webrequest/ts/interceptors/interceptor.manager.ts

/**
 * Interceptor manager for request/response transformation
 */

import type {
  TRequestInterceptor,
  TResponseInterceptor,
  TErrorInterceptor,
} from './interceptor.types.js';

export class InterceptorManager {
  private requestInterceptors: TRequestInterceptor[] = [];
  private responseInterceptors: TResponseInterceptor[] = [];
  private errorInterceptors: TErrorInterceptor[] = [];

  /**
   * Add a request interceptor
   */
  public addRequestInterceptor(interceptor: TRequestInterceptor): void {
    this.requestInterceptors.push(interceptor);
  }

  /**
   * Add a response interceptor
   */
  public addResponseInterceptor(interceptor: TResponseInterceptor): void {
    this.responseInterceptors.push(interceptor);
  }

  /**
   * Add an error interceptor
   */
  public addErrorInterceptor(interceptor: TErrorInterceptor): void {
    this.errorInterceptors.push(interceptor);
  }

  /**
   * Remove a request interceptor
   */
  public removeRequestInterceptor(interceptor: TRequestInterceptor): void {
    const index = this.requestInterceptors.indexOf(interceptor);
    if (index > -1) {
      this.requestInterceptors.splice(index, 1);
    }
  }

  /**
   * Remove a response interceptor
   */
  public removeResponseInterceptor(interceptor: TResponseInterceptor): void {
    const index = this.responseInterceptors.indexOf(interceptor);
    if (index > -1) {
      this.responseInterceptors.splice(index, 1);
    }
  }

  /**
   * Remove an error interceptor
   */
  public removeErrorInterceptor(interceptor: TErrorInterceptor): void {
    const index = this.errorInterceptors.indexOf(interceptor);
    if (index > -1) {
      this.errorInterceptors.splice(index, 1);
    }
  }

  /**
   * Clear all interceptors
   */
  public clearAll(): void {
    this.requestInterceptors = [];
    this.responseInterceptors = [];
    this.errorInterceptors = [];
  }

  /**
   * Process request through all request interceptors
   */
  public async processRequest(request: Request): Promise<Request> {
    let processedRequest = request;

    for (const interceptor of this.requestInterceptors) {
      try {
        processedRequest = await interceptor(processedRequest);
      } catch (error) {
        // If interceptor throws, process through error interceptors
        throw await this.processError(
          error instanceof Error ? error : new Error(String(error)),
        );
      }
    }

    return processedRequest;
  }

  /**
   * Process response through all response interceptors
   */
  public async processResponse(response: Response): Promise<Response> {
    let processedResponse = response;

    for (const interceptor of this.responseInterceptors) {
      try {
        processedResponse = await interceptor(processedResponse);
      } catch (error) {
        // If interceptor throws, process through error interceptors
        throw await this.processError(
          error instanceof Error ? error : new Error(String(error)),
        );
      }
    }

    return processedResponse;
  }

  /**
   * Process error through all error interceptors
   */
  public async processError(error: Error): Promise<Error> {
    let processedError = error;

    for (const interceptor of this.errorInterceptors) {
      try {
        processedError = await interceptor(processedError);
      } catch (newError) {
        // If error interceptor throws, use the new error
        processedError =
          newError instanceof Error ? newError : new Error(String(newError));
      }
    }

    return processedError;
  }

  /**
   * Get count of registered interceptors
   */
  public getInterceptorCounts(): {
    request: number;
    response: number;
    error: number;
  } {
    return {
      request: this.requestInterceptors.length,
      response: this.responseInterceptors.length,
      error: this.errorInterceptors.length,
    };
  }
}