/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the MIT License. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/

import { CharCode } from '../../../../vs/base/common/charCode';
import { CharacterClassifier } from '../../../../vs/editor/common/core/characterClassifier';

export const enum WordCharacterClass {
  Regular = 0,
  Whitespace = 1,
  WordSeparator = 2,
}

export class WordCharacterClassifier extends CharacterClassifier<WordCharacterClass> {
  constructor(wordSeparators: string) {
    super(WordCharacterClass.Regular);

    for (let i = 0, len = wordSeparators.length; i < len; i++) {
      this.set(wordSeparators.charCodeAt(i), WordCharacterClass.WordSeparator);
    }

    this.set(CharCode.Space, WordCharacterClass.Whitespace);
    this.set(CharCode.Tab, WordCharacterClass.Whitespace);
  }
}

function once<R>(computeFn: (input: string) => R): (input: string) => R {
  let cache: { [key: string]: R } = {}; // TODO@Alex unbounded cache
  return (input: string): R => {
    if (!cache.hasOwnProperty(input)) {
      cache[input] = computeFn(input);
    }
    return cache[input];
  };
}

export const getMapForWordSeparators = once<WordCharacterClassifier>(
  (input) => new WordCharacterClassifier(input)
);