import { describe, expect, test } from "bun:test";
import * as Y from "yjs";
import { getOrCreateSession, Session } from "./session";

describe("Session", () => {
  test("creates yjs doc on init", () => {
    const session = new Session("test-room");
    expect(session.doc).toBeInstanceOf(Y.Doc);
    expect(session.name).toBe("test-room");
  });

  test("tracks clients", () => {
    const session = new Session("test-room");
    const mockWs = {
      send: () => {},
      data: { room: null as string | null },
    } as unknown as import("bun").ServerWebSocket<{ room: string | null }>;
    const client = { ws: mockWs };

    expect(session.clients.size).toBe(0);
    session.join(client);
    expect(session.clients.size).toBe(1);
    session.leave(client);
    expect(session.clients.size).toBe(0);
  });

  test("applies yjs updates", () => {
    const session = new Session("test-room");
    const text = session.doc.getText("content");

    // simulate a remote update
    const remoteDoc = new Y.Doc();
    const remoteText = remoteDoc.getText("content");
    remoteText.insert(0, "hello");
    const update = Y.encodeStateAsUpdate(remoteDoc);

    const mockWs = {
      send: () => {},
      data: { room: null as string | null },
    } as unknown as import("bun").ServerWebSocket<{ room: string | null }>;
    session.applyUpdate(update, { ws: mockWs });

    expect(text.toString()).toBe("hello");
  });
});

describe("getOrCreateSession", () => {
  test("returns same session for same room", () => {
    const s1 = getOrCreateSession("room-a");
    const s2 = getOrCreateSession("room-a");
    expect(s1).toBe(s2);
  });

  test("returns different sessions for different rooms", () => {
    const s1 = getOrCreateSession("room-x");
    const s2 = getOrCreateSession("room-y");
    expect(s1).not.toBe(s2);
  });
});