/**
 * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 * SPDX-License-Identifier: Apache-2.0.
 */

package software.amazon.awssdk.crt.http;

import java.nio.ByteBuffer;

/**
 * Interface that Native code knows how to call when handling Http Request bodies
 *
 */
public interface HttpRequestBodyStream {


    /**
     * Called from Native when the Http Request has a Body (Eg PUT/POST requests).
     * Note that this function may be called many times as Native sends the Request Body.
     *
     * Do NOT keep a reference to this ByteBuffer past the lifetime of this function call. The CommonRuntime reserves
     * the right to use DirectByteBuffers pointing to memory that only lives as long as the function call.
     *
     * @param bodyBytesOut The Buffer to write the Request Body Bytes to.
     * @return True if Request body is complete, false otherwise.
     */
    default boolean sendRequestBody(ByteBuffer bodyBytesOut) {
        /* Optional Callback, return empty request body by default unless user wants to return one. */
        return true;
    }

    /**
     * Called from native when the processing needs the stream to rewind itself back to its beginning.
     * If the stream does not support rewinding or the rewind fails, false should be returned
     *
     * Signing requires a rewindable stream, but basic http does not.
     *
     * @return True if the stream was successfully rewound, false otherwise.
     */
    default boolean resetPosition() { return false; }

    /**
     * Called from native when the processing needs to know the length of the stream.
     * If the stream does not know/support length, 0 should be returned.
     *
     * Signing requires a rewindable stream, but basic http does not.
     *
     * @return Stream length, or 0 if unknown stream or length is unsupported
     */
    default long getLength() { return 0; }
}