/*
  Copyright 2018 Google LLC

  Use of this source code is governed by an MIT-style
  license that can be found in the LICENSE file or at
  https://opensource.org/licenses/MIT.
*/

import {assert} from 'workbox-core/_private/assert.js';
import {logger} from 'workbox-core/_private/logger.js';
import {HTTPMethod} from './utils/constants.js';
import {Route} from './Route.js';
import {Handler, MatchCallbackOptions, MatchCallback} from './_types.js';
import './_version.js';


/**
 * RegExpRoute makes it easy to create a regular expression based
 * [Route]{@link module:workbox-routing.Route}.
 *
 * For same-origin requests the RegExp only needs to match part of the URL. For
 * requests against third-party servers, you must define a RegExp that matches
 * the start of the URL.
 *
 * [See the module docs for info.]{@link https://developers.google.com/web/tools/workbox/modules/workbox-routing}
 *
 * @memberof module:workbox-routing
 * @extends module:workbox-routing.Route
 */
class RegExpRoute extends Route {
  /**
   * If the regular expression contains
   * [capture groups]{@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp#grouping-back-references},
   * the captured values will be passed to the
   * [handler's]{@link module:workbox-routing~handlerCallback} `params`
   * argument.
   *
   * @param {RegExp} regExp The regular expression to match against URLs.
   * @param {module:workbox-routing~handlerCallback} handler A callback
   * function that returns a Promise resulting in a Response.
   * @param {string} [method='GET'] The HTTP method to match the Route
   * against.
   */
  constructor(regExp: RegExp, handler: Handler, method?: HTTPMethod) {
    if (process.env.NODE_ENV !== 'production') {
      assert!.isInstance(regExp, RegExp, {
        moduleName: 'workbox-routing',
        className: 'RegExpRoute',
        funcName: 'constructor',
        paramName: 'pattern',
      });
    }

    const match: MatchCallback = ({url}: MatchCallbackOptions) => {
      const result = regExp.exec(url.href);

      // Return immediately if there's no match.
      if (!result) {
        return;
      }

      // Require that the match start at the first character in the URL string
      // if it's a cross-origin request.
      // See https://github.com/GoogleChrome/workbox/issues/281 for the context
      // behind this behavior.
      if ((url.origin !== location.origin) && (result.index !== 0)) {
        if (process.env.NODE_ENV !== 'production') {
          logger.debug(
              `The regular expression '${regExp}' only partially matched ` +
            `against the cross-origin URL '${url}'. RegExpRoute's will only ` +
            `handle cross-origin requests if they match the entire URL.`
          );
        }

        return;
      }

      // If the route matches, but there aren't any capture groups defined, then
      // this will return [], which is truthy and therefore sufficient to
      // indicate a match.
      // If there are capture groups, then it will return their values.
      return result.slice(1);
    };

    super(match, handler, method);
  }
}

export {RegExpRoute};