/**
 *
 * 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.airavata.messaging.core.impl;

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.MessageProperties;
import com.rabbitmq.client.ShutdownListener;
import com.rabbitmq.client.ShutdownSignalException;
import org.apache.airavata.common.exception.AiravataException;
import org.apache.airavata.common.utils.ThriftUtils;
import org.apache.airavata.messaging.core.MessageContext;
import org.apache.airavata.messaging.core.Publisher;
import org.apache.airavata.messaging.core.RabbitMQProperties;
import org.apache.airavata.model.messaging.event.Message;
import org.apache.thrift.TException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.util.function.Function;

public class RabbitMQPublisher implements Publisher {
    private static final Logger log = LoggerFactory.getLogger(RabbitMQPublisher.class);
    private final RabbitMQProperties properties;
    private final Function<MessageContext, String> routingKeySupplier;
    private Connection connection;
    private Channel channel;

    public RabbitMQPublisher(RabbitMQProperties properties, Function<MessageContext, String> routingKeySupplier) throws AiravataException {
        this.properties = properties;
        this.routingKeySupplier = routingKeySupplier;
        connect();
    }

    private void connect() throws AiravataException {
        try {
            ConnectionFactory connectionFactory = new ConnectionFactory();
            connectionFactory.setUri(properties.getBrokerUrl());
            connectionFactory.setAutomaticRecoveryEnabled(properties.isAutoRecoveryEnable());
            connection = connectionFactory.newConnection();
            connection.addShutdownListener(new ShutdownListener() {
                public void shutdownCompleted(ShutdownSignalException cause) {
                }
            });
            log.info("connected to rabbitmq: " + connection + " for " + properties.getExchangeName());
            channel = connection.createChannel();
            if (properties.getPrefetchCount() > 0) {
                channel.basicQos(properties.getPrefetchCount());
            }

            if (properties.getExchangeName() != null) {
                channel.exchangeDeclare(properties.getExchangeName(),
                                        properties.getExchangeType(),
                                        true); //durable
            }
        } catch (Exception e) {
            String msg = "RabbitMQ connection issue for exchange : " + properties.getExchangeName();
            log.error(msg);
            throw new AiravataException(msg, e);
        }


    }


    @Override
    public void publish(MessageContext messageContext) throws AiravataException {
        try {
            byte[] body = ThriftUtils.serializeThriftObject(messageContext.getEvent());
            Message message = new Message();
            message.setEvent(body);
            message.setMessageId(messageContext.getMessageId());
            message.setMessageType(messageContext.getType());
            message.setUpdatedTime(messageContext.getUpdatedTime().getTime());
            String routingKey = routingKeySupplier.apply(messageContext);
//            log.info("publish messageId:" + messageContext.getMessageId() + ", messageType:" + messageContext.getType() + ", to routingKey:" + routingKey);
            byte[] messageBody = ThriftUtils.serializeThriftObject(message);
            send(messageBody, routingKey);
        } catch (TException e) {
            String msg = "Error while deserializing the object";
            log.error(msg, e);
            throw new AiravataException(msg, e);
        } catch (Exception e) {
            String msg = "Error while sending to rabbitmq";
            log.error(msg, e);
            throw new AiravataException(msg, e);
        }
    }

    public void send(byte []message, String routingKey) throws Exception {
        try {
            channel.basicPublish(properties.getExchangeName(), routingKey, MessageProperties.PERSISTENT_TEXT_PLAIN, message);
        } catch (IOException e) {
            String msg = "Failed to publish message to exchange: " + properties.getExchangeName();
            log.error(msg, e);
            throw new Exception(msg, e);
        }
    }
}
