updated implementation of abilities which trigger on gaining life for the first time in a turn

Mage/src/main/java/mage/abilities/common/GainLifeFirstTimeTriggeredAbility.java

@@ -0,0 +1,109 @@
+package mage.abilities.common;
+
+import mage.abilities.Ability;
+import mage.abilities.TriggeredAbilityImpl;
+import mage.abilities.condition.Condition;
+import mage.abilities.effects.Effect;
+import mage.abilities.hint.ConditionHint;
+import mage.abilities.hint.Hint;
+import mage.constants.WatcherScope;
+import mage.constants.Zone;
+import mage.game.Game;
+import mage.game.events.GameEvent;
+import mage.watchers.Watcher;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.UUID;
+
+/**
+ * @author TheElk801
+ */
+public class GainLifeFirstTimeTriggeredAbility extends TriggeredAbilityImpl {
+
+    private static final Hint hint = new ConditionHint(GainLifeCondition.instance);
+    private final boolean when;
+
+    public GainLifeFirstTimeTriggeredAbility(Effect effect) {
+        this(Zone.BATTLEFIELD, effect, false, false);
+    }
+
+    public GainLifeFirstTimeTriggeredAbility(Zone zone, Effect effect, boolean optional, boolean when) {
+        super(zone, effect, optional);
+        this.when = when;
+        this.addWatcher(new GainLifeFirstTimeWatcher());
+    }
+
+    private GainLifeFirstTimeTriggeredAbility(final GainLifeFirstTimeTriggeredAbility ability) {
+        super(ability);
+        this.when = ability.when;
+    }
+
+    @Override
+    public boolean checkEventType(GameEvent event, Game game) {
+        return event.getType() == GameEvent.EventType.GAINED_LIFE;
+    }
+
+    @Override
+    public boolean checkTrigger(GameEvent event, Game game) {
+        GainLifeFirstTimeWatcher watcher = game.getState().getWatcher(GainLifeFirstTimeWatcher.class);
+        return watcher != null && watcher.checkEvent(getControllerId(), event);
+    }
+
+    @Override
+    public String getRule() {
+        return "When" + (when ? "" : "ever") + " you gain life for the first time each turn, " + super.getRule();
+    }
+
+    @Override
+    public GainLifeFirstTimeTriggeredAbility copy() {
+        return new GainLifeFirstTimeTriggeredAbility(this);
+    }
+}
+
+enum GainLifeCondition implements Condition {
+    instance;
+
+    @Override
+    public boolean apply(Game game, Ability source) {
+        GainLifeFirstTimeWatcher watcher = game.getState().getWatcher(GainLifeFirstTimeWatcher.class);
+        return watcher != null && watcher.checkGain(source.getControllerId());
+    }
+
+    @Override
+    public String toString() {
+        return "You haven't gained life this turn";
+    }
+}
+
+class GainLifeFirstTimeWatcher extends Watcher {
+
+    private final Map<UUID, UUID> gainedMap = new HashMap<>();
+
+    GainLifeFirstTimeWatcher() {
+        super(WatcherScope.GAME);
+    }
+
+    @Override
+    public void watch(GameEvent event, Game game) {
+        if (event.getType() != GameEvent.EventType.GAINED_LIFE
+                || event.getAmount() < 1) {
+            return;
+        }
+        gainedMap.putIfAbsent(event.getPlayerId(), event.getId());
+    }
+
+    @Override
+    public void reset() {
+        super.reset();
+        gainedMap.clear();
+    }
+
+    boolean checkEvent(UUID playerId, GameEvent event) {
+        return event.getId().equals(gainedMap.getOrDefault(playerId, null));
+    }
+
+    boolean checkGain(UUID playerId) {
+        return !gainedMap.containsKey(playerId);
+    }
+}