'use strict';

const path = require('path');
const win32 = process.platform === 'win32';
const {
  REGEX_SPECIAL_CHARS,
  REGEX_SPECIAL_CHARS_GLOBAL,
  REGEX_REMOVE_BACKSLASH
} = require('./constants');

exports.isObject = val => val !== null && typeof val === 'object' && !Array.isArray(val);
exports.hasRegexChars = str => REGEX_SPECIAL_CHARS.test(str);
exports.isRegexChar = str => str.length === 1 && exports.hasRegexChars(str);
exports.escapeRegex = str => str.replace(REGEX_SPECIAL_CHARS_GLOBAL, '\\$1');
exports.toPosixSlashes = str => str.replace(/\\/g, '/');

exports.removeBackslashes = str => {
  return str.replace(REGEX_REMOVE_BACKSLASH, match => {
    return match === '\\' ? '' : match;
  });
}

exports.supportsLookbehinds = () => {
  let segs = process.version.slice(1).split('.');
  if (segs.length === 3 && +segs[0] >= 9 || (+segs[0] === 8 && +segs[1] >= 10)) {
    return true;
  }
  return false;
};

exports.isWindows = options => {
  if (options && typeof options.windows === 'boolean') {
    return options.windows;
  }
  return win32 === true || path.sep === '\\';
};

exports.escapeLast = (input, char, lastIdx) => {
  let idx = input.lastIndexOf(char, lastIdx);
  if (idx === -1) return input;
  if (input[idx - 1] === '\\') return exports.escapeLast(input, char, idx - 1);
  return input.slice(0, idx) + '\\' + input.slice(idx);
};