/*
 * jPOS Project [http://jpos.org]
 * Copyright (C) 2000-2026 jPOS Software SRL
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.jpos.iso.channel;

import org.jpos.core.Configurable;
import org.jpos.core.Configuration;
import org.jpos.core.ConfigurationException;
import org.jpos.iso.ISOChannel;
import org.jpos.iso.ISOException;
import org.jpos.iso.ISOMsg;
import org.jpos.iso.ISOPackager;
import org.jpos.util.LogEvent;
import org.jpos.util.LogSource;
import org.jpos.util.Logger;
import org.jpos.util.NameRegistrar;

import java.io.IOException;
import java.util.List;
import java.util.Vector;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

/**
 * A pool of {@link ISOChannel} instances; tries each in order until one connects.
 */
@SuppressWarnings("unchecked")
public class ChannelPool implements ISOChannel, LogSource, Configurable, Cloneable {
    /** Whether this pool is in a usable state. */
    boolean usable = true;
    /** Registered name of this pool. */
    String name = "";
    /** Logger for this pool. */
    protected Logger logger;
    /** Log realm for this pool. */
    protected String realm;
    Configuration cfg = null;
    List pool;
    ISOChannel current;
    Lock lock = new ReentrantLock();

    /** Default constructor. */
    public ChannelPool () {
        super ();
        pool = new Vector ();
    }
    public void setPackager(ISOPackager p) {
        // nothing to do
    }
    public void connect () throws IOException {
        lock.lock();
        try {
            current = null;
            LogEvent evt = new LogEvent (this, "connect");
            evt.addMessage ("pool-size=" + Integer.toString (pool.size()));
            for (int i=0; i<pool.size(); i++) {
                try {
                    evt.addMessage ("pool-" + Integer.toString (i));
                    ISOChannel c = (ISOChannel) pool.get (i);
                    c.connect ();
                    if (c.isConnected()) {
                        current = c;
                        usable = true;
                        break;
                    }
                } catch (IOException e) {
                    evt.addMessage (e);
                }
            }
            if (current == null)
                evt.addMessage ("connect failed");
            Logger.log (evt);
            if (current == null) {
                throw new IOException ("unable to connect");
            }
        } finally {
            lock.unlock();
        }
    }
    public void disconnect () throws IOException {
        lock.lock();
        try {
            current = null;
            LogEvent evt = new LogEvent (this, "disconnect");
            for (Object aPool : pool) {
                try {
                    ISOChannel c = (ISOChannel) aPool;
                    c.disconnect();
                } catch (IOException e) {
                    evt.addMessage(e);
                }
            }
            Logger.log (evt);
        } finally {
            lock.unlock();
        }

    }
    public void reconnect() throws IOException {
        lock.lock();
        try {
            disconnect ();
            connect ();
        } finally {
            lock.unlock();;
        }
    }
    public boolean isConnected() {
        lock.lock();
        try {
            return getCurrent().isConnected ();
        } catch (IOException e) {
            return false;
        } finally {
            lock.unlock();
        }
    }
    public ISOMsg receive() throws IOException, ISOException {
        return getCurrent().receive ();
    }
    public void send (ISOMsg m) throws IOException, ISOException {
        getCurrent().send (m);
    }
    public void send (byte[] b) throws IOException, ISOException {
        getCurrent().send (b);
    }
    public void setUsable(boolean b) {
        this.usable = b;
    }
    public void setName (String name) {
        this.name = name;
        NameRegistrar.register ("channel."+name, this);
    }
    public String getName() {
        return this.name;
    }
    public ISOPackager getPackager () {
        return null;
    }
    public void setLogger (Logger logger, String realm) {
        this.logger = logger;
        this.realm  = realm;
    }
    public String getRealm () {
        return realm;
    }
    public Logger getLogger() {
        return logger;
    }
    public void setConfiguration (Configuration cfg)
        throws ConfigurationException
    {
        this.cfg = cfg;
        String channelName[] = cfg.getAll ("channel");
        for (String aChannelName : channelName) {
            try {
                addChannel(aChannelName);
            } catch (NameRegistrar.NotFoundException e) {
                throw new ConfigurationException(e);
            }
        }
    }
    /**
     * Adds a channel to the pool.
     * @param channel the channel to add
     */
    public void addChannel (ISOChannel channel) {
        pool.add (channel);
    }
    /**
     * Adds a channel to the pool by its registered name.
     * @param name the NameRegistrar name of the channel to add
     * @throws NameRegistrar.NotFoundException if name not found
     */
    public void addChannel (String name) 
        throws NameRegistrar.NotFoundException
    {
        pool.add (NameRegistrar.get ("channel."+name));
    }
    /**
     * Removes a channel from the pool.
     * @param channel the channel to remove
     */
    public void removeChannel (ISOChannel channel) {
        pool.remove (channel);
    }
    /**
     * Removes a channel from the pool by its registered name.
     * @param name the channel name to remove
     * @throws NameRegistrar.NotFoundException if name not found
     */
    public void removeChannel (String name) throws NameRegistrar.NotFoundException {
        pool.remove (NameRegistrar.get ("channel."+name));
    }
    /**
     * Returns the number of channels in the pool.
     * @return channel count
     */
    public int size() {
        return pool.size();
    }
    /** Returns the currently active channel, trying to connect if necessary.
     * @return the active ISOChannel
     * @throws IOException if no channel can be connected
     */
    public ISOChannel getCurrent () throws IOException {
        lock.lock();
        try {
            if (current == null)
                connect();
            else if (!usable)
                reconnect();
        } finally {
            lock.unlock();
        }
        return current;
    }
    
    public Object clone(){
      try {
        return super.clone();
      } catch (CloneNotSupportedException e) {
        throw new InternalError();
      }
    }
}