Send events to appservice based on room membership (#1680)

* Check membership of room

* Use QueryStateAfterEventsResponse

* Fix complexity

* Changes that I made a long time ago

* Rename to appserviceJoinedAtEvent

* Check membership in GetMemberships

* Update QueryMembershipsForRoom

* Tweaks in client API

* Update appserviceJoinedAtEvent

* Comments

* Try QueryMembershipForUser instead

* Undo some changes to client API that shouldn't be needed

* More /event tweaks

* Refactor /event bit

* Go back to QueryMembershipsForRoom because appservices are hard

* Fix bugs in onMessage

* Add comments

Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>

userapi/api/api.go

@@ -241,6 +241,9 @@ type Device struct {
 	LastSeenTS  int64
 	LastSeenIP  string
 	UserAgent   string
+	// If the device is for an appservice user,
+	// this is the appservice ID.
+	AppserviceID string
 }
 
 // Account represents a Matrix account on this home server.

userapi/internal/api.go

@@ -381,7 +381,8 @@ func (a *UserInternalAPI) queryAppServiceToken(ctx context.Context, token, appSe
 		// Use AS dummy device ID
 		ID: types.AppServiceDeviceID,
 		// AS dummy device has AS's token.
-		AccessToken: token,
+		AccessToken:  token,
+		AppserviceID: appService.ID,
 	}
 
 	localpart, err := userutil.ParseUsernameParam(appServiceUserID, &a.ServerName)