package sensors

import (
	"encoding/json"
	"nats-app/internal/iot"

	"github.com/nats-io/nats.go"
)

const (
	subjectSensorsRegister  = "sensors.register"
	subjectSensorsUpdate    = "sensors.update"
	subjectSensorsGet       = "sensors.get"
	subjectSensorsValuesGet = "sensors.values.get"
	subjectSensorsList      = "sensors.list"
)

type Handlers struct {
	service *Service
	*iot.IoTDevice
}

func NewHandlers(service *Service, iot *iot.IoTDevice) *Handlers {
	return &Handlers{
		service:   service,
		IoTDevice: iot,
	}
}

func handleRequest[Req any, Res any](msg *nats.Msg, handler func(Req) (Res, error)) {
	var req Req
	if err := json.Unmarshal(msg.Data, &req); err != nil {
		msg.Respond([]byte(`{"error":"invalid request"}`))
		return
	}

	result, err := handler(req)
	if err != nil {
		msg.Respond([]byte(`{"error":"` + err.Error() + `"}`))
		return
	}

	response, _ := json.Marshal(result)
	msg.Respond(response)
}

func (h *Handlers) SetupEndpoints() *Handlers {
	h.register()
	h.update()
	h.get()
	h.getValues()
	h.list()
	return h
}

func (h *Handlers) register() {
	h.NATS.Subscribe(subjectSensorsRegister, func(msg *nats.Msg) {
		handleRequest(msg, func(req Sensor) (Sensor, error) {
			// service layer

			return req, nil
		})
	})
}

func (h *Handlers) update() {
	h.NATS.Subscribe(subjectSensorsUpdate, func(msg *nats.Msg) {
		handleRequest(msg, func(req Sensor) (Sensor, error) {
			// service layer

			return req, nil
		})
	})
}

func (h *Handlers) get() {
	h.NATS.Subscribe(subjectSensorsGet, func(msg *nats.Msg) {
		handleRequest(msg, func(req struct {
			SensorID string `json:"sensor_id"`
		}) (Sensor, error) {
			// service layer

			return Sensor{}, nil
		})
	})
}

func (h *Handlers) getValues() {
	h.NATS.Subscribe(subjectSensorsValuesGet, func(msg *nats.Msg) {
		handleRequest(msg, func(req struct {
			SensorID string `json:"sensor_id"`
			From     string `json:"from"`
			To       string `json:"to"`
		}) ([]SensorData, error) {
			// service layer

			return []SensorData{}, nil
		})
	})
}

func (h *Handlers) list() {
	h.NATS.Subscribe(subjectSensorsList, func(msg *nats.Msg) {
		handleRequest(msg, func(req struct{}) ([]Sensor, error) {
			// service layer

			return []Sensor{}, nil
		})
	})
}