simplify vanishing implementation

Mage/src/main/java/mage/abilities/keyword/VanishingAbility.java

@@ -0,0 +1,97 @@
+package mage.abilities.keyword;
+
+import mage.abilities.TriggeredAbilityImpl;
+import mage.abilities.common.BeginningOfUpkeepTriggeredAbility;
+import mage.abilities.common.EntersBattlefieldAbility;
+import mage.abilities.condition.Condition;
+import mage.abilities.condition.common.SourceHasCounterCondition;
+import mage.abilities.decorator.ConditionalInterveningIfTriggeredAbility;
+import mage.abilities.effects.common.SacrificeSourceEffect;
+import mage.abilities.effects.common.counter.AddCountersSourceEffect;
+import mage.abilities.effects.common.counter.RemoveCounterSourceEffect;
+import mage.constants.TargetController;
+import mage.constants.Zone;
+import mage.counters.CounterType;
+import mage.game.Game;
+import mage.game.events.GameEvent;
+import mage.game.permanent.Permanent;
+import mage.util.CardUtil;
+
+/**
+ * @author TheElk801
+ */
+public class VanishingAbility extends EntersBattlefieldAbility {
+
+    private static final Condition condition = new SourceHasCounterCondition(CounterType.TIME);
+    private final int amount;
+
+    public VanishingAbility(int amount) {
+        super(new AddCountersSourceEffect(CounterType.TIME.createInstance(amount)));
+        this.amount = amount;
+        this.addSubAbility(new ConditionalInterveningIfTriggeredAbility(
+                new BeginningOfUpkeepTriggeredAbility(
+                        new RemoveCounterSourceEffect(CounterType.TIME.createInstance()),
+                        TargetController.YOU, false
+                ), condition, "At the beginning of your upkeep, if this permanent " +
+                "has a time counter on it, remove a time counter from it."
+        ).setRuleVisible(false));
+        this.addSubAbility(new VanishingTriggeredAbility());
+    }
+
+    private VanishingAbility(final VanishingAbility ability) {
+        super(ability);
+        this.amount = ability.amount;
+    }
+
+    @Override
+    public VanishingAbility copy() {
+        return new VanishingAbility(this);
+    }
+
+    @Override
+    public String getRule() {
+        if (amount > 0) {
+            return "Vanishing " + amount + " <i>(This permanent enters the battlefield with " +
+                    CardUtil.numberToText(amount) + " time counters on it. At the beginning of your upkeep, " +
+                    "remove a time counter from it. When the last is removed, sacrifice it.)</i>";
+        }
+        return "Vanishing <i>(At the beginning of your upkeep, remove a time counter " +
+                "from this permanent. When the last is removed, sacrifice it.)</i>";
+    }
+}
+
+class VanishingTriggeredAbility extends TriggeredAbilityImpl {
+
+    VanishingTriggeredAbility() {
+        super(Zone.BATTLEFIELD, new SacrificeSourceEffect());
+        this.setRuleVisible(false);
+    }
+
+    private VanishingTriggeredAbility(final VanishingTriggeredAbility ability) {
+        super(ability);
+    }
+
+    @Override
+    public VanishingTriggeredAbility copy() {
+        return new VanishingTriggeredAbility(this);
+    }
+
+    @Override
+    public boolean checkEventType(GameEvent event, Game game) {
+        return event.getType() == GameEvent.EventType.COUNTERS_REMOVED;
+    }
+
+    @Override
+    public boolean checkTrigger(GameEvent event, Game game) {
+        if (!CounterType.TIME.getName().equals(event.getData())) {
+            return false;
+        }
+        Permanent permanent = getSourcePermanentIfItStillExists(game);
+        return permanent != null && permanent.getCounters(game).getCount(CounterType.TIME) < 1;
+    }
+
+    @Override
+    public String getRule() {
+        return "When the last time counter is removed from {this}, sacrifice it.";
+    }
+}