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import { matchPath, extractParams } from "./utils/URL.ts";import { DuckRequest } from "./request.ts";import { DuckResponse } from "./response.ts";import { HTTPMethods } from "./router.ts";
export type MiddlewareFunction = (  req: DuckRequest,  res: DuckResponse,  next: Function,) => any;export type ErrorMiddlewareFunction = (  error: any,  req: DuckRequest,  res: DuckResponse,  next: Function,) => any;
export interface Endpoint {  path: Function | string;  method: HTTPMethods;}
export class Middleware {  private endpoint?: Endpoint;  handler: MiddlewareFunction | ErrorMiddlewareFunction;
  /**   *    * @param handler - the function that handles request (or error)   * @param endpoint - optional endpoint to match (path and method)   */  constructor(    handler: MiddlewareFunction | ErrorMiddlewareFunction,    endpoint?: Endpoint,  ) {    this.handler = handler;    this.endpoint = endpoint;  }
  /**   * Sets request parameters, based on request URL and this endpoint's path   * @param {DuckRequest} req - the request   */  setParams(req: DuckRequest): void {    let params = {};    if (this.endpoint) {      const path = this.endpoint.path instanceof Function        ? this.endpoint.path()        : this.endpoint.path;      params = extractParams(req.url, path);    }
    req.params = params;  }
  private matches(request: DuckRequest): boolean {    if (this.endpoint) {      if (        this.endpoint.method === HTTPMethods.ANY ||        this.endpoint.method === request.method      ) {        // if path is a function, it returns the actual path - kinda like computed properties        // it's for router using another router, ex. router('/api') uses another router2        // so every route in router2 has to be prepended with '/api'        const path = this.endpoint.path instanceof Function          ? this.endpoint.path()          : this.endpoint.path;        return matchPath(request.url, path);      }      return false;    }    // if no path specified - it is a global middleware and matches all routes    return true;  }
  /**   * Returns middlewares from given collection, that match given request (based on path and method)   * @param middlewares - middlewares to look through   * @param request - request as filter param   */  static findMatching(    middlewares: Middleware[],    request: DuckRequest,  ): Middleware[] {    return middlewares.filter((middleware) => middleware.matches(request));  }}