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/tgtest/cluster/cluster.go

@@ -0,0 +1,96 @@
+// Package cluster contains Telegram multi-DC setup utilities.
+package cluster
+
+import (
+	"io"
+
+	"go.uber.org/zap"
+
+	"go.mau.fi/mautrix-telegram/pkg/gotd/exchange"
+	"go.mau.fi/mautrix-telegram/pkg/gotd/tdsync"
+	"go.mau.fi/mautrix-telegram/pkg/gotd/telegram/dcs"
+	"go.mau.fi/mautrix-telegram/pkg/gotd/tg"
+	"go.mau.fi/mautrix-telegram/pkg/gotd/tgtest"
+	"go.mau.fi/mautrix-telegram/pkg/gotd/tgtest/services/config"
+)
+
+type setup struct {
+	srv      *tgtest.Server
+	dispatch *tgtest.Dispatcher
+}
+
+// Cluster is a cluster of multiple servers, representing multiple Telegram datacenters.
+type Cluster struct {
+	// denotes to use websocket listener
+	web bool
+
+	setups map[int]setup
+	keys   []exchange.PublicKey
+
+	// DCs config state.
+	cfg     tg.Config
+	cdnCfg  tg.CDNConfig
+	domains map[int]string
+
+	// Signal for readiness.
+	ready *tdsync.Ready
+
+	// RPC dispatcher.
+	common *tgtest.Dispatcher
+
+	log      *zap.Logger
+	random   io.Reader
+	protocol dcs.Protocol
+}
+
+// NewCluster creates new server Cluster.
+func NewCluster(opts Options) *Cluster {
+	opts.setDefaults()
+
+	q := &Cluster{
+		web:      opts.Web,
+		setups:   map[int]setup{},
+		keys:     nil,
+		cfg:      opts.Config,
+		cdnCfg:   opts.CDNConfig,
+		domains:  map[int]string{},
+		ready:    tdsync.NewReady(),
+		common:   tgtest.NewDispatcher(),
+		log:      opts.Logger,
+		random:   opts.Random,
+		protocol: opts.Protocol,
+	}
+	config.NewService(&q.cfg, &q.cdnCfg).Register(q.common)
+	q.common.Fallback(q.fallback())
+
+	return q
+}
+
+// List returns DCs list.
+func (c *Cluster) List() dcs.List {
+	return dcs.List{
+		Options: c.cfg.DCOptions,
+		Domains: c.domains,
+	}
+}
+
+// Resolver returns dcs.Resolver to use.
+func (c *Cluster) Resolver() dcs.Resolver {
+	if c.web {
+		return dcs.Websocket(dcs.WebsocketOptions{})
+	}
+
+	return dcs.Plain(dcs.PlainOptions{
+		Protocol: c.protocol,
+	})
+}
+
+// Keys returns all servers public keys.
+func (c *Cluster) Keys() []exchange.PublicKey {
+	return c.keys
+}
+
+// Ready returns signal channel to await readiness.
+func (c *Cluster) Ready() <-chan struct{} {
+	return c.ready.Ready()
+}