package crm3000

import (
	"encoding/hex"
	"fmt"

	"src.dualinventive.com/go/dinet"
	"src.dualinventive.com/go/dinet/rpc"
	"src.dualinventive.com/go/lib/dilog"
)

// SensorMessageHandler handles a CRM sensor report.
type SensorMessageHandler struct {
	log dilog.Logger
	pd  dinet.ParentDevice
}

//Handle takes hexData byte array and publishes it on dinet.
//Given IMEI will be overwritten if the payload contains a SerialNumber.
func (c *SensorMessageHandler) Handle(payload []byte, imei string) {
	msg, err := Decode(payload)
	if err != nil {
		c.log.WithFields(dilog.Fields{
			"imei":    imei,
			"payload": hex.EncodeToString(payload),
		}).WithError(err).Error("Handle crm3000.Decode failed")
		return
	}

	if msg.IMEI != "" {
		imei = msg.IMEI
	}
	if imei == "" {
		c.log.Error("no imei found in message payload")
		return
	}
	dev, err := c.crm3000GetDevice(imei, c.pd)
	if err != nil {
		c.log.WithError(err).Error("crm3000GetDevice failed")
		return
	}

	dev.Logger().WithFields(dilog.Fields{
		"imei": imei,
	}).Debug("received uplink message report")
	err = dev.Send(&rpc.Msg{
		ClassMethod: rpc.ClassMethodSensorData,
		Type:        rpc.MsgTypePublish,
		Result:      rpc.NewResult(msg.ResultValueItems(msg.Timestamp)),
	})
	if err != nil {
		dev.Logger().WithError(err).Error("dev.send failed")
	}
}

//NewSensorMessageHandler returns a SensorMessageHandler
func NewSensorMessageHandler(log dilog.Logger, pd dinet.ParentDevice) *SensorMessageHandler {
	return &SensorMessageHandler{log: log, pd: pd}
}

func (c *SensorMessageHandler) crm3000GetDevice(imei string, pd dinet.ParentDevice) (*dinet.ChildDevice, error) {
	uid, err := rpc.GenerateDeviceUID(rpc.DeviceUIDPrefixNBIoT, imei)
	if err != nil {
		return nil, err
	}

	dev, err := pd.Search(uid)
	if err == nil {
		cdev, ok := dev.(*Device)
		if !ok {
			return nil, fmt.Errorf("device is not of *crm3000.Device type (type is: %T)", dev)
		}
		return cdev.ChildDevice, nil
	}

	crm3000dev := &Device{IMEI: imei, DeviceUID: uid}
	cdev := dinet.NewChildDevice(crm3000dev, pd)
	cdev.Subscribe(rpc.ClassMethodSensorInfo, rpc.MsgTypeRequest, crm3000dev.SensorInfo)
	err = cdev.Handshake()
	if err != nil {
		return nil, err
	}
	crm3000dev.ChildDevice = cdev
	return cdev, nil
}