Rudimentary Station AI logic, take two

forge-ai/src/main/java/forge/ai/ComputerUtil.java

@@ -692,6 +692,10 @@ public static CardCollection chooseTapType(final Player ai, final String type, f
             return null;
         }
 
+        if (sa.isKeyword(Keyword.STATION)) {
+            typeList.removeAll(CardLists.filter(typeList, c -> c.getNetPower() <= 0));
+        }
+
         CardLists.sortByPowerAsc(typeList);
         // TODO prefer noncreatures without tap abilities
 

forge-ai/src/main/java/forge/ai/ability/CountersPutAi.java

@@ -302,6 +302,8 @@ protected AiAbilityDecision checkApiLogic(Player ai, final SpellAbility sa) {
             return doChargeToOppCtrlCMCLogic(ai, sa);
         } else if (logic.equals("TheOneRing")) {
             return SpecialCardAi.TheOneRing.consider(ai, sa);
+        } else if (sa.isKeyword(Keyword.STATION)) {
+            return doStationAi(ai, sa);
         }
 
         if (sourceName.equals("Feat of Resistance")) { // sub-ability should take precedence
@@ -1237,4 +1239,46 @@ private AiAbilityDecision doChargeToOppCtrlCMCLogic(Player ai, SpellAbility sa)
         // If the AI has enough counters or more than the optimal CMC, it should not play the ability.
         return new AiAbilityDecision(0, AiPlayDecision.CantPlayAi);
     }
+
+    private AiAbilityDecision doStationAi(Player ai, SpellAbility sa) {
+        Card source = sa.getHostCard();
+        PhaseHandler ph = source.getGame().getPhaseHandler();
+
+        int numStation = source.getKeywordMagnitude(Keyword.STATION);
+        int numCharge = source.getCounters(CounterEnumType.CHARGE);
+        CardCollection canTap = CardLists.filter(ai.getCreaturesInPlay(), c -> c.getNetPower() > 0 && c.isUntapped());
+        if (canTap.isEmpty()) {
+            return new AiAbilityDecision(0, AiPlayDecision.CantPlayAi);
+        }
+
+        CardLists.sortByPowerAsc(canTap); // Note: matches the way chooseTapType sorts them; maybe worth sorting in descending order for Station?
+
+        // TODO: make this smarter so that the AI is better at predicting conditions when this is safe
+        // (also needs a modification to willPayCosts and ComputerUtil.chooseTapType to make better choices for what exactly to tap)
+
+        // If a single creature is enough to turn an untapped station into a creature, allow it
+        if (ph.is(PhaseType.MAIN1, ai)) {
+            Card firstToTap = canTap.getFirst();
+            if (source.getType().hasSubtype("Spacecraft") && !source.isCreature() && source.isUntapped()) {
+                if (numCharge < numStation && numCharge + firstToTap.getNetPower() >= numStation
+                        && firstToTap.getNetPower() <= source.getBasePower()) {
+                    return new AiAbilityDecision(100, AiPlayDecision.WillPlay);
+                }
+            }
+        }
+
+        // If there's nothing to possibly block next turn, or we can reasonably stay on high enough life, go for it
+        if (ph.is(PhaseType.MAIN2, ai)) {
+            List<Card> nextTurnAttackers = CardLists.filter(ai.getStrongestOpponent().getCreaturesInPlay(), c -> CombatUtil.canAttackNextTurn(c, ai));
+            CardCollection blockerList = CardLists.filter(canTap, CardPredicates.possibleBlockerForAtLeastOne(nextTurnAttackers));
+
+            if (numCharge < numStation) {
+                if (blockerList.isEmpty() || ComputerUtil.predictNextCombatsRemainingLife(ai, false, true, 0, blockerList) > ai.getStartingLife() * 2 / 3) {
+                    return new AiAbilityDecision(100, AiPlayDecision.WillPlay);
+                }
+            }
+        }
+
+        return new AiAbilityDecision(0, AiPlayDecision.AnotherTime);
+    }
 }