/*
 * PartFactory.java February 2007
 *
 * Copyright (C) 2007, Niall Gallagher <niallg@users.sf.net>
 *
 * 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.
 */

package org.simpleframework.http.message;

import org.simpleframework.util.buffer.Allocator;

/**
 * The <code>PartFactory</code> represents a factory for creating the consumers
 * that are used to read a multipart upload message. This supports two types of
 * consumers for the multipart upload, lists and bodies. A part list is
 * basically a collection of parts and or part lists. The part type is
 * determined from the part header.
 * 
 * @author Niall Gallagher
 * 
 * @see org.simpleframework.http.message.PartSeriesConsumer
 * @see org.simpleframework.http.message.PartBodyConsumer
 */
class PartFactory extends ConsumerFactory {

    /**
     * Constructor for the <code>PartFactory</code> object. This is used to
     * create a factory using a buffer allocator, which will create a buffer for
     * accumulating the entire message body, also to ensure the correct part
     * type is created this requires the header information for the part.
     * 
     * @param allocator
     *            this is used to allocate the internal buffer
     * @param header
     *            this is used to determine the part type
     */
    public PartFactory(Allocator allocator, Segment header) {
        super(allocator, header);
    }

    /**
     * This method is used to create the consumer given the list and boundary
     * for the part. In order to determine the part type this will consult the
     * header consumed for the part. Depending on whether it is a list or body a
     * suitable consumer is created.
     * 
     * @param series
     *            this is the list used to collect the parts
     * @param boundary
     *            this is the boundary used to terminate the part
     * 
     * @return this will return the consumer for the part body
     */
    public BodyConsumer getInstance(PartSeries series, byte[] boundary) {
        byte[] terminal = this.getBoundary(this.segment);

        if (this.isPart(this.segment))
            return new PartSeriesConsumer(this.allocator, series, terminal);
        return new PartBodyConsumer(this.allocator, this.segment, series,
                boundary);
    }
}