/*
 * Copyright (c) 2010-2012 Nathan Rajlich
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

package org.java_websocket;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.ByteChannel;

import org.java_websocket.WebSocket.Role;

public class SocketChannelIOHelper {

	public static boolean read( final ByteBuffer buf, WebSocketImpl ws, ByteChannel channel ) throws IOException {
		buf.clear();
		int read = channel.read( buf );
		buf.flip();

		if( read == -1 ) {
			ws.eot();
			return false;
		}
		return read != 0;
	}

	/**
	 * @see WrappedByteChannel#readMore(ByteBuffer)
	 * @return returns whether there is more data left which can be obtained via {@link #readMore(ByteBuffer, WebSocketImpl, WrappedByteChannel)}
	 **/
	public static boolean readMore( final ByteBuffer buf, WebSocketImpl ws, WrappedByteChannel channel ) throws IOException {
		buf.clear();
		int read = channel.readMore( buf );
		buf.flip();

		if( read == -1 ) {
			ws.eot();
			return false;
		}
		return channel.isNeedRead();
	}

	/** Returns whether the whole outQueue has been flushed */
	public static boolean batch( WebSocketImpl ws, ByteChannel sockchannel ) throws IOException {
		ByteBuffer buffer = ws.outQueue.peek();
		WrappedByteChannel c = null;

		if( buffer == null ) {
			if( sockchannel instanceof WrappedByteChannel ) {
				c = (WrappedByteChannel) sockchannel;
				if( c.isNeedWrite() ) {
					c.writeMore();
				}
			}
		} else {
			do {// FIXME writing as much as possible is unfair!!
				/*int written = */sockchannel.write( buffer );
				if( buffer.remaining() > 0 ) {
					return false;
				} else {
					ws.outQueue.poll(); // Buffer finished. Remove it.
					buffer = ws.outQueue.peek();
				}
			} while ( buffer != null );
		}

		if( ws != null && ws.outQueue.isEmpty() && ws.isFlushAndClose() && ws.getDraft() != null && ws.getDraft().getRole() != null && ws.getDraft().getRole() == Role.SERVER ) {//
			synchronized ( ws ) {
				ws.closeConnection();
			}
		}
		return c != null ? !( (WrappedByteChannel) sockchannel ).isNeedWrite() : true;
	}
}