$baseDirectory = "...\files"
$fileDestination = "...\folder_of_hash"
$hashFilePath = "...\hashes.txt"
$hashesFromFile = @{}
$currentHashes = @{}

function mapAllFiles($basePath) {
  $subFolders = Get-ChildItem $basePath -Directory | foreach {$basePath + "\" + $_.Name} | foreach {mapAllFiles $_}
  $allFilesPath = Get-ChildItem $basePath -File | foreach {$basePath + "\" + $_.Name} | foreach {addFileToMap $_}
}

function exportToFile {
  $currentHashes.GetEnumerator() | Sort-Object Name | foreach {"{0} = {1}" -f $_.Name,$_.Value}  | Add-Content "$fileDestination\hashes.txt"
}

function generateHashFile {
  $currentHashes = @{}
  exportToFile (mapAllFiles $baseDirectory)
}

function addFileToMap($filePath) {
  $hash = Get-FileHash $filePath -Algorithm SHA256 | Select Hash
  $currentHashes.Add($filePath.replace($baseDirectory, ""), $hash.Hash)
}

function compareHashes {
  $currentHashes = @{}
  $hashesFromFile = Get-Content $hashFilePath -Raw | ConvertFrom-StringData

  mapAllFiles $baseDirectory

  foreach ($file in $currentHashes.Keys) {
    if ($currentHashes[$file] -ne $hashesFromFile[$file]){
      Write-Host "Mismatch between hashes at : $file" -BackgroundColor "Red" -ForegroundColor "White"
      exit
    }
    else {
      Write-Host "$file matched ✓" -BackgroundColor "Green" -ForegroundColor "White"
    }
  }

  Write-Host "all files matched ✓✓✓" -BackgroundColor "Green" -ForegroundColor "Black"
}