[LTC] Implement Gollum, Obsessed Stalker (#10712)

Mage.Sets/src/mage/cards/g/GollumObsessedStalker.java

@@ -0,0 +1,197 @@
+package mage.cards.g;
+
+import mage.MageInt;
+import mage.MageObject;
+import mage.abilities.Ability;
+import mage.abilities.common.BeginningOfYourEndStepTriggeredAbility;
+import mage.abilities.dynamicvalue.common.ControllerGainedLifeCount;
+import mage.abilities.effects.OneShotEffect;
+import mage.abilities.hint.Hint;
+import mage.abilities.keyword.SkulkAbility;
+import mage.cards.CardImpl;
+import mage.cards.CardSetInfo;
+import mage.constants.*;
+import mage.game.Game;
+import mage.game.events.DamagedPlayerEvent;
+import mage.game.events.GameEvent;
+import mage.game.permanent.Permanent;
+import mage.players.Player;
+import mage.watchers.Watcher;
+import mage.watchers.common.PlayerGainedLifeWatcher;
+
+import java.util.*;
+import java.util.stream.Collectors;
+
+/**
+ * @author Susucr
+ */
+public final class GollumObsessedStalker extends CardImpl {
+
+    public GollumObsessedStalker(UUID ownerId, CardSetInfo setInfo) {
+        super(ownerId, setInfo, new CardType[]{CardType.CREATURE}, "{1}{B}");
+
+        this.supertype.add(SuperType.LEGENDARY);
+        this.subtype.add(SubType.HALFLING);
+        this.subtype.add(SubType.HORROR);
+        this.power = new MageInt(1);
+        this.toughness = new MageInt(1);
+
+        // Skulk
+        this.addAbility(new SkulkAbility());
+
+        // At the beginning of your end step, each opponent dealt combat damage this game by a creature named Gollum, Obsessed Stalker loses life equal to the amount of life you gained this turn.
+        Ability ability = new BeginningOfYourEndStepTriggeredAbility(
+                new GollumObsessedStalkerEffect(),
+                false
+        );
+        ability.addWatcher(new PlayerGainedLifeWatcher());
+        ability.addWatcher(new GollumObsessedStalkerWatcher());
+        ability.addHint(ControllerGainedLifeCount.getHint());
+        ability.addHint(GollumObsessedStalkerHint.instance);
+
+        this.addAbility(ability);
+    }
+
+    private GollumObsessedStalker(final GollumObsessedStalker card) {
+        super(card);
+    }
+
+    @Override
+    public GollumObsessedStalker copy() {
+        return new GollumObsessedStalker(this);
+    }
+}
+
+class GollumObsessedStalkerWatcher extends Watcher {
+
+    // For each creature name, the players damaged by them during combat.
+    private final Map<String, Set<UUID>> playersPerName = new HashMap<>();
+
+    public GollumObsessedStalkerWatcher() {
+        super(WatcherScope.GAME);
+    }
+
+    @Override
+    public void watch(GameEvent event, Game game) {
+        if (event.getType() != GameEvent.EventType.DAMAGED_PLAYER
+                || !((DamagedPlayerEvent) event).isCombatDamage()) {
+            return;
+        }
+        Permanent creature = game.getPermanent(event.getSourceId());
+        if (creature == null) {
+            return;
+        }
+
+        String name = creature.getName();
+        UUID playerId = event.getPlayerId();
+        if (creature.getName().isEmpty() || playerId == null) {
+            return;
+        }
+
+        playersPerName.computeIfAbsent(name, k -> new HashSet());
+        playersPerName.get(name).add(playerId);
+    }
+
+    public Set<UUID> getPlayersDamagedByNamed(String name) {
+        return playersPerName.getOrDefault(name, new HashSet<>());
+    }
+}
+
+class GollumObsessedStalkerEffect extends OneShotEffect {
+
+    GollumObsessedStalkerEffect() {
+        super(Outcome.LoseLife);
+        staticText = "each opponent dealt combat damage this game by a creature named "
+                + "{this} loses life equal to the amount of life you gained this turn.";
+    }
+
+    private GollumObsessedStalkerEffect(final GollumObsessedStalkerEffect effect) {
+        super(effect);
+    }
+
+    @Override
+    public GollumObsessedStalkerEffect copy() {
+        return new GollumObsessedStalkerEffect(this);
+    }
+
+    @Override
+    public boolean apply(Game game, Ability source) {
+        GollumObsessedStalkerWatcher damageWatcher = game.getState().getWatcher(GollumObsessedStalkerWatcher.class);
+        PlayerGainedLifeWatcher lifeWatcher = game.getState().getWatcher(PlayerGainedLifeWatcher.class);
+        Permanent gollum = game.getPermanentOrLKIBattlefield(source.getSourceId());
+        if (damageWatcher == null || lifeWatcher == null || gollum == null) {
+            return false;
+        }
+
+        String name = gollum.getName();
+        int amount = lifeWatcher.getLifeGained(source.getControllerId());
+        Set<UUID> playersDamaged = damageWatcher.getPlayersDamagedByNamed(name);
+
+        if (amount == 0 || playersDamaged.isEmpty()) {
+            return true;
+        }
+
+        for (UUID playerId : game.getOpponents(source.getControllerId())) {
+            if (!playersDamaged.contains(playerId)) {
+                continue;
+            }
+
+            Player player = game.getPlayer(playerId);
+            if (player == null) {
+                continue;
+            }
+
+            player.loseLife(amount, game, source, false);
+        }
+
+        return true;
+    }
+}
+
+enum GollumObsessedStalkerHint implements Hint {
+    instance;
+
+    @Override
+    public String getText(Game game, Ability ability) {
+        GollumObsessedStalkerWatcher watcher = game.getState().getWatcher(GollumObsessedStalkerWatcher.class);
+        if (watcher == null) {
+            return "";
+        }
+
+        String name = null;
+        Permanent gollum = game.getPermanentOrLKIBattlefield(ability.getSourceId());
+        if (gollum != null) {
+            // Gollum is or was in play, its name is using LKI.
+            name = gollum.getName();
+        } else {
+            // if Gollum LKI not in play (like in hand or in command zone),
+            // find the object.
+            MageObject gollumObj = game.getObject(ability.getSourceId());
+            if (gollumObj != null) {
+                name = gollumObj.getName();
+            }
+        }
+        if (name.isEmpty()) {
+            return "";
+        }
+
+        // Not filtering by opponent intentionally, just to provide full info everywhere.
+        List<String> namesOfPlayersDealtDamage =
+                watcher.getPlayersDamagedByNamed(name)
+                       .stream()
+                       .map(game::getPlayer)
+                       .filter(Objects::nonNull)
+                       .map(Player::getName)
+                       .filter(n -> !n.isEmpty())
+                       .collect(Collectors.toList());
+
+        return "Players dealt combat damage by creatures named " + name + " this game: ["
+                + String.join(", ", namesOfPlayersDealtDamage)
+                + "]";
+    }
+
+    @Override
+    public GollumObsessedStalkerHint copy() {
+        return instance;
+    }
+}

Mage.Sets/src/mage/sets/TalesOfMiddleEarthCommander.java

@@ -126,6 +126,7 @@ public final class TalesOfMiddleEarthCommander extends ExpansionSet {
         cards.add(new SetCardInfo("Go for the Throat", 201, Rarity.UNCOMMON, mage.cards.g.GoForTheThroat.class));
         cards.add(new SetCardInfo("Goblin Cratermaker", 218, Rarity.UNCOMMON, mage.cards.g.GoblinCratermaker.class));
         cards.add(new SetCardInfo("Goblin Dark-Dwellers", 219, Rarity.RARE, mage.cards.g.GoblinDarkDwellers.class));
+        cards.add(new SetCardInfo("Gollum, Obsessed Stalker", 26, Rarity.RARE, mage.cards.g.GollumObsessedStalker.class));
         cards.add(new SetCardInfo("Graypelt Refuge", 316, Rarity.UNCOMMON, mage.cards.g.GraypeltRefuge.class));
         cards.add(new SetCardInfo("Great Oak Guardian", 247, Rarity.UNCOMMON, mage.cards.g.GreatOakGuardian.class));
         cards.add(new SetCardInfo("Grey Host Reinforcements", 14, Rarity.RARE, mage.cards.g.GreyHostReinforcements.class, NON_FULL_USE_VARIOUS));