/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @format
 * @flow
 * @emails oncall+draft_js
 */
'use strict';

import type { DraftInlineStyle } from "./DraftInlineStyle";

const {
  Map,
  OrderedSet,
  Record
} = require("immutable"); // Immutable.map is typed such that the value for every key in the map
// must be the same type


type CharacterMetadataConfigValueType = DraftInlineStyle | ?string;
type CharacterMetadataConfigRawValueType = Array<string> | ?string;
export type CharacterMetadataRawConfig = {
  style?: CharacterMetadataConfigRawValueType,
  entity?: CharacterMetadataConfigRawValueType,
  ...
};
type CharacterMetadataConfig = {
  style?: CharacterMetadataConfigValueType,
  entity?: CharacterMetadataConfigValueType,
  ...
};
const EMPTY_SET = OrderedSet();
const defaultRecord: CharacterMetadataConfig = {
  style: EMPTY_SET,
  entity: null
};
const CharacterMetadataRecord = (Record(defaultRecord): any);

class CharacterMetadata extends CharacterMetadataRecord {
  getStyle(): DraftInlineStyle {
    return this.get('style');
  }

  getEntity(): ?string {
    return this.get('entity');
  }

  hasStyle(style: string): boolean {
    return this.getStyle().includes(style);
  }

  static applyStyle(record: CharacterMetadata, style: string): CharacterMetadata {
    const withStyle = record.set('style', record.getStyle().add(style));
    return CharacterMetadata.create(withStyle);
  }

  static removeStyle(record: CharacterMetadata, style: string): CharacterMetadata {
    const withoutStyle = record.set('style', record.getStyle().remove(style));
    return CharacterMetadata.create(withoutStyle);
  }

  static applyEntity(record: CharacterMetadata, entityKey: ?string): CharacterMetadata {
    const withEntity = record.getEntity() === entityKey ? record : record.set('entity', entityKey);
    return CharacterMetadata.create(withEntity);
  }
  /**
   * Use this function instead of the `CharacterMetadata` constructor.
   * Since most content generally uses only a very small number of
   * style/entity permutations, we can reuse these objects as often as
   * possible.
   */


  static create(config?: CharacterMetadataConfig): CharacterMetadata {
    if (!config) {
      return EMPTY;
    }

    const defaultConfig: CharacterMetadataConfig = {
      style: EMPTY_SET,
      entity: (null: ?string)
    }; // Fill in unspecified properties, if necessary.

    const configMap = Map(defaultConfig).merge(config);
    const existing: ?CharacterMetadata = pool.get(configMap);

    if (existing) {
      return existing;
    }

    const newCharacter = new CharacterMetadata(configMap);
    pool = pool.set(configMap, newCharacter);
    return newCharacter;
  }

  static fromJS({
    style,
    entity
  }: CharacterMetadataRawConfig): CharacterMetadata {
    return new CharacterMetadata({
      style: Array.isArray(style) ? OrderedSet(style) : style,
      entity: Array.isArray(entity) ? OrderedSet(entity) : entity
    });
  }

}

const EMPTY = new CharacterMetadata();
let pool: Map<Map<any, any>, CharacterMetadata> = Map([[Map(defaultRecord), EMPTY]]);
CharacterMetadata.EMPTY = EMPTY;
module.exports = CharacterMetadata;