[Server] Support face-down cards in all public zones (#6539)

* [Server] Support face-down cards in all public zones

* add null check

* Check using zone names instead

* add comment

libcockatrice_network/libcockatrice/network/server/remote/game/server_abstract_player.cpp

@@ -198,6 +198,35 @@ shouldDestroyOnMove(const Server_Card *card, const Server_CardZone *startZone, c
     return true;
 }
 
+/**
+ * @brief Determines whether the moved card should be face-down
+ */
+static bool
+shouldBeFaceDown(const MoveCardStruct &cardStruct, const Server_CardZone *startZone, const Server_CardZone *targetZone)
+{
+    if (!targetZone) {
+        return false;
+    }
+
+    // being face-down only makes sense for public zones
+    if (targetZone->getType() != ServerInfo_Zone::PublicZone) {
+        return false;
+    }
+
+    // face-down property in proto takes precedence
+    if (cardStruct.cardToMove->has_face_down()) {
+        return cardStruct.cardToMove->face_down();
+    }
+
+    // Default to keep face-down the same if zone didn't change.
+    // Compare using zone names because face-down is maintained when changing controllers.
+    if (startZone && startZone->getName() == targetZone->getName()) {
+        return cardStruct.card->getFaceDown();
+    }
+
+    return false;
+}
+
 Response::ResponseCode Server_AbstractPlayer::moveCard(GameEventStorage &ges,
                                                        Server_CardZone *startzone,
                                                        const QList<const CardToMove *> &_cards,
@@ -257,10 +286,7 @@ Response::ResponseCode Server_AbstractPlayer::moveCard(GameEventStorage &ges,
 
     for (auto cardStruct : cardsToMove) {
         Server_Card *card = cardStruct.card;
-        const CardToMove *thisCardProperties = cardStruct.cardToMove;
         int originalPosition = cardStruct.position;
-        bool faceDown = targetzone->hasCoords() &&
-                        (thisCardProperties->has_face_down() ? thisCardProperties->face_down() : card->getFaceDown());
 
         bool sourceBeingLookedAt;
         int position = startzone->removeCard(card, sourceBeingLookedAt);
@@ -315,6 +341,8 @@ Response::ResponseCode Server_AbstractPlayer::moveCard(GameEventStorage &ges,
             ++xIndex;
             int newX = isReversed ? targetzone->getCards().size() - xCoord + xIndex : xCoord + xIndex;
 
+            bool faceDown = shouldBeFaceDown(cardStruct, startzone, targetzone);
+
             if (targetzone->hasCoords()) {
                 newX = targetzone->getFreeGridColumn(newX, yCoord, card->getName(), faceDown);
             } else {

libcockatrice_protocol/libcockatrice/protocol/pb/command_move_card.proto

@@ -6,7 +6,9 @@ message CardToMove {
     // Id of the card in its current zone
     optional sint32 card_id = 1 [default = -1];
 
-    // Places the card face down, hiding its name
+    // If true, places the card face down, hiding its name.
+    // If false, forcibly turns the card face up.
+    // If not set, defers the resulting face down state to the server.
     optional bool face_down = 2;
 
     // When moving add this value to the power/toughness field of the card