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/dcs/find_test.go

@@ -0,0 +1,76 @@
+package dcs
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"go.mau.fi/mautrix-telegram/pkg/gotd/tg"
+)
+
+func TestFindDCs(t *testing.T) {
+	dcOptions := []tg.DCOption{
+		{ID: 1, Ipv6: false},
+		{ID: 1, Ipv6: true},
+		{ID: 1, Ipv6: false, Static: true},
+
+		{ID: 2, Ipv6: true, Static: true},
+		{ID: 2, Ipv6: true},
+		{ID: 2, Ipv6: false},
+	}
+	for i := range dcOptions {
+		dcOptions[i].IPAddress = fmt.Sprintf("DC: %d, Index: %d", dcOptions[i].ID, i)
+	}
+
+	a := require.New(t)
+	dc := FindDCs(dcOptions, -2, false)
+	a.Empty(dc)
+	dc = FindDCs(dcOptions, -2, true)
+	a.Empty(dc)
+
+	// Prefer IPv6.
+	dc = FindDCs(dcOptions, 1, true)
+	a.True(dc[0].Ipv6)
+
+	// Prefer static.
+	dc = FindDCs(dcOptions, 1, false)
+	a.True(dc[0].Static)
+
+	// Prefer static and IPv6.
+	dc = FindDCs(dcOptions, 2, true)
+	a.True(dc[0].Static)
+	a.True(dc[0].Ipv6)
+}
+
+func TestFindPrimaryDCs(t *testing.T) {
+	dcOptions := []tg.DCOption{
+		{ID: 1, Ipv6: false},
+		{ID: 1, Ipv6: true},
+		{ID: 1, Ipv6: false, Static: true},
+
+		{ID: 2, Ipv6: true, Static: true, MediaOnly: true},
+		{ID: 2, Ipv6: true, CDN: true},
+		{ID: 2, Ipv6: false, CDN: true},
+	}
+	for i := range dcOptions {
+		dcOptions[i].IPAddress = fmt.Sprintf("DC: %d, Index: %d", dcOptions[i].ID, i)
+	}
+	a := require.New(t)
+	dc := FindPrimaryDCs(dcOptions, -2, false)
+	a.Empty(dc)
+	dc = FindPrimaryDCs(dcOptions, -2, true)
+	a.Empty(dc)
+
+	// Prefer IPv6.
+	dc = FindPrimaryDCs(dcOptions, 1, true)
+	a.True(dc[0].Ipv6)
+
+	// Prefer static.
+	dc = FindPrimaryDCs(dcOptions, 1, false)
+	a.True(dc[0].Static)
+
+	// Filter CDN/MediaOnly/TCPo.
+	dc = FindPrimaryDCs(dcOptions, 2, false)
+	a.Empty(dc)
+}