Graph.java

package test;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class Graph extends ArrayList<Node> {
    public boolean hasCycles() {
        for (Node node : this) {
            if (node.hasCycles()) {
                return true;
            }
        }
        return false;
    }

    public void createFromTopics() {
        clear();
        Map<Topic, Node> topicNodes = new HashMap<>();
        Map<Agent, Node> agentNodes = new HashMap<>();

        for (Topic topic : TopicManagerSingleton.get().getTopics()) {
            Node topicNode = getOrCreateTopicNode(topicNodes, topic);

            for (Agent agent : topic.getSubscribers()) {
                Node agentNode = getOrCreateAgentNode(agentNodes, agent);
                topicNode.addEdge(agentNode);
            }

            for (Agent agent : topic.getPublishers()) {
                Node agentNode = getOrCreateAgentNode(agentNodes, agent);
                agentNode.addEdge(topicNode);
            }
        }

        addAll(topicNodes.values());
        for (Node agentNode : agentNodes.values()) {
            if (!contains(agentNode)) {
                add(agentNode);
            }
        }
    }

    private Node getOrCreateTopicNode(Map<Topic, Node> topicNodes, Topic topic) {
        Node node = topicNodes.get(topic);
        if (node == null) {
            node = new Node("T" + topic.name);
            topicNodes.put(topic, node);
        }
        return node;
    }

    private Node getOrCreateAgentNode(Map<Agent, Node> agentNodes, Agent agent) {
        Node node = agentNodes.get(agent);
        if (node == null) {
            node = new Node("A" + agent.getName());
            agentNodes.put(agent, node);
        }
        return node;
    }
}