/*
 * ====================================================================
 * 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.protocol;

import java.io.IOException;

import org.apache.http.HttpEntity;
import org.apache.http.HttpEntityEnclosingRequest;
import org.apache.http.HttpHost;
import org.apache.http.HttpRequest;
import org.apache.http.nio.ContentEncoder;
import org.apache.http.nio.IOControl;
import org.apache.http.nio.entity.EntityAsyncContentProducer;
import org.apache.http.nio.entity.HttpAsyncContentProducer;
import org.apache.http.protocol.HttpContext;
import org.apache.http.util.Args;

Basic implementation of HttpAsyncRequestProducer. The producer can make use of the HttpAsyncContentProducer interface to efficiently stream out message content to the underlying non-blocking HTTP connection, if it is implemented by the enclosed HttpEntity. 
See Also:
HttpAsyncContentProducer
Since:
4.2/**
 * Basic implementation of {@link HttpAsyncRequestProducer}. The producer
 * can make use of the {@link HttpAsyncContentProducer} interface to
 * efficiently stream out message content to the underlying non-blocking HTTP
 * connection, if it is implemented by the enclosed {@link HttpEntity}.
 *
 * @see HttpAsyncContentProducer
 *
 * @since 4.2
 */
public class BasicAsyncRequestProducer implements HttpAsyncRequestProducer {

    private final HttpHost target;
    private final HttpRequest request;
    private final HttpAsyncContentProducer producer;

    
Creates a producer that can be used to transmit the given request message. The given content producer will be used to stream out message content. Please note that the request message is expected to enclose an HttpEntity whose properties are consistent with the behavior of the content producer. 
Params:
target – target host.
request – request message.
producer – request content producer./**
     * Creates a producer that can be used to transmit the given request
     * message. The given content producer will be used to stream out message
     * content. Please note that the request message is expected to enclose
     * an {@link HttpEntity} whose properties are consistent with the behavior
     * of the content producer.
     *
     * @param target target host.
     * @param request request message.
     * @param producer request content producer.
     */
    protected BasicAsyncRequestProducer(
            final HttpHost target,
            final HttpEntityEnclosingRequest request,
            final HttpAsyncContentProducer producer) {
        super();
        Args.notNull(target, "HTTP host");
        Args.notNull(request, "HTTP request");
        Args.notNull(producer, "HTTP content producer");
        this.target = target;
        this.request = request;
        this.producer = producer;
    }

    
Creates a producer that can be used to transmit the given request message. If the request message encloses an HttpEntity it is also expected to implement HttpAsyncContentProducer. 
Params:
target – target host.
request – request message./**
     * Creates a producer that can be used to transmit the given request
     * message. If the request message encloses an {@link HttpEntity}
     * it is also expected to implement {@link HttpAsyncContentProducer}.
     *
     * @param target target host.
     * @param request request message.
     */
    public BasicAsyncRequestProducer(final HttpHost target, final HttpRequest request) {
        Args.notNull(target, "HTTP host");
        Args.notNull(request, "HTTP request");
        this.target = target;
        this.request = request;
        if (request instanceof HttpEntityEnclosingRequest) {
            final HttpEntity entity = ((HttpEntityEnclosingRequest) request).getEntity();
            if (entity != null) {
                if (entity instanceof HttpAsyncContentProducer) {
                    this.producer = (HttpAsyncContentProducer) entity;
                } else {
                    this.producer = new EntityAsyncContentProducer(entity);
                }
            } else {
                this.producer = null;
            }
        } else {
            this.producer = null;
        }
    }

    @Override
    public HttpRequest generateRequest() {
        return this.request;
    }

    @Override
    public HttpHost getTarget() {
        return this.target;
    }

    @Override
    public void produceContent(
            final ContentEncoder encoder, final IOControl ioControl) throws IOException {
        if (this.producer != null) {
            this.producer.produceContent(encoder, ioControl);
            if (encoder.isCompleted()) {
                this.producer.close();
            }
        }
    }

    @Override
    public void requestCompleted(final HttpContext context) {
    }

    @Override
    public void failed(final Exception ex) {
    }

    @Override
    public boolean isRepeatable() {
        return this.producer == null || this.producer.isRepeatable();
    }

    @Override
    public void resetRequest() throws IOException {
        if (this.producer != null) {
            this.producer.close();
        }
    }

    @Override
    public void close() throws IOException {
        if (this.producer != null) {
            this.producer.close();
        }
    }

    @Override
    public String toString() {
        final StringBuilder sb = new StringBuilder();
        sb.append(this.target);
        sb.append(' ');
        sb.append(this.request);
        if (this.producer != null) {
            sb.append(' ');
            sb.append(this.producer);
        }
        return sb.toString();
    }

}