/*
 * Copyright (c) 2001-2004 Caucho Technology, Inc.  All rights reserved.
 *
 * The Apache Software License, Version 1.1
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Caucho Technology (http://www.caucho.com/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "Burlap", "Resin", and "Caucho" must not be used to
 *    endorse or promote products derived from this software without prior
 *    written permission. For written permission, please contact
 *    info@caucho.com.
 *
 * 5. Products derived from this software may not be called "Resin"
 *    nor may "Resin" appear in their names without prior written
 *    permission of Caucho Technology.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL CAUCHO TECHNOLOGY OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @author Scott Ferguson
 */

package com.caucho.burlap.io;

import java.io.*;
import java.util.*;
import java.lang.reflect.*;

import com.caucho.hessian.io.SerializerFactory;
import com.caucho.hessian.io.Serializer;

/**
 * Output stream for Burlap requests, compatible with microedition
 * Java.  It only uses classes and types available in JDK.
 *
 * <p>Since BurlapOutput does not depend on any classes other than
 * in the JDK, it can be extracted independently into a smaller package.
 *
 * <p>BurlapOutput is unbuffered, so any client needs to provide
 * its own buffering.
 *
 * <pre>
 * OutputStream os = ...; // from http connection
 * BurlapOutput out = new BurlapOutput(os);
 * String value;
 *
 * out.startCall("hello");  // start hello call
 * out.writeString("arg1"); // write a string argument
 * out.completeCall();      // complete the call
 * </pre>
 */
public class BurlapOutput extends AbstractBurlapOutput {
  // the output stream
  protected OutputStream os;
  // map of references
  private IdentityHashMap _refs;

  private Date date;
  private Calendar utcCalendar;
  private Calendar localCalendar;
  /**
   * Creates a new Burlap output stream, initialized with an
   * underlying output stream.
   *
   * @param os the underlying output stream.
   */
  public BurlapOutput(OutputStream os)
  {
    init(os);
  }

  /**
   * Creates an uninitialized Burlap output stream.
   */
  public BurlapOutput()
  {
  }

  /**
   * Initializes the output
   */
  public void init(OutputStream os)
  {
    this.os = os;

    _refs = null;

    if (_serializerFactory == null)
      _serializerFactory = new SerializerFactory();
  }

  /**
   * Writes a complete method call.
   */
  public void call(String method, Object []args)
    throws IOException
  {
    startCall(method);
    
    if (args != null) {
      for (int i = 0; i < args.length; i++)
        writeObject(args[i]);
    }
    
    completeCall();
  }

  /**
   * Starts the method call.  Clients would use <code>startCall</code>
   * instead of <code>call</code> if they wanted finer control over
   * writing the arguments, or needed to write headers.
   *
   * <code><pre>
   * &lt;burlap:call>
   * &lt;method>method-name&lt;/method>
   * </pre></code>
   *
   * @param method the method name to call.
   */
  public void startCall(String method)
    throws IOException
  {
    print("<burlap:call><method>");
    print(method);
    print("</method>");
  }

  /**
   * Starts the method call.  Clients would use <code>startCall</code>
   * instead of <code>call</code> if they wanted finer control over
   * writing the arguments, or needed to write headers.
   *
   * <code><pre>
   * &lt;method>method-name&lt;/method>
   * </pre></code>
   *
   * @param method the method name to call.
   */
  public void startCall()
    throws IOException
  {
    print("<burlap:call>");
  }

  /**
   * Writes the method for a call.
   *
   * <code><pre>
   * &lt;method>value&lt;/method>
   * </pre></code>
   *
   * @param method the method name to call.
   */
  public void writeMethod(String method)
    throws IOException
  {
    print("<method>");
    print(method);
    print("</method>");
  }
  

  /**
   * Completes.
   *
   * <code><pre>
   * &lt;/burlap:call>
   * </pre></code>
   */
  public void completeCall()
    throws IOException
  {
    print("</burlap:call>");
  }

  /**
   * Starts the reply
   *
   * <p>A successful completion will have a single value:
   *
   * <pre>
   * r
   * </pre>
   */
  public void startReply()
    throws IOException
  {
    print("<burlap:reply>");
  }

  /**
   * Completes reading the reply
   *
   * <p>A successful completion will have a single value:
   *
   * <pre>
   * &lt;/burlap:reply>
   * </pre>
   */
  public void completeReply()
    throws IOException
  {
    print("</burlap:reply>");
  }

  /**
   * Writes a header name.  The header value must immediately follow.
   *
   * <code><pre>
   * &lt;header>foo&lt;/header>&lt;int>value&lt;/int>
   * </pre></code>
   */
  public void writeHeader(String name)
    throws IOException
  {
    print("<header>");
    printString(name);
    print("</header>");
  }

  /**
   * Writes a fault.  The fault will be written
   * as a descriptive string followed by an object:
   *
   * <code><pre>
   * &lt;fault>
   * &lt;string>code
   * &lt;string>the fault code
   *
   * &lt;string>message
   * &lt;string>the fault mesage
   *
   * &lt;string>detail
   * &lt;map>t\x00\xnnjavax.ejb.FinderException
   *     ...
   * &lt;/map>
   * &lt;/fault>
   * </pre></code>
   *
   * @param code the fault code, a three digit
   */
  public void writeFault(String code, String message, Object detail)
    throws IOException
  {
    print("<fault>");
    writeString("code");
    writeString(code);

    writeString("message");
    writeString(message);

    if (detail != null) {
      writeString("detail");
      writeObject(detail);
    }
    print("</fault>");
  }

  /**
   * Writes any object to the output stream.
   */
  public void writeObject(Object object)
    throws IOException
  {
    if (object == null) {
      writeNull();
      return;
    }

    Serializer serializer;

    serializer = _serializerFactory.getSerializer(object.getClass());

    serializer.writeObject(object, this);
  }

  /**
   * Writes the list header to the stream.  List writers will call
   * <code>writeListBegin</code> followed by the list contents and then
   * call <code>writeListEnd</code>.
   *
   * <code><pre>
   * &lt;list>
   *   &lt;type>java.util.ArrayList&lt;/type>
   *   &lt;length>3&lt;/length>
   *   &lt;int>1&lt;/int>
   *   &lt;int>2&lt;/int>
   *   &lt;int>3&lt;/int>
   * &lt;/list>
   * </pre></code>
   */
  public boolean writeListBegin(int length, String type)
    throws IOException
  {
    print("<list><type>");
    
    if (type != null)
      print(type);
    
    print("</type><length>");
    print(length);
    print("</length>");

    return true;
  }

  /**
   * Writes the tail of the list to the stream.
   */
  public void writeListEnd()
    throws IOException
  {
    print("</list>");
  }

  /**
   * Writes the map header to the stream.  Map writers will call
   * <code>writeMapBegin</code> followed by the map contents and then
   * call <code>writeMapEnd</code>.
   *
   * <code><pre>
   * &lt;map>
   *   &lt;type>type&lt;/type>
   *   (&lt;key> &lt;value>)*
   * &lt;/map>
   * </pre></code>
   */
  public void writeMapBegin(String type)
    throws IOException
  {
    print("<map><type>");
    if (type != null)
      print(type);
    
    print("</type>");
  }

  /**
   * Writes the tail of the map to the stream.
   */
  public void writeMapEnd()
    throws IOException
  {
    print("</map>");
  }

  /**
   * Writes a remote object reference to the stream.  The type is the
   * type of the remote interface.
   *
   * <code><pre>
   * &lt;remote>
   *   &lt;type>test.account.Account&lt;/type>
   *   &lt;string>http://caucho.com/foo;ejbid=bar&lt;/string>
   * &lt;/remote>
   * </pre></code>
   */
  public void writeRemote(String type, String url)
    throws IOException
  {
    print("<remote><type>");
    print(type);
    print("</type><string>");
    print(url);
    print("</string></remote>");
  }

  /**
   * Writes a boolean value to the stream.  The boolean will be written
   * with the following syntax:
   *
   * <code><pre>
   * &lt;boolean>0&lt;/boolean>
   * &lt;boolean>1&lt;/boolean>
   * </pre></code>
   *
   * @param value the boolean value to write.
   */
  public void writeBoolean(boolean value)
    throws IOException
  {
    if (value)
      print("<boolean>1</boolean>");
    else
      print("<boolean>0</boolean>");
  }

  /**
   * Writes an integer value to the stream.  The integer will be written
   * with the following syntax:
   *
   * <code><pre>
   * &lt;int>int value&lt;/int>
   * </pre></code>
   *
   * @param value the integer value to write.
   */
  public void writeInt(int value)
    throws IOException
  {
    print("<int>");
    print(value);
    print("</int>");
  }

  /**
   * Writes a long value to the stream.  The long will be written
   * with the following syntax:
   *
   * <code><pre>
   * &lt;long>int value&lt;/long>
   * </pre></code>
   *
   * @param value the long value to write.
   */
  public void writeLong(long value)
    throws IOException
  {
    print("<long>");
    print(value);
    print("</long>");
  }

  /**
   * Writes a double value to the stream.  The double will be written
   * with the following syntax:
   *
   * <code><pre>
   * &lt;double>value&lt;/double>
   * </pre></code>
   *
   * @param value the double value to write.
   */
  public void writeDouble(double value)
    throws IOException
  {
    print("<double>");
    print(value);
    print("</double>");
  }

  /**
   * Writes a date to the stream.
   *
   * <code><pre>
   * &lt;date>iso8901&lt;/date>
   * </pre></code>
   *
   * @param time the date in milliseconds from the epoch in UTC
   */
  public void writeUTCDate(long time)
    throws IOException
  {
    print("<date>");
    if (utcCalendar == null) {
      utcCalendar = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
      date = new Date();
    }

    date.setTime(time);
    utcCalendar.setTime(date);

    printDate(utcCalendar);
    print("</date>");
  }

  /**
   * Writes a null value to the stream.
   * The null will be written with the following syntax
   *
   * <code><pre>
   * &lt;null>&lt;/null>
   * </pre></code>
   *
   * @param value the string value to write.
   */
  public void writeNull()
    throws IOException
  {
    print("<null></null>");
  }

  /**
   * Writes a string value to the stream using UTF-8 encoding.
   * The string will be written with the following syntax:
   *
   * <code><pre>
   * &lt;string>string-value&lt;/string>
   * </pre></code>
   *
   * If the value is null, it will be written as
   *
   * <code><pre>
   * &lt;null>&lt;/null>
   * </pre></code>
   *
   * @param value the string value to write.
   */
  public void writeString(String value)
    throws IOException
  {
    if (value == null) {
      print("<null></null>");
    }
    else {
      print("<string>");
      printString(value);
      print("</string>");
    }
  }

  /**
   * Writes a string value to the stream using UTF-8 encoding.
   * The string will be written with the following syntax:
   *
   * <code><pre>
   * S b16 b8 string-value
   * </pre></code>
   *
   * If the value is null, it will be written as
   *
   * <code><pre>
   * N
   * </pre></code>
   *
   * @param value the string value to write.
   */
  public void writeString(char []buffer, int offset, int length)
    throws IOException
  {
    if (buffer == null) {
      print("<null></null>");
    }
    else {
      print("<string>");
      printString(buffer, offset, length);
      print("</string>");
    }
  }

  /**
   * Writes a byte array to the stream.
   * The array will be written with the following syntax:
   *
   * <code><pre>
   * &lt;base64>bytes&lt;/base64>
   * </pre></code>
   *
   * If the value is null, it will be written as
   *
   * <code><pre>
   * &lt;null>&lt;/null>
   * </pre></code>
   *
   * @param value the string value to write.
   */
  public void writeBytes(byte []buffer)
    throws IOException
  {
    if (buffer == null)
      print("<null></null>");
    else
      writeBytes(buffer, 0, buffer.length);
  }
  /**
   * Writes a byte array to the stream.
   * The array will be written with the following syntax:
   *
   * <code><pre>
   * &lt;base64>bytes&lt;/base64>
   * </pre></code>
   *
   * If the value is null, it will be written as
   *
   * <code><pre>
   * &lt;null>&lt;/null>
   * </pre></code>
   *
   * @param value the string value to write.
   */
  public void writeBytes(byte []buffer, int offset, int length)
    throws IOException
  {
    if (buffer == null) {
      print("<null></null>");
    }
    else {
      print("<base64>");

      int i = 0;
      for (; i + 2 < length; i += 3) {
        if (i != 0 && (i & 0x3f) == 0)
          print('\n');

        int v = (((buffer[offset + i] & 0xff) << 16) +
                 ((buffer[offset + i + 1] & 0xff) << 8) + 
                 (buffer[offset + i + 2] & 0xff));

        print(encode(v >> 18));
        print(encode(v >> 12));
        print(encode(v >> 6));
        print(encode(v));
      }

      if (i + 1 < length) {
        int v = (((buffer[offset + i] & 0xff) << 8) +
                 (buffer[offset + i + 1] & 0xff));

        print(encode(v >> 10));
        print(encode(v >> 4));
        print(encode(v << 2));
        print('=');
      }
      else if (i < length) {
        int v = buffer[offset + i] & 0xff;

        print(encode(v >> 2));
        print(encode(v << 4));
        print('=');
        print('=');
      }
      
      print("</base64>");
    }
  }
  
  /**
   * Writes a byte buffer to the stream.
   */
  public void writeByteBufferStart()
    throws IOException
  {
    throw new UnsupportedOperationException();
  }
  
  /**
   * Writes a byte buffer to the stream.
   *
   * <code><pre>
   * b b16 b18 bytes
   * </pre></code>
   */
  public void writeByteBufferPart(byte []buffer, int offset, int length)
    throws IOException
  {
    throw new UnsupportedOperationException();
  }
  
  /**
   * Writes a byte buffer to the stream.
   *
   * <code><pre>
   * b b16 b18 bytes
   * </pre></code>
   */
  public void writeByteBufferEnd(byte []buffer, int offset, int length)
    throws IOException
  {
    throw new UnsupportedOperationException();
  }

  /**
   * Encodes a digit
   */
  private char encode(int d)
  {
    d &= 0x3f;
    if (d < 26)
      return (char) (d + 'A');
    else if (d < 52)
      return (char) (d + 'a' - 26);
    else if (d < 62)
      return (char) (d + '0' - 52);
    else if (d == 62)
      return '+';
    else
      return '/';
  }

  /**
   * Writes a reference.
   *
   * <code><pre>
   * &lt;ref>int&lt;/ref>
   * </pre></code>
   *
   * @param value the integer value to write.
   */
  public void writeRef(int value)
    throws IOException
  {
    print("<ref>");
    print(value);
    print("</ref>");
  }

  /**
   * If the object has already been written, just write its ref.
   *
   * @return true if we're writing a ref.
   */
  public boolean addRef(Object object)
    throws IOException
  {
    if (_refs == null)
      _refs = new IdentityHashMap();

    Integer ref = (Integer) _refs.get(object);

    if (ref != null) {
      int value = ref.intValue();
      
      writeRef(value);
      return true;
    }
    else {
      _refs.put(object, new Integer(_refs.size()));
      
      return false;
    }
  }

  /**
   * Removes a reference.
   */
  public boolean removeRef(Object obj)
    throws IOException
  {
    if (_refs != null) {
      _refs.remove(obj);

      return true;
    }
    else
      return false;
  }

  /**
   * Replaces a reference from one object to another.
   */
  public boolean replaceRef(Object oldRef, Object newRef)
    throws IOException
  {
    Integer value = (Integer) _refs.remove(oldRef);

    if (value != null) {
      _refs.put(newRef, value);
      return true;
    }
    else
      return false;
  }

  /**
   * Prints a string to the stream, encoded as UTF-8
   *
   * @param v the string to print.
   */
  public void printString(String v)
    throws IOException
  {
    printString(v, 0, v.length());
  }
  
  /**
   * Prints a string to the stream, encoded as UTF-8
   *
   * @param v the string to print.
   */
  public void printString(String v, int offset, int length)
    throws IOException
  {
    for (int i = 0; i < length; i++) {
      char ch = v.charAt(i + offset);

      if (ch == '<') {
        os.write('&');
        os.write('#');
        os.write('6');
        os.write('0');
        os.write(';');
      }
      else if (ch == '&') {
        os.write('&');
        os.write('#');
        os.write('3');
        os.write('8');
        os.write(';');
      }
      else if (ch < 0x80)
        os.write(ch);
      else if (ch < 0x800) {
        os.write(0xc0 + ((ch >> 6) & 0x1f));
        os.write(0x80 + (ch & 0x3f));
      }
      else {
        os.write(0xe0 + ((ch >> 12) & 0xf));
        os.write(0x80 + ((ch >> 6) & 0x3f));
        os.write(0x80 + (ch & 0x3f));
      }
    }
  }
  
  /**
   * Prints a string to the stream, encoded as UTF-8
   *
   * @param v the string to print.
   */
  public void printString(char []v, int offset, int length)
    throws IOException
  {
    for (int i = 0; i < length; i++) {
      char ch = v[i + offset];

      if (ch < 0x80)
        os.write(ch);
      else if (ch < 0x800) {
        os.write(0xc0 + ((ch >> 6) & 0x1f));
        os.write(0x80 + (ch & 0x3f));
      }
      else {
        os.write(0xe0 + ((ch >> 12) & 0xf));
        os.write(0x80 + ((ch >> 6) & 0x3f));
        os.write(0x80 + (ch & 0x3f));
      }
    }
  }
  
  /**
   * Prints a date.
   *
   * @param date the date to print.
   */
  public void printDate(Calendar calendar)
    throws IOException
  {
    int year = calendar.get(Calendar.YEAR);

    os.write((char) ('0' + (year / 1000 % 10)));
    os.write((char) ('0' + (year / 100 % 10)));
    os.write((char) ('0' + (year / 10 % 10)));
    os.write((char) ('0' + (year % 10)));

    int month = calendar.get(Calendar.MONTH) + 1;
    os.write((char) ('0' + (month / 10 % 10)));
    os.write((char) ('0' + (month % 10)));

    int day = calendar.get(Calendar.DAY_OF_MONTH);
    os.write((char) ('0' + (day / 10 % 10)));
    os.write((char) ('0' + (day % 10)));

    os.write('T');

    int hour = calendar.get(Calendar.HOUR_OF_DAY);
    os.write((char) ('0' + (hour / 10 % 10)));
    os.write((char) ('0' + (hour % 10)));

    int minute = calendar.get(Calendar.MINUTE);
    os.write((char) ('0' + (minute / 10 % 10)));
    os.write((char) ('0' + (minute % 10)));

    int second = calendar.get(Calendar.SECOND);
    os.write((char) ('0' + (second / 10 % 10)));
    os.write((char) ('0' + (second % 10)));

    int ms = calendar.get(Calendar.MILLISECOND);
    os.write('.');
    os.write((char) ('0' + (ms / 100 % 10)));
    os.write((char) ('0' + (ms / 10 % 10)));
    os.write((char) ('0' + (ms % 10)));

    os.write('Z');
  }
  
  /**
   * Prints a char to the stream.
   *
   * @param v the char to print.
   */
  protected void print(char v)
    throws IOException
  {
    os.write(v);
  }
  
  /**
   * Prints an integer to the stream.
   *
   * @param v the integer to print.
   */
  protected void print(int v)
    throws IOException
  {
    print(String.valueOf(v));
  }

  /**
   * Prints a long to the stream.
   *
   * @param v the long to print.
   */
  protected void print(long v)
    throws IOException
  {
    print(String.valueOf(v));
  }

  /**
   * Prints a double to the stream.
   *
   * @param v the double to print.
   */
  protected void print(double v)
    throws IOException
  {
    print(String.valueOf(v));
  }

  /**
   * Prints a string as ascii to the stream.  Used for tags, etc.
   * that are known to the ascii.
   *
   * @param s the ascii string to print.
   */
  protected void print(String s)
    throws IOException
  {
    int len = s.length();
    for (int i = 0; i < len; i++) {
      int ch = s.charAt(i);

      os.write(ch);
    }
  }
}
