n9m/smart.go

package n9m

import (
	"errors"
	"fmt"
	"net"
)

type notFoundError struct {
	message string
}

func (e *notFoundError) Error() string {
	return fmt.Sprintf("not found %s", e.message)
}

func NewSmartPackage(conn net.Conn) *SmartPackage {
	return &SmartPackage{
		pack:           Package{},
		conn:           conn,
		buff:           make([]byte, 1024),
		payloadProcess: make(map[PayloadType]ProcessFunc),
		jsonProcess:    make(map[string]ProcessFunc),
		alarmProcess:   make(map[AlarmType]AlarmProcessFunc),
		Storage:        make(map[string]interface{}),
	}
}

func (pack *SmartPackage) AddPayloadHandler(payloadType PayloadType, processFunc ProcessFunc) {
	pack.payloadProcess[payloadType] = processFunc
}

func (pack *SmartPackage) AddJSONHandler(module, operation string, processFunc ProcessFunc) {
	pack.jsonProcess[fmt.Sprintf("%s:%s", module, operation)] = processFunc
}

func (pack *SmartPackage) AddAlarmHandler(alarmType AlarmType, processFunc AlarmProcessFunc) {
	pack.alarmProcess[alarmType] = processFunc
}

func (pack *SmartPackage) handleAlarm() (err error) {
	if !(pack.pack.PayloadType == PayloadTypeData && pack.pack.Payload.Module == "EVEM" && pack.pack.Payload.Operation == "SENDALARMINFO") {
		return fmt.Errorf("invalid payload type or operation for alarm handling")
	}

	var params SendAlarmInfoParameters
	if err = pack.pack.GetParametersAs(&params); err != nil {
		return fmt.Errorf("invalid payload")
	}

	var processFunc AlarmProcessFunc
	var ok bool
	if processFunc, ok = pack.alarmProcess[params.AlarmType]; !ok {
		return &notFoundError{
			message: fmt.Sprintf("alarm %d", params.AlarmType),
		}
	}

	var response SendAlarmInfoResponse

	response.ErrorCode = 0
	response.AlarmType = params.AlarmType
	response.CommandType = params.CommandType
	response.AlarmUID = params.AlarmUID
	response.NumberOfRestarts = params.NumberOfRestarts
	response.InstructionSerial = params.InstructionSerial

	return processFunc(pack, pack.pack, response)
}

func (pack *SmartPackage) handleJson() (err error) {
	if pack.pack.PayloadType != PayloadTypeData {
		return fmt.Errorf("invalid json payload type")
	}

	var nfErr *notFoundError
	if err = pack.handleAlarm(); err == nil || errors.As(err, &nfErr) {
		return
	}

	var processFunc ProcessFunc
	var ok bool
	var key = fmt.Sprintf("%s:%s", pack.pack.Payload.Module, pack.pack.Payload.Operation)
	if processFunc, ok = pack.jsonProcess[key]; !ok {
		return &notFoundError{
			message: fmt.Sprintf("json %s", key),
		}
	}

	return processFunc(pack, pack.pack)
}

func (pack *SmartPackage) handle() (err error) {
	var nfErr *notFoundError
	if err = pack.handleJson(); err == nil || errors.As(err, &nfErr) {
		return
	}

	var processFunc ProcessFunc
	var ok bool
	if processFunc, ok = pack.payloadProcess[pack.pack.PayloadType]; !ok {
		return &notFoundError{
			message: fmt.Sprintf("payload type %d", pack.pack.PayloadType),
		}
	}

	return processFunc(pack, pack.pack)
}

func (pack *SmartPackage) handleLoop() (err error) {
	for pack.pack.ReadPackage() {
		if err = pack.handle(); err != nil {
			return err
		}
	}

	return
}

func (pack *SmartPackage) Handle() (err error) {
	if err = pack.handleLoop(); err != nil {
		return err
	}

	var rn int

	if rn, err = pack.conn.Read(pack.buff); err != nil {
		return
	}

	pack.pack.AddToAccum(pack.buff[:rn])

	return pack.handleLoop()
}

func (pack *SmartPackage) GetPackage() Package {
	return pack.pack
}

func (pack *SmartPackage) Write(data []byte) (int, error) {
	return pack.conn.Write(data)
}