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

import { IRange } from '../../../../../vs/editor/common/core/range';
import { IInplaceReplaceSupportResult } from '../../../../../vs/editor/common/modes';

export class BasicInplaceReplace {
  public static readonly INSTANCE = new BasicInplaceReplace();

  public navigateValueSet(
    range1: IRange,
    text1: string,
    range2: IRange,
    text2: string | null,
    up: boolean
  ): IInplaceReplaceSupportResult | null {
    if (range1 && text1) {
      let result = this.doNavigateValueSet(text1, up);
      if (result) {
        return {
          range: range1,
          value: result,
        };
      }
    }

    if (range2 && text2) {
      let result = this.doNavigateValueSet(text2, up);
      if (result) {
        return {
          range: range2,
          value: result,
        };
      }
    }

    return null;
  }

  private doNavigateValueSet(text: string, up: boolean): string | null {
    let numberResult = this.numberReplace(text, up);
    if (numberResult !== null) {
      return numberResult;
    }
    return this.textReplace(text, up);
  }

  private numberReplace(value: string, up: boolean): string | null {
    let precision = Math.pow(10, value.length - (value.lastIndexOf('.') + 1));
    let n1 = Number(value);
    let n2 = parseFloat(value);

    if (!isNaN(n1) && !isNaN(n2) && n1 === n2) {
      if (n1 === 0 && !up) {
        return null; // don't do negative
        //			} else if(n1 === 9 && up) {
        //				return null; // don't insert 10 into a number
      } else {
        n1 = Math.floor(n1 * precision);
        n1 += up ? precision : -precision;
        return String(n1 / precision);
      }
    }

    return null;
  }

  private readonly _defaultValueSet: string[][] = [
    ['true', 'false'],
    ['True', 'False'],
    [
      'Private',
      'Public',
      'Friend',
      'ReadOnly',
      'Partial',
      'Protected',
      'WriteOnly',
    ],
    ['public', 'protected', 'private'],
  ];

  private textReplace(value: string, up: boolean): string | null {
    return this.valueSetsReplace(this._defaultValueSet, value, up);
  }

  private valueSetsReplace(
    valueSets: string[][],
    value: string,
    up: boolean
  ): string | null {
    let result: string | null = null;
    for (let i = 0, len = valueSets.length; result === null && i < len; i++) {
      result = this.valueSetReplace(valueSets[i], value, up);
    }
    return result;
  }

  private valueSetReplace(
    valueSet: string[],
    value: string,
    up: boolean
  ): string | null {
    let idx = valueSet.indexOf(value);
    if (idx >= 0) {
      idx += up ? +1 : -1;
      if (idx < 0) {
        idx = valueSet.length - 1;
      } else {
        idx %= valueSet.length;
      }
      return valueSet[idx];
    }
    return null;
  }
}