/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.activemq.transport.amqp.interop;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertTrue;

import java.util.concurrent.TimeUnit;

import org.apache.activemq.broker.BrokerService;
import org.apache.activemq.broker.jmx.QueueViewMBean;
import org.apache.activemq.broker.region.policy.PolicyEntry;
import org.apache.activemq.broker.region.policy.PolicyMap;
import org.apache.activemq.broker.region.policy.VMPendingQueueMessageStoragePolicy;
import org.apache.activemq.broker.region.policy.VMPendingSubscriberMessageStoragePolicy;
import org.apache.activemq.transport.amqp.client.AmqpClient;
import org.apache.activemq.transport.amqp.client.AmqpClientTestSupport;
import org.apache.activemq.transport.amqp.client.AmqpConnection;
import org.apache.activemq.transport.amqp.client.AmqpMessage;
import org.apache.activemq.transport.amqp.client.AmqpReceiver;
import org.apache.activemq.transport.amqp.client.AmqpSender;
import org.apache.activemq.transport.amqp.client.AmqpSession;
import org.apache.activemq.transport.amqp.ParallelTest;
import org.apache.activemq.util.Wait;
import org.junit.Test;
import org.junit.experimental.categories.Category;

@Category(ParallelTest.class)
public class AmqpFlowControlTest extends AmqpClientTestSupport {

    @Override
    protected void performAdditionalConfiguration(BrokerService brokerService) throws Exception {
        // Setup a destination policy where it takes only 1 message at a time.
        PolicyMap policyMap = new PolicyMap();
        PolicyEntry policy = new PolicyEntry();
        policy.setMemoryLimit(1);
        policy.setPendingSubscriberPolicy(new VMPendingSubscriberMessageStoragePolicy());
        policy.setPendingQueuePolicy(new VMPendingQueueMessageStoragePolicy());
        policy.setProducerFlowControl(true);
        policyMap.setDefaultEntry(policy);

        brokerService.setDestinationPolicy(policyMap);
    }

    @Test(timeout = 60000)
    public void testCreditNotGrantedUntilBacklogClears() throws Exception {
        final int MSG_COUNT = 1000;

        AmqpClient client = createAmqpClient();
        AmqpConnection connection = trackConnection(client.connect());
        AmqpSession session = connection.createSession();

        AmqpReceiver receiver = session.createReceiver("queue://" + getTestName());
        AmqpSender sender = session.createSender("queue://" + getTestName(), true);

        for (int i = 1; i <= MSG_COUNT; ++i) {
            AmqpMessage message = new AmqpMessage();
            message.setText("Test-Message: " + i);
            sender.send(message);

            if (i % 1000 == 0) {
                LOG.info("Sent message: {}", i);
            }
        }

        // Should only accept one message
        final QueueViewMBean queue = getProxyToQueue(getTestName());
        assertTrue("All messages should arrive", Wait.waitFor(new Wait.Condition() {

            @Override
            public boolean isSatisified() throws Exception {
                return queue.getQueueSize() == 1;
            }
        }));

        assertEquals(0, sender.getEndpoint().getRemoteCredit());

        receiver.flow(1);
        AmqpMessage received = receiver.receive(5, TimeUnit.SECONDS);
        assertNotNull(received);
        received.accept();

        // Should not grant any credit until backlog starts to clear
        assertEquals(0, sender.getEndpoint().getRemoteCredit());

        receiver.flow(MSG_COUNT - 1);
        for (int i = 0; i < MSG_COUNT - 1; ++i) {
            received = receiver.receive(5, TimeUnit.SECONDS);
            assertNotNull(received);
            received.accept();
        }

        // Should have been granted credit once backlog was cleared.
        assertTrue(sender.getEndpoint().getRemoteCredit() > 0);

        sender.close();
        connection.close();
    }
}
