package io.moquette.spi.impl;

import io.moquette.parser.proto.messages.*;
import io.moquette.server.ConnectionDescriptorStore;
import io.moquette.server.netty.NettyUtils;
import io.moquette.spi.ClientSession;
import io.moquette.spi.IMessagesStore;
import io.moquette.spi.ISessionsStore;
import io.moquette.spi.MessageGUID;
import io.moquette.spi.impl.subscriptions.Subscription;
import io.moquette.spi.impl.subscriptions.SubscriptionsStore;
import io.moquette.spi.security.IAuthorizator;
import io.netty.channel.Channel;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


import static io.moquette.spi.impl.ProtocolProcessor.asStoredMessage;

import java.util.List;

class Qos2PublishHandler extends QosPublishHandler  {

    private static final Logger LOG = LoggerFactory.getLogger(Qos1PublishHandler.class);

    private final SubscriptionsStore subscriptions;
    private final IMessagesStore m_messagesStore;
    private final BrokerInterceptor m_interceptor;
    private final ConnectionDescriptorStore connectionDescriptors;
    private final ISessionsStore m_sessionsStore;
    private final MessagesPublisher publisher;

    public Qos2PublishHandler(IAuthorizator authorizator, SubscriptionsStore subscriptions,
                              IMessagesStore messagesStore, BrokerInterceptor interceptor,
                              ConnectionDescriptorStore connectionDescriptors,
                              ISessionsStore sessionsStore, String brokerPort, MessagesPublisher messagesPublisher) {
		super(authorizator);
        this.subscriptions = subscriptions;
        this.m_messagesStore = messagesStore;
        this.m_interceptor = interceptor;
        this.connectionDescriptors = connectionDescriptors;
        this.m_sessionsStore = sessionsStore;
        this.publisher = messagesPublisher;
    }

    void receivedPublishQos2(Channel channel, PublishMessage msg) {
        final String topic = msg.getTopicName();
        //check if the topic can be wrote
        if (checkWriteOnTopic(topic, channel)) {
            return;
        }
        final Integer messageID = msg.getMessageID();

        IMessagesStore.StoredMessage toStoreMsg = asStoredMessage(msg);
        String clientID = NettyUtils.clientID(channel);
        toStoreMsg.setClientID(clientID);

		if (LOG.isTraceEnabled()) {
			LOG.trace("Sending publish message to subscribers. MqttClientId = {}, topic = {}, messageId = {}, payload = {}, subscriptionTree = {}.",
					clientID, topic, msg.getMessageID(), DebugUtils.payload2Str(toStoreMsg.getMessage()),
					subscriptions.dumpTree());
		} else {
			LOG.info("Sending publish message to subscribers. MqttClientId = {}, topic = {}, messageId = {}.", clientID,
					topic, msg.getMessageID());
		}

        //QoS2
        MessageGUID guid = m_messagesStore.storePublishForFuture(toStoreMsg);
        if (msg.isLocal()) {
            sendPubRec(clientID, messageID);
        }
        //Next the client will send us a pub rel
        //NB publish to subscribers for QoS 2 happen upon PUBREL from publisher

        if (msg.isRetainFlag()) {
            if (!msg.getPayload().hasRemaining()) {
                m_messagesStore.cleanRetained(topic);
            } else {
                m_messagesStore.storeRetained(topic, guid);
            }
        }
        String username = NettyUtils.userName(channel);
        m_interceptor.notifyTopicPublished(msg, clientID, username);
    }

    /**
     * Second phase of a publish QoS2 protocol, sent by publisher to the broker. Search the stored message and publish
     * to all interested subscribers.
     * */
    void processPubRel(Channel channel, PubRelMessage msg) {
        String clientID = NettyUtils.clientID(channel);
        int messageID = msg.getMessageID();
        LOG.info("Processing PUBREL message. MqttClientId = {}, messageId = {}.", clientID, messageID);
        ClientSession targetSession = m_sessionsStore.sessionForClient(clientID);
        IMessagesStore.StoredMessage evt = targetSession.storedMessage(messageID);
        final String topic = evt.getTopic();
        List<Subscription> topicMatchingSubscriptions = subscriptions.matches(topic);

		if (LOG.isDebugEnabled()) {
			LOG.debug("Sending publish message to subscribers. MqttClientId = {}, topic = {}, messageId = {}, payload = {}, subscriptionTree = {}.",
					clientID, topic, msg.getMessageID(), DebugUtils.payload2Str(evt.getMessage()),
					subscriptions.dumpTree());
		} else {
			LOG.info("Sending publish message to subscribers. MqttClientId = {}, topic = {}, messageId = {}.", clientID,
					topic, msg.getMessageID());
		}
        this.publisher.publish2Subscribers(evt, topicMatchingSubscriptions);

        if (evt.isRetained()) {
            if (!evt.getMessage().hasRemaining()) {
                m_messagesStore.cleanRetained(topic);
            } else {
                m_messagesStore.storeRetained(topic, evt.getGuid());
            }
        }

        sendPubComp(clientID, messageID);
    }


    private void sendPubRec(String clientID, int messageID) {
        LOG.debug("Sending PUBREC message. MqttClientId = {}, messageId = {}.", clientID, messageID);
        PubRecMessage pubRecMessage = new PubRecMessage();
        pubRecMessage.setMessageID(messageID);
        connectionDescriptors.sendMessage(pubRecMessage,messageID, clientID);
    }

    private void sendPubComp(String clientID, int messageID) {
        LOG.debug("Sending PUBCOMP message. MqttClientId = {}, messageId = {}.", clientID, messageID);
        PubCompMessage pubCompMessage = new PubCompMessage();
        pubCompMessage.setMessageID(messageID);
        connectionDescriptors.sendMessage(pubCompMessage, messageID, clientID);
    }
}