MatrixRTC MembershipManger: remove redundant sendDelayedEventAction and expose status (#4747)

* Remove redundant sendDelayedEventAction
We do already have the state `hasMemberEvent` that allows to distinguish the two cases. No need to create two dedicated actions.

* fix missing return

* Make membership manager an event emitter to inform about status updates.
 - deprecate isJoined (replaced by isActivated)
 - move Interface types to types.ts

* add tests for status updates.

* lint

* test "reschedules delayed leave event" in case the delayed event gets canceled

* review

* fix types

* prettier

* fix legacy membership manager

src/matrixrtc/types.ts

@@ -13,7 +13,10 @@ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 */
-import { type IMentions } from "../matrix.ts";
+import type { IMentions } from "../matrix.ts";
+import type { CallMembership } from "./CallMembership.ts";
+import type { Focus } from "./focus.ts";
+
 export interface EncryptionKeyEntry {
     index: number;
     key: string;
@@ -34,3 +37,83 @@ export interface ICallNotifyContent {
     "notify_type": CallNotifyType;
     "call_id": string;
 }
+
+export enum Status {
+    Disconnected = "Disconnected",
+    Connecting = "Connecting",
+    ConnectingFailed = "ConnectingFailed",
+    Connected = "Connected",
+    Reconnecting = "Reconnecting",
+    Disconnecting = "Disconnecting",
+    Stuck = "Stuck",
+    Unknown = "Unknown",
+}
+
+export enum MembershipManagerEvent {
+    StatusChanged = "StatusChanged",
+}
+
+export type MembershipManagerEventHandlerMap = {
+    [MembershipManagerEvent.StatusChanged]: (prefStatus: Status, newStatus: Status) => void;
+};
+
+/**
+ * This interface defines what a MembershipManager uses and exposes.
+ * This interface is what we use to write tests and allows changing the actual implementation
+ * without breaking tests because of some internal method renaming.
+ *
+ * @internal
+ */
+export interface IMembershipManager {
+    /**
+     * If we are trying to join, or have successfully joined the session.
+     * It does not reflect if the room state is already configured to represent us being joined.
+     * It only means that the Manager should be trying to connect or to disconnect running.
+     * The Manager is still running right after isJoined becomes false to send the disconnect events.
+     * @returns true if we intend to be participating in the MatrixRTC session
+     * @deprecated This name is confusing and replaced by `isActivated()`. (Returns the same as `isActivated()`)
+     */
+    isJoined(): boolean;
+    /**
+     * If the manager is activated. This means it tries to do its job to join the call, resend state events...
+     * It does not imply that the room state is already configured to represent being joined.
+     * It means that the Manager tries to connect or is connected. ("the manager is still active")
+     * Once `leave()` is called the manager is not activated anymore but still running until `leave()` resolves.
+     * @returns `true` if we intend to be participating in the MatrixRTC session
+     */
+    isActivated(): boolean;
+    /**
+     * Get the actual connection status of the manager.
+     */
+    get status(): Status;
+    /**
+     * The current status while the manager is activated
+     */
+    /**
+     * Start sending all necessary events to make this user participate in the RTC session.
+     * @param fociPreferred the list of preferred foci to use in the joined RTC membership event.
+     * @param fociActive the active focus to use in the joined RTC membership event.
+     * @throws can throw if it exceeds a configured maximum retry.
+     */
+    join(fociPreferred: Focus[], fociActive?: Focus, onError?: (error: unknown) => void): void;
+    /**
+     * Send all necessary events to make this user leave the RTC session.
+     * @param timeout the maximum duration in ms until the promise is forced to resolve.
+     * @returns It resolves with true in case the leave was sent successfully.
+     * It resolves with false in case we hit the timeout before sending successfully.
+     */
+    leave(timeout?: number): Promise<boolean>;
+    /**
+     * Call this if the MatrixRTC session members have changed.
+     */
+    onRTCSessionMemberUpdate(memberships: CallMembership[]): Promise<void>;
+    /**
+     * The used active focus in the currently joined session.
+     * @returns the used active focus in the currently joined session or undefined if not joined.
+     */
+    getActiveFocus(): Focus | undefined;
+
+    // TypedEventEmitter methods:
+    on(event: MembershipManagerEvent.StatusChanged, listener: (oldStatus: Status, newStatus: Status) => void): this;
+    off(event: MembershipManagerEvent.StatusChanged, listener: (oldStatus: Status, newStatus: Status) => void): this;
+}