Direct proxy works

_telegram/telegram.go

@@ -0,0 +1,68 @@
+package telegram
+
+import (
+	"context"
+	"math/rand"
+
+	"github.com/juju/errors"
+
+	"github.com/9seconds/mtg/mtproto"
+	"github.com/9seconds/mtg/wrappers"
+)
+
+// Telegram is an interface for different Telegram work modes.
+type Telegram interface {
+	Dial(context.Context, context.CancelFunc, string, *mtproto.ConnectionOpts) (wrappers.StreamReadWriteCloser, error)
+	Init(*mtproto.ConnectionOpts, wrappers.StreamReadWriteCloser) (wrappers.Wrap, error)
+}
+
+type baseTelegram struct {
+	dialer tgDialer
+
+	v4DefaultIdx int16
+	v6DefaultIdx int16
+	v4Addresses  map[int16][]string
+	v6Addresses  map[int16][]string
+}
+
+func (b *baseTelegram) dial(ctx context.Context, cancel context.CancelFunc, dcIdx int16, connID string,
+	proto mtproto.ConnectionProtocol) (wrappers.StreamReadWriteCloser, error) {
+	addrs := make([]string, 2)
+
+	if proto&mtproto.ConnectionProtocolIPv6 != 0 {
+		if addr := b.chooseAddress(b.v6Addresses, dcIdx, b.v6DefaultIdx); addr != "" {
+			addrs = append(addrs, addr)
+		}
+	}
+	if proto&mtproto.ConnectionProtocolIPv4 != 0 {
+		if addr := b.chooseAddress(b.v4Addresses, dcIdx, b.v4DefaultIdx); addr != "" {
+			addrs = append(addrs, addr)
+		}
+	}
+
+	for _, addr := range addrs {
+		if conn, err := b.dialer.dialRWC(ctx, cancel, addr, connID); err == nil {
+			return conn, err
+		}
+	}
+
+	return nil, errors.New("Cannot connect to Telegram")
+}
+
+func (b *baseTelegram) chooseAddress(addresses map[int16][]string, idx, defaultIdx int16) string {
+	if addr, ok := addresses[idx]; ok {
+		return b.chooseRandomAddress(addr)
+	} else if addr, ok := addresses[defaultIdx]; ok {
+		return b.chooseRandomAddress(addr)
+	}
+
+	return ""
+}
+
+func (b *baseTelegram) chooseRandomAddress(addresses []string) string {
+	if len(addresses) > 0 {
+		return addresses[rand.Intn(len(addresses))]
+	}
+
+	return ""
+}