package mqtt

import (
	"context"
	"fmt"
	"log/slog"
	"time"

	"github.com/eclipse/paho.golang/autopaho"
	"github.com/eclipse/paho.golang/paho"
	"google.golang.org/protobuf/proto"
	"google.golang.org/protobuf/reflect/protoreflect"
	"joylink.club/iot/dto"
)

var iotcli *IotClient

type IotClient struct {
	cmc *IotMqttConfig
	cc  *autopaho.ClientConfig
	cm  *autopaho.ConnectionManager
}

// 初始化并启动MQTT客户端服务
func Start(cmc *IotMqttConfig) error {
	if err := checkConfig(cmc); err != nil {
		return err
	}
	BuildTopics(cmc.AppId, cmc.ClientId)
	cc, err := cmc.tryInto()
	if err != nil {
		return err
	}
	cm, err := autopaho.NewConnection(context.Background(), *cc)
	if err != nil {
		return err
	}
	iotcli = &IotClient{
		cmc: cmc,
		cc:  cc,
		cm:  cm,
	}
	return nil
}

// 断开MQTT客户端
func Stop() error {
	slog.Info("停止MQTT客户端")
	ctx, cancle := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancle()
	err := iotcli.cm.Disconnect(ctx)
	return err
}

func checkConfig(cmc *IotMqttConfig) error {
	if cmc.AppId == "" {
		return fmt.Errorf("应用编号不能为空")
	}
	if cmc.ClientId == "" {
		return fmt.Errorf("客户端编号不能为空")
	}
	if cmc.BrokerUrl == "" {
		return fmt.Errorf("MQTT代理服务地址不能为空")
	}
	if cmc.Username == "" {
		return fmt.Errorf("MQTT用户名不能为空")
	}
	if cmc.Password == "" {
		return fmt.Errorf("MQTT密码不能为空")
	}
	return nil
}

// 发布IOT服务状态
func PubIotServiceState(s *dto.IotServiceState) error {
	return pub(GetIotServiceStateTopic(), s)
}

// 发布IOT采集数据
func PubIotCjData(cj *dto.IotCj) error {
	return pub(GetCjTopic(), cj)
}

// 发布IOT驱动数据
func PubIotQdData(qd *dto.IotQd) error {
	return pub(GetQdTopic(), qd)
}

// 注册IOT采集数据处理
func RegIotCjHandler(h func(cj *dto.IotCj)) {
	iotcli.cc.Router.RegisterHandler(GetCjTopic(), func(p *paho.Publish) {
		cmd := &dto.IotCj{}
		err := proto.Unmarshal(p.Payload, cmd)
		if err != nil {
			slog.Error("采集数据proto.Unmarshal异常", "error", err)
			return
		}
		h(cmd)
	})
	slog.Info("注册IOT采集数据处理success")
}

// 注册IOT驱动数据处理
func RegIotQdHandler(h func(qd *dto.IotQd)) {
	iotcli.cc.Router.RegisterHandler(GetQdTopic(), func(p *paho.Publish) {
		cmd := &dto.IotQd{}
		err := proto.Unmarshal(p.Payload, cmd)
		if err != nil {
			slog.Error("驱动数据proto.Unmarshal异常", "error", err)
			return
		}
		h(cmd)
	})
	slog.Info("注册IOT驱动数据处理success")
}

// 注册IOT服务启动请求处理
func RegIotQcServiceStartReqHandler(h func(req *dto.IotQcServiceStartReq) *dto.IotQcServiceCommonResp) {
	iotcli.cc.Router.RegisterHandler(GetIotServiceStartTopic(), func(p *paho.Publish) {
		reqHandle(p, h, &dto.IotQcServiceStartReq{})
	})
}

// 注册IOT服务停止请求处理
func RegIotQcServiceStopReqHandler(h func(req *dto.IotQcServiceStopReq) *dto.IotQcServiceCommonResp) {
	iotcli.cc.Router.RegisterHandler(GetIotServiceStopTopic(), func(p *paho.Publish) {
		reqHandle(p, h, &dto.IotQcServiceStopReq{})
	})
}

// 注册IOT日志查询请求处理
func RegIotLogReqHandler(h func(req *dto.IotServiceLogReq) *dto.IotServiceLogResp) {
	iotcli.cc.Router.RegisterHandler(GetLogReqTopic(), func(p *paho.Publish) {
		reqHandle(p, h, &dto.IotServiceLogReq{})
	})
}

// 注销IOT处理
func UnregHandler(topic string) {
	iotcli.cc.Router.UnregisterHandler(topic)
}

// 注销所有IOT处理
func UnregAllHandler() {
	iotcli.cc.Router = paho.NewStandardRouter()
}

func subIotQc() {
	slog.Info("订阅Iot驱采")
	sub(GetCjTopic())              // 订阅采集
	sub(GetQdTopic())              // 订阅驱动
	sub(GetIotServiceStartTopic()) // 订阅启动请求
	sub(GetIotServiceStopTopic())  // 订阅停止请求
	sub(GetLogReqTopic())          // 订阅日志查询请求
}

// 发起订阅
func sub(topic string) {
	slog.Info("发起订阅", "topic", topic)
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()
	_, err := iotcli.cm.Subscribe(ctx, &paho.Subscribe{
		Subscriptions: []paho.SubscribeOptions{
			{
				Topic:   topic,
				QoS:     0,
				NoLocal: true,
			},
		},
	})
	if err != nil {
		slog.Error("订阅失败", "topic", topic, "error", err)
	}
}

func reqHandle[T proto.Message, P proto.Message](p *paho.Publish, h func(T) P, r T) {
	slog.Info("IOT-MQTT服务收到请求", "publish", p)
	if p.Properties != nil && p.Properties.CorrelationData != nil && p.Properties.ResponseTopic != "" {
		err := proto.Unmarshal(p.Payload, r)
		if err != nil {
			slog.Error("Iot请求响应数据处理proto.Unmarshal异常", "error", err)
			return
		}
		resp := h(r)
		b, err := proto.Marshal(resp)
		if err != nil {
			slog.Error("Iot请求响应数据处理proto.Marshal异常", "error", err)
		}
		_, err = iotcli.cm.Publish(context.Background(), &paho.Publish{
			Topic: p.Properties.ResponseTopic,
			Properties: &paho.PublishProperties{
				CorrelationData: p.Properties.CorrelationData,
			},
			Payload: b,
		})
		if err != nil {
			slog.Error("Iot请求处理回复异常", "error", err)
		}
	}
}

// 发布数据
func pub(topic string, data protoreflect.ProtoMessage) error {
	if data == nil {
		return fmt.Errorf("发布数据引用为nil")
	}
	b, err := proto.Marshal(data)
	if err != nil {
		return err
	}
	switch topic {
	case GetIotServiceStateTopic():
		slog.Debug("IOT-MQTT发布Iot服务状态", "topic", topic, "data", data)
	case GetCjTopic():
		slog.Debug("IOT-MQTT发布采集数据", "topic", topic, "data", data)
	case GetQdTopic():
		slog.Debug("IOT-MQTT发布驱动数据", "topic", topic, "data", data)
	default:
		return fmt.Errorf("IOT-MQTT未知发布主题: topic=%s", topic)
	}
	_, err = iotcli.cm.Publish(context.Background(), &paho.Publish{
		Topic:   topic,
		QoS:     0,
		Payload: b,
	})
	return err
}