/*
 * Copyright (c) 2012-2018 The original author or authors
 * ------------------------------------------------------
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * and Apache License v2.0 which accompanies this distribution.
 *
 * The Eclipse Public License is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * The Apache License v2.0 is available at
 * http://www.opensource.org/licenses/apache2.0.php
 *
 * You may elect to redistribute this code under either of these licenses.
 */

package io.moquette.spi.impl;

import io.moquette.connections.IConnectionsManager;
import io.moquette.server.ConnectionDescriptor;
import io.moquette.server.ConnectionDescriptorStore;
import io.moquette.spi.ClientSession;
import io.netty.handler.codec.mqtt.MqttMessageType;
import io.netty.handler.codec.mqtt.MqttPublishMessage;
import io.netty.handler.codec.mqtt.MqttQoS;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.Optional;

import static io.moquette.spi.impl.ProtocolProcessor.asStoredMessage;
import static io.netty.handler.codec.mqtt.MqttQoS.AT_MOST_ONCE;

class PersistentQueueMessageSender {

    private static final Logger LOG = LoggerFactory.getLogger(PersistentQueueMessageSender.class);
    private final IConnectionsManager connectionDescriptorStore;

    PersistentQueueMessageSender(IConnectionsManager connectionDescriptorStore) {
        this.connectionDescriptorStore = connectionDescriptorStore;
    }

    void sendPublish(ClientSession clientsession, MqttPublishMessage pubMessage) {
        String clientId = clientsession.clientID;
        final int messageId = pubMessage.variableHeader().messageId();
        final String topicName = pubMessage.variableHeader().topicName();
        MqttQoS qos = pubMessage.fixedHeader().qosLevel();
        if (LOG.isDebugEnabled()) {
            LOG.debug("Sending PUBLISH message. MessageId={}, CId={}, topic={}, qos={}, payload={}", messageId,
                clientId, topicName, qos, DebugUtils.payload2Str(pubMessage.payload()));
        } else {
            LOG.info("Sending PUBLISH message. MessageId={}, CId={}, topic={}", messageId, clientId, topicName);
        }

        boolean messageDelivered = false;

        final Optional<ConnectionDescriptor> optDescriptor = connectionDescriptorStore.lookupDescriptor(clientId);
        if (optDescriptor.isPresent()) {
            final ConnectionDescriptor descriptor = optDescriptor.get();
            try {
                descriptor.writeAndFlush(pubMessage);
                messageDelivered = true;
            } catch (Throwable e) {
                LOG.error("Unable to send {} message. CId=<{}>, messageId={}", pubMessage.fixedHeader().messageType(),
                          clientId, messageId, e);
            }
        }

        if (!messageDelivered) {
            if (qos != AT_MOST_ONCE && !clientsession.isCleanSession()) {
                LOG.warn("PUBLISH message could not be delivered. It will be stored. MessageId={}, CId={}, topic={}, " +
                         "qos={}, removeTemporaryQoS2={}", messageId, clientId, topicName, qos, false);
                clientsession.enqueue(asStoredMessage(pubMessage));
            } else {
                LOG.warn("PUBLISH message could not be delivered. It will be discarded. MessageId={}, CId={}, " +
                         "topic={}, qos={}, removeTemporaryQoS2={}", messageId, clientId, topicName, qos, true);
            }
        }
    }
}