Cleanup and simplification

pom.xml

@@ -1,7 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <properties>
         <maven.compiler.source>17</maven.compiler.source>
@@ -11,4 +9,29 @@
     <groupId>schmaeddes</groupId>
     <artifactId>untitledTextAdventure</artifactId>
     <version>1.0-SNAPSHOT</version>
+
+    <dependencies>
+
+        <!-- https://mvnrepository.com/artifact/org.graalvm.js/js -->
+        <dependency>
+            <groupId>org.graalvm.js</groupId>
+            <artifactId>js</artifactId>
+            <version>22.2.0</version>
+        </dependency>
+        <!-- https://mvnrepository.com/artifact/org.graalvm.js/js-scriptengine -->
+        <dependency>
+            <groupId>org.graalvm.js</groupId>
+            <artifactId>js-scriptengine</artifactId>
+            <version>22.2.0</version>
+        </dependency>
+        <!-- https://mvnrepository.com/artifact/org.graalvm.truffle/truffle-api -->
+        <dependency>
+            <groupId>org.graalvm.truffle</groupId>
+            <artifactId>truffle-api</artifactId>
+            <version>22.2.0</version>
+        </dependency>
+
+
+    </dependencies>
+
 </project>

src/main/java/Main.java

@@ -1,8 +1,18 @@
 import java.io.IOException;
 
+import javax.script.ScriptEngine;
+import javax.script.ScriptException;
+
+import org.graalvm.polyglot.Context;
+import org.graalvm.polyglot.Engine;
+import org.graalvm.polyglot.HostAccess;
+
+import com.oracle.truffle.js.scriptengine.GraalJSScriptEngine;
+
 import game.logic.GameLogic;
 import game.logic.Parser;
 import game.state.CircularLocationException;
+import game.state.Entity;
 import startup.Environment;
 import startup.LoadStuff;
 
@@ -12,6 +22,18 @@ public class Main {
         LoadStuff loadStuff = new LoadStuff();
         loadStuff.load(Environment.instance);
 
+        ScriptEngine jse = GraalJSScriptEngine.create(
+                Engine.newBuilder().option("engine.WarnInterpreterOnly", "false").build(),
+                Context.newBuilder("js").allowHostAccess(HostAccess.ALL).allowHostClassLookup(s -> true));
+        try {
+            Entity t = new Entity("test");
+            jse.put("test", t);
+            jse.eval("console.log(test.toString());");
+        } catch (ScriptException e) {
+            // TODO Auto-generated catch block
+            e.printStackTrace();
+        }
+
         Parser parser = new Parser();
         try (GameLogic logic = new GameLogic(parser)) {
             logic.loadGameState("games/damnCoolTextAdventureFTW.json");

src/main/java/game/logic/GameLogic.java

@@ -2,14 +2,12 @@ package game.logic;
 
 import java.io.Closeable;
 import java.io.IOException;
+import java.util.HashMap;
 import java.util.LinkedList;
 import java.util.List;
-import java.util.function.Predicate;
+import java.util.Map;
 
-import game.logic.actionsystem.Action;
-import game.logic.actionsystem.actions.GoDirection;
-import game.logic.actionsystem.actions.Open;
-import game.logic.actionsystem.actions.TakeFrom;
+import game.logic.actionsystem.PlayerAction;
 import game.state.CircularLocationException;
 import game.state.Entity;
 import game.state.EntitySet;
@@ -20,6 +18,7 @@ public class GameLogic implements Closeable {
     private GameState state;
     private Entity player;
     private boolean discontinue = false;
+    private Map<String, List<PlayerAction>> playerActions = new HashMap<>();
 
     public GameLogic(Parser parser) {
         this.parser = parser;
@@ -31,135 +30,175 @@ public class GameLogic implements Closeable {
         // TODO setup code, load from json or so
         ////////////////////////////////////////////////////////////////////////
 
-        // final String NORTH = "north";
-        // final String SOUTH = "south";
-        final String EAST = "east";
-        final String WEST = "west";
-        final String INSIDE = "inside";
-        final String OUTSIDE = "outside";
+        Entity east = this.state.createEntity("east");
+        Entity west = this.state.createEntity("west");
+        Entity inside = this.state.createEntity("inside");
+        Entity outside = this.state.createEntity("outside");
+        EntitySet genericDirections = EntitySet.createPersistent("genericDirections");
+        genericDirections.add(east, west);
+        EntitySet houseDirections = EntitySet.createPersistent("houseDirections");
+        houseDirections.add(inside, outside);
 
         Entity forestPath01 = this.state.createEntity("forest_path_01");
         Entity clearing = this.state.createEntity("clearing");
         Entity houseOutside = this.state.createEntity("house_outside");
         Entity houseInside = this.state.createEntity("house_inside");
         Entity houseMainDoor = this.state.createEntity("house_main_door");
-        houseMainDoor.setClosed(true);
 
-        forestPath01.connectBidirectional(EAST, null, WEST, clearing);
-        forestPath01.connectBidirectional(WEST, null, EAST, houseOutside);
-        houseOutside.connectBidirectional(INSIDE, houseMainDoor, OUTSIDE, houseInside);
+        EntitySet locations = EntitySet.createPersistent("locations");
+        locations.add(forestPath01, clearing, houseInside, houseOutside);
 
-        this.player = this.state.createEntity("player");
-        Entity apple01 = this.state.createEntity("apple_01", "green");
-        Entity apple02 = this.state.createEntity("apple_02", "red");
+        forestPath01.connectBidirectional(east, west, clearing);
+        forestPath01.connectBidirectional(west, east, houseOutside);
+        houseOutside.connectBidirectional(inside, outside, houseInside);
 
-        this.player.setLocation(clearing);
-        apple01.setLocation(forestPath01);
-        apple02.setLocation(forestPath01);
+        this.player = clearing.createContainedEntity(this, "player");
+        Entity apple01 = forestPath01.createContainedEntity(this, "apple_01");
+        Entity apple02 = forestPath01.createContainedEntity(this, "apple_02");
 
-        ////////////////////////////////////////////////////////////////////////
-        // TODO game specific action parsers
-        ////////////////////////////////////////////////////////////////////////
+        EntitySet collectibles = EntitySet.createPersistent("collectibles");
+        collectibles.add(apple01, apple02);
 
-        this.parser.pushActionParser(userInput -> userInput.get(0).equals("go")
-                ? new GoDirection(userInput.size() < 2 ? null : userInput.get(1))
-                : null);
-        this.parser.pushActionParser(userInput -> {
-            if (userInput.get(0).equals("take")) {
-                int fromIdx = userInput.indexOf("from");
-                List<EntityDescription> whatToTake = this
-                        .parseDescriptionList(userInput.subList(1, fromIdx == -1 ? userInput.size() : fromIdx));
-                List<EntityDescription> whereToTakeFrom = fromIdx == -1 ? null
-                        : this.parseDescriptionList(userInput.subList(fromIdx + 1, userInput.size()));
-                return new TakeFrom(whatToTake, whereToTakeFrom);
-            } else {
-                return null;
+        collectibles.pushPlayerAction("take", (logic, args) -> {
+            Entity collectible = args[0];
+            if (logic.getPlayer().getLocation() == collectible.getLocation()) {
+                try {
+                    collectible.setLocation(logic.getPlayer());
+                    logic.printRaw("Du nimmst %s, du Schuft.\n", collectible);
+                } catch (CircularLocationException ex) {
+                    // Should not happpen
+                    ex.printStackTrace();
+                }
             }
+            return true;
         });
-        this.parser.pushActionParser(userInput -> {
-            if (userInput.get(0).equals("open")) {
-                return new Open(this.parseDescriptionList(userInput.subList(1, userInput.size())));
+
+        // this.player becomes first argument by calling pushPlayerAction on it
+        PlayerAction goAction = this.player.pushPlayerAction("go", (logic, args) -> {
+            Entity character = args[0];
+            Entity direction = args[1];
+            Entity newLocation = character.getLocation().getConnectedEntity(direction);
+            if (newLocation != null) {
+                try {
+                    logic.getPlayer().setLocation(newLocation);
+                    logic.printRaw("Du gehst Richtung %s und landest hier: %s, du Lutscher!\n", direction, newLocation);
+                } catch (CircularLocationException ex) {
+                    ex.printStackTrace();
+                }
             } else {
-                return null;
+                logic.printRaw("Hier geht es nicht nach %s, du Nichtsnutz.\n", direction);
             }
+            return true;
         });
+        // second argument must be exactly 1 of the entites contained in genericDirections
+        goAction.pushVaryingNeededEntites(genericDirections, 1);
+
+        // again first argument becomes this.player by calling pushPlayerAction on it
+        PlayerAction goHouseAction = this.player.pushPlayerAction("go", (logic, args) -> {
+            Entity character = args[0];
+            Entity direction = args[1];
+            Entity newLocation = character.getLocation().getConnectedEntity(direction);
+            if (newLocation != null && character.getLocation() == houseInside
+                    || character.getLocation() == houseOutside) {
+                if (houseMainDoor.getBoolAttribute("open")) {
+                    try {
+                        character.setLocation(newLocation);
+                    } catch (CircularLocationException ex) {
+                        ex.printStackTrace();
+                    }
+                    logic.printRaw("Du gehst durch die Tür, du Eumel.\n");
+                } else {
+                    logic.printRaw("Die Tür ist zu, du Dödel.\n");
+                }
+                return true;
+            }
+            return false;
+        });
+        // second argument must be exactly 1 of the entites contained in houseDirections
+        goHouseAction.pushVaryingNeededEntites(houseDirections, 1);
+
+        houseMainDoor.pushPlayerAction("open", (logic, args) -> {
+            if (logic.getPlayer().getLocation() == houseInside || logic.getPlayer().getLocation() == houseOutside) {
+                if (houseMainDoor.getBoolAttribute("open")) {
+                    logic.printRaw("Die Tür ist schon offen, du Hammel.\n");
+                } else {
+                    houseMainDoor.setAttribute("open", true);
+                    logic.printRaw("Du öffnest die Tür, du Dummbatz.\n");
+                }
+                return true;
+            }
+            return false;
+        });
+
+        houseMainDoor.pushPlayerAction("close", (logic, args) -> {
+            if (logic.getPlayer().getLocation() == houseInside || logic.getPlayer().getLocation() == houseOutside) {
+                if (!houseMainDoor.getBoolAttribute("open")) {
+                    logic.printRaw("Die Tür ist schon geschlossen, du Mummenschanz.\n");
+                } else {
+                    houseMainDoor.setAttribute("open", false);
+                    logic.printRaw("Du schließt die Tür, du Angsthase.\n");
+                }
+                return true;
+            }
+            return false;
+        });
+    }
+
+    public GameState getState() {
+        return this.state;
     }
 
     public Entity getPlayer() {
         return this.player;
     }
 
-    public EntitySet searchForEntity(EntityDescription description) {
-        return this.state.searchForEntity(description);
-    }
-
-    public EntitySet searchForEntity(EntityDescription description, Predicate<Entity> acceptFunction) {
-        return this.state.searchForEntity(description).getFiltered(acceptFunction);
-    }
-
-    public EntitySet searchForNearbyEntity(EntityDescription description) {
-        return this.searchForEntity(description, e -> {
-            if (this.player == null) {
-                return false;
-            } else if (this.player.contains(e, false)) {
-                return true;
-            } else if (this.player.getLocation() != null && this.player.getLocation().contains(e, false)) {
-                return true;
-            } else {
-                for (Entity.EntityConnection c : this.player.getLocation().getConnections().stream()
-                        .map(this.player.getLocation()::getConnection).toList()) {
-                    if (c.associatedEntity() == e) {
-                        return true;
-                    }
-                }
-            }
-            return false;
-        });
-    }
-
     public void mainLoop() {
         while (!this.discontinue) {
-            Action action = this.parser.readAction();
-            if (action != null) {
-                action.execute(this);
+            this.parser.executeUserInput(this);
+        }
+    }
+
+    public void printRaw(String rawMessage, Object... args) {
+        System.out.printf(rawMessage, args);
+    }
+
+    public void registerPlayerAction(PlayerAction action) {
+        List<PlayerAction> l = this.playerActions.get(action.getId());
+        if (l == null) {
+            this.playerActions.put(action.getId(), l = new LinkedList<>());
+        }
+        l.add(action);
+    }
+
+    /**
+     * Searches for the first player action that does not use any entity and
+     * executes it if one is found.
+     *
+     * @param id The action id
+     * @return <code>true</code>, if an action was found and executed
+     */
+    public boolean tryExecutePlayerAction(String id) {
+        return this.tryExecutePlayerAction(id, null);
+    }
+
+    /**
+     * Searches for the first player action that can operate on the given set of
+     * entities and executes it if one is found.
+     *
+     * @param id       The action id
+     * @param entities The entities on which the action shoud operate
+     * @return <code>true</code>, if an action was found and executed
+     */
+    public boolean tryExecutePlayerAction(String id, EntitySet entities) {
+        List<PlayerAction> l = this.playerActions.get(id);
+        if (l != null) {
+            for (PlayerAction a : l) {
+                if (a.tryExecute(null, entities, this)) {
+                    return true;
+                }
             }
         }
-    }
-
-    private List<EntityDescription> parseDescriptionList(List<String> words) {
-        List<EntityDescription> descriptions = new LinkedList<>();
-        List<String> desc = new LinkedList<>();
-        for (String word : words) {
-            if (word.equals("and")) {
-                descriptions.add(new EntityDescription(desc));
-                desc = new LinkedList<>();
-            } else {
-                desc.add(word);
-            }
-        }
-        if (!desc.isEmpty()) {
-            descriptions.add(new EntityDescription(desc));
-        }
-        return descriptions;
-    }
-
-    public void printToUser(String messageId, Object... args) {
-        System.out.print(messageId);
-        for (int i = 0; i < args.length; ++i) {
-            System.out.print(i == 0 ? " " : ", ");
-            System.out.print(args[i]);
-        }
-        System.out.println();
-    }
-
-    public boolean canPlayerOpen(Entity entity) {
-        // TODO
-        return true;
-    }
-
-    public boolean canPlayerTake(Entity entity) {
-        // TODO
-        return true;
+        return false;
     }
 
     @Override

src/main/java/game/logic/Parser.java

@@ -2,33 +2,53 @@ package game.logic;
 
 import java.io.Closeable;
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Scanner;
 
-import game.logic.actionsystem.Action;
-import game.logic.actionsystem.ActionParser;
+import game.state.Entity;
+import game.state.EntitySet;
 import startup.Environment;
 import util.Commands;
 import util.TextColors;
 
 public class Parser implements Closeable {
     private final Scanner scanner = new Scanner(System.in);
-    private final List<ActionParser> actionParsers = new LinkedList<>();
 
-    public Action readAction() {
+    public void executeUserInput(GameLogic logic) {
+        // Big TODO
+        // currently just reads an action id followed by entity ids
+
         String greenPrompt = TextColors.BLUE.colorize(">");
         System.out.printf("%s ", greenPrompt);
         List<String> input = Arrays.stream(scanner.nextLine().split("\\s+")).map(String::toLowerCase).toList();
-
-        for (ActionParser actionParser : this.actionParsers) {
-            Action action = actionParser.parseAction(input);
-            if (action != null) {
-                return action;
+        if (!input.isEmpty()) {
+            String actionId = input.get(0);
+            List<Entity> args = new ArrayList<>(input.size() - 1);
+            for (int i = 1; i < input.size(); ++i) {
+                Entity e = logic.getState().getEntityById(input.get(i));
+                if (e == null) {
+                    logic.printRaw("Keine Ahnung, was du mit %s meinst, du Tölpel.\n", input.get(i));
+                    return;
+                }
+                args.add(e);
+            }
+            Entity primaryEntity = this.getPrimaryEntity(logic, actionId, args);
+            if (primaryEntity != null) {
+                primaryEntity.tryExecutePlayerAction(actionId, EntitySet.createTemporary(args), logic);
+            } else if(logic.tryExecutePlayerAction(actionId, EntitySet.createTemporary(args))) {
+                logic.printRaw("Das geht doch so nicht.\n", args);
             }
         }
-        return null;
+    }
+
+    private Entity getPrimaryEntity(GameLogic logic, String actionId, List<Entity> arguments) {
+        return switch (actionId) {
+            case "go" -> logic.getPlayer();
+            case "take", "open", "close" -> arguments.remove(0);
+            default -> null;
+        };
     }
 
     public void parse(List<String> parameter) {
@@ -40,10 +60,6 @@ public class Parser implements Closeable {
         }
     }
 
-    public void pushActionParser(ActionParser actionParser) {
-        this.actionParsers.add(actionParser);
-    }
-
     @Override
     public void close() throws IOException {
         this.scanner.close();

src/main/java/game/logic/actionsystem/Action.java

@@ -1,22 +0,0 @@
-package game.logic.actionsystem;
-
-import game.logic.GameLogic;
-
-public abstract class Action {
-    public enum Type {
-        TAKE, DROP,
-        COMBINE_WITH, USE,
-        GIVE_TO, TAKE_FROM,
-        PUT_ON,
-        PUSH, PULL, ROLL, ROLL_TO,
-        TRACE_RAY_TO,
-        KILL, KILL_WITH,
-        SEARCH, SEARCH_FOR,
-        TALK_TO, TELL_TO, ANNOY,
-        LOOK_AT, EXAMINE, READ, WRITE_ON_WITH,
-        HIT, HIT_WITH,
-        GO_TO,
-    }
-
-    public abstract void execute(GameLogic logic);
-}

src/main/java/game/logic/actionsystem/ActionParser.java

@@ -1,7 +0,0 @@
-package game.logic.actionsystem;
-
-import java.util.List;
-
-public interface ActionParser {
-    public Action parseAction(List<String> userInput);
-}

src/main/java/game/logic/actionsystem/PlayerAction.java

@@ -0,0 +1,121 @@
+package game.logic.actionsystem;
+
+import java.util.Arrays;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Objects;
+
+import game.logic.GameLogic;
+import game.state.Entity;
+import game.state.EntitySet;
+
+/**
+ * A player action represents a single action which operates on any number of
+ * entities.
+ *
+ * It has an identifier, e.g. <code>"combine"</code>, a signature of needed
+ * entities, and an executor. The signature consists multiple entries, each one
+ * being either a single entity or a group of entities. To execute a player
+ * action an <a href="#EntitySet"><code>EntitySet</code></a> must be given which
+ * can be matched against its signature.
+ */
+public class PlayerAction {
+    private record SignatureEntry(EntitySet entities, int count) {
+    }
+
+    private final String id;
+    private final PlayerActionExecutor executor;
+    private final List<SignatureEntry> signatureEntries = new LinkedList<>();
+    private int neededEntitiesTotalCount = 0;
+
+    /**
+     * Constructs a player action by providing an id and an executor.
+     *
+     * @param id       The action id
+     * @param executor The executor which is called when
+     *                 <a href="#tryExecute">tryExecute</a> is called with an entity
+     *                 set which can be matched against the signature.
+     */
+    public PlayerAction(String id, PlayerActionExecutor executor) {
+        this.id = id;
+        this.executor = executor;
+    }
+
+    /**
+     * Getter for the action's id.
+     *
+     * @return The action id
+     */
+    public String getId() {
+        return this.id;
+    }
+
+    /**
+     * Pushes a new entry to this action' signature consisting of a single entity
+     * which is needed for execution.
+     *
+     * @param entity The needed entity to push
+     */
+    public void pushNeededEntity(Entity entity) {
+        this.signatureEntries.add(new SignatureEntry(EntitySet.createTemporary(entity), 1));
+        ++this.neededEntitiesTotalCount;
+    }
+
+    /**
+     * Pushes a new entry to this action's signature consisting of a set of entities
+     * of which a specific count is needed for execution.
+     *
+     * @param entities The set of needed entities
+     * @param count    How many entities of the given set are needed for execution
+     */
+    public void pushVaryingNeededEntites(EntitySet entities, int count) {
+        this.signatureEntries.add(new SignatureEntry(entities, count));
+        this.neededEntitiesTotalCount += count;
+    }
+
+    /**
+     * Tries to match the given entities to this action's signature and executes it
+     * if successful.
+     *
+     * @param primaryEntity     An optional primary entity which will be matched
+     *                          against the first signature entry.
+     * @param secondaryEntities A set of entities which will be matched against the
+     *                          signature (excl. the first entry if
+     *                          <code>primaryEntity</code> was not
+     *                          <code>null</code>)
+     * @param logic             The game logic
+     * @return <code>true</code>, if given entities match the signature and the
+     *         action was executed
+     */
+    public boolean tryExecute(Entity primaryEntity, EntitySet secondaryEntities, GameLogic logic) {
+        if ((primaryEntity == null ? 0 : 1)
+                + (secondaryEntities == null ? 0 : secondaryEntities.getSize()) != this.neededEntitiesTotalCount) {
+            return false;
+        }
+        int entityCounts[] = new int[this.signatureEntries.size()];
+        Entity entitiesToUse[] = new Entity[this.neededEntitiesTotalCount];
+        if (primaryEntity != null) {
+            if (this.signatureEntries.isEmpty() || !this.signatureEntries.get(0).entities().contains(primaryEntity)) {
+                return false;
+            }
+            entitiesToUse[entityCounts[0]++] = primaryEntity;
+        }
+        if (secondaryEntities != null) {
+            for (Entity e : secondaryEntities.getAll()) {
+                int idx = 0;
+                for (int i = 0; i < this.signatureEntries.size(); ++i) {
+                    SignatureEntry signatureEntry = this.signatureEntries.get(i);
+                    if (entityCounts[i] != signatureEntry.count() && signatureEntry.entities().contains(e)) {
+                        entitiesToUse[idx + entityCounts[i]++] = e;
+                        break;
+                    }
+                    idx += signatureEntry.count();
+                }
+            }
+        }
+        if (Arrays.stream(entitiesToUse).anyMatch(Objects::isNull)) {
+            return false;
+        }
+        return this.executor.execute(logic, entitiesToUse);
+    }
+}

src/main/java/game/logic/actionsystem/PlayerActionExecutor.java

@@ -0,0 +1,19 @@
+package game.logic.actionsystem;
+
+import game.logic.GameLogic;
+import game.state.Entity;
+
+/**
+ * A player action executor provides specific instructions how to manipulate the
+ * game logic.
+ */
+public interface PlayerActionExecutor {
+
+    /**
+     * Executes the game logic manupulation.
+     *
+     * @param logic The game logic
+     * @param args  Arguments
+     */
+    public boolean execute(GameLogic logic, Entity... args);
+}

src/main/java/game/logic/actionsystem/actions/GoDirection.java

@@ -1,44 +0,0 @@
-package game.logic.actionsystem.actions;
-
-import game.logic.GameLogic;
-import game.logic.actionsystem.Action;
-import game.state.CircularLocationException;
-import game.state.Entity;
-
-public class GoDirection extends Action {
-    private final String directionId;
-
-    public GoDirection(String directionId) {
-        this.directionId = directionId;
-    }
-
-    public String getDirectionId() {
-        return this.directionId;
-    }
-
-    @Override
-    public void execute(GameLogic logic) {
-        if (logic.getPlayer() == null) {
-            logic.printToUser("go.player.null");
-        } else {
-            Entity location = logic.getPlayer().getLocation();
-            if (location == null) {
-                logic.printToUser("go.player.location.null", logic.getPlayer());
-            } else {
-                Entity.EntityConnection connection = location.getConnection(this.directionId);
-                if (connection == null || connection.to() == null) {
-                    logic.printToUser("go.direction.unknown", logic.getPlayer().getLocation(), this.directionId);
-                } else if (connection.associatedEntity() != null && connection.associatedEntity().isClosed()) {
-                    logic.printToUser("go.location.closed", connection.associatedEntity());
-                } else {
-                    try {
-                        logic.getPlayer().setLocation(connection.to());
-                        logic.printToUser("go.success", location, connection.to());
-                    } catch (CircularLocationException ex) {
-                        logic.printToUser("go.locationCircular", ex);
-                    }
-                }
-            }
-        }
-    }
-}

src/main/java/game/logic/actionsystem/actions/Open.java

@@ -1,32 +0,0 @@
-package game.logic.actionsystem.actions;
-
-import java.util.List;
-
-import game.logic.EntityDescription;
-import game.logic.GameLogic;
-import game.logic.actionsystem.Action;
-import game.state.Entity;
-import game.state.EntitySet;
-
-public class Open extends Action {
-    private final List<EntityDescription> descriptions;
-
-    public Open(List<EntityDescription> descriptions) {
-        this.descriptions = descriptions;
-    }
-
-    @Override
-    public void execute(GameLogic logic) {
-        for (EntitySet set : this.descriptions.stream().map(logic::searchForNearbyEntity).toList()) {
-            Entity e = set.collapse(logic);
-            if(e == null) {
-                logic.printToUser("open.noEntity");
-            } else if (logic.canPlayerOpen(e)) {
-                e.setClosed(false);
-                logic.printToUser("open.success", e);
-            } else {
-                logic.printToUser("open.failed", e);
-            }
-        }
-    }
-}

src/main/java/game/logic/actionsystem/actions/TakeFrom.java

@@ -1,50 +0,0 @@
-package game.logic.actionsystem.actions;
-
-import java.util.List;
-
-import game.logic.EntityDescription;
-import game.logic.GameLogic;
-import game.logic.actionsystem.Action;
-import game.state.CircularLocationException;
-import game.state.Entity;
-import game.state.EntitySet;
-
-public class TakeFrom extends Action {
-    private final List<EntityDescription> what;
-    private final List<EntityDescription> fromWhere;
-
-    public TakeFrom(List<EntityDescription> what, List<EntityDescription> fromWhere) {
-        this.what = what;
-        this.fromWhere = fromWhere;
-    }
-
-    public List<EntityDescription> getWhat() {
-        return this.what;
-    }
-
-    public List<EntityDescription> getFromWhere() {
-        return this.fromWhere;
-    }
-
-    @Override
-    public void execute(GameLogic logic) {
-        // TODO incorporate fromWhere
-        for (EntityDescription ed : this.what) {
-            EntitySet es = logic.searchForNearbyEntity(ed);
-            if(es.isEmpty()) {
-                logic.printToUser("entity.notFound", ed);
-            }
-            Entity e = es.collapse(logic);
-            if (e != null && logic.canPlayerTake(e)) {
-                try {
-                    e.setLocation(logic.getPlayer());
-                    logic.printToUser("take.success", e);
-                } catch (CircularLocationException ex) {
-                    logic.printToUser("take.error", ex);
-                }
-            } else {
-                logic.printToUser("take.failed", e);
-            }
-        }
-    }
-}

src/main/java/game/state/Entity.java

@@ -1,57 +1,64 @@
 package game.state;
 
-import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
+import game.logic.GameLogic;
+import game.logic.actionsystem.PlayerAction;
+import game.logic.actionsystem.PlayerActionExecutor;
+
+/**
+ * Entities are the building blocks of the game logic's world.
+ *
+ * They can represent objects, creatures, the player(s), locations, and more.
+ * Each entity can also contain zero or more other entities, working as an
+ * abstract container. It can be connected to other entities through keywords,
+ * e.g. north, south, west, east. A connection can also be associated with
+ * another entity to model doors or other types of portals. Finally, an entity
+ * can store generic attributes.
+ */
 public class Entity {
-    public record EntityConnection(Entity to, Entity associatedEntity) {
-
-    }
-
     private final String id;
-    private final Set<String> attributes = new HashSet<>();
+    final Set<EntitySet> containingPersistentSets = new HashSet<>();
+    private final Map<String, String> attributes = new HashMap<>();
     private Entity location;
-    private boolean closed = false;
-    private final EntitySet contents = new EntitySet();
-    private final Map<String, EntityConnection> connections = new HashMap<>();
+    private final EntitySet contents;
+    private final Map<Entity, Entity> connections = new HashMap<>();
+    private final Map<String, List<PlayerAction>> playerActions = new HashMap<>();
 
-    public Entity(String id, String... attributes) {
+    public Entity(String id) {
         this.id = id;
-        this.attributes.addAll(Arrays.asList(attributes));
+        this.contents = EntitySet.createPersistent(this.id + "::contents");
     }
 
     public String getId() {
         return this.id;
     }
 
-    public Set<String> getAttributes() {
-        return Collections.unmodifiableSet(this.attributes);
+    public String getAttribute(String key) {
+        String value = this.attributes.get(key);
+        return value == null ? "" : value;
     }
 
-    public boolean addAttribute(String attribute) {
-        return this.attributes.add(attribute);
+    public boolean getBoolAttribute(String key) {
+        return Boolean.parseBoolean(this.getAttribute(key));
     }
 
-    public boolean removeAttribute(String attribute) {
-        return this.attributes.remove(attribute);
-    }
-
-    public void toggleAttribute(String attribute) {
-        if (!this.attributes.remove(attribute)) {
-            this.attributes.add(attribute);
+    public void setAttribute(String key, Object value) {
+        if (value == null) {
+            this.attributes.remove(key);
+        } else {
+            this.attributes.put(key, value.toString());
         }
     }
 
-    public void switchAttribute(String attr1, String attr2) {
-        if (this.attributes.remove(attr1)) {
-            this.attributes.add(attr2);
-        } else if (this.attributes.remove(attr2)) {
-            this.attributes.add(attr1);
-        }
+    public void removeAttribute(String key) {
+        this.setAttribute(key, null);
     }
 
     public void setLocation(Entity location) throws CircularLocationException {
@@ -70,18 +77,21 @@ public class Entity {
         }
     }
 
-    public boolean isClosed() {
-        return this.closed;
-    }
-
-    public void setClosed(boolean closed) {
-        this.closed = closed;
-    }
-
     public boolean contains(Entity other, boolean recursive) {
         return this.contents.getAll().stream().anyMatch(e -> e == other || (recursive && e.contains(other, true)));
     }
 
+    public Entity createContainedEntity(GameLogic logic, String id) {
+        Entity e = logic.getState().createEntity(id);
+        try {
+            e.setLocation(this);
+        } catch (CircularLocationException ex) {
+            // should not happen
+            ex.printStackTrace();
+        }
+        return e;
+    }
+
     public Entity getLocation() {
         return this.location;
     }
@@ -90,34 +100,88 @@ public class Entity {
         return this.contents.getAll();
     }
 
-    public void connectUnidirectional(String directionId, Entity to, Entity associatedEntity) {
-        this.connections.put(directionId, new EntityConnection(to, associatedEntity));
+    public void connectUnidirectional(Entity direction, Entity to) {
+        this.connections.put(direction, to);
     }
 
-    public void connectBidirectional(String dirIdFromThisToOther, Entity associatedEntity, String dirIdFromOtherToThis, Entity to) {
-        this.connections.put(dirIdFromThisToOther, new EntityConnection(to, associatedEntity));
-        to.connections.put(dirIdFromOtherToThis, new EntityConnection(this, associatedEntity));
+    public void connectBidirectional(Entity dirFromThisToOther, Entity dirFromOtherToThis, Entity other) {
+        this.connections.put(dirFromThisToOther, other);
+        other.connections.put(dirFromOtherToThis, this);
     }
 
-    public void removeSingleConnection(String directionId) {
-        this.connections.remove(directionId);
+    public void removeSingleConnection(Entity direction) {
+        this.connections.remove(direction);
     }
 
-    public void removeBidirectionalConnection(String dirIdFromThisToOther, String dirIdFromOtherToThis) {
-        EntityConnection c = this.connections.remove(dirIdFromThisToOther);
-        if (c != null) {
-            c.to.connections.remove(dirIdFromOtherToThis);
+    public void removeBidirectionalConnection(Entity dirFromThisToOther, Entity dirFromOtherToThis) {
+        Entity other = this.connections.remove(dirFromThisToOther);
+        if (other != null && other.connections.get(dirFromOtherToThis) == this) {
+            other.connections.remove(dirFromOtherToThis);
         }
     }
 
-    public EntityConnection getConnection(String directionId) {
-        return this.connections.get(directionId);
+    public Entity getConnectedEntity(Entity direction) {
+        return this.connections.get(direction);
     }
 
-    public Set<String> getConnections() {
+    public Set<Entity> getConnectionDirections() {
         return Collections.unmodifiableSet(this.connections.keySet());
     }
 
+    public PlayerAction pushPlayerAction(String id, PlayerActionExecutor executor) {
+        List<PlayerAction> l = this.playerActions.get(id);
+        if (l == null) {
+            this.playerActions.put(id, l = new LinkedList<>());
+        }
+        PlayerAction action = new PlayerAction(id, executor);
+        action.pushNeededEntity(this);
+        l.add(action);
+        return action;
+    }
+
+    /**
+     * Searches for the first player action that can operate on this entity and the
+     * given secondary entities and executes it if one is found.
+     *
+     * @param id                The action id
+     * @param secondaryEntities The set of secondary entities on which the action
+     *                          should operate
+     * @return <code>true</code>, if an action was found and executed
+     */
+    public boolean tryExecutePlayerAction(String id, EntitySet secondaryEntities, GameLogic logic) {
+        if (!this.tryExecutePlayerAction(this.playerActions.get(id), secondaryEntities, logic)) {
+            for (EntitySet set : this.containingPersistentSets) {
+                if (this.tryExecutePlayerAction(set.getPlayerActions(id), secondaryEntities, logic)) {
+                    return true;
+                }
+            }
+            return false;
+        }
+        return true;
+    }
+
+    /**
+     * Searches for the first player action that can operate on this entity and no
+     * secondary entities executes it if one is found.
+     *
+     * @param id The action id
+     * @return <code>true</code>, if an action was found and executed
+     */
+    public boolean tryExecutePlayerAction(String id, GameLogic logic) {
+        return this.tryExecutePlayerAction(id, null, logic);
+    }
+
+    private boolean tryExecutePlayerAction(List<PlayerAction> actions, EntitySet secondaryEntities, GameLogic logic) {
+        if (actions != null) {
+            for (PlayerAction a : actions) {
+                if (a.tryExecute(this, secondaryEntities, logic)) {
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
     @Override
     public String toString() {
         return this.id;

src/main/java/game/state/EntitySet.java

@@ -3,21 +3,42 @@ package game.state;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
 import java.util.Set;
 import java.util.function.Predicate;
 
 import game.logic.GameLogic;
+import game.logic.actionsystem.PlayerAction;
+import game.logic.actionsystem.PlayerActionExecutor;
 
 public class EntitySet {
-    private final Set<Entity> entities;
-
-    public EntitySet(Entity... entities) {
-        this(Arrays.asList(entities));
+    public static EntitySet createTemporary(Entity... entities) {
+        return new EntitySet(null, Arrays.asList(entities));
     }
 
-    public EntitySet(Collection<Entity> entities) {
-        this.entities = new HashSet<>(entities);
+    public static EntitySet createTemporary(Collection<Entity> entities) {
+        return new EntitySet(null, entities);
+    }
+
+    public static EntitySet createPersistent(String name, Entity... entities) {
+        return new EntitySet(name, Arrays.asList(entities));
+    }
+
+    public static EntitySet createPersistent(String name, Collection<Entity> entities) {
+        return new EntitySet(name, entities);
+    }
+
+    private final String name;
+    private final Set<Entity> entities = new HashSet<>();
+    private final Map<String, List<PlayerAction>> playerActions = new HashMap<>();
+
+    private EntitySet(String name, Collection<Entity> entities) {
+        this.name = name;
+        this.add(entities.toArray(new Entity[0]));
     }
 
     public boolean isEmpty() {
@@ -28,12 +49,24 @@ public class EntitySet {
         return Collections.unmodifiableSet(this.entities);
     }
 
-    public boolean add(Entity entity) {
-        return this.entities.add(entity);
+    public int getSize() {
+        return this.entities.size();
     }
 
-    public boolean remove(Entity entity) {
-        return this.entities.remove(entity);
+    public void add(Entity... entities) {
+        for (Entity e : entities) {
+            if (this.entities.add(e) && this.name != null) {
+                e.containingPersistentSets.add(this);
+            }
+        }
+    }
+
+    public void remove(Entity... entities) {
+        for (Entity e : entities) {
+            if (this.entities.remove(e) && this.name != null) {
+                e.containingPersistentSets.remove(this);
+            }
+        }
     }
 
     public boolean contains(Entity entity) {
@@ -41,7 +74,7 @@ public class EntitySet {
     }
 
     public Entity collapse(GameLogic logic) {
-        if(this.entities.size() <= 1) {
+        if (this.entities.size() <= 1) {
             return this.entities.stream().findAny().orElse(null);
         } else {
             // TODO if more than 1 candidate, ask user to specify
@@ -50,6 +83,22 @@ public class EntitySet {
     }
 
     public EntitySet getFiltered(Predicate<Entity> acceptFunction) {
-        return new EntitySet(this.entities.stream().filter(acceptFunction).toList());
+        return EntitySet.createTemporary(this.entities.stream().filter(acceptFunction).toList());
+    }
+
+    public PlayerAction pushPlayerAction(String id, PlayerActionExecutor executor) {
+        List<PlayerAction> l = this.playerActions.get(id);
+        if (l == null) {
+            this.playerActions.put(id, l = new LinkedList<>());
+        }
+        PlayerAction action = new PlayerAction(id, executor);
+        action.pushVaryingNeededEntites(this, 1);
+        l.add(action);
+        return action;
+    }
+
+    public List<PlayerAction> getPlayerActions(String id) {
+        List<PlayerAction> l = this.playerActions.get(id);
+        return l == null ? Collections.emptyList() : Collections.unmodifiableList(this.playerActions.get(id));
     }
 }

src/main/java/game/state/GameState.java

@@ -1,25 +1,22 @@
 package game.state;
 
-import java.util.LinkedList;
-import java.util.List;
-
-import game.logic.EntityDescription;
+import java.util.HashMap;
+import java.util.Map;
 
 public class GameState {
-    private final List<Entity> entities = new LinkedList<>();
+    private final Map<String, Entity> entities = new HashMap<>();
 
     public GameState() {
 
     }
 
-    public Entity createEntity(String id, String... attributes) {
-        Entity e = new Entity(id, attributes);
-        this.entities.add(e);
+    public Entity createEntity(String id) {
+        Entity e = new Entity(id);
+        this.entities.put(id, e);
         return e;
     }
 
-    public EntitySet searchForEntity(EntityDescription description) {
-        return new EntitySet(this.entities.stream().filter(e -> e.getId().equals(description.getMainWord())
-                && e.getAttributes().containsAll(description.getAttributes())).toList());
+    public Entity getEntityById(String id) {
+        return this.entities.get(id);
     }
 }