BattleFaction2019.psm1
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function Get-CaesarCipher { [CmdletBinding()] param ( [parameter(Mandatory = $true)] [string]$Text, [parameter(Mandatory = $true)] [int]$SecretNumber, [string]$RootString = $([char[]]$(32..126) -join ''), [switch]$Encode, [switch]$Decode ) begin { # If you are decoding, you need to reverse the lookup if ($Decode) { $SecretNumber = -$SecretNumber } # Modulus is used to keep the values inside array of possible positions $Modulus = $RootString.length Write-Verbose "Modulus: $Modulus" If ($SecretNumber -lt 0) { $SecretNumber = $Modulus + ($SecretNumber % $Modulus) } Write-Verbose $SecretNumber } process { # Build 2 hashtables. One for looking a letter based on poition in the string and one for looking up the position in the string based on the letter $Counter = @{ } $Letter = @{ } $i = 0 [int[]][char[]]$RootString | ForEach-Object { $Counter.add($i, $_); $Letter.Add($_, $i); $i++ } # Convert original chars to the char ints matching the secret number $Converted = [int[]][char[]]$Text | ForEach-Object { try { if ($_ -eq 10 -or $_ -eq 13) { $_ } else { $no = $letter[$_] $Counter[$($($no + $SecretNumber) % $Modulus)] } } catch { Write-Warning "Error on $_" } } } end { # Just joining the string would remove new line carriage return, formatting a string allows them to expand correctly $str = "" for ($j = 0; $j -le $Converted.count - 1; $j++) { $str += "{$j}" } $str -f $($Converted.foreach{ [char]$_ }) } } |