/**
 * quiXzoom SSO Client v2.0
 * Universal cross-domain silent login
 * 
 * Usage:
 *   <script src="https://auth.quixzoom.com/sso-client-v2.js"></script>
 *   <script>
 *     QZAuth.init({
 *       ssoUrl: 'https://auth.quixzoom.com',
 *       onLogin: (user) => console.log('Logged in:', user),
 *       onLogout: () => console.log('Logged out'),
 *     });
 *   </script>
 */

(function(global) {
  'use strict';

  const DEFAULT_CONFIG = {
    ssoUrl: 'https://auth.quixzoom.com',
    checkInterval: 60000, // Check auth every 60 seconds
    silentTimeout: 5000,
  };

  class QZAuthClient {
    constructor() {
      this.config = { ...DEFAULT_CONFIG };
      this.user = null;
      this.isAuthenticated = false;
      this.callbacks = {
        onLogin: null,
        onLogout: null,
        onError: null,
      };
      this.checkIntervalId = null;
    }

    init(config = {}) {
      this.config = { ...this.config, ...config };
      
      if (config.onLogin) this.callbacks.onLogin = config.onLogin;
      if (config.onLogout) this.callbacks.onLogout = config.onLogout;
      if (config.onError) this.callbacks.onError = config.onError;

      // Check auth immediately
      this.checkAuth();

      // Set up periodic checks
      this.checkIntervalId = setInterval(() => {
        this.checkAuth();
      }, this.config.checkInterval);

      // Listen for storage events (login from other tabs)
      window.addEventListener('storage', (e) => {
        if (e.key === 'qz_auth_event') {
          const event = JSON.parse(e.newValue || '{}');
          if (event.type === 'login') {
            this.checkAuth();
          } else if (event.type === 'logout') {
            this.logout();
          }
        }
      });

      // Listen for messages from SSO iframe
      window.addEventListener('message', (e) => {
        if (e.origin !== this.config.ssoUrl) return;
        
        if (e.data.type === 'qz_auth_silent_response') {
          this.handleSilentResponse(e.data);
        }
      });

      console.log('[QZAuth] Initialized');
    }

    async checkAuth() {
      try {
        // Try silent login first (uses refresh token cookie)
        const response = await fetch(`${this.config.ssoUrl}/auth/silent`, {
          method: 'GET',
          credentials: 'include',
        });

        if (response.ok) {
          const data = await response.json();
          if (data.authenticated) {
            this.setUser(data.user);
            return;
          }
        }

        // Silent login failed, check if we have a token in URL (OAuth redirect)
        const urlParams = new URLSearchParams(window.location.search);
        const accessToken = urlParams.get('access_token');
        
        if (accessToken) {
          // Verify token with SSO
          const verifyResponse = await fetch(`${this.config.ssoUrl}/auth/me`, {
            headers: {
              'Authorization': `Bearer ${accessToken}`,
            },
          });

          if (verifyResponse.ok) {
            const user = await verifyResponse.json();
            this.setUser(user);
            // Clean URL
            window.history.replaceState({}, document.title, window.location.pathname);
            return;
          }
        }

        // Not authenticated
        this.clearUser();
      } catch (error) {
        console.error('[QZAuth] Auth check failed:', error);
        if (this.callbacks.onError) {
          this.callbacks.onError(error);
        }
      }
    }

    handleSilentResponse(data) {
      if (data.authenticated) {
        this.setUser(data.user);
      } else {
        this.clearUser();
      }
    }

    setUser(user) {
      const wasAuthenticated = this.isAuthenticated;
      this.user = user;
      this.isAuthenticated = true;

      // Store in localStorage for other tabs
      localStorage.setItem('qz_user', JSON.stringify(user));
      localStorage.setItem('qz_auth_event', JSON.stringify({
        type: 'login',
        timestamp: Date.now(),
      }));

      // Update UI
      this.updateUI();

      // Trigger callback if newly logged in
      if (!wasAuthenticated && this.callbacks.onLogin) {
        this.callbacks.onLogin(user);
      }
    }

    clearUser() {
      const wasAuthenticated = this.isAuthenticated;
      this.user = null;
      this.isAuthenticated = false;

      localStorage.removeItem('qz_user');
      localStorage.setItem('qz_auth_event', JSON.stringify({
        type: 'logout',
        timestamp: Date.now(),
      }));

      this.updateUI();

      if (wasAuthenticated && this.callbacks.onLogout) {
        this.callbacks.onLogout();
      }
    }

    updateUI() {
      // Update all elements with data-qz-auth attribute
      document.querySelectorAll('[data-qz-auth]').forEach(el => {
        const action = el.getAttribute('data-qz-auth');
        
        if (action === 'show-when-authenticated') {
          el.style.display = this.isAuthenticated ? '' : 'none';
        } else if (action === 'show-when-guest') {
          el.style.display = !this.isAuthenticated ? '' : 'none';
        } else if (action === 'user-name') {
          el.textContent = this.user?.name || '';
        } else if (action === 'user-email') {
          el.textContent = this.user?.email || '';
        } else if (action === 'user-avatar') {
          el.src = this.user?.avatar || '/default-avatar.png';
        }
      });
    }

    async login(email, password) {
      try {
        const response = await fetch(`${this.config.ssoUrl}/auth/login`, {
          method: 'POST',
          headers: { 'Content-Type': 'application/json' },
          credentials: 'include',
          body: JSON.stringify({ email, password }),
        });

        if (!response.ok) {
          throw new Error('Login failed');
        }

        const data = await response.json();
        this.setUser(data.user);
        return data;
      } catch (error) {
        console.error('[QZAuth] Login failed:', error);
        throw error;
      }
    }

    async logout() {
      try {
        await fetch(`${this.config.ssoUrl}/auth/logout`, {
          method: 'POST',
          credentials: 'include',
        });
      } catch (error) {
        console.error('[QZAuth] Logout error:', error);
      } finally {
        this.clearUser();
      }
    }

    getUser() {
      return this.user;
    }

    isLoggedIn() {
      return this.isAuthenticated;
    }

    destroy() {
      if (this.checkIntervalId) {
        clearInterval(this.checkIntervalId);
      }
    }
  }

  // Create global instance
  global.QZAuth = new QZAuthClient();

})(window);