connector: fix UserLogin lifecycle during provisioning

Bridge provisioning would crash because we wouldn't thread the necessary
database models through.

pkg/connector/client.go

@@ -37,6 +37,7 @@ type DiscordClient struct {
 	usersFromReady  map[string]*discordgo.User
 	UserLogin       *bridgev2.UserLogin
 	Session         *discordgo.Session
+	hasBegunSyncing bool
 }
 
 func (d *DiscordConnector) LoadUserLogin(ctx context.Context, login *bridgev2.UserLogin) error {
@@ -116,23 +117,6 @@ func (cl *DiscordClient) connect(ctx context.Context) error {
 	user := cl.Session.State.User
 	log.Info().Str("user_id", user.ID).Str("user_username", user.Username).Msg("Connected to Discord")
 
-	if cl.UserLogin != nil {
-		// Feels a bit hacky to check for this here, but it should be true when
-		// logging in initially. The UserLogin is only ever created if we know
-		// that we connected successfully. We _do_ know that by now here, but we're
-		// not tasked with creating the UserLogin; the login code is. Alas.
-
-		// FIXME(skip): Avatar.
-		cl.UserLogin.RemoteProfile = status.RemoteProfile{
-			Email: user.Email,
-			Phone: user.Phone,
-			Name:  user.String(),
-		}
-		if err := cl.UserLogin.Save(ctx); err != nil {
-			log.Err(err).Msg("Couldn't save UserLogin after connecting")
-		}
-	}
-
 	// Stash all of the users we received in READY so we can perform quick lookups
 	// keyed by user ID.
 	cl.usersFromReady = make(map[string]*discordgo.User)
@@ -140,7 +124,11 @@ func (cl *DiscordClient) connect(ctx context.Context) error {
 		cl.usersFromReady[user.ID] = user
 	}
 
-	go cl.syncChannels(ctx)
+	// We won't have a UserLogin during provisioning, because the UserLogin can
+	// only be properly constructed once we know what the Discord user ID is
+	// (i.e. we have returned from this function). Thus, rely on the login
+	// process calling this method manually.
+	cl.BeginSyncingIfUserLoginPresent(ctx)
 
 	return nil
 }
@@ -160,6 +148,33 @@ func (d *DiscordClient) LogoutRemote(ctx context.Context) {
 	d.Disconnect()
 }
 
+func (cl *DiscordClient) BeginSyncingIfUserLoginPresent(ctx context.Context) {
+	if cl.UserLogin == nil {
+		cl.connector.bridge.Log.Warn().Msg("Not syncing just yet as we don't have a UserLogin")
+		return
+	}
+	if cl.hasBegunSyncing {
+		cl.connector.bridge.Log.Warn().Msg("Not beginning sync more than once")
+		return
+	}
+	cl.hasBegunSyncing = true
+
+	log := cl.UserLogin.Log
+	user := cl.Session.State.User
+
+	// FIXME(skip): Avatar.
+	cl.UserLogin.RemoteProfile = status.RemoteProfile{
+		Email: user.Email,
+		Phone: user.Phone,
+		Name:  user.String(),
+	}
+	if err := cl.UserLogin.Save(ctx); err != nil {
+		log.Err(err).Msg("Couldn't save UserLogin after connecting")
+	}
+
+	go cl.syncChannels(ctx)
+}
+
 func (d *DiscordClient) syncChannels(ctx context.Context) {
 	for _, dm := range d.Session.State.PrivateChannels {
 		d.UserLogin.Log.Debug().Str("channel_id", dm.ID).Msg("Syncing private channel")

pkg/connector/login.go

@@ -48,10 +48,11 @@ func (d *DiscordConnector) CreateLogin(ctx context.Context, user *bridgev2.User,
 		return nil, fmt.Errorf("unknown login flow ID")
 	}
 
-	return &DiscordLogin{User: user}, nil
+	return &DiscordLogin{connector: d, User: user}, nil
 }
 
 type DiscordLogin struct {
+	connector *DiscordConnector
 	User      *bridgev2.User
 	Token     string
 	Session   *discordgo.Session
@@ -104,6 +105,7 @@ func (dl *DiscordLogin) SubmitUserInput(ctx context.Context, input map[string]st
 	}
 
 	client := DiscordClient{
+		connector: dl.connector,
 		Session:   session,
 	}
 	err = client.connect(ctx)
@@ -123,9 +125,14 @@ func (dl *DiscordLogin) SubmitUserInput(ctx context.Context, input map[string]st
 			HeartbeatSession: session.HeartbeatSession,
 		},
 	}, &bridgev2.NewLoginParams{
-		// We already have a Session; call this instead of the connector's main LoadUserLogin method and thread the Session through.
+		// We already have a Session; let's call this instead of the connector's
+		// main LoadUserLogin method, and thread the Session through.
 		LoadUserLogin: func(ctx context.Context, login *bridgev2.UserLogin) error {
 			login.Client = &client
+			client.UserLogin = login
+
+			// Only now that we have a UserLogin can we begin syncing.
+			client.BeginSyncingIfUserLoginPresent(ctx)
 			return nil
 		},
 		DeleteOnConflict:  true,