warn if "play top card until" filter expression doesn't match any card in database (#5243)

* make FilterString::check const

* implement thing

cockatrice/src/dialogs/dlg_move_top_cards_until.cpp

@@ -1,5 +1,7 @@
 #include "dlg_move_top_cards_until.h"
 
+#include "../game/cards/card_database.h"
+#include "../game/cards/card_database_manager.h"
 #include "../game/filters/filter_string.h"
 #include "trice_limits.h"
 
@@ -45,14 +47,57 @@ DlgMoveTopCardsUntil::DlgMoveTopCardsUntil(QWidget *parent, QString _expr, uint
     setWindowTitle(tr("Put top cards on stack until..."));
 }
 
+/**
+ * @brief Checks if a card matching the expr exists in the card database.
+ *
+ * @returns true if a card matching the expression exists.
+ */
+static bool matchExistsInDb(const FilterString &filterString)
+{
+    const auto cardDatabase = CardDatabaseManager::getInstance();
+    const auto allCards = cardDatabase->getCardList();
+
+    const auto it = std::find_if(allCards.begin(), allCards.end(),
+                                 [&filterString](const CardInfoPtr &card) { return filterString.check(card); });
+
+    return it != allCards.end();
+}
+
+/**
+ * @brief Validates that a card matching the expr exists in the card database.
+ * If no match is found, then pop up a window to warn the user, giving them a chance to back out.
+ *
+ * @returns whether to proceed with the action
+ */
+bool DlgMoveTopCardsUntil::validateMatchExists(const FilterString &filterString)
+{
+    if (matchExistsInDb(filterString)) {
+        return true;
+    }
+
+    const auto msg = tr("No cards matching the search expression exists in the card database. Proceed anyways?");
+    const auto res =
+        QMessageBox::warning(this, tr("Cockatrice"), msg, QMessageBox::Yes | QMessageBox::No, QMessageBox::No);
+    if (res == QMessageBox::No) {
+        return false;
+    }
+
+    return true;
+}
+
 void DlgMoveTopCardsUntil::validateAndAccept()
 {
     auto movingCardsUntilFilter = FilterString(exprEdit->text());
-    if (movingCardsUntilFilter.valid()) {
-        accept();
-    } else {
+    if (!movingCardsUntilFilter.valid()) {
         QMessageBox::warning(this, tr("Invalid filter"), movingCardsUntilFilter.error(), QMessageBox::Ok);
+        return;
     }
+
+    if (!validateMatchExists(movingCardsUntilFilter)) {
+        return;
+    }
+
+    accept();
 }
 
 QString DlgMoveTopCardsUntil::getExpr() const

cockatrice/src/dialogs/dlg_move_top_cards_until.h

@@ -6,7 +6,8 @@
 #include <QLabel>
 #include <QLineEdit>
 #include <QSpinBox>
-#include <QString>
+
+class FilterString;
 
 class DlgMoveTopCardsUntil : public QDialog
 {
@@ -18,6 +19,7 @@ class DlgMoveTopCardsUntil : public QDialog
     QDialogButtonBox *buttonBox;
 
     void validateAndAccept();
+    bool validateMatchExists(const FilterString &filterString);
 
 public:
     explicit DlgMoveTopCardsUntil(QWidget *parent = nullptr, QString expr = QString(), uint numberOfHits = 1);

cockatrice/src/game/filters/filter_string.h

@@ -26,7 +26,7 @@ class FilterString
 public:
     FilterString();
     explicit FilterString(const QString &exp);
-    bool check(const CardData &card)
+    bool check(const CardData &card) const
     {
         return result(card);
     }