//
//  ========================================================================
//  Copyright (c) 1995-2020 Mort Bay Consulting Pty Ltd and others.
//  ------------------------------------------------------------------------
//  All rights reserved. This program and the accompanying materials
//  are made available under the terms of the Eclipse Public License v1.0
//  and Apache License v2.0 which accompanies this distribution.
//
//      The Eclipse Public License is available at
//      http://www.eclipse.org/legal/epl-v10.html
//
//      The Apache License v2.0 is available at
//      http://www.opensource.org/licenses/apache2.0.php
//
//  You may elect to redistribute this code under either of these licenses.
//  ========================================================================
//

package org.eclipse.jetty.io;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.util.concurrent.TimeoutException;

import org.eclipse.jetty.util.BufferUtil;
import org.eclipse.jetty.util.Callback;
import org.eclipse.jetty.util.log.Log;
import org.eclipse.jetty.util.log.Logger;
import org.eclipse.jetty.util.thread.Scheduler;

public abstract class AbstractEndPoint extends IdleTimeout implements EndPoint
{
    private static final Logger LOG = Log.getLogger(AbstractEndPoint.class);
    private final long _created=System.currentTimeMillis();
    private final InetSocketAddress _local;
    private final InetSocketAddress _remote;
    private volatile Connection _connection;

    private final FillInterest _fillInterest = new FillInterest()
    {
        @Override
        protected boolean needsFill() throws IOException
        {
            return AbstractEndPoint.this.needsFill();
        }
    };

    private final WriteFlusher _writeFlusher = new WriteFlusher(this)
    {
        @Override
        protected void onIncompleteFlushed()
        {
            AbstractEndPoint.this.onIncompleteFlush();
        }
    };

    protected AbstractEndPoint(Scheduler scheduler,InetSocketAddress local,InetSocketAddress remote)
    {
        super(scheduler);
        _local=local;
        _remote=remote;
    }

    @Override
    public long getCreatedTimeStamp()
    {
        return _created;
    }

    @Override
    public InetSocketAddress getLocalAddress()
    {
        return _local;
    }

    @Override
    public InetSocketAddress getRemoteAddress()
    {
        return _remote;
    }

    @Override
    public Connection getConnection()
    {
        return _connection;
    }

    @Override
    public void setConnection(Connection connection)
    {
        _connection = connection;
    }

    @Override
    public void onOpen()
    {
        if (LOG.isDebugEnabled())
            LOG.debug("onOpen {}",this);
        super.onOpen();
    }

    @Override
    public void onClose()
    {
        super.onClose();
        if (LOG.isDebugEnabled())
            LOG.debug("onClose {}",this);
        _writeFlusher.onClose();
        _fillInterest.onClose();
    }

    @Override
    public void close()
    {
        onClose();
    }

    @Override
    public void fillInterested(Callback callback) throws IllegalStateException
    {
        notIdle();
        _fillInterest.register(callback);
    }

    @Override
    public void write(Callback callback, ByteBuffer... buffers) throws IllegalStateException
    {
        _writeFlusher.write(callback, buffers);
    }

    protected abstract void onIncompleteFlush();

    protected abstract boolean needsFill() throws IOException;

    protected FillInterest getFillInterest()
    {
        return _fillInterest;
    }

    protected WriteFlusher getWriteFlusher()
    {
        return _writeFlusher;
    }

    @Override
    protected void onIdleExpired(TimeoutException timeout)
    {
        boolean output_shutdown=isOutputShutdown();
        boolean input_shutdown=isInputShutdown();
        boolean fillFailed = _fillInterest.onFail(timeout);
        boolean writeFailed = _writeFlusher.onFail(timeout);

        // If the endpoint is half closed and there was no fill/write handling, then close here.
        // This handles the situation where the connection has completed its close handling
        // and the endpoint is half closed, but the other party does not complete the close.
        // This perhaps should not check for half closed, however the servlet spec case allows
        // for a dispatched servlet or suspended request to extend beyond the connections idle
        // time.  So if this test would always close an idle endpoint that is not handled, then
        // we would need a mode to ignore timeouts for some HTTP states
        if (isOpen() && (output_shutdown || input_shutdown) && !(fillFailed || writeFailed))
            close();
        else
            LOG.debug("Ignored idle endpoint {}",this);
    }

    @Override
    public void upgrade(Connection newConnection)
    {
        Connection old_connection = getConnection();

        if (LOG.isDebugEnabled())
            LOG.debug("{} upgrading from {} to {}", this, old_connection, newConnection);

        ByteBuffer prefilled = (old_connection instanceof Connection.UpgradeFrom)
                ?((Connection.UpgradeFrom)old_connection).onUpgradeFrom():null;
        old_connection.onClose();
        old_connection.getEndPoint().setConnection(newConnection);

        if (newConnection instanceof Connection.UpgradeTo)
            ((Connection.UpgradeTo)newConnection).onUpgradeTo(prefilled);
        else if (BufferUtil.hasContent(prefilled))
            throw new IllegalStateException();

        newConnection.onOpen();
    }

    @Override
    public String toString()
    {
        return String.format("%s@%x{%s<->%d,%s,%s,%s,%s,%s,%d/%d,%s}",
                getClass().getSimpleName(),
                hashCode(),
                getRemoteAddress(),
                getLocalAddress().getPort(),
                isOpen()?"Open":"CLOSED",
                isInputShutdown()?"ISHUT":"in",
                isOutputShutdown()?"OSHUT":"out",
                _fillInterest.isInterested()?"R":"-",
                _writeFlusher.isInProgress()?"W":"-",
                getIdleFor(),
                getIdleTimeout(),
                getConnection()==null?null:getConnection().getClass().getSimpleName());
    }
}
