move gotd fork into repo. (#111)

- update to latest telegram layer
- remove some references to fields in tg.Entities that don't exist in
the schema
- originally added here:
https://github.com/beeper/td/commit/820929062a2ba0104397bc01235ab58a9cff780e
  - referenced here
-
https://github.com/mautrix/telegramgo/commit/124f0967ed195b5a380c9bd02e170ada9710dde3
-
https://github.com/mautrix/telegramgo/commit/4205047aab2e0639217148b5d125bfaab668bd8e

pkg/gotd/telegram/auth/qrlogin/qrlogin.go

@@ -0,0 +1,175 @@
+// Package qrlogin provides QR login flow implementation.
+//
+// See https://core.telegram.org/api/qr-login.
+package qrlogin
+
+import (
+	"context"
+	"time"
+
+	"github.com/go-faster/errors"
+
+	"go.mau.fi/mautrix-telegram/pkg/gotd/clock"
+	"go.mau.fi/mautrix-telegram/pkg/gotd/tg"
+)
+
+// QR implements Telegram QR login flow.
+type QR struct {
+	api     *tg.Client
+	appID   int
+	appHash string
+	migrate func(ctx context.Context, dcID int) error
+	clock   clock.Clock
+}
+
+// NewQR creates new QR
+func NewQR(api *tg.Client, appID int, appHash string, opts Options) QR {
+	opts.setDefaults()
+	return QR{
+		api:     api,
+		appID:   appID,
+		appHash: appHash,
+		clock:   opts.Clock,
+		migrate: opts.Migrate,
+	}
+}
+
+// Export exports new login token.
+//
+// See https://core.telegram.org/api/qr-login#exporting-a-login-token.
+func (q QR) Export(ctx context.Context, exceptIDs ...int64) (Token, error) {
+	result, err := q.api.AuthExportLoginToken(ctx, &tg.AuthExportLoginTokenRequest{
+		APIID:     q.appID,
+		APIHash:   q.appHash,
+		ExceptIDs: exceptIDs,
+	})
+	if err != nil {
+		return Token{}, errors.Wrap(err, "export")
+	}
+
+	t, ok := result.(*tg.AuthLoginToken)
+	if !ok {
+		return Token{}, errors.Errorf("unexpected type %T", result)
+	}
+	return NewToken(t.Token, t.Expires), nil
+}
+
+// Accept accepts given token.
+//
+// See https://core.telegram.org/api/qr-login#accepting-a-login-token.
+func (q QR) Accept(ctx context.Context, t Token) (*tg.Authorization, error) {
+	return AcceptQR(ctx, q.api, t)
+}
+
+// Import imports accepted token.
+//
+// See https://core.telegram.org/api/qr-login#confirming-importing-the-login-token.
+func (q QR) Import(ctx context.Context) (*tg.AuthAuthorization, error) {
+	result, err := q.api.AuthExportLoginToken(ctx, &tg.AuthExportLoginTokenRequest{
+		APIID:   q.appID,
+		APIHash: q.appHash,
+	})
+	if err != nil {
+		return nil, errors.Wrap(err, "import")
+	}
+
+	switch t := result.(type) {
+	case *tg.AuthLoginTokenMigrateTo:
+		if q.migrate == nil {
+			return nil, &MigrationNeededError{
+				MigrateTo: t,
+			}
+		}
+		if err := q.migrate(ctx, t.DCID); err != nil {
+			return nil, errors.Wrap(err, "migrate")
+		}
+
+		res, err := q.api.AuthImportLoginToken(ctx, t.Token)
+		if err != nil {
+			return nil, errors.Wrap(err, "import")
+		}
+
+		success, ok := res.(*tg.AuthLoginTokenSuccess)
+		if !ok {
+			return nil, errors.Errorf("unexpected type %T", res)
+		}
+
+		auth, ok := success.Authorization.(*tg.AuthAuthorization)
+		if !ok {
+			return nil, errors.Errorf("unexpected type %T", success.Authorization)
+		}
+		return auth, nil
+	case *tg.AuthLoginTokenSuccess:
+		auth, ok := t.Authorization.(*tg.AuthAuthorization)
+		if !ok {
+			return nil, errors.Errorf("unexpected type %T", t.Authorization)
+		}
+		return auth, nil
+	default:
+		return nil, errors.Errorf("unexpected type %T", result)
+	}
+}
+
+// LoggedIn is signal channel to notify about tg.UpdateLoginToken.
+type LoggedIn <-chan struct{}
+
+// OnLoginToken sets handler for given dispatcher and returns signal channel.
+func OnLoginToken(d interface {
+	OnLoginToken(tg.LoginTokenHandler)
+},
+) LoggedIn {
+	loggedIn := make(chan struct{})
+	d.OnLoginToken(func(ctx context.Context, e tg.Entities, update *tg.UpdateLoginToken) error {
+		select {
+		case loggedIn <- struct{}{}:
+			return nil
+		default:
+		}
+		return nil
+	})
+	return loggedIn
+}
+
+// Auth generates new QR login token, shows it and awaits acceptation.
+//
+// NB: Show callback may be called more than once if QR expires.
+func (q QR) Auth(
+	ctx context.Context,
+	loggedIn LoggedIn,
+	show func(ctx context.Context, token Token) error,
+	exceptIDs ...int64,
+) (*tg.AuthAuthorization, error) {
+	until := func(token Token) time.Duration {
+		return token.Expires().Sub(q.clock.Now()).Truncate(time.Second)
+	}
+
+	token, err := q.Export(ctx, exceptIDs...)
+	if err != nil {
+		return nil, err
+	}
+	timer := q.clock.Timer(until(token))
+	defer clock.StopTimer(timer)
+
+	for {
+		if err := show(ctx, token); err != nil {
+			return nil, errors.Wrap(err, "show")
+		}
+
+		select {
+		case <-ctx.Done():
+			return nil, ctx.Err()
+		case <-timer.C():
+			t, err := q.Export(ctx, exceptIDs...)
+			if err != nil {
+				return nil, err
+			}
+			token = t
+			timer.Reset(until(token))
+
+			continue
+		case <-loggedIn:
+		}
+
+		return q.Import(ctx)
+	}
+}