feat: add user client

userclient/middlewares/middlewares.go

@@ -0,0 +1,29 @@
+package middlewares
+
+import (
+	"context"
+	"time"
+
+	"github.com/cenkalti/backoff/v4"
+	"github.com/gotd/contrib/middleware/floodwait"
+	"github.com/gotd/td/telegram"
+	"github.com/krau/SaveAny-Bot/userclient/middlewares/recovery"
+	"github.com/krau/SaveAny-Bot/userclient/middlewares/retry"
+)
+
+func NewDefaultMiddlewares(ctx context.Context, timeout time.Duration) []telegram.Middleware {
+	return []telegram.Middleware{
+		recovery.New(ctx, newBackoff(timeout)),
+		retry.New(5),
+		floodwait.NewSimpleWaiter(),
+	}
+}
+
+func newBackoff(timeout time.Duration) backoff.BackOff {
+	b := backoff.NewExponentialBackOff()
+
+	b.Multiplier = 1.1
+	b.MaxElapsedTime = timeout
+	b.MaxInterval = 10 * time.Second
+	return b
+}

userclient/middlewares/recovery/recovery.go

@@ -0,0 +1,61 @@
+package recovery
+
+import (
+	"context"
+	"time"
+
+	"github.com/cenkalti/backoff/v4"
+	"github.com/go-faster/errors"
+	"github.com/gotd/td/bin"
+	"github.com/gotd/td/telegram"
+	"github.com/gotd/td/tg"
+	"github.com/gotd/td/tgerr"
+	"github.com/krau/SaveAny-Bot/common"
+)
+
+type recovery struct {
+	ctx     context.Context
+	backoff backoff.BackOff
+}
+
+func New(ctx context.Context, backoff backoff.BackOff) telegram.Middleware {
+	return &recovery{
+		ctx:     ctx,
+		backoff: backoff,
+	}
+}
+
+func (r *recovery) Handle(next tg.Invoker) telegram.InvokeFunc {
+	return func(ctx context.Context, input bin.Encoder, output bin.Decoder) error {
+
+		return backoff.RetryNotify(func() error {
+			if err := next.Invoke(ctx, input, output); err != nil {
+				if r.shouldRecover(ctx, err) {
+					return errors.Wrap(err, "recover")
+				}
+
+				return backoff.Permanent(err)
+			}
+
+			return nil
+		}, r.backoff, func(err error, duration time.Duration) {
+			common.Log.Debug("Wait for connection recovery", "error", err, "duration", duration)
+		})
+	}
+}
+
+func (r *recovery) shouldRecover(ctx context.Context, err error) bool {
+	// context in recovery is used to stop recovery process by external os signal, otherwise we will wait till max retries when user press ctrl+c
+	select {
+	case <-r.ctx.Done():
+		return false
+	case <-ctx.Done():
+		return false
+	default:
+	}
+
+	// we try recover when encountered any error that is not telegram business error
+	_, ok := tgerr.As(err)
+
+	return !ok
+}

userclient/middlewares/retry/retry.go

@@ -0,0 +1,56 @@
+package retry
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/go-faster/errors"
+	"github.com/gotd/td/bin"
+	"github.com/gotd/td/telegram"
+	"github.com/gotd/td/tg"
+	"github.com/gotd/td/tgerr"
+	"github.com/krau/SaveAny-Bot/common"
+)
+
+var internalErrors = []string{
+	"Timedout", // #373
+	"No workers running",
+	"RPC_CALL_FAIL",
+	"RPC_MCGET_FAIL",
+	"WORKER_BUSY_TOO_LONG_RETRY", // #462
+	"memory limit exit",          // #504
+}
+
+type retry struct {
+	max    int
+	errors []string
+}
+
+func (r retry) Handle(next tg.Invoker) telegram.InvokeFunc {
+	return func(ctx context.Context, input bin.Encoder, output bin.Decoder) error {
+		retries := 0
+
+		for retries < r.max {
+			if err := next.Invoke(ctx, input, output); err != nil {
+				if tgerr.Is(err, r.errors...) {
+					common.Log.Debug("retry middleware", "retries", retries, "error", err)
+					retries++
+					continue
+				}
+				return errors.Wrap(err, "retry middleware skip")
+			}
+
+			return nil
+		}
+
+		return fmt.Errorf("retry limit reached after %d attempts", r.max)
+	}
+}
+
+// New returns middleware that retries request if it fails with one of provided errors.
+func New(max int, errors ...string) telegram.Middleware {
+	return retry{
+		max:    max,
+		errors: append(errors, internalErrors...), // #373
+	}
+}