- Introduce PhaseIn and PhaseOut triggers

- Added Teferi's Imp (as an example of both)

forge-game/src/main/java/forge/game/card/Card.java

@@ -4879,7 +4879,7 @@ public class Card extends GameEntity implements Comparable<Card> {
         final boolean phasingIn = this.isPhasedOut();
 
         if (!this.switchPhaseState()) {
-            // Switch Phase State returns False if the Permanent can't Phase Out
+            // Switch Phase State bails early if the Permanent can't Phase Out
             return;
         }
 
@@ -4913,6 +4913,15 @@ public class Card extends GameEntity implements Comparable<Card> {
             return false;
         }
 
+        final Map<String, Object> runParams = new TreeMap<String, Object>();
+        runParams.put("Card", this);
+
+        if (!this.isPhasedOut()) {
+            // If this is currently PhasedIn, it's about to phase out.
+            // Run trigger before it does because triggers don't work with phased out objects
+            getGame().getTriggerHandler().runTrigger(TriggerType.PhaseOut, runParams, false);
+        }
+
         this.phasedOut = !this.phasedOut;
         final Combat combat = this.getGame().getPhaseHandler().getCombat();
         if (combat != null && this.phasedOut) {
@@ -4934,6 +4943,12 @@ public class Card extends GameEntity implements Comparable<Card> {
             getGame().getAction().exile(this);
             getGame().getTriggerHandler().clearSuppression(TriggerType.ChangesZone);
         }
+
+        if (!this.phasedOut) {
+            // Just phased in, time to run the phased in trigger
+            getGame().getTriggerHandler().runTrigger(TriggerType.PhaseIn, runParams, false);
+        }
+
         return true;
     }
 

forge-game/src/main/java/forge/game/trigger/TriggerPhaseIn.java

@@ -0,0 +1,34 @@
+package forge.game.trigger;
+
+import forge.game.card.Card;
+import forge.game.spellability.SpellAbility;
+
+import java.util.Map;
+
+public class TriggerPhaseIn extends Trigger {
+
+    public TriggerPhaseIn(final Map<String, String> params, final Card host, final boolean intrinsic) {
+        super(params, host, intrinsic);
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public final boolean performTest(final java.util.Map<String, Object> runParams2) {
+        final Card phaser = (Card) runParams2.get("Card");
+
+        if (this.mapParams.containsKey("ValidCard")) {
+            if (!phaser.isValid(this.mapParams.get("ValidCard").split(","), this.getHostCard().getController(),
+                    this.getHostCard())) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public final void setTriggeringObjects(final SpellAbility sa) {
+        sa.setTriggeringObject("Card", this.getRunParams().get("Card"));
+    }
+}

forge-game/src/main/java/forge/game/trigger/TriggerPhaseOut.java

@@ -0,0 +1,40 @@
+package forge.game.trigger;
+
+import forge.game.card.Card;
+import forge.game.spellability.SpellAbility;
+
+import java.util.Map;
+
+public class TriggerPhaseOut extends Trigger {
+
+    public TriggerPhaseOut(final Map<String, String> params, final Card host, final boolean intrinsic) {
+        super(params, host, intrinsic);
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public final boolean performTest(final java.util.Map<String, Object> runParams2) {
+        final Card phaser = (Card) runParams2.get("Card");
+
+        if (this.mapParams.containsKey("ValidCard")) {
+            if (this.mapParams.get("ValidCard").equals("Card.Self")) {
+                // Since Phased out cards aren't visible in .isValid, use a special check here.
+                // NOTE: All Phase Out Triggers should use ValidCard$ Card.Self
+                if (phaser != this.getHostCard()) {
+                    return false;
+                }
+            } else if (!phaser.isValid(this.mapParams.get("ValidCard").split(","), this.getHostCard().getController(),
+                    this.getHostCard())) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public final void setTriggeringObjects(final SpellAbility sa) {
+        sa.setTriggeringObject("Card", this.getRunParams().get("Card"));
+    }
+}

forge-game/src/main/java/forge/game/trigger/TriggerType.java

@@ -46,6 +46,8 @@ public enum TriggerType {
     NewGame(TriggerNewGame.class),
     PayCumulativeUpkeep(TriggerPayCumulativeUpkeep.class),
     Phase(TriggerPhase.class),
+    PhaseIn(TriggerPhaseIn.class),
+    PhaseOut(TriggerPhaseOut.class),
     PlanarDice(TriggerPlanarDice.class),
     PlaneswalkedFrom(TriggerPlaneswalkedFrom.class),
     PlaneswalkedTo(TriggerPlaneswalkedTo.class),