/**
 * 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 strict-local
 * @emails oncall+draft_js
 */
'use strict';

const Immutable = require("immutable");

const {
  Record
} = Immutable;
const defaultRecord: {
  anchorKey: string,
  anchorOffset: number,
  focusKey: string,
  focusOffset: number,
  isBackward: boolean,
  hasFocus: boolean,
  ...
} = {
  anchorKey: '',
  anchorOffset: 0,
  focusKey: '',
  focusOffset: 0,
  isBackward: false,
  hasFocus: false
};
/* $FlowFixMe[unclear-type] This comment suppresses an error found when
 * automatically adding a type annotation with the codemod Komodo/Annotate_
 * exports. To see the error delete this comment and run Flow. */

const SelectionStateRecord = (Record(defaultRecord): any);

class SelectionState extends SelectionStateRecord {
  serialize(): string {
    return 'Anchor: ' + this.getAnchorKey() + ':' + this.getAnchorOffset() + ', ' + 'Focus: ' + this.getFocusKey() + ':' + this.getFocusOffset() + ', ' + 'Is Backward: ' + String(this.getIsBackward()) + ', ' + 'Has Focus: ' + String(this.getHasFocus());
  }

  getAnchorKey(): string {
    return this.get('anchorKey');
  }

  getAnchorOffset(): number {
    return this.get('anchorOffset');
  }

  getFocusKey(): string {
    return this.get('focusKey');
  }

  getFocusOffset(): number {
    return this.get('focusOffset');
  }

  getIsBackward(): boolean {
    return this.get('isBackward');
  }

  getHasFocus(): boolean {
    return this.get('hasFocus');
  }
  /**
   * Return whether the specified range overlaps with an edge of the
   * SelectionState.
   */


  hasEdgeWithin(blockKey: string, start: number, end: number): boolean {
    const anchorKey = this.getAnchorKey();
    const focusKey = this.getFocusKey();

    if (anchorKey === focusKey && anchorKey === blockKey) {
      const selectionStart = this.getStartOffset();
      const selectionEnd = this.getEndOffset();
      return start <= selectionStart && selectionStart <= end || // selectionStart is between start and end, or
      start <= selectionEnd && selectionEnd <= end // selectionEnd is between start and end
      ;
    }

    if (blockKey !== anchorKey && blockKey !== focusKey) {
      return false;
    }

    const offsetToCheck = blockKey === anchorKey ? this.getAnchorOffset() : this.getFocusOffset();
    return start <= offsetToCheck && end >= offsetToCheck;
  }

  isCollapsed(): boolean {
    return this.getAnchorKey() === this.getFocusKey() && this.getAnchorOffset() === this.getFocusOffset();
  }

  getStartKey(): string {
    return this.getIsBackward() ? this.getFocusKey() : this.getAnchorKey();
  }

  getStartOffset(): number {
    return this.getIsBackward() ? this.getFocusOffset() : this.getAnchorOffset();
  }

  getEndKey(): string {
    return this.getIsBackward() ? this.getAnchorKey() : this.getFocusKey();
  }

  getEndOffset(): number {
    return this.getIsBackward() ? this.getAnchorOffset() : this.getFocusOffset();
  }

  static createEmpty(key: string): SelectionState {
    return new SelectionState({
      anchorKey: key,
      anchorOffset: 0,
      focusKey: key,
      focusOffset: 0,
      isBackward: false,
      hasFocus: false
    });
  }

}

module.exports = SelectionState;