export interface TokenMessage {
  type: 'UM_AUTH_TOKEN';
  token: string;
  refreshToken: string;
}

/**
 * Manages authentication tokens received from parent window (host)
 * Used by iframe modules to receive and store auth tokens
 */
class TokenManager {
  private token: string | null = null;
  private refreshToken: string | null = null;
  private tokenResolve: ((token: string) => void) | null = null;
  private tokenPromise: Promise<string>;
  private isFramed: boolean;

  constructor() {
    // Check if we're running in an iframe
    this.isFramed = window.self !== window.top;

    // Create a promise that resolves when token is received
    this.tokenPromise = new Promise((resolve) => {
      this.tokenResolve = resolve;
    });

    if (this.isFramed) {
      this.setupMessageListener();

      // Request token after 2 seconds if not received
      setTimeout(() => {
        if (!this.token) {
          this.requestTokenFromHost();
        }
      }, 2000);
    }
  }

  private setupMessageListener() {
    window.addEventListener('message', (event) => {
      // Security: Only accept from parent window
      if (event.source !== window.parent) {
        return;
      }

      const data = event.data as TokenMessage | undefined;

      if (data?.type === 'UM_AUTH_TOKEN') {
        this.token = data.token;
        this.refreshToken = data.refreshToken;

        // Store in localStorage for persistence
        localStorage.setItem('um_auth_token', data.token);
        localStorage.setItem('um_refresh_token', data.refreshToken);

        console.log('✅ Token received from host');

        // Resolve the promise
        if (this.tokenResolve) {
          this.tokenResolve(data.token);
        }
      }
    });
  }

  private requestTokenFromHost() {
    console.log('📤 Requesting token from host...');
    window.parent.postMessage(
      { type: 'UM_REQUEST_AUTH' },
      window.location.origin
    );
  }

  /**
   * Get token - waits for it if not yet received
   */
  async getToken(): Promise<string> {
    if (this.token) {
      return this.token;
    }

    // Check localStorage as fallback
    const stored = localStorage.getItem('um_auth_token');
    if (stored) {
      this.token = stored;
      return stored;
    }

    // Wait for token to arrive from parent
    return this.tokenPromise;
  }

  /**
   * Get token synchronously (returns null if not available)
   */
  getTokenSync(): string | null {
    return this.token || localStorage.getItem('um_auth_token');
  }

  getRefreshToken(): string | null {
    return this.refreshToken || localStorage.getItem('um_refresh_token');
  }

  clearTokens() {
    this.token = null;
    this.refreshToken = null;
    localStorage.removeItem('um_auth_token');
    localStorage.removeItem('um_refresh_token');
  }

  isInFrame(): boolean {
    return this.isFramed;
  }
}

// Export singleton instance
export const tokenManager = new TokenManager();