/**
 * @license
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

export interface Selector {
  refinedBy?: this;
  type?: SelectorType;
}

export type SelectorType = string; // not enumerating known options: we allow extensibility.

export interface CssSelector extends Selector {
  type: 'CssSelector';
  value: string;
}

export interface TextQuoteSelector extends Selector {
  type: 'TextQuoteSelector';
  exact: string;
  prefix?: string;
  suffix?: string;
}

export interface RangeSelector extends Selector {
  type: 'RangeSelector';
  startSelector: Selector;
  endSelector: Selector;
}

export interface Matcher<TScope, TMatch> {
  (scope: TScope): AsyncGenerator<TMatch, void, void>;
}

export type MatcherCreator<TScope, TMatch> = (selector: Selector) => Matcher<TScope, TMatch>;

export type Plugin<TScope, TMatch> =
  (
    next: MatcherCreator<TScope, TMatch>,
    recurse: MatcherCreator<TScope, TMatch>,
  ) => typeof next;


// Basic form of a plugin: (two equivalents)
// const identity: Plugin<any, any> = (next, recurse) => next;
// const identity: Plugin<any, any> = (next, recurse) => {
//   return function (selector: Selector): Matcher<any, any> {
//     return next(selector); // or do something else here.
//   };
// };