/*
 * $Header: /home/cvs/jakarta-commons/httpclient/src/java/org/apache/commons/httpclient/methods/InputStreamRequestEntity.java,v 1.4 2004/05/17 21:46:03 olegk Exp $
 * $Revision: 1.4 $
 * $Date: 2004/05/17 21:46:03 $
 *
 * ====================================================================
 *
 *  Copyright 2004 The Apache Software Foundation
 *
 *  Licensed 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.
 * ====================================================================
 *
 * 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/>.
 *
 * [Additional notices, if required by prior licensing conditions]
 *
 */
package org.apache.commons.httpclient.methods;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * A RequestEntity that contains an InputStream.
 * 
 * @since 3.0
 */
public class InputStreamRequestEntity implements RequestEntity {

    /**
     * The content length will be calculated automatically. This implies
     * buffering of the content.
     */
    public static final int CONTENT_LENGTH_AUTO = -2;
    
    private static final Log LOG = LogFactory.getLog(InputStreamRequestEntity.class);
    
    private long contentLength;
    
    private InputStream content;

    /** The buffered request body, if any. */
    private byte[] buffer = null;
    
    /** The content type */
    private String contentType;

    /**
     * Creates a new InputStreamRequestEntity with the given content and a content type of
     * {@link #CONTENT_LENGTH_AUTO}.
     * @param content The content to set.
     */
    public InputStreamRequestEntity(InputStream content) {
        this(content, null);
    }
    
    /**
     * Creates a new InputStreamRequestEntity with the given content, content type, and a 
     * content length of {@link #CONTENT_LENGTH_AUTO}.
     * @param content The content to set.
     * @param contentType The type of the content, or <code>null</code>.
     */
    public InputStreamRequestEntity(InputStream content, String contentType) {
        this(content, CONTENT_LENGTH_AUTO, contentType);
    }

    /**
     * Creates a new InputStreamRequestEntity with the given content and content length.
     * @param content The content to set.
     * @param contentLength The content size in bytes or any of 
     *  {@link EntityEnclosingMethod#CONTENT_LENGTH_AUTO CONTENT_LENGTH_AUTO},
     *  {@link EntityEnclosingMethod#CONTENT_LENGTH_CHUNKED CONTENT_LENGTH_CHUNKED}. If the number 
     *  of bytes or <code>CONTENT_LENGTH_CHUNKED</code> is specified the content will not be 
     *  buffered when {@link #getContentLength()} is called.
     */
    public InputStreamRequestEntity(InputStream content, long contentLength) {
        this(content, contentLength, null);
    }
    
    /**
     * Creates a new InputStreamRequestEntity with the given content, content length, and 
     * content type.
     * @param content The content to set.
     * @param contentLength The content size in bytes or any of 
     *  {@link EntityEnclosingMethod#CONTENT_LENGTH_AUTO CONTENT_LENGTH_AUTO},
     *  {@link EntityEnclosingMethod#CONTENT_LENGTH_CHUNKED CONTENT_LENGTH_CHUNKED}. If the number 
     *  of bytes or <code>CONTENT_LENGTH_CHUNKED</code> is specified the content will not be 
     *  buffered when {@link #getContentLength()} is called.
     * @param contentType The type of the content, or <code>null</code>.
     */
    public InputStreamRequestEntity(InputStream content, long contentLength, String contentType) {
        if (content == null) {
            throw new IllegalArgumentException("The content cannot be null");
        }
        this.content = content;
        this.contentLength = contentLength;
        this.contentType = contentType;
    }

    /* (non-Javadoc)
     * @see org.apache.commons.httpclient.methods.RequestEntity#getContentType()
     */
    public String getContentType() {
        return contentType;
    }
    
    /**
     * Buffers request body input stream.
     */
    private void bufferContent() {

        if (this.buffer != null) {
            // Already been buffered
            return;
        }
        if (this.content != null) {
            try {
                ByteArrayOutputStream tmp = new ByteArrayOutputStream();
                byte[] data = new byte[4096];
                int l = 0;
                while ((l = this.content.read(data)) >= 0) {
                    tmp.write(data, 0, l);
                }
                this.buffer = tmp.toByteArray();
                this.content = null;
                this.contentLength = buffer.length;
            } catch (IOException e) {
                LOG.error(e.getMessage(), e);
                this.buffer = null;
                this.content = null;
                this.contentLength = 0;
            }
        }
    }
    
    /**
     * Tests if this method is repeatable.  Only <code>true</code> if the content has been
     * buffered.
     * 
     * @see #getContentLength()
     */
    public boolean isRepeatable() {
        return content != null;
    }

    /* (non-Javadoc)
     * @see org.apache.commons.httpclient.RequestEntity#writeRequest(java.io.OutputStream)
     */
    public void writeRequest(OutputStream out) throws IOException {
        
        if (content != null) {
            byte[] tmp = new byte[4096];
            int total = 0;
            int i = 0;
            while ((i = content.read(tmp)) >= 0) {
                out.write(tmp, 0, i);
                total += i;
            }        
        } else if (buffer != null) {
            out.write(buffer);
        } else {
            throw new IllegalStateException("Content must be set before entity is written");
        }
    }

    /**
     * Gets the content length.  If the content length has not been set, the content will be
     * buffered to determine the actual content length.
     */
    public long getContentLength() {
        if (contentLength == CONTENT_LENGTH_AUTO && buffer == null) {
            bufferContent();
        }
        return contentLength;
    }

    /**
     * @return Returns the content.
     */
    public InputStream getContent() {
        return content;
    }

}