/*

Copyright (c) 2013 Cloudbase.io Limited

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 com.cloudbase;

import org.apache.http.util.ByteArrayBuffer;

import org.apache.http.util.EncodingUtils;

/**

* Parent class for FilePart and StringPart.

*/

abstract class CBBasePart implements CBPart {

protected static final byte[] CRLF = EncodingUtils.getAsciiBytes(CBMultipartEntity.CRLF);

protected interface IHeadersProvider {

public String getContentDisposition();

public String getContentType();

public String getContentTransferEncoding();

}

protected IHeadersProvider headersProvider; // must be initialized in descendant constructor

private byte[] header;

protected byte[] getHeader(CBBoundary boundary) {

if (header == null) {

header = generateHeader(boundary); // lazy init

}

return header;

}

private byte[] generateHeader(CBBoundary boundary) {

if (headersProvider == null) {

throw new RuntimeException("Uninitialized headersProvider"); //$NON-NLS-1$

}

final ByteArrayBuffer buf = new ByteArrayBuffer(256);

append(buf, boundary.getStartingBoundary());

append(buf, headersProvider.getContentDisposition());

append(buf, CRLF);

append(buf, headersProvider.getContentType());

append(buf, CRLF);

append(buf, headersProvider.getContentTransferEncoding());

append(buf, CRLF);

append(buf, CRLF);

return buf.toByteArray();

}

private static void append(ByteArrayBuffer buf, String data) {

append(buf, EncodingUtils.getAsciiBytes(data));

}

private static void append(ByteArrayBuffer buf, byte[] data) {

buf.append(data, 0, data.length);

}

}