/**
    *  BlueCove - Java library for Bluetooth
    *  Copyright (C) 2007-2008 Vlad Skarzhevskyy
    *
    *  Licensed to the Apache Software Foundation (ASF) under one
    *  or more contributor license agreements.  See the NOTICE file
    *  distributed with this work for additional information
    *  regarding copyright ownership.  The ASF licenses this file
    *  to you 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.
   *
   *  @author vlads
   *  @version $Id: OBEXSessionBase.java 2641 2008-12-22 23:28:52Z skarzhevskyy $
   */
  package com.intel.bluetooth.obex;
  
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.util.Enumeration;
  import java.util.Vector;
  
  import javax.bluetooth.RemoteDevice;
  import javax.bluetooth.ServiceRecord;
  import javax.microedition.io.Connection;
  import javax.microedition.io.StreamConnection;
  import javax.obex.Authenticator;
  import javax.obex.HeaderSet;
  import javax.obex.ServerRequestHandler;
  
  import com.intel.bluetooth.BluetoothConnectionAccess;
  import com.intel.bluetooth.BluetoothStack;
  import com.intel.bluetooth.DebugLog;
  import com.intel.bluetooth.obex.OBEXAuthentication.Challenge;
  
  /**
   * Base for Client and Server implementations. See <a
   * href="http://bluetooth.com/Bluetooth/Learn/Technology/Specifications/" >Bluetooth Specification Documents</A> for
   * details.
   * 
   */
  abstract class OBEXSessionBase implements Connection, BluetoothConnectionAccess {
  
  	protected boolean isConnected;
  
  	private StreamConnection conn;
  
  	private InputStream is;
  
  	private OutputStream os;
  
  	protected long connectionID;
  
  	protected int mtu = OBEXOperationCodes.OBEX_DEFAULT_MTU;
  
  	protected Authenticator authenticator;
  
  	protected OBEXConnectionParams obexConnectionParams;
  
  	protected int packetsCountWrite;
  
  	protected int packetsCountRead;
  
  	private Vector authChallengesSent;
  
  	/**
  	 * Each request packet flowed by response. This flag is from Client point of view
  	 */
  	protected boolean requestSent;
  
  	public OBEXSessionBase(StreamConnection conn, OBEXConnectionParams obexConnectionParams) throws IOException {
  		if (obexConnectionParams == null) {
  			throw new NullPointerException("obexConnectionParams is null");
  		}
  		this.isConnected = false;
  		this.conn = conn;
  		this.obexConnectionParams = obexConnectionParams;
  		this.mtu = obexConnectionParams.mtu;
  		this.connectionID = -1;
  		this.packetsCountWrite = 0;
  		this.packetsCountRead = 0;
  		boolean initOK = false;
  		try {
  			this.os = conn.openOutputStream();
  			this.is = conn.openInputStream();
  			initOK = true;
  		} finally {
  			if (!initOK) {
 				try {
 					this.close();
 				} catch (IOException e) {
 					DebugLog.error("close error", e);
 				}
 			}
 		}
 	}
 
 	public void close() throws IOException {
 		StreamConnection c = this.conn;
 		this.conn = null;
 		try {
 			if (this.is != null) {
 				this.is.close();
 				this.is = null;
 			}
 			if (this.os != null) {
 				this.os.close();
 				this.os = null;
 			}
 		} finally {
 			if (c != null) {
 				c.close();
 			}
 		}
 
 	}
 
 	static OBEXHeaderSetImpl createOBEXHeaderSetImpl() {
 		return new OBEXHeaderSetImpl();
 	}
 
 	public static HeaderSet createOBEXHeaderSet() {
 		return createOBEXHeaderSetImpl();
 	}
 
 	static void validateCreatedHeaderSet(HeaderSet headers) {
 		OBEXHeaderSetImpl.validateCreatedHeaderSet(headers);
 	}
 
 	protected void writePacket(int commId, OBEXHeaderSetImpl headers) throws IOException {
 		writePacketWithFlags(commId, null, headers);
 	}
 
 	protected synchronized void writePacketWithFlags(int commId, byte[] headerFlagsData, OBEXHeaderSetImpl headers)
 			throws IOException {
 		if (this.requestSent) {
 			throw new IOException("Write packet out of order");
 		}
 		this.requestSent = true;
 		int len = 3;
 		if (this.connectionID != -1) {
 			len += 5;
 		}
 		if (headerFlagsData != null) {
 			len += headerFlagsData.length;
 		}
 		byte[] data = null;
 		if (headers != null) {
 			data = OBEXHeaderSetImpl.toByteArray(headers);
 			len += data.length;
 		}
 		if (len > mtu) {
 			throw new IOException("Can't sent more data than in MTU, len=" + len + ", mtu=" + mtu);
 		}
 		this.packetsCountWrite++;
 		ByteArrayOutputStream buf = new ByteArrayOutputStream();
 		OBEXHeaderSetImpl.writeObexLen(buf, commId, len);
 		if (headerFlagsData != null) {
 			buf.write(headerFlagsData);
 		}
 		if (this.connectionID != -1) {
 			OBEXHeaderSetImpl.writeObexInt(buf, OBEXHeaderSetImpl.OBEX_HDR_CONNECTION, this.connectionID);
 		}
 		if (data != null) {
 			buf.write(data);
 		}
 		DebugLog.debug0x("obex send (" + this.packetsCountWrite + ")", OBEXUtils.toStringObexResponseCodes(commId),
 				commId);
 		os.write(buf.toByteArray());
 		os.flush();
 		DebugLog.debug("obex sent (" + this.packetsCountWrite + ") len", len);
 
 		if ((headers != null) && (headers.hasAuthenticationChallenge())) {
 			if (authChallengesSent == null) {
 				authChallengesSent = new Vector();
 			}
 			for (Enumeration iter = headers.getAuthenticationChallenges(); iter.hasMoreElements();) {
 				byte[] authChallenge = (byte[]) iter.nextElement();
 				Challenge challenge = new Challenge(authChallenge);
 				authChallengesSent.addElement(challenge);
 			}
 		}
 	}
 
 	protected synchronized byte[] readPacket() throws IOException {
 		if (!this.requestSent) {
 			throw new IOException("Read packet out of order");
 		}
 		this.requestSent = false;
 		byte[] header = new byte[3];
 		OBEXUtils.readFully(is, obexConnectionParams, header);
 		this.packetsCountRead++;
 		DebugLog.debug0x("obex received (" + this.packetsCountRead + ")", OBEXUtils
 				.toStringObexResponseCodes(header[0]), header[0] & 0xFF);
 		int lenght = OBEXUtils.bytesToShort(header[1], header[2]);
 		if (lenght == 3) {
 			return header;
 		}
 		if ((lenght < 3) || (lenght > OBEXOperationCodes.OBEX_MAX_PACKET_LEN)) {
 			throw new IOException("Invalid packet length " + lenght);
 		}
 		byte[] data = new byte[lenght];
 		System.arraycopy(header, 0, data, 0, header.length);
 		OBEXUtils.readFully(is, obexConnectionParams, data, header.length, lenght - header.length);
 		if (is.available() > 0) {
 			DebugLog.debug("has more data after read", is.available());
 		}
 		return data;
 	}
 
 	private void validateBluetoothConnection() {
 		if ((conn != null) && !(conn instanceof BluetoothConnectionAccess)) {
 			throw new IllegalArgumentException("Not a Bluetooth connection " + conn.getClass().getName());
 		}
 	}
 
 	void validateAuthenticationResponse(OBEXHeaderSetImpl requestHeaders, OBEXHeaderSetImpl incomingHeaders)
 			throws IOException {
 		if ((requestHeaders != null) && requestHeaders.hasAuthenticationChallenge()
 				&& (!incomingHeaders.hasAuthenticationResponses())) {
 			// TODO verify that this appropriate Exception
 			throw new IOException("Authentication response is missing");
 		}
 		handleAuthenticationResponse(incomingHeaders, null);
 	}
 
 	boolean handleAuthenticationResponse(OBEXHeaderSetImpl incomingHeaders, ServerRequestHandler serverHandler)
 			throws IOException {
 		if (incomingHeaders.hasAuthenticationResponses()) {
 			if (authenticator == null) {
 				throw new IOException("Authenticator required for authentication");
 			}
 			if ((authChallengesSent == null) && (authChallengesSent.size() == 0)) {
 				throw new IOException("Authentication challenges had not been sent");
 			}
 			boolean authenticated = false;
 			try {
 				authenticated = OBEXAuthentication.handleAuthenticationResponse(incomingHeaders, authenticator,
 						serverHandler, authChallengesSent);
 			} finally {
 				if ((authenticated) && (authChallengesSent != null)) {
 					authChallengesSent.removeAllElements();
 				}
 			}
 			return authenticated;
 		} else {
 			if ((authChallengesSent != null) && (authChallengesSent.size() > 0)) {
 				throw new IOException("Authentication response is missing");
 			}
 			return true;
 		}
 	}
 
 	void handleAuthenticationChallenge(OBEXHeaderSetImpl incomingHeaders, OBEXHeaderSetImpl replyHeaders)
 			throws IOException {
 		if (incomingHeaders.hasAuthenticationChallenge()) {
 			if (authenticator == null) {
 				throw new IOException("Authenticator required for authentication");
 			}
 			OBEXAuthentication.handleAuthenticationChallenge(incomingHeaders, replyHeaders, authenticator);
 		}
 	}
 
 	/*
 	 * (non-Javadoc)
 	 * 
 	 * @see com.intel.bluetooth.BluetoothConnectionAccess#getRemoteAddress()
 	 */
 	public long getRemoteAddress() throws IOException {
 		validateBluetoothConnection();
 		if (conn == null) {
 			throw new IOException("Connection closed");
 		}
 		return ((BluetoothConnectionAccess) conn).getRemoteAddress();
 	}
 
 	/*
 	 * (non-Javadoc)
 	 * 
 	 * @see com.intel.bluetooth.BluetoothConnectionAccess#getRemoteDevice()
 	 */
 	public RemoteDevice getRemoteDevice() {
 		validateBluetoothConnection();
 		if (conn == null) {
 			return null;
 		}
 		return ((BluetoothConnectionAccess) conn).getRemoteDevice();
 	}
 
 	/*
 	 * (non-Javadoc)
 	 * 
 	 * @see com.intel.bluetooth.BluetoothConnectionAccess#isClosed()
 	 */
 	public boolean isClosed() {
 		if (conn == null) {
 			return true;
 		}
 		if (this.conn instanceof BluetoothConnectionAccess) {
 			return ((BluetoothConnectionAccess) conn).isClosed();
 		} else {
 			return false;
 		}
 	}
 
 	/*
 	 * (non-Javadoc)
 	 * 
 	 * @see com.intel.bluetooth.BluetoothConnectionAccess#shutdown()
 	 */
 	public void shutdown() throws IOException {
 		if (this.conn instanceof BluetoothConnectionAccess) {
 			((BluetoothConnectionAccess) conn).shutdown();
 		}
 	}
 
 	/*
 	 * (non-Javadoc)
 	 * 
 	 * @see com.intel.bluetooth.BluetoothConnectionAccess#markAuthenticated()
 	 */
 	public void markAuthenticated() {
 		validateBluetoothConnection();
 		if (conn != null) {
 			((BluetoothConnectionAccess) conn).markAuthenticated();
 		}
 	}
 
 	/*
 	 * (non-Javadoc)
 	 * 
 	 * @see com.intel.bluetooth.BluetoothConnectionAccess#getSecurityOpt()
 	 */
 	public int getSecurityOpt() {
 		validateBluetoothConnection();
 		if (conn == null) {
 			return ServiceRecord.NOAUTHENTICATE_NOENCRYPT;
 		} else {
 			return ((BluetoothConnectionAccess) conn).getSecurityOpt();
 		}
 	}
 
 	/*
 	 * (non-Javadoc)
 	 * 
 	 * @see com.intel.bluetooth.BluetoothConnectionAccess#encrypt(boolean)
 	 */
 	public boolean encrypt(long address, boolean on) throws IOException {
 		validateBluetoothConnection();
 		if (conn == null) {
 			throw new IOException("Connection closed");
 		}
 		return ((BluetoothConnectionAccess) conn).encrypt(address, on);
 	}
 
 	/*
 	 * (non-Javadoc)
 	 * 
 	 * @see com.intel.bluetooth.BluetoothConnectionAccess#setRemoteDevice(javax.bluetooth .RemoteDevice)
 	 */
 	public void setRemoteDevice(RemoteDevice remoteDevice) {
 		validateBluetoothConnection();
 		if (conn != null) {
 			((BluetoothConnectionAccess) conn).setRemoteDevice(remoteDevice);
 		}
 	}
 
 	/*
 	 * (non-Javadoc)
 	 * 
 	 * @see com.intel.bluetooth.BluetoothConnectionAccess#getBluetoothStack()
 	 */
 	public BluetoothStack getBluetoothStack() {
 		validateBluetoothConnection();
 		if (conn == null) {
 			return null;
 		}
 		return ((BluetoothConnectionAccess) conn).getBluetoothStack();
 	}
 
 	/**
 	 * Function used in unit tests.
 	 * 
 	 * @return the packetsCountWrite
 	 */
 	int getPacketsCountWrite() {
 		return this.packetsCountWrite;
 	}
 
 	/**
 	 * Function used in unit tests.
 	 * 
 	 * @return the packetsCountRead
 	 */
 	int getPacketsCountRead() {
 		return this.packetsCountRead;
 	}
 
 	/**
 	 * Function used in unit tests.
 	 * 
 	 * @return the mtu
 	 */
 	int getPacketSize() {
 		return this.mtu;
 	}
 
 	/**
 	 * Function used to change the connection mtu
 	 * 
 	 * @param mtu
 	 * @throws IOException
 	 */
 	void setPacketSize(int mtu) throws IOException {
 		if (isConnected) {
 			throw new IOException("Session already connected");
 		}
 		obexConnectionParams.mtu = mtu;
 	}
 }