package com.usky.utils.mqtt;

import lombok.extern.log4j.Log4j2;
import org.springframework.integration.mqtt.outbound.MqttPahoMessageHandler;
import org.springframework.integration.mqtt.support.MqttHeaders;
import org.springframework.integration.support.MessageBuilder;
import org.springframework.messaging.Message;

import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

/**
 * mqtt工具类,可以根据通道名称发送消息
 */
@Log4j2
public class MqttUtils {

    /**
     * qos 0
     */
    public static final int QOS_0 = 0;
    /**
     * qos 1
     */
    public static final int QOS_1 = 1;
    /**
     * qos 2
     */
    public static final int QOS_2 = 2;

    private final static Map<String, MqttPahoMessageHandler> HANDLER_MAP = new HashMap<>(16);
    public final static String CHANNEL_NAME_SUFFIX = "MqttPahoMessageHandler";

    /**
     * 存放handler
     *
     * @param channelName
     * @param handler
     */
    public static void put(String channelName, MqttPahoMessageHandler handler) {
        HANDLER_MAP.put(channelName + CHANNEL_NAME_SUFFIX, handler);
    }

    /**
     * 发送消息
     *
     * @param topic       要发送的主题
     * @param message     消息内容
     * @param qos         qos级别
     * @param channelName 发送到指定的通道
     */
    public static void sendMessage(String topic, String message, int qos, String channelName) {
        MqttPahoMessageHandler handler = getHandler(channelName);
        Message<String> mqttMessage = MessageBuilder.withPayload(message).setHeader(MqttHeaders.TOPIC, topic)
                .setHeader(MqttHeaders.QOS, qos).build();
        handler.handleMessage(mqttMessage);
    }

    /**
     * 发送消息,默认qos级别为1
     *
     * @param topic       要发送的主题
     * @param message     消息内容
     * @param channelName 发送到指定的通道
     */
    public static void sendMessage(String topic, String message, String channelName) {
        MqttPahoMessageHandler handler = getHandler(channelName);
        Message<String> mqttMessage = MessageBuilder.withPayload(message).setHeader(MqttHeaders.TOPIC, topic)
                .setHeader(MqttHeaders.QOS, QOS_1).build();
        handler.handleMessage(mqttMessage);
    }

    /**
     * 发送消息
     *
     * @param mqttMessage 消息
     * @param channelName 发送到指定的通道
     */
    public static void sendMessage(Message<String> mqttMessage, String channelName) {
        MqttPahoMessageHandler handler = getHandler(channelName);
        handler.handleMessage(mqttMessage);
    }

    /**
     * 如果只有一个通道将使用该通道发送消息
     *
     * @param topic
     * @param message
     * @param qos
     */
    public static void sendMessage(String topic, String message, int qos) {
        MqttPahoMessageHandler handler = getDefaultHeadler();
        Message<String> mqttMessage = MessageBuilder.withPayload(message).setHeader(MqttHeaders.TOPIC, topic)
                .setHeader(MqttHeaders.QOS, qos).build();
        handler.handleMessage(mqttMessage);
    }

    /**
     * 如果只有一个通道将使用该通道发送消息，默认qos级别为1
     *
     * @param topic
     * @param message
     */
    public static void sendMessage(String topic, String message) {
        MqttPahoMessageHandler handler = getDefaultHeadler();
        Message<String> mqttMessage = MessageBuilder.withPayload(message).setHeader(MqttHeaders.TOPIC, topic)
                .setHeader(MqttHeaders.QOS, QOS_1).build();
        handler.handleMessage(mqttMessage);
    }

    /**
     * 如果只有一个通道将使用该通道发送消息，默认qos级别为1
     *
     * @param mqttMessage 消息信息
     */
    public static void sendMessage(Message<String> mqttMessage) {
        MqttPahoMessageHandler handler = getDefaultHeadler();
        handler.handleMessage(mqttMessage);
    }

    /**
     * 获取默认的handler
     *
     * @return
     */
    private static MqttPahoMessageHandler getDefaultHeadler() {
        Collection<MqttPahoMessageHandler> values = HANDLER_MAP.values();
        Iterator<MqttPahoMessageHandler> iterator = values.iterator();
        MqttPahoMessageHandler handler = iterator.next();
        if (handler == null) {
            log.error("发送消息失败,无可用的headler");
            throw new RuntimeException("发送消息失败,无可用的headler");
        }
        return handler;
    }

    /**
     * 根据通道获取handler
     *
     * @param channelName
     * @return
     */
    private static MqttPahoMessageHandler getHandler(String channelName) {
        MqttPahoMessageHandler handler = HANDLER_MAP.get(channelName + CHANNEL_NAME_SUFFIX);
        if (handler == null) {
            log.error("未查询到相应通道{}的handler，存在的通道名称{}", channelName, HANDLER_MAP.keySet());
            throw new IllegalArgumentException("未查询到相应通道" + channelName + "的handler");
        }
        return handler;
    }
}