/*_############################################################################
  _## 
  _##  SNMP4J - TransportStateEvent.java  
  _## 
  _##  Copyright (C) 2003-2026  Frank Fock (SNMP4J.org)
  _##  
  _##  Licensed under the Apache License, Version 2.0 (the "License");
  _##  you may not use this file except in compliance with the License.
  _##  You may obtain a copy of the License at
  _##  
  _##      http://www.apache.org/licenses/LICENSE-2.0
  _##  
  _##  Unless required by applicable law or agreed to in writing, software
  _##  distributed under the License is distributed on an "AS IS" BASIS,
  _##  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  _##  See the License for the specific language governing permissions and
  _##  limitations under the License.
  _##  
  _##########################################################################*/
package org.snmp4j.transport;

import java.io.*;
import java.util.*;

import org.snmp4j.smi.*;

/**
 * The {@code TransportStateEvent} describes a state change for
 * a transport connection. Optionally, connection establishment can be
 * cancelled.
 *
 * @author Frank Fock
 * @version 2.4
 * @since 1.7
 */
public class TransportStateEvent extends EventObject {

    private static final long serialVersionUID = 6440139076579035559L;

    public static final int STATE_UNKNOWN = 0;
    public static final int STATE_CONNECTED = 1;
    public static final int STATE_DISCONNECTED_REMOTELY = 2;
    public static final int STATE_DISCONNECTED_TIMEOUT = 3;
    public static final int STATE_CLOSED = 4;

    private final int newState;
    private final Address peerAddress;
    private final IOException causingException;
    private ArrayList<byte[]> discardedMessages;

    private boolean cancelled = false;


    public TransportStateEvent(AbstractTransportMapping<?> source,
                               Address peerAddress,
                               int newState,
                               IOException causingException) {
        super(source);
        this.newState = newState;
        this.peerAddress = peerAddress;
        this.causingException = causingException;
    }

    public TransportStateEvent(AbstractTransportMapping<?> source,
                               Address peerAddress,
                               int newState,
                               IOException causingException,
                               List<byte[]> discardedMessages) {
        this(source, peerAddress, newState, causingException);
        this.discardedMessages = new ArrayList<byte[]>(discardedMessages);
    }

    public IOException getCausingException() {
        return causingException;
    }

    public int getNewState() {
        return newState;
    }

    public Address getPeerAddress() {
        return peerAddress;
    }

    /**
     * Gets the messages that were discarded due to a state change of the transport connection.
     * @return
     *    a (possibly empty) list of messages that were discarded or {@code null} if the event has not terminated
     *    the transport connection.
     * @since 2.4.0
     */
    public List<byte[]> getDiscardedMessages() {
        return discardedMessages;
    }

    /**
     * Indicates whether this event has been canceled. Only
     * {@link #STATE_CONNECTED} events can be canceled.
     * @return
     *    {@code true} if the event has been canceled.
     * @since 1.8
     */
    public boolean isCancelled() {
        return cancelled;
    }

    public String toString() {
        return TransportStateEvent.class.getName()+"[source="+source+
                ",peerAddress="+peerAddress+
                ",newState="+newState+
                ",cancelled="+cancelled+
                ",causingException="+causingException+"]";
    }

    /**
     * Sets the canceled state of the transport event. Only
     * {@link #STATE_CONNECTED} events can be canceled.
     * @param cancelled
     *    {@code true} if the event should be canceled, i.e. a connection
     *    attempt should be rejected.
     * @since 1.8
     */
    public void setCancelled(boolean cancelled) {
        this.cancelled = cancelled;
    }
}
