package dbOperate

import (
	"crypto/tls"
	"crypto/x509"
	"fmt"
	mqtt "github.com/eclipse/paho.mqtt.golang"
	"log"
	"os"
	"time"
)

type MqttHelper struct {
	Host           string
	Port           int
	ClientId       string
	UserName       string
	Password       string
	client         mqtt.Client
	subscribeCalls []subscribeCall //纪录 重连订阅
}
type subscribeCall struct {
	topic string
	f     func(topic string, callMsg string)
}

func (the *MqttHelper) reConn2Subscribe(client mqtt.Client) {
	log.Println("mqtt触发链接后的自动订阅")
	for _, call := range the.subscribeCalls {
		the.Subscribe(call.topic, call.f)
	}
}
func (the *MqttHelper) initialClient(sslEnable bool, caCertPath, clientCertPath, clientKeyPath string) {
	maxReConnCount := 3
	ReConnDurationSec := 30
reConn:
	tag := "tcp"
	if sslEnable {
		tag = "ssl"
	}
	mqttConnectStr := fmt.Sprintf("%s://%v:%d", tag, the.Host, the.Port)
	opts := mqtt.NewClientOptions().AddBroker(mqttConnectStr)
	opts.SetUsername(the.UserName)
	opts.SetPassword(the.Password)
	opts.SetClientID(the.ClientId)
	opts.SetOnConnectHandler(the.reConn2Subscribe)
	if sslEnable {
		opts.SetTLSConfig(NewTlsConfig(caCertPath, clientCertPath, clientKeyPath))
	}
	the.client = mqtt.NewClient(opts)
	if token := the.client.Connect(); token.Wait() && token.Error() != nil {
		log.Printf("mqtt连接状态异常 %v [ u:%v,p:%v,cid:%v ] [err=%s]", mqttConnectStr, the.UserName, the.Password, the.ClientId, token.Error())
		log.Printf("mqtt重连,%ds后尝试,剩余次数=%d", ReConnDurationSec, maxReConnCount)
		if maxReConnCount > 0 {
			maxReConnCount--
			time.Sleep(time.Duration(ReConnDurationSec) * time.Second)
			goto reConn
		}
		os.Exit(1)

	}
	time.Sleep(time.Second * 1)

}
func (the *MqttHelper) Initial() {
	the.initialClient(false, "", "", "")

}

func (the *MqttHelper) InitialWithSSL(caCertPath, clientCertPath, clientKeyPath string) {
	the.initialClient(true, caCertPath, clientCertPath, clientKeyPath)
}

func NewTlsConfig(caCertPath, clientCertPath, clientKeyPath string) *tls.Config {
	//"ssl/centerCA.crt"
	certPool := x509.NewCertPool()
	ca, err := os.ReadFile(caCertPath)
	if err != nil {
		log.Fatalln(err.Error())
	}
	certPool.AppendCertsFromPEM(ca)

	tlsConfig := &tls.Config{
		RootCAs:            certPool,
		InsecureSkipVerify: true,
	}
	if len(clientCertPath) > 0 && len(clientKeyPath) > 0 {
		// 读取客户端证书和密钥
		clientCert, err := tls.LoadX509KeyPair(clientCertPath, clientKeyPath)
		if err != nil {
			fmt.Printf("Error loading client certificate and key: %v\n", err)
		}
		tlsConfig.Certificates = append(tlsConfig.Certificates, clientCert)
	}
	return tlsConfig
}

func (the *MqttHelper) Publish(topic string, messageBytes []byte) {
	if the.client != nil {
		token := the.client.Publish(topic, 1, false, messageBytes)
		token.Wait()
		//the.client.Disconnect(200)
		log.Printf("[%s] -[%v]推送Msg 长度=%d byte \n", topic, the.client.IsConnected(), len(messageBytes))
	}
}

func (the *MqttHelper) Subscribe(topic string, myCallback func(topic string, callMsg string)) {
	var callback mqtt.MessageHandler = func(client mqtt.Client, msg mqtt.Message) {
		//log.Printf("收到数据 [%v] TOPIC: %s,MSGLen: %v", msg.MessageID(), msg.Topic(), len(msg.Payload()))
		Msg := string(msg.Payload())
		myCallback(msg.Topic(), Msg)
	}
	log.Printf("=================开始订阅 %s [%s]=================", the.Host, topic)
	t := the.client.Subscribe(topic, 1, callback)
	f := func() {
		_ = t.Wait() // Can also use '<-t.Done()' in releases > 1.2.0
		if t.Error() != nil {
			log.Println(t.Error()) // Use your preferred logging technique (or just fmt.Printf)
		}
	}
	go f()

	//纪录需要重连的 callback
	the.subscribeCalls = append(the.subscribeCalls, subscribeCall{
		topic: topic,
		f:     myCallback,
	})
}

func MqttInitial(host string, port int, clientId string, userName string, password string, isSSL bool, caPtah ...string) *MqttHelper {
	mqHelpers := MqttHelper{
		Host:     host,
		Port:     port,
		ClientId: clientId,
		UserName: userName,
		Password: password,
	}
	if isSSL && len(caPtah) > 0 {
		log.Println("SSL mqHelpers初始化")
		switch len(caPtah) {
		case 1:
			mqHelpers.InitialWithSSL(caPtah[0], "", "")
		case 3:
			mqHelpers.InitialWithSSL(caPtah[0], caPtah[1], caPtah[2])
		default:
			log.Printf("caPtah 参数量错误，请注意")
		}

	} else {
		mqHelpers.Initial()
	}
	//topic = "t/500103"  //龙河桥
	time.Sleep(time.Second * 1)
	return &mqHelpers
}