import EventEmitter from "../src/shared/EventEmitter";

class TestEmitter extends EventEmitter {
  public dispatch(event: string, detail?: unknown) {
    this.emit(event, detail);
  }
}

describe("shared EventEmitter", () => {
  it("reports listenerCount per event", () => {
    const emitter = new TestEmitter();
    const listenerA1 = jest.fn();
    const listenerA2 = jest.fn();
    const listenerB = jest.fn();

    emitter.on("event:a", listenerA1);
    emitter.on("event:a", listenerA2);
    emitter.on("event:b", listenerB);

    expect(emitter.listenerCount("event:a")).toBe(2);
    expect(emitter.listenerCount("event:b")).toBe(1);
    expect(emitter.listenerCount("event:missing")).toBe(0);

    emitter.off("event:a", listenerA1);
    expect(emitter.listenerCount("event:a")).toBe(1);

    emitter.removeAllListeners("event:a");
    expect(emitter.listenerCount("event:a")).toBe(0);
    expect(emitter.listenerCount("event:b")).toBe(1);
  });

  it("decrements listenerCount for once listeners after first emit", () => {
    const emitter = new TestEmitter();
    const listener = jest.fn();

    emitter.once("event:once", listener);
    expect(emitter.listenerCount("event:once")).toBe(1);

    emitter.dispatch("event:once", { ok: true });

    expect(listener).toHaveBeenCalledWith({ ok: true });
    expect(emitter.listenerCount("event:once")).toBe(0);
  });
});