improved null safety

wizard-client/wizard-client-cli/src/main/java/eu/jonahbauer/wizard/client/cli/commands/LobbyCommand.java

@@ -42,7 +42,7 @@ public class LobbyCommand {
             if (count == 1) builder.append("There is one open session:\n");
             else builder.append("There are ").append(count).append(" open sessions:\n");
 
-            sessions.forEach((session) -> builder.append(session).append('\n'));
+            sessions.forEach((uuid, session) -> builder.append(session).append('\n'));
             client.println(builder);
         } else {
             client.println("No sessions.");
@@ -106,7 +106,7 @@ public class LobbyCommand {
         @NotNull
         @Override
         public Iterator<String> iterator() {
-            return lobby.getSessions().stream().map(SessionData::getUuid).map(UUID::toString).iterator();
+            return lobby.getSessions().values().stream().map(SessionData::getUuid).map(UUID::toString).iterator();
         }
     }
 }

wizard-client/wizard-client-cli/src/main/java/eu/jonahbauer/wizard/client/cli/state/Lobby.java

@@ -10,10 +10,10 @@ import java.util.*;
 
 public final class Lobby extends BaseState {
     @Getter
-    private final Set<SessionData> sessions = new HashSet<>();
+    private final Map<UUID, SessionData> sessions = new HashMap<>();
 
     public Lobby(SessionListMessage list) {
-        sessions.addAll(list.getSessions());
+        list.getSessions().forEach(session -> sessions.put(session.getUuid(), session));
     }
 
     @Override
@@ -30,18 +30,18 @@ public final class Lobby extends BaseState {
     public Optional<ClientState> onMessage(Client client, ServerMessage message) {
         if (message instanceof SessionCreatedMessage created) {
             var session = created.getSession();
-            sessions.add(session);
+            sessions.put(session.getUuid(), session);
             return Optional.empty();
         } else if (message instanceof SessionRemovedMessage removed) {
-            sessions.remove(new SessionData(removed.getSession(), null, 0, null));
+            sessions.remove(removed.getSession());
             return Optional.empty();
         } else if (message instanceof SessionModifiedMessage modified) {
-            sessions.remove(modified.getSession());
+            var session = modified.getSession();
-            sessions.add(modified.getSession());
+            sessions.put(session.getUuid(), session);
             return Optional.empty();
         } else if (message instanceof SessionListMessage list) {
             sessions.clear();
-            sessions.addAll(list.getSessions());
+            list.getSessions().forEach(session -> sessions.put(session.getUuid(), session));
             return Optional.empty();
         } else {
             return unexpectedMessage(client, message);

wizard-client/wizard-client-libgdx/core/src/main/java/eu/jonahbauer/wizard/client/libgdx/actors/game/CardActor.java

@@ -8,6 +8,7 @@ import eu.jonahbauer.wizard.client.libgdx.GameAtlas;
 import eu.jonahbauer.wizard.common.model.Card;
 import lombok.Getter;
 import lombok.Setter;
+import org.jetbrains.annotations.NotNull;
 
 import java.util.Collections;
 import java.util.EnumMap;
@@ -115,23 +116,23 @@ public class CardActor extends Actor {
         setOrigin(PREF_WIDTH / 2, PREF_HEIGHT / 2);
     }
 
-    public CardActor(Card card, TextureAtlas atlas) {
+    public CardActor(@NotNull Card card, @NotNull TextureAtlas atlas) {
         this(atlas);
         setCard(card);
     }
 
-    public CardActor(Card.Suit suit, TextureAtlas atlas) {
+    public CardActor(@NotNull Card.Suit suit, @NotNull TextureAtlas atlas) {
         this(atlas);
         setCard(suit);
     }
 
-    public void setCard(Card card) {
+    public void setCard(@NotNull Card card) {
         this.card = card;
         this.background = atlas.findRegion(ATLAS_PATHS.get(card));
         if (this.background == null) throw new NoSuchElementException("Could not find texture for card " + card + ".");
     }
 
-    public void setCard(Card.Suit suit) {
+    public void setCard(@NotNull Card.Suit suit) {
         this.card = null;
         this.background = atlas.findRegion(switch (suit) {
             case NONE -> GameAtlas.CARDS_BACKGROUND;

wizard-client/wizard-client-libgdx/core/src/main/java/eu/jonahbauer/wizard/client/libgdx/actors/game/CardsGroup.java

@@ -13,6 +13,8 @@ import eu.jonahbauer.wizard.client.libgdx.util.Pair;
 import eu.jonahbauer.wizard.common.model.Card;
 import lombok.Getter;
 import lombok.Setter;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.*;
 import java.util.function.Consumer;
@@ -180,7 +182,7 @@ public class CardsGroup extends WidgetGroup {
         animate = false;
     }
 
-    public Pair<List<CardActor>, List<CardActor>> update(List<Card> cards) {
+    public @NotNull Pair<List<CardActor>, List<CardActor>> update(@NotNull List<Card> cards) {
         var added = new ArrayList<>(cards);
         var removed = new ArrayList<Card>();
 
@@ -203,7 +205,7 @@ public class CardsGroup extends WidgetGroup {
         return Pair.of(removedActors, addedActors);
     }
 
-    public CardActor remove(Card card) {
+    public @Nullable CardActor remove(Card card) {
         var actor = find(card);
         if (actor == null) return null;
 
@@ -223,7 +225,7 @@ public class CardsGroup extends WidgetGroup {
         return actor;
     }
 
-    public CardActor find(Card card) {
+    public @Nullable CardActor find(Card card) {
         var children = getChildren();
         for (int i = 0; i < children.size; i++) {
             if (children.get(i) instanceof CardActor cardActor && cardActor.getCard() == card) {

wizard-client/wizard-client-libgdx/core/src/main/java/eu/jonahbauer/wizard/client/libgdx/actors/game/overlay/ChangePredictionOverlay.java

@@ -4,10 +4,11 @@ import com.badlogic.gdx.scenes.scene2d.ui.VerticalGroup;
 import eu.jonahbauer.wizard.client.libgdx.actors.game.CardActor;
 import eu.jonahbauer.wizard.client.libgdx.screens.GameScreen;
 import eu.jonahbauer.wizard.common.model.Card;
+import org.jetbrains.annotations.NotNull;
 
 public class ChangePredictionOverlay extends MakePredictionOverlay {
 
-    public ChangePredictionOverlay(GameScreen gameScreen, long timeout, int round, int oldPrediction) {
+    public ChangePredictionOverlay(@NotNull GameScreen gameScreen, long timeout, int round, int oldPrediction) {
         super(
                 gameScreen,
                 timeout,

wizard-client/wizard-client-libgdx/core/src/main/java/eu/jonahbauer/wizard/client/libgdx/actors/game/overlay/MakePredictionOverlay.java

@@ -7,7 +7,7 @@ import com.badlogic.gdx.scenes.scene2d.ui.TextButton;
 import com.badlogic.gdx.scenes.scene2d.ui.VerticalGroup;
 import com.badlogic.gdx.scenes.scene2d.utils.ChangeListener;
 import eu.jonahbauer.wizard.client.libgdx.screens.GameScreen;
-import eu.jonahbauer.wizard.common.messages.player.PredictMessage;
+import org.jetbrains.annotations.NotNull;
 
 import java.util.stream.IntStream;
 
@@ -16,11 +16,11 @@ public class MakePredictionOverlay extends Overlay implements InteractionOverlay
     private final int[] values;
     private final TextButton[] buttons;
 
-    public MakePredictionOverlay(GameScreen gameScreen, long timeout, int round) {
+    public MakePredictionOverlay(@NotNull GameScreen gameScreen, long timeout, int round) {
         this(gameScreen, timeout, IntStream.range(0, round + 2).toArray());
     }
 
-    protected MakePredictionOverlay(GameScreen gameScreen, long timeout, int[] values) {
+    protected MakePredictionOverlay(@NotNull GameScreen gameScreen, long timeout, int[] values) {
         super(gameScreen, timeout);
         this.values = values;
         this.buttons = new TextButton[values.length];

wizard-client/wizard-client-libgdx/core/src/main/java/eu/jonahbauer/wizard/client/libgdx/actors/game/overlay/Overlay.java

@@ -13,6 +13,7 @@ import eu.jonahbauer.wizard.client.libgdx.WizardGame;
 import eu.jonahbauer.wizard.client.libgdx.screens.GameScreen;
 import lombok.AccessLevel;
 import lombok.Getter;
+import org.jetbrains.annotations.NotNull;
 
 import static com.badlogic.gdx.scenes.scene2d.actions.Actions.*;
 
@@ -29,7 +30,7 @@ public abstract class Overlay extends Action {
     private boolean closing;
     private boolean closed;
 
-    public Overlay(GameScreen gameScreen, long timeout) {
+    public Overlay(@NotNull GameScreen gameScreen, long timeout) {
         this.screen = gameScreen;
         this.data = gameScreen.getData();
         this.messages = gameScreen.getMessages();

wizard-client/wizard-client-libgdx/core/src/main/java/eu/jonahbauer/wizard/client/libgdx/actors/game/overlay/PickTrumpOverlay.java

@@ -9,6 +9,7 @@ import com.badlogic.gdx.scenes.scene2d.utils.ClickListener;
 import eu.jonahbauer.wizard.client.libgdx.actors.game.CardActor;
 import eu.jonahbauer.wizard.client.libgdx.screens.GameScreen;
 import eu.jonahbauer.wizard.common.model.Card;
+import org.jetbrains.annotations.NotNull;
 
 import java.util.EnumMap;
 
@@ -18,7 +19,7 @@ public class PickTrumpOverlay extends Overlay implements InteractionOverlay {
 
     private final EnumMap<Card.Suit, CardActor> cards = new EnumMap<>(Card.Suit.class);
 
-    public PickTrumpOverlay(GameScreen gameScreen, long timeout, boolean allowNone) {
+    public PickTrumpOverlay(@NotNull GameScreen gameScreen, long timeout, boolean allowNone) {
         super(gameScreen, timeout);
         this.allowNone = allowNone;
     }

wizard-client/wizard-client-libgdx/core/src/main/java/eu/jonahbauer/wizard/client/libgdx/actors/game/overlay/PlayColoredCardOverlay.java

@@ -11,6 +11,7 @@ import com.badlogic.gdx.scenes.scene2d.utils.ClickListener;
 import eu.jonahbauer.wizard.client.libgdx.actors.game.CardActor;
 import eu.jonahbauer.wizard.client.libgdx.screens.GameScreen;
 import eu.jonahbauer.wizard.common.model.Card;
+import org.jetbrains.annotations.NotNull;
 
 import java.util.EnumMap;
 
@@ -21,7 +22,9 @@ public class PlayColoredCardOverlay extends Overlay implements InteractionOverla
 
     private final Card card;
 
-    public PlayColoredCardOverlay(GameScreen gameScreen, long timeout, Card card, Card red, Card green, Card blue, Card yellow) {
+    public PlayColoredCardOverlay(@NotNull GameScreen gameScreen, long timeout, @NotNull Card card,
+                                  @NotNull Card red, @NotNull Card green, @NotNull Card blue, @NotNull Card yellow)
+    {
         super(gameScreen, timeout);
         this.card = card;
         this.cards.put(Card.Suit.RED, red);

wizard-client/wizard-client-libgdx/core/src/main/java/eu/jonahbauer/wizard/client/libgdx/actors/game/overlay/StartRoundOverlay.java

@@ -6,6 +6,7 @@ import com.badlogic.gdx.scenes.scene2d.ui.Label;
 import com.badlogic.gdx.scenes.scene2d.ui.VerticalGroup;
 import eu.jonahbauer.wizard.client.libgdx.AnimationTimings;
 import eu.jonahbauer.wizard.client.libgdx.screens.GameScreen;
+import org.jetbrains.annotations.NotNull;
 
 import static com.badlogic.gdx.scenes.scene2d.actions.Actions.*;
 
@@ -13,7 +14,7 @@ public class StartRoundOverlay extends Overlay {
 
     private final int round;
 
-    public StartRoundOverlay(GameScreen gameScreen, int round) {
+    public StartRoundOverlay(@NotNull GameScreen gameScreen, int round) {
         super(gameScreen, Long.MAX_VALUE);
         this.round = round;
     }

wizard-client/wizard-client-libgdx/core/src/main/java/eu/jonahbauer/wizard/client/libgdx/actors/game/overlay/TrumpOverlay.java

@@ -12,8 +12,11 @@ import eu.jonahbauer.wizard.client.libgdx.actions.MyActions;
 import eu.jonahbauer.wizard.client.libgdx.actors.game.CardActor;
 import eu.jonahbauer.wizard.client.libgdx.screens.GameScreen;
 import eu.jonahbauer.wizard.common.model.Card;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.Map;
+import java.util.Objects;
 
 import static com.badlogic.gdx.scenes.scene2d.actions.Actions.*;
 import static eu.jonahbauer.wizard.client.libgdx.actions.MyActions.*;
@@ -81,22 +84,22 @@ public class TrumpOverlay extends Overlay {
             Map.entry(Card.FAIRY, Card.Suit.NONE)
     );
 
-    private final String player;
+    private final @Nullable String player;
-    private final Card card;
+    private final @NotNull Card card;
-    private final Card.Suit suit;
+    private final @Nullable Card.Suit suit;
 
-    private final CardActor trumpCardActor;
+    private final @NotNull CardActor trumpCardActor;
-    private final CardActor trumpSuitActor;
+    private final @NotNull CardActor trumpSuitActor;
 
     private boolean animateCard = true;
 
-    public TrumpOverlay(GameScreen gameScreen, String player, Card card, Card.Suit suit) {
+    public TrumpOverlay(@NotNull GameScreen gameScreen, @Nullable String player, @NotNull Card card, @Nullable Card.Suit suit) {
         super(gameScreen, Long.MAX_VALUE);
         this.player = player;
         this.card = card;
         this.suit = suit;
-        this.trumpCardActor = gameScreen.getTrumpCardActor();
+        this.trumpCardActor = Objects.requireNonNull(gameScreen.getTrumpCardActor());
-        this.trumpSuitActor = gameScreen.getTrumpSuitActor();
+        this.trumpSuitActor = Objects.requireNonNull(gameScreen.getTrumpSuitActor());
     }
 
     @Override
@@ -141,7 +144,7 @@ public class TrumpOverlay extends Overlay {
         }
 
         trumpSuitActor.remove();
-        if (suit != DEFAULT_SUITES.get(card)) {
+        if (suit != null && suit != DEFAULT_SUITES.get(card)) {
             trumpSuitActor.setRotation(0);
             trumpSuitActor.setOrigin(0, 0);
             cardGroup.addActor(trumpSuitActor);
@@ -164,7 +167,7 @@ public class TrumpOverlay extends Overlay {
             ));
         }
 
-        if (suit != DEFAULT_SUITES.get(card)) {
+        if (suit != null && suit != DEFAULT_SUITES.get(card)) {
             cardAnimation.addAction(sequence(
                     targeting(trumpSuitActor, removeActorSilently()),
                     targeting(trumpSuitActor, changeParent(parent)),

wizard-client/wizard-client-libgdx/core/src/main/java/eu/jonahbauer/wizard/client/libgdx/screens/GameScreen.java

@@ -203,11 +203,11 @@ public class GameScreen extends MenuScreen {
         return self.equals(uuid);
     }
 
-    public void onCardClicked(Card card) {
+    public void onCardClicked(@NotNull Card card) {
         game.getClient().execute(Game.class, (s, c) -> s.onCardClicked(c, card));
     }
 
-    public void onSuitClicked(Card.Suit suit) {
+    public void onSuitClicked(@NotNull Card.Suit suit) {
         game.getClient().execute(Game.class, (s, c) -> s.onSuitClicked(c, suit));
     }
 
@@ -241,7 +241,7 @@ public class GameScreen extends MenuScreen {
         execute(() -> cardStack.clearChildren());
     }
 
-    public void finishTrick(UUID player) {
+    public void finishTrick(@NotNull UUID player) {
         var seat = seats.getOrDefault(player, Seat.FALLBACK);
 
         var action = parallel();
@@ -272,7 +272,7 @@ public class GameScreen extends MenuScreen {
     /**
      * Updates the given players hand cards.
      */
-    public void setHand(UUID player, List<Card> cards, boolean juggle) {
+    public void setHand(@NotNull UUID player, @NotNull List<Card> cards, boolean juggle) {
         if (isSelf(player)) {
             var sequence = sequence();
             sequence.addAction(run(() -> {
@@ -291,7 +291,7 @@ public class GameScreen extends MenuScreen {
      * Adds the prediction for the given round and player to the {@linkplain #padOfTruth pad of truth} and
      * shows a corresponding message.
      */
-    public void addPrediction(int round, UUID player, int prediction, boolean changed) {
+    public void addPrediction(int round, @NotNull UUID player, int prediction, boolean changed) {
         if (isSelf(player)) {
             addMessage(game.messages.format("game.action." + (changed ? "change" : "make") + "_prediction.self", prediction));
         } else {
@@ -299,13 +299,16 @@ public class GameScreen extends MenuScreen {
             addMessage(game.messages.format("game.action."  + (changed ? "change" : "make") + "_prediction.other", name, prediction));
         }
 
-        execute(() -> padOfTruth.setPrediction(orderedPlayers.indexOf(player), round, prediction));
+        var index = orderedPlayers.indexOf(player);
+        if (index == -1) throw new NoSuchElementException();
+
+        execute(() -> padOfTruth.setPrediction(index, round, prediction));
     }
 
     /**
      * Removes the card from the players hand and puts it into the {@linkplain #cardStack stack}.
      */
-    public void playCard(UUID player, Card card) {
+    public void playCard(@NotNull UUID player, @NotNull Card card) {
         if (isSelf(player)) {
             addMessage(game.messages.get("game.action.play_card.self"));
         } else {
@@ -336,11 +339,11 @@ public class GameScreen extends MenuScreen {
     /**
      * Adds the scores for a round to the corresponding row of the {@linkplain #padOfTruth pad of truth}.
      */
-    public void addScores(int round, Map<UUID, Integer> scores) {
+    public void addScores(int round, @NotNull Map<UUID, Integer> scores) {
         execute(() -> {
             for (int i = 0; i < orderedPlayers.size(); i++) {
                 UUID player = orderedPlayers.get(i);
-                padOfTruth.setScore(i, round, scores.get(player));
+                padOfTruth.setScore(i, round, scores.getOrDefault(player, 0));
             }
         });
     }
@@ -356,10 +359,10 @@ public class GameScreen extends MenuScreen {
      * Highlights the given players label and sets the {@linkplain #setPersistentMessage(String) persistent message}
      * accordingly.
      */
-    public void setActivePlayer(UUID player, UserInputMessage.Action action, long timeout) {
+    public void setActivePlayer(@Nullable UUID player, @Nullable UserInputMessage.Action action, long timeout) {
         execute(() -> nameLabels.forEach((p, l) -> l.setStyle(p.equals(player) ? labelStyleActive : labelStyleDefault)));
 
-        if (isSelf(player) || player == null && action == null) {
+        if (isSelf(player) || action == null) {
             setPersistentMessage(null);
         } else {
             var key = switch (action) {
@@ -390,7 +393,7 @@ public class GameScreen extends MenuScreen {
      * Swaps the current {@linkplain #trumpCardActor trump card} (if present) with a {@linkplain Card#WEREWOLF werewolf}
      * card on the given players hand.
      */
-    public void swapTrumpCard(UUID player) {
+    public void swapTrumpCard(@NotNull UUID player) {
         var seat = seats.getOrDefault(player, Seat.FALLBACK);
 
         var sequence = sequence();
@@ -448,7 +451,7 @@ public class GameScreen extends MenuScreen {
     }
 
     //<editor-fold desc="Overlays" defaultstate="collapsed">
-    public void showTrumpOverlay(UUID player, Card trumpCard, Card.Suit trumpSuit) {
+    public void showTrumpOverlay(@Nullable UUID player, @NotNull Card trumpCard, @Nullable Card.Suit trumpSuit) {
         if (trumpCardActor == null) {
             trumpCardActor = new CardActor(Card.HIDDEN, atlas);
         }
@@ -460,7 +463,7 @@ public class GameScreen extends MenuScreen {
         execute(new TrumpOverlay(this, players.get(player), trumpCard, trumpSuit));
     }
 
-    public void showColoredCardOverlay(Card card, long timeout) {
+    public void showColoredCardOverlay(@NotNull Card card, long timeout) {
         if (card == Card.JUGGLER) {
             execute(new PlayColoredCardOverlay(this, timeout, card, Card.JUGGLER_RED, Card.JUGGLER_GREEN, Card.JUGGLER_BLUE, Card.JUGGLER_YELLOW));
         } else if (card == Card.CLOUD) {
@@ -587,7 +590,7 @@ public class GameScreen extends MenuScreen {
         return game.messages;
     }
 
-    private Action animateJuggle(List<CardActor> removed, List<CardActor> added) {
+    private Action animateJuggle(@NotNull List<CardActor> removed, @NotNull List<CardActor> added) {
         // find left- and rightmost seat
         Seat tmpLeft = null, tmpRight = null;
         for (Seat seat : seats.values()) {

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/client/CreateSessionMessage.java

@@ -3,8 +3,8 @@ package eu.jonahbauer.wizard.common.messages.client;
 import eu.jonahbauer.wizard.common.model.Configuration;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.NonNull;
 import lombok.RequiredArgsConstructor;
-import org.jetbrains.annotations.Range;
 
 @Getter
 @RequiredArgsConstructor
@@ -13,11 +13,11 @@ public final class CreateSessionMessage extends ClientMessage {
     /**
      * Name of the session
      */
-    private final String sessionName;
+    private final @NonNull String sessionName;
     /**
      * Name of the creating and joining player
      */
-    private final String playerName;
+    private final @NonNull String playerName;
     /**
      * timout in milliseconds for user interactions
      */
@@ -25,5 +25,5 @@ public final class CreateSessionMessage extends ClientMessage {
     /**
      * Game configuration
      */
-    private final Configuration configuration;
+    private final @NonNull Configuration configuration;
 }

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/client/InteractionMessage.java

@@ -3,6 +3,7 @@ package eu.jonahbauer.wizard.common.messages.client;
 import eu.jonahbauer.wizard.common.messages.player.PlayerMessage;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.NonNull;
 import lombok.RequiredArgsConstructor;
 
 @Getter
@@ -12,5 +13,5 @@ public final class InteractionMessage extends ClientMessage {
     /**
      * Wrapped {@link PlayerMessage}
      */
-    private final PlayerMessage playerMessage;
+    private final @NonNull PlayerMessage playerMessage;
 }

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/client/JoinSessionMessage.java

@@ -2,6 +2,7 @@ package eu.jonahbauer.wizard.common.messages.client;
 
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.NonNull;
 import lombok.RequiredArgsConstructor;
 
 import java.util.UUID;
@@ -13,9 +14,9 @@ public final class JoinSessionMessage extends ClientMessage {
     /**
      * UUID of the session
      */
-    private final UUID session;
+    private final @NonNull UUID session;
     /**
      * Name of the joining player
      */
-    private final String playerName;
+    private final @NonNull String playerName;
 }

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/client/RejoinMessage.java

@@ -2,6 +2,7 @@ package eu.jonahbauer.wizard.common.messages.client;
 
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.NonNull;
 import lombok.RequiredArgsConstructor;
 
 import java.util.UUID;
@@ -13,13 +14,13 @@ public final class RejoinMessage extends ClientMessage {
     /**
      * UUID of the session
      */
-    private final UUID session;
+    private final @NonNull UUID session;
     /**
      * UUID of the rejoining player
      */
-    private final UUID player;
+    private final @NonNull UUID player;
     /**
      * Secret in order to assure that no malicious user wants to join the message
      */
-    private final String secret;
+    private final @NonNull String secret;
 }

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/data/PlayerData.java

@@ -1,9 +1,6 @@
 package eu.jonahbauer.wizard.common.messages.data;
 
-import lombok.EqualsAndHashCode;
+import lombok.*;
-import lombok.Getter;
-import lombok.RequiredArgsConstructor;
-import lombok.ToString;
 
 import java.util.UUID;
 
@@ -15,11 +12,11 @@ public class PlayerData {
     /**
      * UUID of the player
      */
-    private final UUID uuid;
+    private final @NonNull UUID uuid;
     /**
      * Name of the player
      */
-    private final String name;
+    private final @NonNull String name;
     /**
      * Readiness state of the player
      */

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/data/SessionData.java

@@ -1,10 +1,7 @@
 package eu.jonahbauer.wizard.common.messages.data;
 
 import eu.jonahbauer.wizard.common.model.Configuration;
-import lombok.EqualsAndHashCode;
+import lombok.*;
-import lombok.Getter;
-import lombok.RequiredArgsConstructor;
-import lombok.ToString;
 
 import java.util.UUID;
 
@@ -16,11 +13,11 @@ public class SessionData {
     /**
      * UUID of the session
      */
-    private final UUID uuid;
+    private final @NonNull UUID uuid;
     /**
      * Name of the session
      */
-    private final String name;
+    private final @NonNull String name;
     /**
      * Number of players currently in the session
      */
@@ -28,5 +25,5 @@ public class SessionData {
     /**
      * Configuration of the session
      */
-    private final Configuration configuration;
+    private final @NonNull Configuration configuration;
 }

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/observer/CardMessage.java

@@ -3,8 +3,8 @@ package eu.jonahbauer.wizard.common.messages.observer;
 import eu.jonahbauer.wizard.common.model.Card;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.NonNull;
 import lombok.RequiredArgsConstructor;
-import org.jetbrains.annotations.NotNull;
 
 import java.util.UUID;
 
@@ -18,9 +18,9 @@ public final class CardMessage extends ObserverMessage {
     /**
      * The UUID of the player.
      */
-    private final @NotNull UUID player;
+    private final @NonNull UUID player;
     /**
      * The card played.
      */
-    private final @NotNull Card card;
+    private final @NonNull Card card;
 }

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/observer/HandMessage.java

@@ -3,7 +3,9 @@ package eu.jonahbauer.wizard.common.messages.observer;
 import eu.jonahbauer.wizard.common.model.Card;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.NonNull;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Unmodifiable;
 
 import java.util.List;
 import java.util.UUID;
@@ -17,14 +19,14 @@ public final class HandMessage extends ObserverMessage {
     /**
      * The UUID of player whose hand cards are sent.
      */
-    private final @NotNull UUID player;
+    private final @NonNull UUID player;
     /**
      * A list of all the hand cards. May consist only of {@link Card#HIDDEN} if the cards are not visible to the player
      * receiving this message.
      */
-    private final @NotNull List<@NotNull Card> hand;
+    private final @Unmodifiable @NonNull List<@NotNull Card> hand;
 
-    public HandMessage(@NotNull UUID player, @NotNull List<@NotNull Card> hand) {
+    public HandMessage(@NonNull UUID player, @NonNull List<@NonNull Card> hand) {
         this.player = player;
         this.hand = List.copyOf(hand);
     }

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/observer/PredictionMessage.java

@@ -2,8 +2,7 @@ package eu.jonahbauer.wizard.common.messages.observer;
 
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
-import lombok.RequiredArgsConstructor;
+import lombok.NonNull;
-import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Range;
 
 import java.util.UUID;
@@ -12,15 +11,20 @@ import java.util.UUID;
  * A {@link PredictionMessage} is sent after a player makes (or changes) his prediction.
  */
 @Getter
-@RequiredArgsConstructor
 @EqualsAndHashCode(callSuper = true)
 public final class PredictionMessage extends ObserverMessage {
     /**
      * The UUID of the player who made a prediction.
      */
-    private final @NotNull UUID player;
+    private final @NonNull UUID player;
     /**
      * The prediction.
      */
     private final @Range(from = 0, to = Integer.MAX_VALUE) int prediction;
+
+    public PredictionMessage(@NonNull UUID player, int prediction) {
+        if (prediction < 0) throw new IllegalArgumentException("prediction is out of bounds");
+        this.player = player;
+        this.prediction = prediction;
+    }
 }

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/observer/ScoreMessage.java

@@ -2,7 +2,9 @@ package eu.jonahbauer.wizard.common.messages.observer;
 
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.NonNull;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Unmodifiable;
 
 import java.util.Map;
 import java.util.UUID;
@@ -17,9 +19,9 @@ public final class ScoreMessage extends ObserverMessage {
     /**
      * The number of points for each player.
      */
-    private final @NotNull Map<@NotNull UUID, @NotNull Integer> points;
+    private final @Unmodifiable @NonNull Map<@NonNull UUID, @NonNull Integer> points;
 
-    public ScoreMessage(@NotNull Map<@NotNull UUID, @NotNull Integer> points) {
+    public ScoreMessage(@NonNull Map<@NonNull UUID, @NonNull Integer> points) {
         this.points = Map.copyOf(points);
     }
 }

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/observer/StateMessage.java

@@ -2,7 +2,9 @@ package eu.jonahbauer.wizard.common.messages.observer;
 
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.NonNull;
 import lombok.RequiredArgsConstructor;
+import org.jetbrains.annotations.NotNull;
 
 /**
  * A {@link StateMessage} is sent whenever the game changes its internal state.
@@ -14,5 +16,5 @@ public final class StateMessage extends ObserverMessage {
     /**
      * The name of the new state in snake_case.
      */
-    private final String state;
+    private final @NonNull String state;
 }

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/observer/TrickMessage.java

@@ -3,6 +3,8 @@ package eu.jonahbauer.wizard.common.messages.observer;
 import eu.jonahbauer.wizard.common.model.Card;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.NonNull;
+import org.jetbrains.annotations.Unmodifiable;
 
 import java.util.List;
 import java.util.UUID;
@@ -17,13 +19,13 @@ public final class TrickMessage extends ObserverMessage {
     /**
      * The UUID of the player who won the trick.
      */
-    private final UUID player;
+    private final @NonNull UUID player;
     /**
      * The cards played.
      */
-    private final List<Card> cards;
+    private final @Unmodifiable @NonNull List<@NonNull Card> cards;
 
-    public TrickMessage(UUID player, List<Card> cards) {
+    public TrickMessage(@NonNull UUID player, @NonNull List<@NonNull Card> cards) {
         this.player = player;
         this.cards = List.copyOf(cards);
     }

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/observer/UserInputMessage.java

@@ -7,7 +7,9 @@ import eu.jonahbauer.wizard.common.messages.player.PredictMessage;
 import eu.jonahbauer.wizard.common.model.Card;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.NonNull;
 import lombok.RequiredArgsConstructor;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.UUID;
 
@@ -22,11 +24,11 @@ public final class UserInputMessage extends ObserverMessage {
      * The UUID of the player whose input is required. May be {@code null} to indicate that an input is required from
      * every player.
      */
-    private final UUID player;
+    private final @Nullable UUID player;
     /**
      * The type of input that is required.
      */
-    private final Action action;
+    private final @NonNull Action action;
     /**
      * A timeout in {@link System#currentTimeMillis() UNIX time} after which a default action is taken.
      */

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/player/JuggleMessage.java

@@ -3,11 +3,12 @@ package eu.jonahbauer.wizard.common.messages.player;
 import eu.jonahbauer.wizard.common.model.Card;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.NonNull;
 import lombok.RequiredArgsConstructor;
 
 @Getter
 @RequiredArgsConstructor
 @EqualsAndHashCode(callSuper = true)
 public final class JuggleMessage extends PlayerMessage {
-    private final Card card;
+    private final @NonNull Card card;
 }

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/player/PickTrumpMessage.java

@@ -3,11 +3,12 @@ package eu.jonahbauer.wizard.common.messages.player;
 import eu.jonahbauer.wizard.common.model.Card;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.NonNull;
 import lombok.RequiredArgsConstructor;
 
 @Getter
 @RequiredArgsConstructor
 @EqualsAndHashCode(callSuper = true)
 public final class PickTrumpMessage extends PlayerMessage {
-    private final Card.Suit trumpSuit;
+    private final @NonNull Card.Suit trumpSuit;
 }

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/player/PlayCardMessage.java

@@ -3,11 +3,12 @@ package eu.jonahbauer.wizard.common.messages.player;
 import eu.jonahbauer.wizard.common.model.Card;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.NonNull;
 import lombok.RequiredArgsConstructor;
 
 @Getter
 @RequiredArgsConstructor
 @EqualsAndHashCode(callSuper = true)
 public final class PlayCardMessage extends PlayerMessage {
-    private final Card card;
+    private final @NonNull Card card;
 }

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/server/GameMessage.java

@@ -3,6 +3,7 @@ package eu.jonahbauer.wizard.common.messages.server;
 import eu.jonahbauer.wizard.common.messages.observer.ObserverMessage;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.NonNull;
 import lombok.RequiredArgsConstructor;
 
 @Getter
@@ -12,5 +13,5 @@ public final class GameMessage extends ServerMessage {
     /**
      * Wrapped {@link ObserverMessage}
      */
-    private final ObserverMessage observerMessage;
+    private final @NonNull ObserverMessage observerMessage;
 }

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/server/KickVotedMessage.java

@@ -2,6 +2,7 @@ package eu.jonahbauer.wizard.common.messages.server;
 
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.NonNull;
 import lombok.RequiredArgsConstructor;
 
 import java.util.UUID;
@@ -13,11 +14,11 @@ public final class KickVotedMessage extends ServerMessage {
     /**
      * UUID of the voting player
      */
-    private final UUID voter;
+    private final @NonNull UUID voter;
     /**
      * UUID of player who is supposed to be kicked
      */
-    private final UUID player;
+    private final @NonNull UUID player;
     /**
      * Time until the vote ends in {@link System#currentTimeMillis() UNIX time}
      */

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/server/KickedMessage.java

@@ -2,6 +2,7 @@ package eu.jonahbauer.wizard.common.messages.server;
 
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.NonNull;
 import lombok.RequiredArgsConstructor;
 
 import java.util.UUID;
@@ -13,5 +14,5 @@ public final class KickedMessage extends ServerMessage {
     /**
      * UUID of player who was kicked
      */
-    private final UUID player;
+    private final @NonNull UUID player;
 }

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/server/NackMessage.java

@@ -2,6 +2,7 @@ package eu.jonahbauer.wizard.common.messages.server;
 
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.NonNull;
 import org.intellij.lang.annotations.MagicConstant;
 
 @Getter
@@ -26,9 +27,9 @@ public final class NackMessage extends ServerMessage implements Response {
     public static final int BAD_REQUEST = 999;
 
     private final int code;
-    private final String message;
+    private final @NonNull String message;
 
-    public NackMessage(@MagicConstant(valuesFromClass = NackMessage.class) int code, String message) {
+    public NackMessage(@MagicConstant(valuesFromClass = NackMessage.class) int code, @NonNull String message) {
         this.code = code;
         this.message = message;
     }

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/server/PlayerJoinedMessage.java

@@ -2,11 +2,12 @@ package eu.jonahbauer.wizard.common.messages.server;
 
 import eu.jonahbauer.wizard.common.messages.data.PlayerData;
 import lombok.EqualsAndHashCode;
+import lombok.NonNull;
 
 @EqualsAndHashCode(callSuper = true)
 public final class PlayerJoinedMessage extends PlayerModifiedMessage {
 
-    public PlayerJoinedMessage(PlayerData playerData) {
+    public PlayerJoinedMessage(@NonNull PlayerData player) {
-        super(playerData);
+        super(player);
     }
 }

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/server/PlayerLeftMessage.java

@@ -2,6 +2,7 @@ package eu.jonahbauer.wizard.common.messages.server;
 
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.NonNull;
 import lombok.RequiredArgsConstructor;
 
 import java.util.UUID;
@@ -13,5 +14,5 @@ public final class PlayerLeftMessage extends ServerMessage {
     /**
      * UUID of player who has left
      */
-    private final UUID player;
+    private final @NonNull UUID player;
 }

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/server/PlayerModifiedMessage.java

@@ -3,6 +3,7 @@ package eu.jonahbauer.wizard.common.messages.server;
 import eu.jonahbauer.wizard.common.messages.data.PlayerData;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.NonNull;
 import lombok.RequiredArgsConstructor;
 
 @Getter
@@ -12,5 +13,5 @@ public sealed class PlayerModifiedMessage extends ServerMessage permits PlayerJo
     /**
      * Joining player
      */
-    private final PlayerData player;
+    private final @NonNull PlayerData player;
 }

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/server/SessionCreatedMessage.java

@@ -2,11 +2,12 @@ package eu.jonahbauer.wizard.common.messages.server;
 
 import eu.jonahbauer.wizard.common.messages.data.SessionData;
 import lombok.EqualsAndHashCode;
+import lombok.NonNull;
 
 @EqualsAndHashCode(callSuper = true)
 public final class SessionCreatedMessage extends SessionModifiedMessage {
 
-    public SessionCreatedMessage(SessionData session) {
+    public SessionCreatedMessage(@NonNull SessionData session) {
         super(session);
     }
 }

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/server/SessionJoinedMessage.java

@@ -3,6 +3,8 @@ package eu.jonahbauer.wizard.common.messages.server;
 import eu.jonahbauer.wizard.common.messages.data.PlayerData;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.NonNull;
+import org.jetbrains.annotations.Unmodifiable;
 
 import java.util.List;
 import java.util.UUID;
@@ -13,21 +15,21 @@ public final class SessionJoinedMessage extends ServerMessage implements Respons
     /**
      * UUID of joined session
      */
-    private final UUID session;
+    private final @NonNull UUID session;
     /**
      * UUID assigned to the player
      */
-    private final UUID player;
+    private final @NonNull UUID player;
     /**
      * List of players already in the session
      */
-    private final List<PlayerData> players;
+    private final @Unmodifiable @NonNull List<@NonNull PlayerData> players;
     /**
      * Secret notified to player in order to ensure that if necessary the correct player rejoins
      */
-    private final String secret;
+    private final @NonNull String secret;
 
-    public SessionJoinedMessage(UUID session, UUID player, List<PlayerData> players, String secret) {
+    public SessionJoinedMessage(@NonNull UUID session, @NonNull UUID player, @NonNull List<@NonNull PlayerData> players, @NonNull String secret) {
         this.session = session;
         this.player = player;
         this.players = List.copyOf(players);

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/server/SessionListMessage.java

@@ -3,6 +3,8 @@ package eu.jonahbauer.wizard.common.messages.server;
 import eu.jonahbauer.wizard.common.messages.data.SessionData;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.NonNull;
+import org.jetbrains.annotations.Unmodifiable;
 
 import java.util.List;
 
@@ -12,9 +14,9 @@ public final class SessionListMessage extends ServerMessage implements Response
     /**
      * List of available sessions
      */
-    private final List<SessionData> sessions;
+    private final @Unmodifiable @NonNull List<@NonNull SessionData> sessions;
 
-    public SessionListMessage(List<SessionData> sessions) {
+    public SessionListMessage(@NonNull List<@NonNull SessionData> sessions) {
         this.sessions = List.copyOf(sessions);
     }
 }

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/server/SessionModifiedMessage.java

@@ -3,6 +3,7 @@ package eu.jonahbauer.wizard.common.messages.server;
 import eu.jonahbauer.wizard.common.messages.data.SessionData;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.NonNull;
 import lombok.RequiredArgsConstructor;
 
 @Getter
@@ -12,5 +13,5 @@ public sealed class SessionModifiedMessage extends ServerMessage permits Session
     /**
      * The created session
      */
-    private final SessionData session;
+    private final @NonNull SessionData session;
 }

wizard-common/src/main/java/eu/jonahbauer/wizard/common/messages/server/SessionRemovedMessage.java

@@ -2,6 +2,7 @@ package eu.jonahbauer.wizard.common.messages.server;
 
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.NonNull;
 import lombok.RequiredArgsConstructor;
 
 import java.util.UUID;
@@ -13,5 +14,5 @@ public final class SessionRemovedMessage extends ServerMessage {
     /**
      * UUID of the removed session
      */
-    private final UUID session;
+    private final @NonNull UUID session;
 }