/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights 
 * reserved.
 *
 * 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 
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written 
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * 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 THE APACHE SOFTWARE FOUNDATION 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */ 

package org.apache.jasper.runtime;

import java.io.IOException;
import java.io.Writer;
import java.io.Reader;
import java.io.CharArrayReader;
import java.io.PrintWriter;

import javax.servlet.ServletResponse;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.tagext.BodyContent;

import org.apache.jasper.Constants;

/**
 * Write text to a character-output stream, buffering characters so as
 * to provide for the efficient writing of single characters, arrays,
 * and strings. 
 *
 * Provide support for discarding for the output that has been buffered. 
 *
 * @author Rajiv Mordani
 */
public class BodyContentImpl extends BodyContent {

    private char[] cb;
    protected int bufferSize = Constants.DEFAULT_BUFFER_SIZE;
    private int nextChar;
    static String lineSeparator = System.getProperty("line.separator");
    private boolean closed = false;

    public BodyContentImpl (JspWriter writer) {
        super(writer);
	cb = new char[bufferSize];
	nextChar = 0;
    }

    private void ensureOpen() throws IOException {
	if (closed)
	    throw new IOException("Stream closed");
    }

    /**
     * Write a single character.
     *
     */
    public void write(int c) throws IOException {
	ensureOpen();
        synchronized (lock) {
            if (nextChar >= bufferSize) {
	        reAllocBuff (0);
	    }
            cb[nextChar++] = (char) c;
        }
    }

    private void reAllocBuff (int len) {
        //Need to re-allocate the buffer since it is to be
	//unbounded according to the updated spec..

	char[] tmp = null;

	//XXX Should it be multiple of DEFAULT_BUFFER_SIZE??

	if (len <= Constants.DEFAULT_BUFFER_SIZE) {
	    tmp = new char [bufferSize + Constants.DEFAULT_BUFFER_SIZE];
	    bufferSize += Constants.DEFAULT_BUFFER_SIZE;
	} else {
	    tmp = new char [bufferSize + len];
	    bufferSize += len;
	}
	System.arraycopy(cb, 0, tmp, 0, cb.length);
	cb = tmp;
	tmp = null;
    }

    /**
     * Write a portion of an array of characters.
     *
     * <p> Ordinarily this method stores characters from the given array into
     * this stream's buffer, flushing the buffer to the underlying stream as
     * needed.  If the requested length is at least as large as the buffer,
     * however, then this method will flush the buffer and write the characters
     * directly to the underlying stream.  Thus redundant
     * <code>DiscardableBufferedWriter</code>s will not copy data unnecessarily.
     *
     * @param  cbuf  A character array
     * @param  off   Offset from which to start reading characters
     * @param  len   Number of characters to write
     *
     */
    public void write(char cbuf[], int off, int len) 
        throws IOException 
    {
	ensureOpen();
        synchronized (lock) {

            if ((off < 0) || (off > cbuf.length) || (len < 0) ||
                ((off + len) > cbuf.length) || ((off + len) < 0)) {
                throw new IndexOutOfBoundsException();
            } else if (len == 0) {
                return;
            } 

            if (len >= bufferSize - nextChar)
		   reAllocBuff (len);

            System.arraycopy(cbuf, off, cb, nextChar, len);
	    nextChar+=len;
        }
    }

    /**
     * Write an array of characters.  This method cannot be inherited from the
     * Writer class because it must suppress I/O exceptions.
     */
    public void write(char buf[]) throws IOException {
	write(buf, 0, buf.length);
    }

    /**
     * Write a portion of a String.
     *
     * @param  s     String to be written
     * @param  off   Offset from which to start reading characters
     * @param  len   Number of characters to be written
     *
     */
    public void write(String s, int off, int len) throws IOException {
	ensureOpen();
        synchronized (lock) {
	    if (len >= bufferSize - nextChar)
	        reAllocBuff(len);

            s.getChars(off, off + len, cb, nextChar);
	    nextChar += len;
        }
    }

    /**
     * Write a string.  This method cannot be inherited from the Writer class
     * because it must suppress I/O exceptions.
     */
    public void write(String s) throws IOException {
	write(s, 0, s.length());
    }


    /**
     * Write a line separator.  The line separator string is defined by the
     * system property <tt>line.separator</tt>, and is not necessarily a single
     * newline ('\n') character.
     *
     * @exception  IOException  If an I/O error occurs
     */

    public void newLine() throws IOException {
	write(lineSeparator);
    }

    /**
     * Print a boolean value.  The string produced by <code>{@link
     * java.lang.String#valueOf(boolean)}</code> is translated into bytes
     * according to the platform's default character encoding, and these bytes
     * are written in exactly the manner of the <code>{@link
     * #write(int)}</code> method.
     *
     * @param      b   The <code>boolean</code> to be printed
     * @throws	   java.io.IOException
     */

    public void print(boolean b) throws IOException {
	write(b ? "true" : "false");
    }

    /**
     * Print a character.  The character is translated into one or more bytes
     * according to the platform's default character encoding, and these bytes
     * are written in exactly the manner of the <code>{@link
     * #write(int)}</code> method.
     *
     * @param      c   The <code>char</code> to be printed
     * @throws	   java.io.IOException
     */

    public void print(char c) throws IOException {
	write(String.valueOf(c));
    }

    /**
     * Print an integer.  The string produced by <code>{@link
     * java.lang.String#valueOf(int)}</code> is translated into bytes according
     * to the platform's default character encoding, and these bytes are
     * written in exactly the manner of the <code>{@link #write(int)}</code>
     * method.
     *
     * @param      i   The <code>int</code> to be printed
     * @throws	   java.io.IOException
     */

    public void print(int i) throws IOException {
	write(String.valueOf(i));
    }

    /**
     * Print a long integer.  The string produced by <code>{@link
     * java.lang.String#valueOf(long)}</code> is translated into bytes
     * according to the platform's default character encoding, and these bytes
     * are written in exactly the manner of the <code>{@link #write(int)}</code>
     * method.
     *
     * @param      l   The <code>long</code> to be printed
     * @throws	   java.io.IOException
     */

    public void print(long l) throws IOException {
	write(String.valueOf(l));
    }

    /**
     * Print a floating-point number.  The string produced by <code>{@link
     * java.lang.String#valueOf(float)}</code> is translated into bytes
     * according to the platform's default character encoding, and these bytes
     * are written in exactly the manner of the <code>{@link #write(int)}</code>
     * method.
     *
     * @param      f   The <code>float</code> to be printed
     * @throws	   java.io.IOException
     */

    public void print(float f) throws IOException {
	write(String.valueOf(f));
    }

    /**
     * Print a double-precision floating-point number.  The string produced by
     * <code>{@link java.lang.String#valueOf(double)}</code> is translated into
     * bytes according to the platform's default character encoding, and these
     * bytes are written in exactly the manner of the <code>{@link
     * #write(int)}</code> method.
     *
     * @param      d   The <code>double</code> to be printed
     * @throws	   java.io.IOException
     */

    public void print(double d) throws IOException {
	write(String.valueOf(d));
    }

    /**
     * Print an array of characters.  The characters are converted into bytes
     * according to the platform's default character encoding, and these bytes
     * are written in exactly the manner of the <code>{@link #write(int)}</code>
     * method.
     *
     * @param      s   The array of chars to be printed
     *
     * @throws  NullPointerException  If <code>s</code> is <code>null</code>
     * @throws	   java.io.IOException
     */

    public void print(char s[]) throws IOException {
	write(s);
    }

    /**
     * Print a string.  If the argument is <code>null</code> then the string
     * <code>"null"</code> is printed.  Otherwise, the string's characters are
     * converted into bytes according to the platform's default character
     * encoding, and these bytes are written in exactly the manner of the
     * <code>{@link #write(int)}</code> method.
     *
     * @param      s   The <code>String</code> to be printed
     * @throws	   java.io.IOException
     */

    public void print(String s) throws IOException {
	if (s == null) {
	    s = "null";
	}
	write(s);
    }

    /**
     * Print an object.  The string produced by the <code>{@link
     * java.lang.String#valueOf(Object)}</code> method is translated into bytes
     * according to the platform's default character encoding, and these bytes
     * are written in exactly the manner of the <code>{@link #write(int)}</code>
     * method.
     *
     * @param      obj   The <code>Object</code> to be printed
     * @throws	   java.io.IOException
     */

    public void print(Object obj) throws IOException {
	write(String.valueOf(obj));
    }

    /**
     * Terminate the current line by writing the line separator string.  The
     * line separator string is defined by the system property
     * <code>line.separator</code>, and is not necessarily a single newline
     * character (<code>'\n'</code>).
     * @throws	   java.io.IOException
     */

    public void println() throws IOException {
	newLine();
    }

    /**
     * Print a boolean value and then terminate the line.  This method behaves
     * as though it invokes <code>{@link #print(boolean)}</code> and then
     * <code>{@link #println()}</code>.
     * @throws	   java.io.IOException
     */

    public void println(boolean x) throws IOException {
	synchronized (lock) {
	    print(x);
	    println();
	}
    }

    /**
     * Print a character and then terminate the line.  This method behaves as
     * though it invokes <code>{@link #print(char)}</code> and then <code>{@link
     * #println()}</code>.
     * @throws	   java.io.IOException
     */

    public void println(char x) throws IOException {
	synchronized (lock) {
	    print(x);
	    println();
	}
    }

    /**
     * Print an integer and then terminate the line.  This method behaves as
     * though it invokes <code>{@link #print(int)}</code> and then <code>{@link
     * #println()}</code>.
     * @throws	   java.io.IOException
     */

    public void println(int x) throws IOException {
	synchronized (lock) {
	    print(x);
	    println();
	}
    }

    /**
     * Print a long integer and then terminate the line.  This method behaves
     * as though it invokes <code>{@link #print(long)}</code> and then
     * <code>{@link #println()}</code>.
     * @throws	   java.io.IOException
     */

    public void println(long x) throws IOException {
	synchronized (lock) {
	    print(x);
	    println();
	}
    }

    /**
     * Print a floating-point number and then terminate the line.  This method
     * behaves as though it invokes <code>{@link #print(float)}</code> and then
     * <code>{@link #println()}</code>.
     * @throws	   java.io.IOException
     */

    public void println(float x) throws IOException {
	synchronized (lock) {
	    print(x);
	    println();
	}
    }

    /**
     * Print a double-precision floating-point number and then terminate the
     * line.  This method behaves as though it invokes <code>{@link
     * #print(double)}</code> and then <code>{@link #println()}</code>.
     * @throws	   java.io.IOException
     */

    public void println(double x) throws IOException{
	synchronized (lock) {
	    print(x);
	    println();
	}
    }

    /**
     * Print an array of characters and then terminate the line.  This method
     * behaves as though it invokes <code>{@link #print(char[])}</code> and then
     * <code>{@link #println()}</code>.
     * @throws	   java.io.IOException
     */

    public void println(char x[]) throws IOException {
	synchronized (lock) {
	    print(x);
	    println();
	}
    }

    /**
     * Print a String and then terminate the line.  This method behaves as
     * though it invokes <code>{@link #print(String)}</code> and then
     * <code>{@link #println()}</code>.
     * @throws	   java.io.IOException
     */

    public void println(String x) throws IOException {
	synchronized (lock) {
	    print(x);
	    println();
	}
    }

    /**
     * Print an Object and then terminate the line.  This method behaves as
     * though it invokes <code>{@link #print(Object)}</code> and then
     * <code>{@link #println()}</code>.
     * @throws	   java.io.IOException
     */

    public void println(Object x) throws IOException {
	synchronized (lock) {
	    print(x);
	    println();
	}
    }

    /**
     * Clear the contents of the buffer. If the buffer has been already
     * been flushed then the clear operation shall throw an IOException
     * to signal the fact that some data has already been irrevocably 
     * written to the client response stream.
     *
     * @throws IOException		If an I/O error occurs
     */

    public void clear() throws IOException {
        synchronized (lock) {
	    nextChar = 0;
	}
    }

    /**
     * Clears the current contents of the buffer. Unlike clear(), this
     * mehtod will not throw an IOException if the buffer has already been
     * flushed. It merely clears the current content of the buffer and
     * returns.
     *
     * @throws IOException		If an I/O error occurs
     */

    public void clearBuffer() throws IOException {
        this.clear();
    }

    /**
     * Close the stream, flushing it first.  Once a stream has been closed,
     * further write() or flush() invocations will cause an IOException to be
     * thrown.  Closing a previously-closed stream, however, has no effect.
     *
     * @exception  IOException  If an I/O error occurs
     */

    public void close() throws IOException {
	cb = null;	
	closed = true;
    }

    /**
     * @return the number of bytes unused in the buffer
     */

    public int getRemaining() {
        return bufferSize - nextChar;
    }

    /**
     * Return the value of this BodyJspWriter as a Reader.
     * Note: this is after evaluation!!  There are no scriptlets,
     * etc in this stream.
     *
     * @returns the value of this BodyJspWriter as a Reader
     */
    public Reader getReader() {
        return new CharArrayReader (cb, 0, nextChar);
    }

    /**
     * Return the value of the BodyJspWriter as a String.
     * Note: this is after evaluation!!  There are no scriptlets,
     * etc in this stream.
     *
     * @returns the value of the BodyJspWriter as a String
     */
    public String getString() {
        return new String(cb, 0, nextChar);
    }
	
    /**
     * Write the contents of this BodyJspWriter into a Writer.
     * Subclasses are likely to do interesting things with the
     * implementation so some things are extra efficient.
     *
     * @param out The writer into which to place the contents of
     * this body evaluation
     */
    public void writeOut(Writer out) throws IOException {
        out.write(cb, 0, nextChar);
	// Flush not called as the writer passed could be a BodyContent and
	// it doesn't allow to flush.
    }


    public static void main (String[] args) throws Exception {
	char[] buff = {'f','o','o','b','a','r','b','a','z','y'};
   	BodyContentImpl bodyContent = new BodyContentImpl(new JspWriterImpl(
							null, 100, false));
	bodyContent.println (buff);
	System.out.println (bodyContent.getString ());
	bodyContent.writeOut (new PrintWriter (System.out));
    }
}
