sorare/subscriptions/wsscheduler.go

package subscriptions

import (
	"context"
	"math/rand"
	"time"

	"github.com/pkg/errors"
)

const (
	minDurationSeconds = 3600
	maxDurationSeconds = 5400
	sleepDuration      = 10 * time.Second
	maxRetries         = 3
)

func scheduleWs[T any](
	ctx context.Context,
	subscriptionName string,
	subscriptionParams string,
	debug bool,
) (chan T, error) {
	res := make(chan T)
	go func() {
		defer close(res)
		duration := newRandomDuration(minDurationSeconds, maxDurationSeconds)
		t := time.NewTicker(duration)
		var ws *wsClient[T]
		ws, err := getNewWsClientWithRetry[T](
			ctx,
			subscriptionName,
			subscriptionParams,
			res,
			maxRetries,
			debug,
		)
		if err != nil {
			return
		}
		for {
			select {
			case <-ctx.Done():
				ws.Stop()
				<-ws.Done
				return

			case <-t.C:

				newws, err := getNewWsClientWithRetry[T](
					ctx,
					subscriptionName,
					subscriptionParams,
					res,
					maxRetries,
					debug,
				)
				if err != nil {
					return
				}
				time.Sleep(10 * time.Second)
				ws.Stop()
				ws = newws
			case <-ws.Done:

				newws, err := getNewWsClientWithRetry[T](
					ctx,
					subscriptionName,
					subscriptionParams,
					res,
					maxRetries,
					debug,
				)
				if err != nil {
					return
				}
				time.Sleep(10 * time.Second)
				ws.Stop()
				ws = newws
			}
		}
	}()
	return res, nil
}

func newRandomDuration(minseconds int, maxseconds int) time.Duration {
	return time.Duration(rand.Intn(maxseconds-minseconds)+minseconds) * time.Second
}

func getNewWsClientWithRetry[T any](
	ctx context.Context,
	subscriptionName string,
	subscriptionParams string,
	resultChan chan T,
	maxRetries int,
	debug bool,
) (*wsClient[T], error) {
	var ws *wsClient[T]
	var err error
	for i := 0; i < maxRetries; i++ {
		ws, err = newWsClient[T](ctx, subscriptionName, subscriptionParams, debug)
		if err == nil {
			break
		}
		time.Sleep(time.Duration(i+1) * sleepDuration)
	}
	if err != nil {
		return nil, errors.Wrap(err, "creating new websocket graphQlClient")
	}
	go func() {
		for data := range ws.Data {
			resultChan <- data
		}
	}()
	return ws, nil
}