/*
 * Copyright (C) 2012 The Android Open Source Project
 *
 * 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 libcore.net.http;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.CacheRequest;

interface Transport {
    /**
     * Returns an output stream where the request body can be written. The
     * returned stream will of one of two types:
     * <ul>
     *     <li><strong>Direct.</strong> Bytes are written to the socket and
     *     forgotten. This is most efficient, particularly for large request
     *     bodies. The returned stream may be buffered; the caller must call
     *     {@link #flushRequest} before reading the response.</li>
     *     <li><strong>Buffered.</strong> Bytes are written to an in memory
     *     buffer, and must be explicitly flushed with a call to {@link
     *     #writeRequestBody}. This allows HTTP authorization (401, 407)
     *     responses to be retransmitted transparently.</li>
     * </ul>
     */
    // TODO: don't bother retransmitting the request body? It's quite a corner
    // case and there's uncertainty whether Firefox or Chrome do this
    OutputStream createRequestBody() throws IOException;

    /**
     * This should update the HTTP engine's sentRequestMillis field.
     */
    void writeRequestHeaders() throws IOException;

    /**
     * Sends the request body returned by {@link #createRequestBody} to the
     * remote peer.
     */
    void writeRequestBody(RetryableOutputStream requestBody) throws IOException;

    /**
     * Flush the request body to the underlying socket.
     */
    void flushRequest() throws IOException;

    /**
     * Read response headers and update the cookie manager.
     */
    ResponseHeaders readResponseHeaders() throws IOException;

    // TODO: make this the content stream?
    InputStream getTransferStream(CacheRequest cacheRequest) throws IOException;

    /**
     * Returns true if the underlying connection can be recycled.
     */
    boolean makeReusable(OutputStream requestBodyOut, InputStream responseBodyIn);
}