/*
 * ====================================================================
 * 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.
 * ====================================================================
 *
 * 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.http.nio.entity;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.nio.ByteBuffer;

import org.apache.http.entity.AbstractHttpEntity;
import org.apache.http.nio.ContentEncoder;
import org.apache.http.nio.IOControl;
import org.apache.http.nio.protocol.AsyncNHttpServiceHandler;
import org.apache.http.protocol.HTTP;

/**
 * A simple, self contained, repeatable non-blocking entity that retrieves
 * its content from a {@link String} object.
 *
 * @see AsyncNHttpServiceHandler
 * @since 4.0
 *
 */
public class NStringEntity extends AbstractHttpEntity implements ProducingNHttpEntity {

    protected final byte[] content;
    protected final ByteBuffer buffer;

    public NStringEntity(final String s, String charset)
            throws UnsupportedEncodingException {
        if (s == null) {
            throw new IllegalArgumentException("Source string may not be null");
        }
        if (charset == null) {
            charset = HTTP.DEFAULT_CONTENT_CHARSET;
        }
        this.content = s.getBytes(charset);
        this.buffer = ByteBuffer.wrap(this.content);
        setContentType(HTTP.PLAIN_TEXT_TYPE + HTTP.CHARSET_PARAM + charset);
    }

    public NStringEntity(final String s) throws UnsupportedEncodingException {
        this(s, null);
    }

    public boolean isRepeatable() {
        return true;
    }

    public long getContentLength() {
        return this.buffer.limit();
    }

    public void finish() {
        buffer.rewind();
    }

    public void produceContent(ContentEncoder encoder, IOControl ioctrl)
            throws IOException {
        encoder.write(buffer);
        if(!buffer.hasRemaining())
            encoder.complete();
    }

    public boolean isStreaming() {
        return false;
    }

    public InputStream getContent() {
        return new ByteArrayInputStream(content);
    }

    public void writeTo(final OutputStream outstream) throws IOException {
        if (outstream == null) {
            throw new IllegalArgumentException("Output stream may not be null");
        }
        outstream.write(content);
        outstream.flush();
    }

}