import type { SelectionEventPayload } from "./services/selection";

export type KnownEventType =
  /**
   * TODO: Rename DataEvent with UIEXT-1791
   */
  | "DataEvent"
  | "SelectionEvent"
  | "ApplyDataEvent"
  | "DisplayModeEvent"
  | "DataValueViewShownEvent";

export interface DisplayModeEventPayload {
  mode: "small" | "large";
}

type KnownPushEvents = {
  SelectionEvent: SelectionEventPayload;
  DisplayModeEvent: DisplayModeEventPayload;
  DataEvent: unknown;
  ApplyDataEvent: undefined;
  DataValueViewShownEvent: boolean;
};

/**
 * For autocompletion
 */
export type EventType = KnownEventType | Omit<string, KnownEventType>;

type MakePayloadOptionalIfUndefined<
  T extends { eventType: unknown; payload: unknown },
> = T["payload"] extends undefined
  ? {
      eventType: T["eventType"];
      payload?: undefined; // NOSONAR
    }
  : T;

export type PushEvent<
  N extends EventType = EventType,
  P = unknown,
> = MakePayloadOptionalIfUndefined<{
  eventType: N;
  payload: N extends keyof KnownPushEvents ? KnownPushEvents[N] : P;
}>;

export type SelectionEvent = PushEvent<"SelectionEvent">;
export type DataEvent = PushEvent<"DataEvent">;
export type DisplayModeEvent = PushEvent<"DisplayModeEvent">;

export type PushEventListenerCallback<T extends EventType> = (
  payload: PushEvent<T>["payload"],
) => void;

export interface AddPushEventListener {
  /**
   * This method is to be used by the client ui extension to listen
   * for events dispatched by an embedder
   * @returns a method to remove the added listener
   */
  addPushEventListener<T extends EventType>(
    eventType: T,
    callback: PushEventListenerCallback<T>,
  ): () => void;
}

export interface DispatchPushEvent {
  /**
   * This method is to be used by the embedder of a ui extension to
   * trigger registered client event listeners.
   */
  dispatchPushEvent<T extends EventType>(event: PushEvent<T>): void;
}