package com.yvan.logisticsModel;

import com.yvan.logisticsEnv.EnvConfig;
import lombok.SneakyThrows;
import lombok.extern.slf4j.Slf4j;
import org.eclipse.paho.mqttv5.client.*;
import org.eclipse.paho.mqttv5.common.MqttException;
import org.eclipse.paho.mqttv5.common.MqttMessage;
import org.eclipse.paho.mqttv5.common.packet.MqttProperties;

import java.nio.charset.StandardCharsets;
import java.util.concurrent.CountDownLatch;

@Slf4j
public class FrontendPushService implements MqttCallback {
    private final LogisticsRuntime runtime;
    public final String rcsFrontendTopic;
    private volatile MqttClient clientForSend;
    private volatile MqttClient client;
    private CountDownLatch connectLatch = new CountDownLatch(1);

    public FrontendPushService(LogisticsRuntime runtime) {
        this.runtime = runtime;
        this.rcsFrontendTopic = "/rcs/" + runtime.projectUUID + "/" + runtime.envId + "/frontend";
    }

    @Override
    public void disconnected(MqttDisconnectResponse disconnectResponse) {
        log.info("mqtt disconnected");
    }

    @Override
    public void mqttErrorOccurred(MqttException exception) {
        log.error("mqtt error occurred");
    }

    @Override
    public void messageArrived(String topic, MqttMessage message) throws Exception {
        log.info("Message arrived on topic {}: {}", topic, new String(message.getPayload(), StandardCharsets.UTF_8));
    }

    @Override
    public void deliveryComplete(IMqttToken token) {
        log.info("Message delivery complete: {}", token);
    }

    @Override
    public void connectComplete(boolean reconnect, String serverURI) {
        // BannerUtils.printConfig(log, "MQTT 开启监听", new String[]{serverURI + " topic: /agv_robot/status"});
        log.info("MQTT client connected to server: {}", serverURI);
        connectLatch.countDown(); // 放行
    }

    @Override
    public void authPacketArrived(int reasonCode, MqttProperties properties) {
    }

    @SneakyThrows
    public void stop() {
        if (client != null && client.isConnected()) {
            client.disconnect();
            client.close();
            log.info("MQTT client disconnected and closed.");
        } else {
            log.warn("MQTT client is not connected, no action taken.");
        }

        if (clientForSend != null && clientForSend.isConnected()) {
            clientForSend.disconnect();
            clientForSend.close();
            log.info("MQTT clientForSend disconnected and closed.");
        } else {
            log.warn("MQTT clientForSend is not connected, no action taken.");
        }
    }

    /**
     * 创建一个表示服务器离线的最后消息
     */
    public MqttMessage createWillMessage() {
        MqttMessage lastMessage = new MqttMessage();
        String msg = String.format("""
            {
                "id": "serverOffline",
                "content": {
                    "project": "%s",
                    "env": %s,
                    "status": "offline",
                    "server": "%s",
                }
            }
            """, runtime.projectUUID, runtime.envId, runtime.clientId);
        lastMessage.setPayload(msg.getBytes(StandardCharsets.UTF_8));
        lastMessage.setQos(0);
        lastMessage.setRetained(true);
        return lastMessage;
    }

    @SneakyThrows
    public void start(EnvConfig.MqttConfig mqttConfig) {
        String brokerUrl = mqttConfig.getBrokerUrl(); // "tcp://10.10.203.239:1885"
        String username = mqttConfig.getUsername(); // admin
        String password = mqttConfig.getPassword(); // admin

        clientForSend = new MqttClient(brokerUrl, runtime.clientId + "_front_send"); // String clientId = "LUOYIFAN-PC_send"
        client = new MqttClient(brokerUrl, runtime.clientId + "_front"); // String clientId = "LUOYIFAN-PC"
        MqttConnectionOptions options = new MqttConnectionOptions();
        options.setServerURIs(new String[]{brokerUrl});
        options.setAutomaticReconnect(true);
        options.setUserName(username);
        options.setPassword(password.getBytes());
        options.setConnectionTimeout(1);
        options.setKeepAliveInterval(20);
        options.setExecutorServiceTimeout(1);
        // 最后一条消息，表示服务离线
        options.setWill(this.rcsFrontendTopic, createWillMessage());

        client.setCallback(this);
        client.connect(options);

        clientForSend.connect(options);
        connectLatch.await();

        // 发送一条消息代表上线
        this.publish(String.format("""
            {
                "id": "serverOnline",
                "content": {
                    "project": "%s",
                    "env": %s,
                    "status": "online",
                    "server": "%s"
                }
            }
            """, runtime.projectUUID, runtime.envId, runtime.clientId));
    }

    @SneakyThrows
    void publish(String payloadString) {
        MqttMessage message = new MqttMessage(payloadString.getBytes(StandardCharsets.UTF_8));
        message.setQos(0);
        message.setRetained(false);

        if (this.clientForSend.isConnected()) {
            this.clientForSend.publish(this.rcsFrontendTopic, message);
        } else {
            throw new RuntimeException("MQTT client is not connected");
        }
    }
}