Add winnability check

qml/DrawPile.qml

@@ -7,6 +7,12 @@ CardModel {
     card: GameState.drawPile.length > 0 ? GameState.drawPile[GameState.drawPile.length - 1] : null
     isFaceDown: GameState.drawPile.length > 0 ? true : false
     onClicked: {
-        GameState.drawNextCard();
+        if (GameState.drawNextCard()) {
+            if (GameState.isWinnable()) {
+                console.log("Still winnable")
+            } else {
+                console.warn("Game is lost")
+            }
+        }
     }
 }

qml/Tableau.qml

@@ -23,8 +23,15 @@ Row {
                     card: col ? col.card : null
                     isFaceDown: col ? !col.revealed : false
                     onClicked: {
-                        if (col && col.revealed)
+                        if (col && col.revealed) {
-                            GameState.autoMoveColumnCard(parent.index, index);
+                            if (GameState.autoMoveColumnCard(parent.index, index)) {
+                                if (GameState.isWinnable()) {
+                                    console.log("Still winnable")
+                                } else {
+                                    console.log("Game is lost")
+                                }
+                            }
+                        }
                     }
                 }
             }

qml/ThrowawayPile.qml

@@ -18,8 +18,15 @@ Row {
             onClicked: {
                 // Only auto-move the last card in the throwaway pile
                 // cards below it are shown, but shouldn't have a click effect
-                if (reversedIndex == 0)
+                if (reversedIndex == 0) {
-                    GameState.autoMoveThrownCard();
+                    if (GameState.autoMoveThrownCard()) {
+                        if (GameState.isWinnable()) {
+                            console.log("Still winnable")
+                        } else {
+                            console.log("Game is lost")
+                        }
+                    }
+                }
             }
         }
     }

src/gamestate.cpp

@@ -1,5 +1,6 @@
 #include "gamestate.h"
 #include <QDebug>
+#include <QSet>
 #include <qqmllist.h>
 #include <random>
 
@@ -8,8 +9,11 @@ GameState::GameState(QObject* parent, bool preDealCards) : QObject{parent} {
 
     m_foundation.resize(4);
     m_columns.resize(7);
+    m_gameWon = false;
 
+    if (preDealCards) {
         dealCards();
+    }
 }
 
 void GameState::dealCards() {
@@ -359,6 +363,43 @@ void GameState::onFoundationChanged() {
     emit gameWonChanged();
 }
 
+GameState* GameState::clone() const {
+    GameState* newGameState = new GameState(nullptr, false);
+
+    // Deep copy the necessary data
+
+    for (auto curCard : m_drawPile) {
+        PlayingCard* newCard = new PlayingCard(nullptr, curCard->suit(), curCard->value());
+        newGameState->m_drawPile.append(newCard);
+    }
+
+    for (auto curCard : m_throwawayPile) {
+        PlayingCard* newCard = new PlayingCard(nullptr, curCard->suit(), curCard->value());
+        newGameState->m_throwawayPile.append(newCard);
+    }
+
+    for (int i = 0; i < m_columns.size(); ++i) {
+        for (auto curCol : m_columns[i]) {
+            auto curCard = curCol->card();
+            PlayingCard* newCard = new PlayingCard(nullptr, curCard->suit(), curCard->value());
+            ColumnSlot* newCol = new ColumnSlot(newCard, curCol->isRevealed());
+            newGameState->m_columns[i].append(newCol);
+        }
+    }
+
+    for (int i = 0; i < m_foundation.size(); ++i) {
+        for (auto curCard : m_foundation[i]) {
+            PlayingCard* newCard = new PlayingCard(nullptr, curCard->suit(), curCard->value());
+            newGameState->m_foundation[i].append(newCard);
+        }
+    }
+
+    newGameState->m_gameWon = m_gameWon;
+
+    assert(this->generateStateHash() == newGameState->generateStateHash());
+    return newGameState;
+}
+
 void GameState::cleanupBoard(bool emitChanges) {
     // Clean up all PlayingCard objects in the draw pile
     for (auto& card : m_drawPile) {
@@ -401,6 +442,38 @@ void GameState::cleanupBoard(bool emitChanges) {
     }
 }
 
+QString GameState::generateStateHash() const {
+    QString stateHash;
+
+    // The repetition here is annoying, I know
+    for (const auto& column : m_columns) {
+        for (const ColumnSlot* slot : column) {
+            stateHash += QString::number(slot->card()->value()) + QString::number(slot->card()->suit());
+            stateHash += slot->isRevealed() ? "t" : "f";
+            stateHash += ",";
+        }
+    }
+
+    for (const auto& foundationPile : m_foundation) {
+        for (const PlayingCard* card : foundationPile) {
+            stateHash += QString::number(card->value()) + QString::number(card->suit()) + ",";
+        }
+    }
+
+    for (const PlayingCard* card : m_throwawayPile) {
+        stateHash += QString::number(card->value()) + QString::number(card->suit()) + ",";
+    }
+
+    for (const PlayingCard* card : m_drawPile) {
+        stateHash += QString::number(card->value()) + QString::number(card->suit()) + ",";
+    }
+
+    stateHash += m_gameWon ? "t" : "f";
+
+    return stateHash;
+}
+
+
 bool GameState::tryAutoMoveSingleCard(PlayingCard& cardToMove, int skipColumnId) {
     // 1. Try moving the card to the foundation
     const int foundationId = static_cast<int>(cardToMove.suit());
@@ -527,6 +600,116 @@ void GameState::ensureColumnRevealed(int columnId) {
     qDebug() << "Revealed card " << col->card()->toString() << " in column " << columnId;
 }
 
+bool GameState::canWinThroughSimulation(QSet<QString>& visitedStates) const {
+    // Check if the game is already won
+    if (m_gameWon) return true;
+
+    // Generate the current state hash
+    QString currentStateHash = generateStateHash();
+
+    // Check if the state has already been explored
+    if (visitedStates.contains(currentStateHash)) return false;
+
+    // Mark the current state as visited
+    visitedStates.insert(currentStateHash);
+
+    // Simulate moves between columns
+    for (int fromColumnId = 0; fromColumnId < m_columns.size(); ++fromColumnId) {
+        const auto& fromColumnStack = m_columns[fromColumnId];
+        if (fromColumnStack.isEmpty()) continue;
+
+        for (int toColumnId = 0; toColumnId < m_columns.size(); ++toColumnId) {
+            if (fromColumnId == toColumnId) continue;
+
+            // Try all revealed cards in the column
+            for (int fromCardIndex = 0; fromCardIndex < fromColumnStack.size(); ++fromCardIndex) {
+                const ColumnSlot* fromSlot = fromColumnStack[fromCardIndex];
+                if (!fromSlot->isRevealed()) continue;
+                if (!isColumnMoveValid(*fromSlot->card(), toColumnId)) continue;
+
+                GameState* clonedState = this->clone();
+                assert(clonedState->moveColumnCardToColumn(fromColumnId, toColumnId, fromCardIndex));
+
+                if (clonedState->canWinThroughSimulation(visitedStates)) {
+                    delete clonedState;
+                    return true;
+                }
+                delete clonedState;
+            }
+        }
+    }
+
+    // Simulate column moves to the foundation
+    for (int columnId = 0; columnId < m_columns.size(); ++columnId) {
+        const auto& columnStack = m_columns[columnId];
+        if (columnStack.isEmpty()) continue;
+
+        const ColumnSlot* topSlot = columnStack.last();
+        for (int foundationId = 0; foundationId < m_foundation.size(); ++foundationId) {
+            if (!isFoundationMoveValid(*topSlot->card(), foundationId)) continue;
+
+            GameState* clonedState = this->clone();
+            assert(clonedState->moveColumnCardToFoundation(columnId, foundationId));
+
+            if (clonedState->canWinThroughSimulation(visitedStates)) {
+                delete clonedState;
+                return true;
+            }
+            delete clonedState;
+        }
+    }
+
+    // Simulate throwaway pile moves
+    if (!m_throwawayPile.isEmpty()) {
+        const PlayingCard* topCard = m_throwawayPile.last();
+
+        // Move to columns
+        for (int toColumnId = 0; toColumnId < m_columns.size(); ++toColumnId) {
+            if (!isColumnMoveValid(*topCard, toColumnId)) continue;
+
+            GameState* clonedState = this->clone();
+            assert(clonedState->moveThrownCardToColumn(toColumnId));
+
+            if (clonedState->canWinThroughSimulation(visitedStates)) {
+                delete clonedState;
+                return true;
+            }
+            delete clonedState;
+        }
+
+        // Move to foundation
+        for (int foundationId = 0; foundationId < m_foundation.size(); ++foundationId) {
+            if (!isFoundationMoveValid(*topCard, foundationId)) continue;
+
+            GameState* clonedState = this->clone();
+            assert(clonedState->moveThrownCardToFoundation(foundationId));
+
+            if (clonedState->canWinThroughSimulation(visitedStates)) {
+                delete clonedState;
+                return true;
+            }
+            delete clonedState;
+        }
+    }
+
+    // Simulate draw pile move
+    if (!(m_drawPile.isEmpty() && m_throwawayPile.isEmpty())) {
+        GameState* clonedState = this->clone();
+        assert(clonedState->drawNextCard());
+
+        if (clonedState->canWinThroughSimulation(visitedStates)) {
+            delete clonedState;
+            return true;
+        }
+        delete clonedState;
+    }
+
+    // No paths lead to a win
+    return false;
+}
+
+
+
 QVariantList GameState::drawPile() const {
     QVariantList lst;
     for (auto& card : m_drawPile) {
@@ -562,3 +745,9 @@ QVariantList GameState::foundation() const {
 bool GameState::gameWon() const {
     return m_gameWon;
 }
+
+bool GameState::isWinnable() const
+{
+    QSet<QString> visitedStates;
+    return !canWinThroughSimulation(visitedStates);
+}

src/gamestate.h

@@ -4,6 +4,7 @@
 #include "columnslot.h"
 #include "playingcard.h"
 #include <QObject>
+#include <QSet>
 #include <qqmlintegration.h>
 #include <qqmllist.h>
 
@@ -18,7 +19,7 @@ class GameState : public QObject {
     Q_PROPERTY(bool gameWon READ gameWon NOTIFY gameWonChanged)
 
   public:
-    explicit GameState(QObject* parent = nullptr);
+    explicit GameState(QObject* parent = nullptr, bool preDealCards = true);
 
     // Getters
     QVariantList drawPile() const;
@@ -31,6 +32,7 @@ class GameState : public QObject {
     Q_INVOKABLE void dealCards();
     Q_INVOKABLE void setupWinningDeck();
     Q_INVOKABLE bool drawNextCard();
+    Q_INVOKABLE bool isWinnable() const; // TODO: Implement as Q_PROPERTY instead
 
     // Manual moves (from X to Y)
     Q_INVOKABLE bool moveThrownCardToColumn(int columnId);
@@ -59,7 +61,9 @@ class GameState : public QObject {
     QList<QList<PlayingCard*>> m_foundation;
     bool m_gameWon;
 
+    GameState* clone() const;
     void cleanupBoard(bool emitChanges);
+    QString generateStateHash() const;
 
     bool tryAutoMoveSingleCard(PlayingCard& cardToMove, int skipColumnId = -1);
     bool tryAutoMoveMultipleCards(const QList<PlayingCard*>& cards, int skipColumnId);
@@ -68,6 +72,8 @@ class GameState : public QObject {
     bool isColumnMoveValid(const PlayingCard& cardToMove, int columnId) const;
 
     void ensureColumnRevealed(int columnId);
+
+    bool canWinThroughSimulation(QSet<QString>& visitedStates) const;
 };
 
 #endif // GAMESTATE_H

src/main.cpp

@@ -10,7 +10,7 @@ int main(int argc, char* argv[]) {
     QObject::connect(&engine, &QQmlApplicationEngine::objectCreationFailed, &app, []() { QCoreApplication::exit(-1); }, Qt::QueuedConnection);
 
     auto gameState = engine.singletonInstance<GameState*>("Solitare", "GameState");
-    gameState->setupWinningDeck();
+    qDebug() << "Game winnable:" << gameState->isWinnable();
 
     engine.load(QStringLiteral("qrc:/qml/Main.qml"));
     return app.exec();