package device

import (
	"errors"
	"fmt"
	"strconv"
	"sync"
	"time"

	"src.dualinventive.com/go/cp3000-interface/internal/statusupdate"
	"src.dualinventive.com/go/cp3000-interface/internal/storage"
	"src.dualinventive.com/go/dinet"
	"src.dualinventive.com/go/dinet/rpc"
	"src.dualinventive.com/go/lib/cp3000"
	"src.dualinventive.com/go/lib/dilog"
)

// DefaultCommandTimeout for CP3000 request-reply
//nolint: gochecknoglobals
var DefaultCommandTimeout = time.Second * 10

// Base is a CP3000 base-device
type Base struct {
	uid            string
	devType        rpc.DeviceType
	client         cp3000.Router
	dev            *dinet.ChildDevice
	decoder        statusupdate.Decoder
	hwVersion      string
	databaseID     uint32
	repo           storage.Repository
	commandTimeout time.Duration
	clientMu       sync.Mutex
}

func newBaseDevice(r cp3000.Router, repo storage.Repository, hwVersion string, databaseID int) (*Base, error) {
	b := &Base{
		client:         r,
		decoder:        nil,
		hwVersion:      hwVersion,
		databaseID:     uint32(databaseID),
		repo:           repo,
		commandTimeout: DefaultCommandTimeout,
	}
	uid, err := rpc.GenerateDeviceUID(rpc.DeviceUIDPrefixLegacy, strconv.Itoa(databaseID))
	if err != nil {
		return nil, err
	}
	b.uid = uid
	return b, nil
}

func (z *Base) cp3000ReqRep(timeout time.Duration, cmd cp3000.Command, args ...string) (*cp3000.Msg, rpc.ErrorCode) {
	z.clientMu.Lock()
	defer z.clientMu.Unlock()
	if err := z.client.Send(cmd, args...); err != nil {
		z.dev.Logger().WithError(err).Error("Error sending to the device...")
		return nil, rpc.EBackendCp3000CommError
	}
	rep, err := z.client.ReceiveReply(timeout)
	if err != nil {
		z.dev.Logger().WithError(err).Error("Error receiving from device...")
		if err == cp3000.ErrTimeout {
			return nil, rpc.ETimeout
		}
		return nil, rpc.EBackendCp3000CommError
	}
	return rep, rpc.Ok
}

func (z *Base) requestValue(field string) (string, rpc.ErrorCode) {
	msg, rpcerr := z.cp3000ReqRep(z.commandTimeout, cp3000.CommandRetrieve, field)
	if rpcerr != rpc.Ok {
		z.dev.Logger().WithField("field", field).Error("cannot get field")
		return "", rpcerr
	}
	if msg.Command != "00" {
		z.dev.Logger().WithField("cp3000-code", msg.Command).Error("cp3000 error")
		return "", rpc.EBackendCp3000CommError
	}
	return msg.Params[0], rpc.Ok
}

func (z *Base) requestVersion(field string) (string, rpc.ErrorCode) {
	return z.requestValue(fmt.Sprintf("VERSION[%s]", field))
}

func (z *Base) updateError(active bool, errDescription string, rpcErr rpc.ErrorCode) bool {
	var changed bool
	if active {
		changed = z.dev.SetError(rpcErr)
	} else {
		changed = z.dev.ClearError(rpcErr)
	}
	if changed {
		z.dev.Logger().WithFields(dilog.Fields{
			"active": active,
			"error":  errDescription,
		}).Info("reported error")
	}
	return changed
}

// heartbeatCmd is the Watchdog callback (used as heartbeat)
// Suppress the linter because heartbeatCmd needs to satisfy the interface
//nolint: unparam
func (z *Base) heartbeatCmd(r cp3000.Router, args []string) error {
	if err := z.dev.SendDeviceData(); err != nil {
		return err
	}
	return z.client.Send("WD")
}

func (z *Base) syncCmd(r cp3000.Router, args []string) error {
	return nil
}

func (z *Base) exitCmd(r cp3000.Router, args []string) error {
	return errors.New("exiting connection")
}

// UID returns the device UID of this device
func (z *Base) UID() string {
	return z.uid
}

// Type returns the device type of this device
func (z *Base) Type() rpc.DeviceType {
	return z.devType
}

// Close unregisters the connection from SMP
func (z *Base) Close() error {
	z.dev.Logger().Debug("close device")
	if z.client != nil {
		z.client.RemoveDevice(z.UID())
		if err := z.client.Close(); err != nil {
			return err
		}
	}

	if err := z.dev.Close(); err != nil {
		return err
	}

	return nil
}

// configSetEndpoint request
func (z *Base) configSetEndpoint(p rpc.ConfigParam) rpc.ErrorCode {
	s, ok := p.Value.(string)
	if !ok {
		return rpc.EParam
	}
	if err := z.client.Send(cp3000.CommandStore, "DBSERVER", s); err != nil {
		z.dev.Logger().WithError(err).Warning("setting tcpserver failed")
		return rpc.EBackendCp3000CommError
	}
	srv, errcode := z.requestValue("DBSERVER")
	if errcode != rpc.Ok {
		return errcode
	}
	if srv != s {
		z.dev.Logger().WithField("current", srv).Warning("tcpserver verification failed")
		return rpc.EBackendCp3000CommError
	}
	// todo: reset the device
	return rpc.Ok
}

func (z *Base) configGetEndpoint(rep *rpc.Msg) *rpc.Msg {
	srv, err := z.requestValue("DBSERVER")
	if err != rpc.Ok {
		return rep.SetError(err)
	}
	rep.Result = rpc.NewResult([]*rpc.ResultConfigValueItem{rpc.ConfigEndpoint.Data(srv)})
	return rep
}

func (z *Base) cp3000Transport() (interface{}, rpc.ErrorCode) {
	var cp3000Info rpc.ConnectionInfoCP3000
	var rpcerr rpc.ErrorCode
	cp3000Info.DatabaseID = z.databaseID
	if cp3000Info.Imsi, rpcerr = z.requestVersion("IMSI"); rpcerr != rpc.Ok {
		return nil, rpcerr
	}
	if cp3000Info.Iccid, rpcerr = z.requestVersion("SIM"); rpcerr != rpc.Ok {
		return nil, rpcerr
	}
	if cp3000Info.Imei, rpcerr = z.requestVersion("IMEI"); rpcerr != rpc.Ok {
		return nil, rpcerr
	}
	if cp3000Info.Endpoint, rpcerr = z.requestValue("DBSERVER"); rpcerr != rpc.Ok {
		return nil, rpcerr
	}
	if cp3000Info.GPRSApn, rpcerr = z.requestValue("GPRS"); rpcerr != rpc.Ok {
		return nil, rpcerr
	}
	return &cp3000Info, rpc.Ok
}