Move telegram to separate module

telegram/telegram.go

@@ -0,0 +1,38 @@
+package telegram
+
+import (
+	"io"
+	"math/rand"
+
+	"github.com/juju/errors"
+)
+
+type Telegram interface {
+	Dial(int16) (io.ReadWriteCloser, error)
+	Init(io.ReadWriteCloser) (io.ReadWriteCloser, error)
+}
+
+type baseTelegram struct {
+	dialer *tgDialer
+
+	v4Addresses map[int16][]string
+	v6Addresses map[int16][]string
+}
+
+func (b *baseTelegram) Dial(dcIdx int16) (io.ReadWriteCloser, error) {
+	addrs := make([]string, 2)
+	if addr, ok := b.v6Addresses[dcIdx]; ok && len(addr) > 0 {
+		addrs = append(addrs, addr[rand.Intn(len(addr))])
+	}
+	if addr, ok := b.v4Addresses[dcIdx]; ok && len(addr) > 0 {
+		addrs = append(addrs, addr[rand.Intn(len(addr))])
+	}
+
+	for _, addr := range addrs {
+		if conn, err := b.dialer.dialRWC(addr); err == nil {
+			return conn, err
+		}
+	}
+
+	return nil, errors.New("Cannot connect to Telegram")
+}