Bought resources refactoring

14 files changed, 188 insertions, 133 deletions

diff --git a/game-engine/src/main/java/org/luxons/sevenwonders/game/api/PlayerMove.java b/game-engine/src/main/java/org/luxons/sevenwonders/game/api/PlayerMove.java
index bad8f852..807e51a9 100644
--- a/game-engine/src/main/java/org/luxons/sevenwonders/game/api/PlayerMove.java
+++ b/game-engine/src/main/java/org/luxons/sevenwonders/game/api/PlayerMove.java
@@ -1,10 +1,10 @@
 package org.luxons.sevenwonders.game.api;
 
 import java.util.ArrayList;
-import java.util.List;
+import java.util.Collection;
 
 import org.luxons.sevenwonders.game.moves.MoveType;
-import org.luxons.sevenwonders.game.resources.BoughtResources;
+import org.luxons.sevenwonders.game.resources.ResourceTransaction;
 
 public class PlayerMove {
 
@@ -12,7 +12,7 @@ public class PlayerMove {
 
     private String cardName;
 
-    private List<BoughtResources> boughtResources = new ArrayList<>();
+    private Collection<ResourceTransaction> transactions = new ArrayList<>();
 
     public MoveType getType() {
         return type;
@@ -30,12 +30,12 @@ public class PlayerMove {
         this.cardName = cardName;
     }
 
-    public List<BoughtResources> getBoughtResources() {
-        return boughtResources;
+    public Collection<ResourceTransaction> getTransactions() {
+        return transactions;
     }
 
-    public void setBoughtResources(List<BoughtResources> boughtResources) {
-        this.boughtResources = boughtResources;
+    public void setTransactions(Collection<ResourceTransaction> transactions) {
+        this.transactions = transactions;
     }
 
     @Override
diff --git a/game-engine/src/main/java/org/luxons/sevenwonders/game/cards/Card.java b/game-engine/src/main/java/org/luxons/sevenwonders/game/cards/Card.java
index 084d19a5..2d2f6777 100644
--- a/game-engine/src/main/java/org/luxons/sevenwonders/game/cards/Card.java
+++ b/game-engine/src/main/java/org/luxons/sevenwonders/game/cards/Card.java
@@ -6,7 +6,7 @@ import java.util.Objects;
 import org.luxons.sevenwonders.game.api.Table;
 import org.luxons.sevenwonders.game.boards.Board;
 import org.luxons.sevenwonders.game.effects.Effect;
-import org.luxons.sevenwonders.game.resources.BoughtResources;
+import org.luxons.sevenwonders.game.resources.ResourceTransactions;
 
 public class Card {
 
@@ -93,13 +93,13 @@ public class Card {
         if (!isAllowedOnBoard(board)) {
             return false;
         }
-        return isChainableOn(board) || requirements.couldBeMetBy(table, playerIndex);
+        return isChainableOn(board) || requirements.areMetBy(table, playerIndex);
     }
 
-    public void applyTo(Table table, int playerIndex, List<BoughtResources> boughtResources) {
+    public void applyTo(Table table, int playerIndex, ResourceTransactions transactions) {
         Board playerBoard = table.getBoard(playerIndex);
         if (!isChainableOn(playerBoard)) {
-            requirements.pay(table, playerIndex, boughtResources);
+            requirements.pay(table, playerIndex, transactions);
         }
         effects.forEach(e -> e.apply(table, playerIndex));
     }
diff --git a/game-engine/src/main/java/org/luxons/sevenwonders/game/cards/Requirements.java b/game-engine/src/main/java/org/luxons/sevenwonders/game/cards/Requirements.java
index 3f9c4409..8c7245ed 100644
--- a/game-engine/src/main/java/org/luxons/sevenwonders/game/cards/Requirements.java
+++ b/game-engine/src/main/java/org/luxons/sevenwonders/game/cards/Requirements.java
@@ -1,12 +1,9 @@
 package org.luxons.sevenwonders.game.cards;
 
-import java.util.List;
-
 import org.luxons.sevenwonders.game.api.Table;
 import org.luxons.sevenwonders.game.boards.Board;
-import org.luxons.sevenwonders.game.boards.RelativeBoardPosition;
 import org.luxons.sevenwonders.game.resources.BestPriceCalculator;
-import org.luxons.sevenwonders.game.resources.BoughtResources;
+import org.luxons.sevenwonders.game.resources.ResourceTransactions;
 import org.luxons.sevenwonders.game.resources.Resources;
 
 public class Requirements {
@@ -53,7 +50,7 @@ public class Requirements {
      *
      * @return true if the given board meets these requirements
      */
-    public boolean areMetWithHelpBy(Board board, List<BoughtResources> boughtResources) {
+    public boolean areMetWithHelpBy(Board board, ResourceTransactions boughtResources) {
         if (!hasRequiredGold(board, boughtResources)) {
             return false;
         }
@@ -64,7 +61,7 @@ public class Requirements {
     }
 
     /**
-     * Returns whether the given player's board could meet these requirements, on its own or by buying resources to
+     * Returns whether the given player's board meets these requirements, either on its own or by buying resources to
      * neighbours.
      *
      * @param table
@@ -74,7 +71,7 @@ public class Requirements {
      *
      * @return true if the given player's board could meet these requirements
      */
-    boolean couldBeMetBy(Table table, int playerIndex) {
+    boolean areMetBy(Table table, int playerIndex) {
         Board board = table.getBoard(playerIndex);
         if (!hasRequiredGold(board)) {
             return false;
@@ -89,8 +86,8 @@ public class Requirements {
         return board.getGold() >= gold;
     }
 
-    private boolean hasRequiredGold(Board board, List<BoughtResources> boughtResources) {
-        int resourcesPrice = board.getTradingRules().computeCost(boughtResources);
+    private boolean hasRequiredGold(Board board, ResourceTransactions resourceTransactions) {
+        int resourcesPrice = board.getTradingRules().computeCost(resourceTransactions);
         return board.getGold() >= gold + resourcesPrice;
     }
 
@@ -98,34 +95,14 @@ public class Requirements {
         return board.getProduction().contains(resources);
     }
 
-    private boolean producesRequiredResourcesWithHelp(Board board, List<BoughtResources> boughtResources) {
-        Resources totalBoughtResources = getTotalResources(boughtResources);
+    private boolean producesRequiredResourcesWithHelp(Board board, ResourceTransactions transactions) {
+        Resources totalBoughtResources = transactions.asResources();
         Resources remainingResources = this.resources.minus(totalBoughtResources);
         return board.getProduction().contains(remainingResources);
     }
 
-    private static Resources getTotalResources(List<BoughtResources> boughtResources) {
-        return boughtResources.stream().map(BoughtResources::getResources).reduce(new Resources(), (r1, r2) -> {
-            r1.addAll(r2);
-            return r1;
-        });
-    }
-
-    public void pay(Table table, int playerIndex, List<BoughtResources> boughtResources) {
+    public void pay(Table table, int playerIndex, ResourceTransactions transactions) {
         table.getBoard(playerIndex).removeGold(gold);
-        payBoughtResources(table, playerIndex, boughtResources);
-    }
-
-    private void payBoughtResources(Table table, int playerIndex, List<BoughtResources> boughtResourcesList) {
-        boughtResourcesList.forEach(res -> payBoughtResources(table, playerIndex, res));
-    }
-
-    private void payBoughtResources(Table table, int playerIndex, BoughtResources boughtResources) {
-        Board board = table.getBoard(playerIndex);
-        int price = board.getTradingRules().computeCost(boughtResources);
-        board.removeGold(price);
-        RelativeBoardPosition providerPosition = boughtResources.getProvider().getBoardPosition();
-        Board providerBoard = table.getBoard(playerIndex, providerPosition);
-        providerBoard.addGold(price);
+        transactions.execute(table, playerIndex);
     }
 }
diff --git a/game-engine/src/main/java/org/luxons/sevenwonders/game/moves/BuildWonderMove.java b/game-engine/src/main/java/org/luxons/sevenwonders/game/moves/BuildWonderMove.java
index f1cb50b3..f70d2626 100644
--- a/game-engine/src/main/java/org/luxons/sevenwonders/game/moves/BuildWonderMove.java
+++ b/game-engine/src/main/java/org/luxons/sevenwonders/game/moves/BuildWonderMove.java
@@ -18,7 +18,7 @@ public class BuildWonderMove extends CardFromHandMove {
     public void validate(Table table, List<Card> playerHand) throws InvalidMoveException {
         super.validate(table, playerHand);
         Board board = table.getBoard(getPlayerIndex());
-        if (!board.getWonder().isNextStageBuildable(table, getPlayerIndex(), getBoughtResources())) {
+        if (!board.getWonder().isNextStageBuildable(table, getPlayerIndex(), getTransactions())) {
             throw new InvalidMoveException(
                     String.format("Player %d cannot upgrade his wonder with the given resources", getPlayerIndex()));
         }
@@ -34,6 +34,6 @@ public class BuildWonderMove extends CardFromHandMove {
     public void activate(Table table, List<Card> discardedCards, Settings settings) {
         int playerIndex = getPlayerIndex();
         Board board = table.getBoard(playerIndex);
-        board.getWonder().activateLastBuiltStage(table, playerIndex, getBoughtResources());
+        board.getWonder().activateLastBuiltStage(table, playerIndex, getTransactions());
     }
 }
diff --git a/game-engine/src/main/java/org/luxons/sevenwonders/game/moves/Move.java b/game-engine/src/main/java/org/luxons/sevenwonders/game/moves/Move.java
index 230b9ef1..cfb12e67 100644
--- a/game-engine/src/main/java/org/luxons/sevenwonders/game/moves/Move.java
+++ b/game-engine/src/main/java/org/luxons/sevenwonders/game/moves/Move.java
@@ -6,7 +6,7 @@ import org.luxons.sevenwonders.game.Settings;
 import org.luxons.sevenwonders.game.api.PlayerMove;
 import org.luxons.sevenwonders.game.api.Table;
 import org.luxons.sevenwonders.game.cards.Card;
-import org.luxons.sevenwonders.game.resources.BoughtResources;
+import org.luxons.sevenwonders.game.resources.ResourceTransactions;
 
 public abstract class Move {
 
@@ -16,13 +16,13 @@ public abstract class Move {
 
     private MoveType type;
 
-    private List<BoughtResources> boughtResources;
+    private ResourceTransactions transactions;
 
     Move(int playerIndex, Card card, PlayerMove move) {
         this.playerIndex = playerIndex;
         this.card = card;
         this.type = move.getType();
-        this.boughtResources = move.getBoughtResources();
+        this.transactions = new ResourceTransactions(move.getTransactions());
     }
 
     public int getPlayerIndex() {
@@ -37,8 +37,8 @@ public abstract class Move {
         return type;
     }
 
-    public List<BoughtResources> getBoughtResources() {
-        return boughtResources;
+    public ResourceTransactions getTransactions() {
+        return transactions;
     }
 
     public abstract void validate(Table table, List<Card> playerHand) throws InvalidMoveException;
diff --git a/game-engine/src/main/java/org/luxons/sevenwonders/game/moves/PlayCardMove.java b/game-engine/src/main/java/org/luxons/sevenwonders/game/moves/PlayCardMove.java
index 82052981..18d6ba90 100644
--- a/game-engine/src/main/java/org/luxons/sevenwonders/game/moves/PlayCardMove.java
+++ b/game-engine/src/main/java/org/luxons/sevenwonders/game/moves/PlayCardMove.java
@@ -19,7 +19,7 @@ public class PlayCardMove extends CardFromHandMove {
         super.validate(table, playerHand);
         Board board = table.getBoard(getPlayerIndex());
         if (!getCard().isChainableOn(board) && !getCard().getRequirements()
-                                                         .areMetWithHelpBy(board, getBoughtResources())) {
+                                                         .areMetWithHelpBy(board, getTransactions())) {
             throw new InvalidMoveException(
                     String.format("Player %d cannot play the card %s with the given resources", getPlayerIndex(),
                             getCard().getName()));
@@ -34,6 +34,6 @@ public class PlayCardMove extends CardFromHandMove {
 
     @Override
     public void activate(Table table, List<Card> discardedCards, Settings settings) {
-        getCard().applyTo(table, getPlayerIndex(), getBoughtResources());
+        getCard().applyTo(table, getPlayerIndex(), getTransactions());
     }
 }
diff --git a/game-engine/src/main/java/org/luxons/sevenwonders/game/resources/BestPriceCalculator.java b/game-engine/src/main/java/org/luxons/sevenwonders/game/resources/BestPriceCalculator.java
index bde6dcb9..10ac8343 100644
--- a/game-engine/src/main/java/org/luxons/sevenwonders/game/resources/BestPriceCalculator.java
+++ b/game-engine/src/main/java/org/luxons/sevenwonders/game/resources/BestPriceCalculator.java
@@ -14,11 +14,11 @@ public class BestPriceCalculator {
 
     private final List<ResourcePool> pools;
 
-    private final List<BoughtResources> boughtResources;
+    private final ResourceTransactions boughtResources;
 
     private int pricePaid;
 
-    private List<BoughtResources> bestSolution;
+    private ResourceTransactions bestSolution;
 
     private int bestPrice;
 
@@ -26,7 +26,7 @@ public class BestPriceCalculator {
         Board board = table.getBoard(playerIndex);
         this.resourcesLeftToPay = resourcesToPay.minus(board.getProduction().getFixedResources());
         this.pools = createResourcePools(table, playerIndex);
-        this.boughtResources = new ArrayList<>();
+        this.boughtResources = new ResourceTransactions();
         this.pricePaid = 0;
         this.bestSolution = null;
         this.bestPrice = Integer.MAX_VALUE;
@@ -56,10 +56,10 @@ public class BestPriceCalculator {
         return bestPriceCalculator.bestPrice;
     }
 
-    public static List<BoughtResources> bestSolution(Resources resources, Table table, int playerIndex) {
-        BestPriceCalculator bestPriceCalculator = new BestPriceCalculator(resources, table, playerIndex);
-        bestPriceCalculator.computePossibilities();
-        return bestPriceCalculator.bestSolution;
+    public static ResourceTransactions bestSolution(Resources resources, Table table, int playerIndex) {
+        BestPriceCalculator calculator = new BestPriceCalculator(resources, table, playerIndex);
+        calculator.computePossibilities();
+        return calculator.bestSolution;
     }
 
     private void computePossibilities() {
@@ -77,15 +77,14 @@ public class BestPriceCalculator {
                         resourcesLeftToPay.add(type, 1);
                         continue;
                     }
-                    BoughtResources boughtRes = new BoughtResources(pool.getProvider(), Resources.of(type));
                     int cost = pool.getCost(type);
 
                     resourcesLeftToPay.remove(type, 1);
-                    boughtResources.add(boughtRes);
+                    boughtResources.add(pool.getProvider(), Resources.of(type));
                     pricePaid += cost;
                     computePossibilitiesWhenUsing(type, pool);
                     pricePaid -= cost;
-                    boughtResources.remove(boughtRes);
+                    boughtResources.remove(pool.getProvider(), Resources.of(type));
                     resourcesLeftToPay.add(type, 1);
                 }
             }
@@ -106,7 +105,7 @@ public class BestPriceCalculator {
     private void updateBestSolutionIfNeeded() {
         if (pricePaid < bestPrice) {
             bestPrice = pricePaid;
-            bestSolution = new ArrayList<>(boughtResources);
+            bestSolution = new ResourceTransactions(boughtResources.toTransactions());
         }
     }
 }
diff --git a/game-engine/src/main/java/org/luxons/sevenwonders/game/resources/BoughtResources.java b/game-engine/src/main/java/org/luxons/sevenwonders/game/resources/BoughtResources.java
deleted file mode 100644
index 71293190..00000000
--- a/game-engine/src/main/java/org/luxons/sevenwonders/game/resources/BoughtResources.java
+++ /dev/null
@@ -1,56 +0,0 @@
-package org.luxons.sevenwonders.game.resources;
-
-import java.util.Objects;
-
-public class BoughtResources {
-
-    private Provider provider;
-
-    private Resources resources;
-
-    public BoughtResources() {
-    }
-
-    public BoughtResources(Provider provider, Resources resources) {
-        this.provider = provider;
-        this.resources = resources;
-    }
-
-    public Provider getProvider() {
-        return provider;
-    }
-
-    public void setProvider(Provider provider) {
-        this.provider = provider;
-    }
-
-    public Resources getResources() {
-        return resources;
-    }
-
-    public void setResources(Resources resources) {
-        this.resources = resources;
-    }
-
-    @Override
-    public boolean equals(Object o) {
-        if (this == o) {
-            return true;
-        }
-        if (o == null || getClass() != o.getClass()) {
-            return false;
-        }
-        BoughtResources that = (BoughtResources) o;
-        return provider == that.provider && Objects.equals(resources, that.resources);
-    }
-
-    @Override
-    public int hashCode() {
-        return Objects.hash(provider, resources);
-    }
-
-    @Override
-    public String toString() {
-        return "BoughtResources{" + "provider=" + provider + ", resources=" + resources + '}';
-    }
-}
diff --git a/game-engine/src/main/java/org/luxons/sevenwonders/game/resources/ResourceTransaction.java b/game-engine/src/main/java/org/luxons/sevenwonders/game/resources/ResourceTransaction.java
new file mode 100644
index 00000000..3cb8eea1
--- /dev/null
+++ b/game-engine/src/main/java/org/luxons/sevenwonders/game/resources/ResourceTransaction.java
@@ -0,0 +1,53 @@
+package org.luxons.sevenwonders.game.resources;
+
+import java.util.Objects;
+
+import org.luxons.sevenwonders.game.api.Table;
+import org.luxons.sevenwonders.game.boards.Board;
+import org.luxons.sevenwonders.game.boards.RelativeBoardPosition;
+
+public class ResourceTransaction {
+
+    private final Provider provider;
+
+    private final Resources resources;
+
+    public ResourceTransaction(Provider provider, Resources resources) {
+        this.provider = provider;
+        this.resources = resources;
+    }
+
+    public Provider getProvider() {
+        return provider;
+    }
+
+    public Resources getResources() {
+        return resources;
+    }
+
+    void execute(Table table, int playerIndex) {
+        Board board = table.getBoard(playerIndex);
+        int price = board.getTradingRules().computeCost(this);
+        board.removeGold(price);
+        RelativeBoardPosition providerPosition = provider.getBoardPosition();
+        Board providerBoard = table.getBoard(playerIndex, providerPosition);
+        providerBoard.addGold(price);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        ResourceTransaction that = (ResourceTransaction) o;
+        return provider == that.provider && Objects.equals(resources, that.resources);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(provider, resources);
+    }
+}
diff --git a/game-engine/src/main/java/org/luxons/sevenwonders/game/resources/ResourceTransactions.java b/game-engine/src/main/java/org/luxons/sevenwonders/game/resources/ResourceTransactions.java
new file mode 100644
index 00000000..a8fdc6c7
--- /dev/null
+++ b/game-engine/src/main/java/org/luxons/sevenwonders/game/resources/ResourceTransactions.java
@@ -0,0 +1,71 @@
+package org.luxons.sevenwonders.game.resources;
+
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+import org.luxons.sevenwonders.game.api.Table;
+
+public class ResourceTransactions {
+
+    private final Map<Provider, Resources> resourcesByProvider;
+
+    public ResourceTransactions() {
+        this.resourcesByProvider = new HashMap<>();
+    }
+
+    public ResourceTransactions(Collection<ResourceTransaction> transactions) {
+        this();
+        transactions.forEach(t -> add(t.getProvider(), t.getResources()));
+    }
+
+    public void add(Provider provider, Resources resources) {
+        resourcesByProvider.putIfAbsent(provider, new Resources());
+        resourcesByProvider.merge(provider, resources, Resources::addAll);
+    }
+
+    public void remove(Provider provider, Resources resources) {
+        resourcesByProvider.compute(provider, (p, prevResources) -> {
+            if (prevResources == null) {
+                throw new IllegalStateException("Cannot remove resources from resource transactions");
+            }
+            return prevResources.minus(resources);
+        });
+    }
+
+    public void execute(Table table, int playerIndex) {
+        toTransactions().forEach(t -> t.execute(table, playerIndex));
+    }
+
+    public Set<ResourceTransaction> toTransactions() {
+        return resourcesByProvider.entrySet()
+                                  .stream()
+                                  .filter(e -> !e.getValue().isEmpty())
+                                  .map(e -> new ResourceTransaction(e.getKey(), e.getValue()))
+                                  .collect(Collectors.toSet());
+    }
+
+    public Resources asResources() {
+        return resourcesByProvider.values().stream().reduce(new Resources(), Resources::addAll);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        ResourceTransactions that = (ResourceTransactions) o;
+        return Objects.equals(resourcesByProvider, that.resourcesByProvider);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(resourcesByProvider);
+    }
+}
diff --git a/game-engine/src/main/java/org/luxons/sevenwonders/game/resources/Resources.java b/game-engine/src/main/java/org/luxons/sevenwonders/game/resources/Resources.java
index 1b263760..d354f121 100644
--- a/game-engine/src/main/java/org/luxons/sevenwonders/game/resources/Resources.java
+++ b/game-engine/src/main/java/org/luxons/sevenwonders/game/resources/Resources.java
@@ -32,8 +32,9 @@ public class Resources {
         quantities.computeIfPresent(type, (t, oldQty) -> oldQty - quantity);
     }
 
-    public void addAll(Resources resources) {
+    public Resources addAll(Resources resources) {
         resources.quantities.forEach(this::add);
+        return this;
     }
 
     public int getQuantity(ResourceType type) {
@@ -55,6 +56,13 @@ public class Resources {
         return quantity.getValue() <= getQuantity(quantity.getKey());
     }
 
+    public Resources plus(Resources resources) {
+        Resources merged = new Resources();
+        merged.addAll(this);
+        merged.addAll(resources);
+        return merged;
+    }
+
     /**
      * Creates new {@link Resources} object containing these resources minus the given resources.
      *
diff --git a/game-engine/src/main/java/org/luxons/sevenwonders/game/resources/TradingRules.java b/game-engine/src/main/java/org/luxons/sevenwonders/game/resources/TradingRules.java
index 8cd1d9bc..ffbce8ab 100644
--- a/game-engine/src/main/java/org/luxons/sevenwonders/game/resources/TradingRules.java
+++ b/game-engine/src/main/java/org/luxons/sevenwonders/game/resources/TradingRules.java
@@ -1,7 +1,6 @@
 package org.luxons.sevenwonders.game.resources;
 
 import java.util.EnumMap;
-import java.util.List;
 import java.util.Map;
 
 public class TradingRules {
@@ -26,13 +25,17 @@ public class TradingRules {
         costs.computeIfAbsent(type, t -> new EnumMap<>(Provider.class)).put(provider, cost);
     }
 
-    public int computeCost(List<BoughtResources> boughtResources) {
-        return boughtResources.stream().mapToInt(this::computeCost).sum();
+    public int computeCost(ResourceTransactions transactions) {
+        return transactions.toTransactions().stream().mapToInt(this::computeCost).sum();
     }
 
-    public int computeCost(BoughtResources boughtResources) {
-        Resources resources = boughtResources.getResources();
-        Provider provider = boughtResources.getProvider();
+    int computeCost(ResourceTransaction transaction) {
+        Resources resources = transaction.getResources();
+        Provider provider = transaction.getProvider();
+        return computeCost(resources, provider);
+    }
+
+    private int computeCost(Resources resources, Provider provider) {
         int total = 0;
         for (ResourceType type : ResourceType.values()) {
             int count = resources.getQuantity(type);
diff --git a/game-engine/src/main/java/org/luxons/sevenwonders/game/wonders/Wonder.java b/game-engine/src/main/java/org/luxons/sevenwonders/game/wonders/Wonder.java
index 73fff305..dd0170da 100644
--- a/game-engine/src/main/java/org/luxons/sevenwonders/game/wonders/Wonder.java
+++ b/game-engine/src/main/java/org/luxons/sevenwonders/game/wonders/Wonder.java
@@ -5,7 +5,7 @@ import java.util.List;
 
 import org.luxons.sevenwonders.game.api.Table;
 import org.luxons.sevenwonders.game.cards.CardBack;
-import org.luxons.sevenwonders.game.resources.BoughtResources;
+import org.luxons.sevenwonders.game.resources.ResourceTransactions;
 import org.luxons.sevenwonders.game.resources.ResourceType;
 
 public class Wonder {
@@ -63,7 +63,7 @@ public class Wonder {
         this.image = image;
     }
 
-    public boolean isNextStageBuildable(Table table, int playerIndex, List<BoughtResources> boughtResources) {
+    public boolean isNextStageBuildable(Table table, int playerIndex, ResourceTransactions boughtResources) {
         int nextLevel = getNbBuiltStages();
         if (nextLevel == stages.size()) {
             return false;
@@ -83,7 +83,7 @@ public class Wonder {
         return stages.get(nextLevel);
     }
 
-    public void activateLastBuiltStage(Table table, int playerIndex, List<BoughtResources> boughtResources) {
+    public void activateLastBuiltStage(Table table, int playerIndex, ResourceTransactions boughtResources) {
         getLastBuiltStage().activate(table, playerIndex, boughtResources);
     }
 
diff --git a/game-engine/src/main/java/org/luxons/sevenwonders/game/wonders/WonderStage.java b/game-engine/src/main/java/org/luxons/sevenwonders/game/wonders/WonderStage.java
index a53e2694..f4ec1140 100644
--- a/game-engine/src/main/java/org/luxons/sevenwonders/game/wonders/WonderStage.java
+++ b/game-engine/src/main/java/org/luxons/sevenwonders/game/wonders/WonderStage.java
@@ -7,7 +7,7 @@ import org.luxons.sevenwonders.game.boards.Board;
 import org.luxons.sevenwonders.game.cards.CardBack;
 import org.luxons.sevenwonders.game.cards.Requirements;
 import org.luxons.sevenwonders.game.effects.Effect;
-import org.luxons.sevenwonders.game.resources.BoughtResources;
+import org.luxons.sevenwonders.game.resources.ResourceTransactions;
 
 public class WonderStage {
 
@@ -38,7 +38,7 @@ public class WonderStage {
         return cardBack != null;
     }
 
-    public boolean isBuildable(Table table, int playerIndex, List<BoughtResources> boughtResources) {
+    public boolean isBuildable(Table table, int playerIndex, ResourceTransactions boughtResources) {
         Board board = table.getBoard(playerIndex);
         return requirements.areMetWithHelpBy(board, boughtResources);
     }
@@ -47,7 +47,7 @@ public class WonderStage {
         this.cardBack = cardBack;
     }
 
-    void activate(Table table, int playerIndex, List<BoughtResources> boughtResources) {
+    void activate(Table table, int playerIndex, ResourceTransactions boughtResources) {
         effects.forEach(e -> e.apply(table, playerIndex));
         requirements.pay(table, playerIndex, boughtResources);
     }