/**
 * Job-Info Auth Flow - Standalone
 * 
 * Complete, self-contained authentication for Job-Info app
 * - Check localStorage for active tokens on load
 * - Prompt for login if tokens missing/inactive
 * - Get user display name from PocketBase metadata
 * - Refresh all tokens to keep them fresh
 * - Only replace pb-user when we have a new token
 * - Graph token is optional after first login
 * - Do not prompt again unless pb-user is missing/inactive
 */

interface TokenMetadata {
  value: string;
  displayName: string;
  lastFourDigits: string;
  expiresAt: number;
  acquiredAt: number;
}

interface JobInfoAuthState {
  'pb-user'?: TokenMetadata;
  'graph-user'?: TokenMetadata;
  userDisplayName: string;
}

class JobInfoAuthFlow {
  private state: JobInfoAuthState = {
    userDisplayName: 'Unknown'
  };
  private pb: any = null;
  private initialized = false;

  /**
   * Initialize and check token status
   */
  async init(): Promise<void> {
    if (this.initialized) return;

    console.log('[JobInfoAuth] Starting init');

    // Initialize PocketBase
    const PocketBase = (window as any).PocketBase;
    if (!PocketBase) {
      throw new Error('PocketBase SDK not loaded. Include: <script src="https://cdn.jsdelivr.net/npm/pocketbase@0.26.5/dist/pocketbase.umd.js"></script>');
    }

    this.pb = new PocketBase('http://localhost:8090');
    console.log('[JobInfoAuth] PocketBase initialized');

    // Load persisted tokens from localStorage
    this.loadPersistedTokens();

    // Check token status
    const pbUserActive = this.isTokenActive('pb-user');
    const graphUserActive = this.isTokenActive('graph-user');

    console.log('[JobInfoAuth] Token status - pb-user:', pbUserActive, 'graph-user:', graphUserActive);

    // If pb-user is missing or inactive: prompt for login
    if (!pbUserActive) {
      console.log('[JobInfoAuth] pb-user token missing or inactive, prompting login');
      await this.promptLogin();
    } else {
      console.log('[JobInfoAuth] pb-user token is active, loading display name');
      // Get display name from state or try to refresh
      if (!this.state.userDisplayName || this.state.userDisplayName === 'Unknown') {
        const userInfo = this.getUserInfo();
        this.state.userDisplayName = userInfo.displayName || 'Unknown';
      }
    }

    // Refresh all tokens to keep them fresh
    await this.refreshAllTokens();

    this.initialized = true;
    console.log('[JobInfoAuth] Initialized. State:', this.state);
  }

  /**
   * Prompt for login via PocketBase OAuth
   */
  private async promptLogin(): Promise<void> {
    console.log('[JobInfoAuth] Prompting for login with OAuth');

    try {
      // Authenticate with PocketBase OAuth (Microsoft provider)
      const authData = await this.pb.collection('users').authWithOAuth2({
        provider: 'microsoft'
      });

      console.log('[JobInfoAuth] OAuth successful, authData:', authData);

      // Extract tokens
      const pbUserToken = authData.token;
      const graphUserToken = this.extractGraphToken(authData.meta || {});

      if (!pbUserToken) {
        throw new Error('No pb-user token in OAuth response');
      }

      // Get user display name
      const userInfo = this.getUserInfo();
      this.state.userDisplayName = userInfo.displayName || 'Unknown';

      // Store tokens
      this.storeToken('pb-user', pbUserToken);
      if (graphUserToken) {
        this.storeToken('graph-user', graphUserToken);
      }

      console.log('[JobInfoAuth] Login successful. User:', this.state.userDisplayName);
    } catch (err) {
      console.error('[JobInfoAuth] Login failed:', err);
      throw err;
    }
  }

  /**
   * Extract Graph token from OAuth metadata
   */
  private extractGraphToken(meta: any): string | null {
    return (
      meta?.graphAccessToken ||
      meta?.graph_token ||
      meta?.graphToken ||
      meta?.accessToken ||
      meta?.access_token ||
      meta?.token ||
      meta?.rawToken ||
      meta?.authData?.access_token ||
      null
    );
  }

  /**
   * Refresh all tokens to keep them fresh
   */
  private async refreshAllTokens(): Promise<void> {
    console.log('[JobInfoAuth] Refreshing all tokens');

    try {
      // Refresh pb-user if we have an active session
      if (this.pb.authStore.isValid) {
        console.log('[JobInfoAuth] PocketBase session is valid, refreshing');
        const authData = await this.pb.collection('users').authRefresh();
        
        const newPbToken = authData.token;
        const currentPbToken = this.state['pb-user']?.value;

        // Only replace pb-user if we got a new token
        if (newPbToken && newPbToken !== currentPbToken) {
          console.log('[JobInfoAuth] pb-user token refreshed (new token)');
          this.storeToken('pb-user', newPbToken);
        } else if (newPbToken) {
          console.log('[JobInfoAuth] pb-user token still fresh, keeping existing');
        }

        // Try to get updated graph token
        const graphToken = this.extractGraphToken(authData.meta || {});
        if (graphToken && graphToken !== this.state['graph-user']?.value) {
          console.log('[JobInfoAuth] graph-user token refreshed');
          this.storeToken('graph-user', graphToken);
        }
      }
    } catch (err) {
      console.error('[JobInfoAuth] Token refresh error:', err);
      // Don't throw - token refresh is best-effort
    }
  }

  /**
   * Store token with metadata
   */
  private storeToken(type: 'pb-user' | 'graph-user', token: string): void {
    const lastFour = token.substring(token.length - 4);
    const metadata: TokenMetadata = {
      value: token,
      displayName: this.state.userDisplayName,
      lastFourDigits: lastFour,
      expiresAt: Date.now() + 7 * 24 * 60 * 60 * 1000, // Assume 7 days
      acquiredAt: Date.now()
    };

    this.state[type] = metadata;

    // Persist to localStorage
    const key = `auth:${type}`;
    localStorage.setItem(key, JSON.stringify(metadata));
    console.log(`[JobInfoAuth] Token stored: ${type} (last 4: ${lastFour})`);
  }

  /**
   * Load tokens from localStorage
   */
  private loadPersistedTokens(): void {
    try {
      const pbKey = 'auth:pb-user';
      const graphKey = 'auth:graph-user';

      const pbData = localStorage.getItem(pbKey);
      const graphData = localStorage.getItem(graphKey);

      if (pbData) {
        this.state['pb-user'] = JSON.parse(pbData);
        this.state.userDisplayName = this.state['pb-user'].displayName || 'Unknown';
        console.log('[JobInfoAuth] Loaded pb-user from localStorage');
      }

      if (graphData) {
        this.state['graph-user'] = JSON.parse(graphData);
        console.log('[JobInfoAuth] Loaded graph-user from localStorage');
      }
    } catch (err) {
      console.error('[JobInfoAuth] Error loading persisted tokens:', err);
    }
  }

  /**
   * Check if a token is active (exists and not expired)
   */
  private isTokenActive(type: 'pb-user' | 'graph-user'): boolean {
    const token = this.state[type];
    if (!token || !token.value) {
      return false;
    }

    // Check if expired
    if (token.expiresAt && token.expiresAt < Date.now()) {
      console.log(`[JobInfoAuth] Token expired: ${type}`);
      return false;
    }

    return true;
  }

  /**
   * Get user info from PocketBase
   */
  private getUserInfo(): { displayName: string; email: string } {
    const model = this.pb?.authStore?.model;
    if (!model) {
      return { displayName: 'Unknown', email: '' };
    }

    return {
      displayName: model.display_name || model.name || model.email || model.username || 'Unknown',
      email: model.email || model.username || ''
    };
  }

  /**
   * Get current state (for UI)
   */
  getState(): JobInfoAuthState {
    return { ...this.state };
  }

  /**
   * Get specific token value
   */
  getToken(type: 'pb-user' | 'graph-user'): string | undefined {
    return this.state[type]?.value;
  }

  /**
   * Get user display name
   */
  getUserDisplayName(): string {
    return this.state.userDisplayName;
  }

  /**
   * Logout
   */
  logout(): void {
    console.log('[JobInfoAuth] Logging out');
    this.pb?.authStore?.clear?.();
    localStorage.removeItem('auth:pb-user');
    localStorage.removeItem('auth:graph-user');
    this.state = { userDisplayName: 'Unknown' };
    this.initialized = false;
  }
}

const JobInfoAuth = new JobInfoAuthFlow();

// Expose globally
if (typeof window !== 'undefined') {
  window.JobInfoAuth = JobInfoAuth;
}

export default JobInfoAuth;