/*
 * Copyright (c) 2011 Tony Garnock-Jones. All rights reserved.
 */

package hop;

import java.lang.ref.WeakReference;
import java.util.Hashtable;
import java.util.Map;
import java.util.UUID;

/**
 */
public class NodeContainer {
    public String _name;
    public Map<String, WeakReference<Node>> _directory;

    public NodeContainer() {
        this(UUID.randomUUID().toString());
    }

    public NodeContainer(String name) {
        _name = name;
        _directory = new Hashtable<String, WeakReference<Node>>();
    }

    public String getName() {
        return _name;
    }

    public synchronized boolean bind(String name, Node n) {
        if (_directory.containsKey(name))
            return false;
        _directory.put(name, new WeakReference<Node>(n));
        return true;
    }

    public synchronized boolean unbind(String name) {
        if (!_directory.containsKey(name))
            return false;
        _directory.remove(name);
        return true;
    }

    public synchronized void unbindReferencesTo(Node n) {
        for (Map.Entry<String, WeakReference<Node>> e : _directory.entrySet()) {
            if (e.getValue().get() == n) {
                _directory.remove(e.getKey());
            }
        }
    }

    public synchronized Node lookup(String name) {
        WeakReference<Node> r = _directory.get(name);
        return (r == null) ? null : r.get();
    }

    public boolean post(String sink, Object name, Object message, Object token) {
        return send(sink, SexpMessage.post(name, message, token));
    }

    public boolean send(String name, Object message) {
        Node n = lookup(name);
        if (n == null) {
            System.err.println("Warning: sending to nonexistent node " + name + "; message " + message);
            return false;
        }
        n.handle(message);
        return true;
    }
}