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

import { IndentationRule } from '../../../../../vs/editor/common/modes/languageConfiguration';

export const enum IndentConsts {
  INCREASE_MASK = 0b00000001,
  DECREASE_MASK = 0b00000010,
  INDENT_NEXTLINE_MASK = 0b00000100,
  UNINDENT_MASK = 0b00001000,
}

function resetGlobalRegex(reg: RegExp) {
  if (reg.global) {
    reg.lastIndex = 0;
  }

  return true;
}

export class IndentRulesSupport {
  private readonly _indentationRules: IndentationRule;

  constructor(indentationRules: IndentationRule) {
    this._indentationRules = indentationRules;
  }

  public shouldIncrease(text: string): boolean {
    if (this._indentationRules) {
      if (
        this._indentationRules.increaseIndentPattern &&
        resetGlobalRegex(this._indentationRules.increaseIndentPattern) &&
        this._indentationRules.increaseIndentPattern.test(text)
      ) {
        return true;
      }
      // if (this._indentationRules.indentNextLinePattern && this._indentationRules.indentNextLinePattern.test(text)) {
      // 	return true;
      // }
    }
    return false;
  }

  public shouldDecrease(text: string): boolean {
    if (
      this._indentationRules &&
      this._indentationRules.decreaseIndentPattern &&
      resetGlobalRegex(this._indentationRules.decreaseIndentPattern) &&
      this._indentationRules.decreaseIndentPattern.test(text)
    ) {
      return true;
    }
    return false;
  }

  public shouldIndentNextLine(text: string): boolean {
    if (
      this._indentationRules &&
      this._indentationRules.indentNextLinePattern &&
      resetGlobalRegex(this._indentationRules.indentNextLinePattern) &&
      this._indentationRules.indentNextLinePattern.test(text)
    ) {
      return true;
    }

    return false;
  }

  public shouldIgnore(text: string): boolean {
    // the text matches `unIndentedLinePattern`
    if (
      this._indentationRules &&
      this._indentationRules.unIndentedLinePattern &&
      resetGlobalRegex(this._indentationRules.unIndentedLinePattern) &&
      this._indentationRules.unIndentedLinePattern.test(text)
    ) {
      return true;
    }

    return false;
  }

  public getIndentMetadata(text: string): number {
    let ret = 0;
    if (this.shouldIncrease(text)) {
      ret += IndentConsts.INCREASE_MASK;
    }
    if (this.shouldDecrease(text)) {
      ret += IndentConsts.DECREASE_MASK;
    }
    if (this.shouldIndentNextLine(text)) {
      ret += IndentConsts.INDENT_NEXTLINE_MASK;
    }
    if (this.shouldIgnore(text)) {
      ret += IndentConsts.UNINDENT_MASK;
    }
    return ret;
  }
}