/**
 * OAuth Popup Login - Production Integration Example
 * 
 * Shows how to integrate the standalone OAuth popup module into the Job-Info app.
 * This example uses actual project configuration values.
 * 
 * Setup:
 *   1. Import OAuthPopupLogin from auth/oauth-popup-login.ts
 *   2. Call from user gesture (click button, etc.)
 *   3. Tokens automatically stored in localStorage
 *   4. Use tokens for API calls to backend
 */

import OAuthPopupLogin from './oauth-popup-login';

/**
 * Example 1: Basic login flow
 * Call this when user clicks "Login" button
 */
export async function initiateLogin(): Promise<void> {
  try {
    // Create popup with production defaults
    // (http://localhost:8090, microsoft provider, job-info scopes)
    const loginPopup = new OAuthPopupLogin();
    
    // Open popup (must be called from user gesture)
    await loginPopup.open();
    
    // Tokens are now acquired and stored in localStorage:
    // - localStorage.getItem('auth:pb-user')
    // - localStorage.getItem('auth:pb-agent')
    
    const { pbUser, pbAgent } = loginPopup.getTokens();
    
    console.log('[Auth] Login successful');
    console.log('[Auth] PB User token:', pbUser?.value.substring(0, 30) + '...');
    console.log('[Auth] PB Agent token:', pbAgent?.value.substring(0, 30) + '...');
    
    // Redirect to app or refresh UI
    window.location.href = '/app';
  } catch (error) {
    console.error('[Auth] Login failed:', error);
  }
}

/**
 * Example 2: Check if user is authenticated
 * Call during app initialization
 */
export function isAuthenticated(): boolean {
  const pbUserToken = localStorage.getItem('auth:pb-user');
  const pbAgentToken = localStorage.getItem('auth:pb-agent');
  
  return !!(pbUserToken && pbAgentToken);
}

/**
 * Example 3: Get current tokens for API calls
 * Used by fetch/axios interceptors
 */
export function getAuthTokens(): {
  pbUser: string | null;
  pbAgent: string | null;
} {
  return {
    pbUser: localStorage.getItem('auth:pb-user'),
    pbAgent: localStorage.getItem('auth:pb-agent')
  };
}

/**
 * Example 4: Logout (clear all tokens)
 * Call when user clicks "Sign Out"
 */
export function logout(): void {
  localStorage.removeItem('auth:pb-user');
  localStorage.removeItem('auth:pb-agent');
  window.location.href = '/signin';
}

/**
 * Example 5: API call with token (fetch interceptor)
 * Use this wrapper for all API requests
 */
export async function fetchWithAuth(
  url: string,
  options: RequestInit = {}
): Promise<Response> {
  const { pbUser } = getAuthTokens();
  
  if (!pbUser) {
    throw new Error('Not authenticated. Tokens missing.');
  }
  
  const headers = {
    ...options.headers,
    'Authorization': `Bearer ${pbUser}`,
    'Content-Type': 'application/json'
  };
  
  const response = await fetch(url, {
    ...options,
    headers
  });
  
  // If 401, tokens expired - trigger re-auth
  if (response.status === 401) {
    logout();
  }
  
  return response;
}

/**
 * Example 6: Frontend integration with HTML button
 * 
 * HTML:
 *   <button id="loginBtn" class="btn-primary">Login with Microsoft</button>
 * 
 * JavaScript:
 *   document.getElementById('loginBtn').addEventListener('click', initiateLogin);
 */

// Example HTML button setup (can be in your main app)
if (typeof window !== 'undefined') {
  // Check auth status on page load
  if (!isAuthenticated()) {
    console.log('[Auth] No tokens found. User needs to login.');
    // Show login UI
  } else {
    console.log('[Auth] User already authenticated. Loading app...');
    // Load app
  }
}

export default {
  initiateLogin,
  isAuthenticated,
  getAuthTokens,
  logout,
  fetchWithAuth
};