import nodePath from 'path'

export function realpath(path: string): string {
  //  discuss at: https://locutus.io/php/realpath/
  // original by: mk.keck
  // improved by: Kevin van Zonneveld (https://kvz.io)
  //      note 1: Returned path is an url like e.g. 'https://yourhost.tld/path/'
  //   example 1: realpath('some/dir/.././_supporters/pj_test_supportfile_1.htm')
  //   returns 1: 'some/_supporters/pj_test_supportfile_1.htm'

  if (typeof window === 'undefined') {
    return nodePath.normalize(path)
  }

  let hasProtocol = false
  let parts: string[] = [] // Save the root, if not given
  const href = window.location.href // Avoid input failures

  // Check if there's a port in path (like 'https://')
  let normalizedPath = String(path).replace('\\', '/')
  if (normalizedPath.includes('://')) {
    hasProtocol = true
  }

  // Ok, there's not a port in path, so let's take the root
  if (!hasProtocol) {
    normalizedPath = href.substring(0, href.lastIndexOf('/') + 1) + normalizedPath
  }

  // Explode the given path into it's parts
  parts = normalizedPath.split('/') // The path is an array now
  const resolvedParts: string[] = [] // Foreach part make a check
  for (const part of parts) {
    // This is'nt really interesting
    if (part === '.') {
      continue
    }
    // This reduces the realpath
    if (part === '..') {
      /* But only if there more than 3 parts in the path-array.
       * The first three parts are for the uri */
      if (resolvedParts.length > 3) {
        resolvedParts.pop()
      }
    } else {
      // This adds parts to the realpath
      // But only if the part is not empty or the uri
      // (the first three parts ar needed) was not
      // saved
      if (resolvedParts.length < 2 || part !== '') {
        resolvedParts.push(part)
      }
    }
  }

  // Returns the absloute path as a string
  return resolvedParts.join('/')
}