/*
 * Copyright (c) 2022 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

package org.glassfish.jersey.client.innate;

import org.glassfish.jersey.client.ClientProperties;
import org.glassfish.jersey.client.ClientRequest;
import org.glassfish.jersey.client.RequestEntityProcessing;

/**
 * Utility class to check whether it's possible to send the Expect header within request.
 */
public final class Expect100ContinueUsage {

    private Expect100ContinueUsage() {
        //do not instantiate
    }

    /**
     * Checks if usage of the Expect header with 100-Continue value is allowed
     *
     * @param request client's request
     * @param requestMethod method of the request (GET, POST, PUT etc).
     * @return true if the Expect header is allowed.
     */
    public static boolean isAllowed(ClientRequest request, String requestMethod) {

        long requestLength = request.getLengthLong();

        final RequestEntityProcessing entityProcessing = request.resolveProperty(
                ClientProperties.REQUEST_ENTITY_PROCESSING, RequestEntityProcessing.class);

        final Boolean expectContinueActivated = request.resolveProperty(
                ClientProperties.EXPECT_100_CONTINUE, Boolean.class);
        final Long expectContinueSizeThreshold = request.resolveProperty(
                ClientProperties.EXPECT_100_CONTINUE_THRESHOLD_SIZE,
                ClientProperties.DEFAULT_EXPECT_100_CONTINUE_THRESHOLD_SIZE);

        final boolean allowStreaming = requestLength > expectContinueSizeThreshold
                || entityProcessing == RequestEntityProcessing.CHUNKED;

        return !(!Boolean.TRUE.equals(expectContinueActivated)
                || !("POST".equals(requestMethod) || "PUT".equals(requestMethod))
                || !allowStreaming
        );
    }
}
