/**
 * Setup file for frontend tests with Vitest + jsdom.
 * 
 * This file:
 * - Configures the DOM environment
 * - Mocks fetch API
 * - Mocks WebSocket
 * - Mocks localStorage
 * - Provides utility functions for tests
 */

import { vi, beforeEach, afterEach } from 'vitest';

// ============================================================================
// MOCK: localStorage
// ============================================================================

const localStorageMock = (() => {
  let store = {};
  return {
    getItem: vi.fn((key) => store[key] || null),
    setItem: vi.fn((key, value) => {
      store[key] = String(value);
    }),
    removeItem: vi.fn((key) => {
      delete store[key];
    }),
    clear: vi.fn(() => {
      store = {};
    }),
    get length() {
      return Object.keys(store).length;
    },
    key: vi.fn((i) => Object.keys(store)[i] || null),
  };
})();

Object.defineProperty(global, 'localStorage', {
  value: localStorageMock,
  writable: true,
});

// ============================================================================
// MOCK: fetch API
// ============================================================================

/**
 * Create a mock fetch response.
 * @param {object} data - Response data
 * @param {number} status - HTTP status code
 * @returns {Response} Mock Response object
 */
export function createMockResponse(data, status = 200) {
  return {
    ok: status >= 200 && status < 300,
    status,
    statusText: status === 200 ? 'OK' : 'Error',
    json: vi.fn().mockResolvedValue(data),
    text: vi.fn().mockResolvedValue(JSON.stringify(data)),
    headers: new Headers({ 'Content-Type': 'application/json' }),
  };
}

/**
 * Setup fetch mock with default responses.
 * @param {object} responses - Map of URL patterns to responses
 */
export function setupFetchMock(responses = {}) {
  const defaultResponses = {
    '/api/auth/status': { setup_required: false, authenticated: true, user: { username: 'test' } },
    '/api/hosts': [],
    '/api/tasks': [],
    '/api/schedules': [],
    '/api/playbooks': [],
    '/api/health': { status: 'healthy' },
    ...responses,
  };

  global.fetch = vi.fn((url, options = {}) => {
    const urlPath = new URL(url, 'http://localhost').pathname;
    
    for (const [pattern, response] of Object.entries(defaultResponses)) {
      if (urlPath.includes(pattern) || urlPath === pattern) {
        return Promise.resolve(createMockResponse(response));
      }
    }
    
    // Default 404 for unmatched URLs
    return Promise.resolve(createMockResponse({ detail: 'Not found' }, 404));
  });

  return global.fetch;
}

// ============================================================================
// MOCK: WebSocket
// ============================================================================

export class MockWebSocket {
  static CONNECTING = 0;
  static OPEN = 1;
  static CLOSING = 2;
  static CLOSED = 3;

  constructor(url) {
    this.url = url;
    this.readyState = MockWebSocket.CONNECTING;
    this.onopen = null;
    this.onclose = null;
    this.onmessage = null;
    this.onerror = null;
    this._messageQueue = [];

    // Auto-connect after a tick
    setTimeout(() => {
      this.readyState = MockWebSocket.OPEN;
      if (this.onopen) {
        this.onopen({ type: 'open' });
      }
    }, 0);
  }

  send(data) {
    if (this.readyState !== MockWebSocket.OPEN) {
      throw new Error('WebSocket is not open');
    }
    this._messageQueue.push(data);
  }

  close(code = 1000, reason = '') {
    this.readyState = MockWebSocket.CLOSED;
    if (this.onclose) {
      this.onclose({ type: 'close', code, reason });
    }
  }

  // Test helper: simulate receiving a message
  _receiveMessage(data) {
    if (this.onmessage) {
      this.onmessage({
        type: 'message',
        data: typeof data === 'string' ? data : JSON.stringify(data),
      });
    }
  }

  // Test helper: simulate an error
  _triggerError(error) {
    if (this.onerror) {
      this.onerror({ type: 'error', error });
    }
  }
}

global.WebSocket = MockWebSocket;

// ============================================================================
// DOM UTILITIES
// ============================================================================

/**
 * Create a minimal DOM structure for testing.
 */
export function setupMinimalDOM() {
  document.body.innerHTML = `
    <div id="main-content">
      <nav class="nav-sidebar"></nav>
      <main class="main-content">
        <div id="page-dashboard" class="page-section active"></div>
        <div id="page-hosts" class="page-section"></div>
        <div id="page-tasks" class="page-section"></div>
        <div id="page-schedules" class="page-section"></div>
      </main>
    </div>
    <div id="login-screen" class="hidden"></div>
    <div id="setup-screen" class="hidden"></div>
    <div id="notification-container"></div>
  `;
}

/**
 * Wait for DOM updates.
 * @param {number} ms - Milliseconds to wait
 */
export function waitForDOM(ms = 0) {
  return new Promise((resolve) => setTimeout(resolve, ms));
}

// ============================================================================
// HOOKS
// ============================================================================

beforeEach(() => {
  // Clear localStorage
  localStorageMock.clear();
  
  // Reset fetch mock
  if (global.fetch) {
    global.fetch.mockClear?.();
  }
  
  // Clear DOM
  document.body.innerHTML = '';
});

afterEach(() => {
  vi.clearAllMocks();
});

// ============================================================================
// EXPORTS
// ============================================================================

export { localStorageMock };