Graph.java

package test;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.logging.Logger;
import java.util.logging.Level;

public class Graph extends ArrayList<Node> {
    private static final Logger LOGGER = Logger.getLogger(Graph.class.getName());
    
    public boolean hasCycles() {
        Set<Node> visited = new HashSet<>();
        Set<Node> recursionStack = new HashSet<>();
        
        for (Node node : this) {
            if (hasCycle(node, visited, recursionStack)) {
                return true;
            }
        }
        return false;
    }

    private boolean hasCycle(Node node, Set<Node> visited, Set<Node> recursionStack) {
        if (recursionStack.contains(node)) {
            return true;
        }
        
        if (visited.contains(node)) {
            return false;
        }
        
        visited.add(node);
        recursionStack.add(node);
        
        for (Node neighbor : node.getEdges()) {
            if (hasCycle(neighbor, visited, recursionStack)) {
                return true;
            }
        }
        
        recursionStack.remove(node);
        return false;
    }

    public void createFromTopics() {
        clear();

        TopicManagerSingleton.TopicManager tm = TopicManagerSingleton.get();
        
        if (tm == null) {
            LOGGER.severe("TopicManager is null. Cannot create graph.");
            return;
        }

        Collection<Topic> topics = tm.getTopics();
        if (topics == null || topics.isEmpty()) {
            LOGGER.warning("No topics found. Cannot create graph.");
            return;
        }

        Map<String, Node> nodes = new HashMap<>();
        
        for (Topic topic : topics) {
            if (topic == null || topic.name == null) {
                LOGGER.warning("Skipping null topic");
                continue;
            }
            
            String topicNodeName = "T" + topic.name;
            Node topicNode = nodes.computeIfAbsent(topicNodeName, k -> {
                Node newNode = new Node(topicNodeName);
                add(newNode);
                return newNode;
            });
            
            for (Agent agent : topic.getSubs()) {
                String agentNodeName = "A" + agent.getName();
                Node agentNode = nodes.computeIfAbsent(agentNodeName, k -> {
                    Node newNode = new Node(agentNodeName);
                    add(newNode);
                    return newNode;
                });
                
                topicNode.addEdge(agentNode);
            }

            for (Agent agent : topic.getPubs()) {
                String agentNodeName = "A" + agent.getName();
                Node agentNode = nodes.computeIfAbsent(agentNodeName, k -> {
                    Node newNode = new Node(agentNodeName);
                    add(newNode);
                    return newNode;
                });
                
                agentNode.addEdge(topicNode);
            }
        }
    }
}