zone.BATTLEFIELD, abEffect);
            staticAbility.setRuleVisible(false);
            constructed.add(staticAbility);
        }
        ContinuousEffect effect = new SetBasePowerToughnessSourceEffect(power, toughness, Duration.WhileOnBattlefield, SubLayer.SetPT_7b);
        ConditionalContinuousEffect ptEffect = new ConditionalContinuousEffect(effect, condition, rule);
        constructed.add(new SimpleStaticAbility(Zone.BATTLEFIELD, ptEffect));

        return constructed;
    }

    public LevelerCardBuilder setLevel1(int level1) {
        this.level1 = level1;
        return this;
    }

    public LevelerCardBuilder setLevel2(int level2) {
        this.level2 = level2;
        return this;
    }

    public LevelerCardBuilder setPower(int power) {
        this.power = power;
        return this;
    }

    public LevelerCardBuilder setToughness(int toughness) {
        this.toughness = toughness;
        return this;
    }

    public LevelerCardBuilder addAbility(Ability ability) {
        this.abilities.add(ability);
        return this;
    }

    public LevelerCardBuilder setRule(String rule) {
        this.rule = rule;
        return this;
    }

    public LevelerCardBuilder reset() {
        this.level1 = 0;
        this.level2 = 0;
        this.power = 0;
        this.toughness = 0;
        this.abilities.clear();
        this.rule = "";
        return this;
    }

    /**
     * Add abilities to card to enable switching between levels.
     *
     * @param card
     * @param levelAbilities
     * @return list of levelAbilities to add to card
     */
    public static List<Ability> construct(LevelAbility... levelAbilities) {
        LevelerCardBuilder builder = new LevelerCardBuilder();
        List<Ability> abilities = new ArrayList<>();

        for (LevelAbility levelAbility : levelAbilities) {
            // set main params
            builder = builder
                    .reset()
                    .setLevel1(levelAbility.getLevel1())
                    .setLevel2(levelAbility.getLevel2() == -1 ? Integer.MAX_VALUE : levelAbility.getLevel2())
                    .setPower(levelAbility.getPower())
                    .setToughness(levelAbility.getToughness())
                    .setRule(levelAbility.getRule());

            // set abilities that give the next level
            for (Ability addedAbility : levelAbility.getAbilities()) {
                builder.addAbility(addedAbility);
            }

            // build static abilities and add them to list
            abilities.addAll(builder.build());
        }

        return abilities;
    }

    public static class LevelAbility {

        private final int level1;
        private final int level2;
        private final int power;
        private final int toughness;

        private Abilities<Ability> abilities = new AbilitiesImpl<>();

        public LevelAbility(int level1, int level2, Abilities<Ability> abilities, int power, int toughness) {
            this.level1 = level1;
            this.level2 = level2;
            this.abilities.addAll(abilities);
            this.power = power;
            this.toughness = toughness;
        }

        public LevelAbility(LevelAbility ability) {
            this.level1 = ability.level1;
            this.level2 = ability.level2;
            this.abilities = ability.abilities.copy();
            this.power = ability.power;
            this.toughness = ability.toughness;
        }

        public int getLevel1() {
            return level1;
        }

        public int getLevel2() {
            return level2;
        }

        public Abilities<Ability> getAbilities() {
            return abilities;
        }

        public int getPower() {
            return power;
        }

        public int getToughness() {
            return toughness;
        }

        public String getRule() {
            StringBuilder sb = new StringBuilder("<b>LEVEL ");
            sb.append(level1);
            if (level2 == -1) {
                sb.append('+');
            } else {
                sb.append('-');
                sb.append(level2);
            }
            sb.append("</b><br>");
            sb.append(power);
            sb.append('/');
            sb.append(toughness);
            List<String> abilityText = abilities.getRules("{this}");
            if (!abilityText.isEmpty()) {
                sb.append("<br>");
                sb.append(abilityText.stream().collect(Collectors.joining("<br>")));
            }
            return sb.toString();
        }
    }
}