/*
 * 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.
 */

package org.apache.axis2.transport.http.util;

import org.apache.commons.httpclient.methods.multipart.PartBase;
import org.apache.commons.httpclient.util.EncodingUtil;

import java.io.IOException;
import java.io.OutputStream;

public class ComplexPart extends PartBase {

    /**
     * Default content encoding of string parameters.
     */
    public static final String DEFAULT_CONTENT_TYPE = "application/xml";

    /**
     * Default charset of string parameters
     */
    public static final String DEFAULT_CHARSET = "US-ASCII";

    /**
     * Default transfer encoding of string parameters
     */
    public static final String DEFAULT_TRANSFER_ENCODING = "8bit";

    /**
     * Contents of this StringPart.
     */
    private byte[] content;

    /**
     * The String value of this part.
     */
    private String value;

    /**
     * Constructor.
     *
     * @param name    The name of the part
     * @param value   the string to post
     * @param charset the charset to be used to encode the string, if <code>null</code>
     *                the {@link #DEFAULT_CHARSET default} is used
     */
    public ComplexPart(String name, String value, String charset) {

        super(
                name,
                DEFAULT_CONTENT_TYPE,
                charset == null ? DEFAULT_CHARSET : charset,
                DEFAULT_TRANSFER_ENCODING
        );
        if (value == null) {
            throw new IllegalArgumentException("Value may not be null");
        }
        if (value.indexOf(0) != -1) {
            // See RFC 2048, 2.8. "8bit Data"
            throw new IllegalArgumentException("NULs may not be present in string parts");
        }
        this.value = value;
    }

    /**
     * Constructor.
     *
     * @param name  The name of the part
     * @param value the string to post
     */
    public ComplexPart(String name, String value) {
        this(name, value, null);
    }

    /**
     * Gets the content in bytes.  Bytes are lazily created to allow the charset to be changed
     * after the part is created.
     *
     * @return the content in bytes
     */
    private byte[] getContent() {
        if (content == null) {
            content = EncodingUtil.getBytes(value, getCharSet());
        }
        return content;
    }

    /**
     * Writes the data to the given OutputStream.
     *
     * @param out the OutputStream to write to
     * @throws IOException if there is a write error
     */
    protected void sendData(OutputStream out) throws IOException {
        out.write(getContent());
    }

    /**
     * Return the length of the data.
     *
     * @return The length of the data.
     * @throws IOException If an IO problem occurs
     * @see org.apache.commons.httpclient.methods.multipart.Part#lengthOfData()
     */
    protected long lengthOfData() throws IOException {
        return getContent().length;
    }

    /* (non-Javadoc)
     * @see org.apache.commons.httpclient.methods.multipart.BasePart#setCharSet(java.lang.String)
     */
    public void setCharSet(String charSet) {
        super.setCharSet(charSet);
        this.content = null;
    }

}