/**
 * DC-076: Tests for the dashboard WebSocket server
 */
const http = require('http');
const WebSocket = require('ws');
const EventEmitter = require('events');
const createDashboardWS = require('../../src/websocket/dashboard-ws');

function createMockServer() {
  return http.createServer((req, res) => {
    res.writeHead(404);
    res.end();
  });
}

describe('DC-076: Dashboard WebSocket', () => {
  let server, wsServer, port;

  beforeEach((done) => {
    server = createMockServer();
    server.listen(0, () => {
      port = server.address().port;

      const resourceMonitor = new EventEmitter();
      const healthChecker = new EventEmitter();
      const updateManager = new EventEmitter();

      wsServer = createDashboardWS(server, {
        resourceMonitor,
        healthChecker,
        updateManager,
        log: { info: jest.fn(), error: jest.fn() },
      });
      done();
    });
  });

  afterEach((done) => {
    wsServer.close();
    server.close(done);
  });

  it('accepts connections at the upgrade path', (done) => {
    const ws = new WebSocket(`ws://localhost:${port}/api/v1/ws`);
    ws.on('open', () => {
      ws.close();
    });
    ws.on('close', () => {
      done();
    });
    ws.on('error', done);
  });

  it('sends a connected event on join', (done) => {
    const ws = new WebSocket(`ws://localhost:${port}/api/v1/ws`);
    ws.on('message', (raw) => {
      const msg = JSON.parse(raw.toString());
      if (msg.type === 'connected') {
        expect(msg.data).toHaveProperty('clients');
        ws.close();
        done();
      }
    });
    ws.on('error', done);
  });

  it('responds to ping with pong', (done) => {
    const ws = new WebSocket(`ws://localhost:${port}/api/v1/ws`);
    ws.on('open', () => {
      ws.send(JSON.stringify({ type: 'ping' }));
    });
    ws.on('message', (raw) => {
      const msg = JSON.parse(raw.toString());
      if (msg.type === 'pong') {
        ws.close();
        done();
      }
    });
    ws.on('error', done);
  });

  it('responds to subscribe with subscribed confirmation', (done) => {
    const ws = new WebSocket(`ws://localhost:${port}/api/v1/ws`);
    ws.on('open', () => {
      ws.send(JSON.stringify({ type: 'subscribe', events: ['resource-alert', 'incident'] }));
    });
    ws.on('message', (raw) => {
      const msg = JSON.parse(raw.toString());
      if (msg.type === 'subscribed') {
        expect(msg.events).toEqual(['resource-alert', 'incident']);
        ws.close();
        done();
      }
    });
    ws.on('error', done);
  });

  it('responds to client-count request', (done) => {
    const ws = new WebSocket(`ws://localhost:${port}/api/v1/ws`);
    ws.on('open', () => {
      ws.send(JSON.stringify({ type: 'client-count' }));
    });
    ws.on('message', (raw) => {
      const msg = JSON.parse(raw.toString());
      if (msg.type === 'client-count') {
        expect(msg.count).toBeGreaterThanOrEqual(1);
        ws.close();
        done();
      }
    });
    ws.on('error', done);
  });

  it('returns error for invalid JSON', (done) => {
    const ws = new WebSocket(`ws://localhost:${port}/api/v1/ws`);
    ws.on('open', () => {
      ws.send('not json');
    });
    ws.on('message', (raw) => {
      const msg = JSON.parse(raw.toString());
      if (msg.type === 'error') {
        expect(msg.error).toContain('Invalid JSON');
        ws.close();
        done();
      }
    });
    ws.on('error', done);
  });

  it('tracks client count', () => {
    expect(wsServer.getClientCount()).toBe(0);
  });

  it('broadcast method does not throw with no clients', () => {
    expect(() => wsServer.broadcast('test', { foo: 'bar' })).not.toThrow();
  });
});