Tried to enable picking method

app/src/main/java/ru/dragonestia/picker/repository/impl/NodeRepositoryImpl.java

@@ -16,6 +16,7 @@ import java.util.concurrent.ConcurrentHashMap;
 public class NodeRepositoryImpl implements NodeRepository {
 
     private final RoomRepository roomRepository;
+    private final PickerRepository pickerRepository;
     private final Map<String, Node> nodeMap = new ConcurrentHashMap<>();
 
     @Override
@@ -26,6 +27,7 @@ public class NodeRepositoryImpl implements NodeRepository {
             }
 
             nodeMap.put(node.id(), node);
+            pickerRepository.create(node.id(), node.mode());
         }
 
         roomRepository.onCreateNode(node);
@@ -35,6 +37,7 @@ public class NodeRepositoryImpl implements NodeRepository {
     public void delete(Node node) {
         synchronized (nodeMap) {
             nodeMap.remove(node.id());
+            pickerRepository.remove(node.id());
         }
 
         roomRepository.onRemoveNode(node);

app/src/main/java/ru/dragonestia/picker/repository/impl/PickerRepository.java

@@ -0,0 +1,59 @@
+package ru.dragonestia.picker.repository.impl;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Component;
+import ru.dragonestia.picker.model.Room;
+import ru.dragonestia.picker.model.User;
+import ru.dragonestia.picker.model.type.PickingMode;
+import ru.dragonestia.picker.repository.UserRepository;
+import ru.dragonestia.picker.repository.impl.picker.LeastPickedPicker;
+import ru.dragonestia.picker.repository.impl.picker.Picker;
+import ru.dragonestia.picker.repository.impl.picker.RoundRobinPicker;
+import ru.dragonestia.picker.repository.impl.picker.SequentialFillingPicker;
+
+import java.security.InvalidParameterException;
+import java.util.Collection;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+@Component
+@RequiredArgsConstructor
+public class PickerRepository {
+
+    private final UserRepository userRepository;
+    private final Map<String, Picker<Room, User>> pickers = new ConcurrentHashMap<>();
+
+    public void create(String nodeId, PickingMode mode) {
+        pickers.put(nodeId, of(mode));
+    }
+
+    public void remove(String nodeId) {
+        pickers.remove(nodeId);
+    }
+
+    public Picker<Room, User> find(String nodeId) {
+        return pickers.get(nodeId);
+    }
+
+    public Room pick(String nodeId, Collection<User> users) {
+        return pickers.get(nodeId).pick(users);
+    }
+
+    private Picker<Room, User> of(PickingMode mode) {
+        switch (mode) {
+            case SEQUENTIAL_FILLING -> {
+                return new SequentialFillingPicker(userRepository);
+            }
+
+            case ROUND_ROBIN -> {
+                return new RoundRobinPicker(userRepository);
+            }
+
+            case LEAST_PICKED -> {
+                return new LeastPickedPicker(userRepository);
+            }
+
+            default -> throw new InvalidParameterException("Taken: " + mode);
+        }
+    }
+}

app/src/main/java/ru/dragonestia/picker/repository/impl/RoomRepositoryImpl.java

@@ -17,6 +17,7 @@ import java.util.concurrent.atomic.AtomicInteger;
 public class RoomRepositoryImpl implements RoomRepository {
 
     private final UserRepository userRepository;
+    private final PickerRepository pickerRepository;
     private final Map<Node, Rooms> node2roomsMap = new ConcurrentHashMap<>();
 
     @Override
@@ -37,6 +38,7 @@ public class RoomRepositoryImpl implements RoomRepository {
                 throw new IllegalArgumentException("Room already exists");
             }
             rooms.put(room.getId(), new RoomContainer(room, new AtomicInteger(0)));
+            pickerRepository.find(room.getNodeId()).add(room);
         }
     }
 
@@ -53,6 +55,7 @@ public class RoomRepositoryImpl implements RoomRepository {
             }
 
             node2roomsMap.get(node.get()).remove(room.getId());
+            pickerRepository.find(room.getNodeId()).remove(room);
         }
 
         userRepository.onRemoveRoom(room);
@@ -91,10 +94,14 @@ public class RoomRepositoryImpl implements RoomRepository {
                 throw new IllegalArgumentException("Node '" + node.id() + "' does not exist");
             }
 
-            var requiredSlots = users.size();
+            Room room = null;
-            var container = node2roomsMap.get(node).values().stream() // TODO: pick room with used node balancing mode
+            try {
-                    .filter(r -> r.isAvailable(requiredSlots))
+                room = pickerRepository.pick(node.id(), users);
-                    .findFirst();
+            } catch (RuntimeException ignore) {} // TODO: may be problem. Check it later
+
+            Optional<RoomContainer> container = room == null?
+                    Optional.empty() :
+                    Optional.of(node2roomsMap.get(node).get(room.getId()));
 
             if (container.isPresent()) {
                 var cont = container.get();