import { expect } from 'chai';
import { Server, WebSocket } from 'mock-socket';
import type {Server as HttpServer} from 'node:http';
import { Realm } from '../../../src/models/realm';
import { WebSocketServer } from '../../../src/services/webSocketServer';
import { Errors, MessageType } from '../../../src/enums';
import { wait } from '../../utils';

type Destroyable<T> = T & { destroy?: () => Promise<void>; };

const checkOpen = async (c: WebSocket): Promise<boolean> => {
  return new Promise(resolve => {
    c.onmessage = (event: object & { data?: string; }): void => {
      const message = JSON.parse(event.data as string);
      resolve(message.type === MessageType.OPEN);
    };
  });
};

const checkSequence = async (c: WebSocket, msgs: { type: MessageType; error?: Errors; }[]): Promise<boolean> => {
  return new Promise(resolve => {
    const restMessages = [...msgs];

    const finish = (success = false): void => {
      resolve(success);
    };

    c.onmessage = (event: object & { data?: string; }): void => {
      const [mes] = restMessages;

      if (!mes) {
        return finish();
      }

      restMessages.shift();

      const message = JSON.parse(event.data as string);
      if (message.type !== mes.type) {
        return finish();
      }

      const isOk = !mes.error || message.payload?.msg === mes.error;

      if (!isOk) {
        return finish();
      }

      if (restMessages.length === 0) {
        finish(true);
      }
    };
  });
};

const createTestServer = ({ realm, config, url }: { realm: Realm; config: { path: string; key: string; concurrent_limit: number; }; url: string; }): Destroyable<WebSocketServer> => {
  const server = new Server(url) as Server & HttpServer;
  const webSocketServer: Destroyable<WebSocketServer> = new WebSocketServer({ server, realm, config });

  server.on('connection', (socket: WebSocket & { on?: (eventName: string, callback: () => void) => void; }) => {
    const s = webSocketServer.socketServer;
    s.emit('connection', socket, { url: socket.url });

    socket.onclose = (): void => {
      const userId = socket.url.split('?')[1]?.split('&').find(p => p.startsWith('id'))?.split('=')[1];

      if (!userId) return;

      const client = realm.getClientById(userId);

      const clientSocket = client?.getSocket();

      if (!clientSocket) return;

      (clientSocket as unknown as WebSocket).listeners['server::close']?.forEach((s: () => void) => s());
    };

    socket.onmessage = (event: object & { data?: string; }): void => {
      const userId = socket.url.split('?')[1]?.split('&').find(p => p.startsWith('id'))?.split('=')[1];

      if (!userId) return;

      const client = realm.getClientById(userId);

      const clientSocket = client?.getSocket();

      if (!clientSocket) return;

      (clientSocket as unknown as WebSocket).listeners['server::message']?.forEach((s: (data: object) => void) => s(event));
    };
  });

  webSocketServer.destroy = async (): Promise<void> => {
    server.close();
  };

  return webSocketServer;
};

describe('WebSocketServer', () => {

  it('should return valid path', () => {
    const realm = new Realm();
    const config = { path: '/', key: 'testKey', concurrent_limit: 1 };
    const config2 = { ...config, path: 'path' };
    const server = new Server('path1') as Server & HttpServer;
    const server2 = new Server('path2') as Server & HttpServer;

    const webSocketServer = new WebSocketServer({ server, realm, config });

    expect(webSocketServer.path).to.be.eq('/peerjs');

    const webSocketServer2 = new WebSocketServer({ server: server2, realm, config: config2 });

    expect(webSocketServer2.path).to.be.eq('path/peerjs');

    server.stop();
    server2.stop();
  });

  it(`should check client's params`, async () => {
    const realm = new Realm();
    const config = { path: '/', key: 'testKey', concurrent_limit: 1 };
    const fakeURL = 'ws://localhost:8080/peerjs';

    const getError = async (url: string, validError: Errors = Errors.INVALID_WS_PARAMETERS): Promise<boolean> => {
      const webSocketServer = createTestServer({ url, realm, config });

      const ws = new WebSocket(url);

      const errorSent = await checkSequence(ws, [{ type: MessageType.ERROR, error: validError }]);

      ws.close();

      await webSocketServer.destroy?.();

      return errorSent;
    };

    expect(await getError(fakeURL)).to.be.true;
    expect(await getError(`${fakeURL}?key=${config.key}`)).to.be.true;
    expect(await getError(`${fakeURL}?key=${config.key}&id=1`)).to.be.true;
    expect(await getError(`${fakeURL}?key=notValidKey&id=userId&token=userToken`, Errors.INVALID_KEY)).to.be.true;
  });

  it(`should check concurrent limit`, async () => {
    const realm = new Realm();
    const config = { path: '/', key: 'testKey', concurrent_limit: 1 };
    const fakeURL = 'ws://localhost:8080/peerjs';

    const createClient = (id: string): Destroyable<WebSocket> => {
      // id in the path ensures that all mock servers listen on different urls
      const url = `${fakeURL}${id}?key=${config.key}&id=${id}&token=${id}`;
      const webSocketServer = createTestServer({ url, realm, config });
      const ws: Destroyable<WebSocket> = new WebSocket(url);

      ws.destroy = async (): Promise<void> => {
        ws.close();

         wait(10);

         webSocketServer.destroy?.();

         wait(10);

        ws.destroy = undefined;
      };

      return ws;
    };


    const c1 = createClient('1');

    expect(await checkOpen(c1)).to.be.true;

    const c2 = createClient('2');

    expect(await checkSequence(c2, [
      { type: MessageType.ERROR, error: Errors.CONNECTION_LIMIT_EXCEED }
    ])).to.be.true;

    await c1.destroy?.();
    await c2.destroy?.();

    await wait(10);

    expect(realm.getClientsIds().length).to.be.eq(0);

    const c3 = createClient('3');

    expect(await checkOpen(c3)).to.be.true;

    await c3.destroy?.();
  });
});