cloud-services/pkg/tmobile/wrapper.go

package tmobile

import (
	"context"
	"time"

	"github.com/fiskerinc/cloud-services/pkg/grpc/sms"
	"github.com/fiskerinc/cloud-services/pkg/kafka"
	"github.com/fiskerinc/cloud-services/pkg/logger"
	"github.com/pkg/errors"
)

// I want to move the check sms loop into a less thread intensive action
// This is done in the following way
// Have a single/limit a couple look at all the messages we need to see if they are successfully sent
// If they are successfully sent then we notify something else that will properly return the status

// Currently the return is going to be the hardest part
// Wrapper wraps the client with an auto-refresh and auth-token retry.

type SMSClientWrapper interface {
	Start(ctx context.Context)
	SendSMS(ctx context.Context, req *SendSMSRequest) (out *SMSDetailsResponse, err error)
	SendSMSQueue(ctx context.Context, req *SendSMSRequest) (out *SMSQueueResponse, err error)
	HandleChangeRatePlan(context.Context, *ChangeRatePlanRequest) (*ChangeRatePlanResponse, error)
	HandleCustomAttributes(context.Context, *CustomAtributesRequest) (*CustomAtributesResponse, error)
	HandleGetProducts(context.Context, *sms.GetAvailableProductsRequest) (*sms.GetAvailableProductsResponse, error)
	HandleDeviceDetails(context.Context, *DeviceDetailsRequest) (*DeviceDetailsResponse, error)
	HandleChangeDeviceStatus(ctx context.Context, cda ChangeDeviceActivation) (err error)
}

type SMSClient struct {
	client TMobClienter
	queue  *RunningQueue
}


func NewSMSClient(client TMobClienter, kafkaProducer kafka.ProducerInterface) *SMSClient {
	nc := &SMSClient{
		client: client,
	}
	nc.queue = NewQueue(client, kafkaProducer)
	return nc
}

func (w *SMSClient) Start(ctx context.Context) {
}

// If the SMS is not delivered, out will be null, and this will need to be checked
func (w *SMSClient) SendSMS(ctx context.Context, req *SendSMSRequest) (out *SMSDetailsResponse, err error) {
	logger.Debug().Msgf("Sending SMS: %+v", req)

	var smr *SendSMSResponse

	// Giving 3 tries for a gateway failure
	for x := 0; x < 3; x++ {
		smr, err = w.client.SendSMS(ctx, req)
		if err != nil {
			if errors.Is(err, ErrBadGatewayCode) {
				logger.Warn().Err(err).Msgf("ICCID %s gateway failure sending sms", req.ICCID)
				time.Sleep(time.Millisecond * 300) // 300 milliseconds seems to work best for me
				continue
			}
			if errors.Is(err, ErrAccessTokenExpired) {
				logger.Err(err).Msgf("Access token for sms expired, should never happen")
			}
			return nil, errors.WithMessagef(err, "failed to send SMS to ICCID: %s", req.ICCID)
		}
		break
	}

	if smr == nil {
		return nil, errors.WithMessagef(err, "failed to send SMS to ICCID: %s", req.ICCID)
	}

	expDur := time.Second * 5
	logger.Debug().Msgf("SMS sent, expires in %d ms, id: %s  currently %d", expDur.Milliseconds(), smr.SmsMessageID, time.Now().UnixMilli())

	waitTill := time.After(expDur)
	checkTimer := time.NewTicker(time.Millisecond * 300)
	for {
		select {
		case <-waitTill:
			logger.Debug().Msgf("SMS with id %s not delivered after %d ms currently %d", smr.SmsMessageID, expDur.Milliseconds(), time.Now().UnixMilli())
			return nil, ErrTimeoutSendingMessage // Lots of messages seem to hit here
		case <-checkTimer.C:
			// Doing the wait before the first check, increases the chance of a first check success
			out, err = w.client.Details(ctx, smr.SmsMessageID)
			if err != nil {
				// Ignoring and retrying a bad gateway request
				if errors.Is(err, ErrBadGatewayCode) {
					logger.Warn().Err(err).Msgf("Bad gateway request from t-mobileICCID %s, Message ID: %s", req.ICCID, smr.SmsMessageID)
					continue
				}
				// If we get this error, t-mobile has rejected our details request
				logger.Err(err).Msgf("failed to get sms details with smsMsgID: %s to ICCID: %s", smr.SmsMessageID, req.ICCID)
				return nil, errors.WithMessagef(err, "failed to get sms details with smsMsgID: %s to ICCID: %s", smr.SmsMessageID, req.ICCID)
			}

			if !req.await {
				return out, nil
			}

			switch out.Status {
			case Pending, CancelPending:
				logger.Debug().Msgf("MSG %s had Pending Status", smr.SmsMessageID)
				continue
			case Delivered:
				return out, nil
			default:
				logger.Warn().Msgf("Fell through to default of sms status id: %s status: %s", smr.SmsMessageID, out.Status)
				return out, errors.WithMessagef(
					ErrBadMsgStatus,
					"message with id %s failed with status %s",
					out.SmsMsgID,
					out.Status,
				)
			}
		}
	}
}

func (w *SMSClient) SendSMSQueue(ctx context.Context, req *SendSMSRequest) (out *SMSQueueResponse, err error) {
	msgID, err := w.queue.SendSMS(ctx, req)
	out = &SMSQueueResponse{}
	out.SmsMsgID = msgID
	out.SentSuccessful = err == nil
	return
}

func (w *SMSClient) HandleChangeRatePlan(ctx context.Context, req *ChangeRatePlanRequest) (*ChangeRatePlanResponse, error) {
	return w.client.ChangeRatePlan(ctx, req)
}

func (w *SMSClient) HandleCustomAttributes(ctx context.Context, req *CustomAtributesRequest) (*CustomAtributesResponse, error) {
	return w.client.CustomAttributes(ctx, req)
}

func (w *SMSClient) HandleGetProducts(ctx context.Context, req *sms.GetAvailableProductsRequest) (*sms.GetAvailableProductsResponse, error) {
	return w.client.GetProducts(ctx, req)
}

func (w *SMSClient) HandleDeviceDetails(ctx context.Context, req *DeviceDetailsRequest) (*DeviceDetailsResponse, error) {
	return w.client.DeviceDetails(ctx, req)
}

func (w *SMSClient) HandleChangeDeviceStatus(ctx context.Context, cda ChangeDeviceActivation) (err error) {
	return w.client.ChangeDeviceStatus(ctx, cda)
}