import type { PhpRuntimeValue } from '../_helpers/_phpTypes.ts'

type IntValue = PhpRuntimeValue

export function is_int(mixedVar: IntValue): mixedVar is number {
  //      discuss at: https://locutus.io/php/is_int/
  // parity verified: PHP 8.3
  //     original by: Alex
  //     improved by: Kevin van Zonneveld (https://kvz.io)
  //     improved by: WebDevHobo (https://webdevhobo.blogspot.com/)
  //     improved by: Rafał Kukawski (https://blog.kukawski.pl)
  //      revised by: Matt Bradley
  //     bugfixed by: Kevin van Zonneveld (https://kvz.io)
  //          note 1: 1.0 is simplified to 1 before it can be accessed by the function, this makes
  //          note 1: it different from the PHP implementation. We can't fix this unfortunately.
  //       example 1: is_int(23)
  //       returns 1: true
  //       example 2: is_int('23')
  //       returns 2: false
  //       example 3: is_int(23.5)
  //       returns 3: false
  //       example 4: is_int(true)
  //       returns 4: false

  const num = Number(mixedVar)
  return typeof mixedVar === 'number' && mixedVar === num && Number.isFinite(num) && Number.isInteger(num)
}