#requires -version 2.0

# -----------------------------------------------------------------------------
# Script: Out-Rainbow.ps1
# Version: 1.0
# Author: Jeffery Hicks
#    http://jdhitsolutions.com/blog
#    http://twitter.com/JeffHicks
# Date: 1/21/2011
# Keywords:
# Comments:
# This function works best with the PowerShell console. It will 
# work with the ISE but the background color won't be filtered out.
#
# "Those who neglect to script are doomed to repeat their work."
#
#  ****************************************************************
#  * DO NOT USE IN A PRODUCTION ENVIRONMENT UNTIL YOU HAVE TESTED *
#  * THOROUGHLY IN A LAB ENVIRONMENT. USE AT YOUR OWN RISK.  IF   *
#  * YOU DO NOT UNDERSTAND WHAT THIS SCRIPT DOES OR HOW IT WORKS, *
#  * DO NOT USE IT OUTSIDE OF A SECURE, TEST SETTING.             *
#  ****************************************************************
# -----------------------------------------------------------------------------

Function Out-Rainbow {

<#
   .Synopsis
    Write rainbow colored output to the console.
    .Description
    This function takes string input and writes each word in a random color to the host.
    The function works best with the PowerShell console.
    .Parameter Message
    The string of text to colorize.
    .Parameter Background
    Temporarily change the background color. The screen will be cleared. At the end of the
    command the background color will be changed back and you will manually need to run
    Clear-Host.
    
    Valid colors are:  "Black","DarkMagenta","DarkRed","DarkBlue","DarkGreen","DarkCyan",
    "DarkYellow","Red","Blue","Green","Cyan","Magenta","Yellow","DarkGray","Gray","White"
   .Example
    PS C:\>"Take the first step in faith. You don't have to see the whole staircase,",
"just take the first step.",
"  --Martin Luther King, Jr." | out-Rainbow
    
    .Example
    PS C:\> (get-process w* | out-string).Split("`r") | out-rainbow
  
    You'll get better results by converting the output to a string and then splitting it so
    that each line is processed completely by the function.
   .Notes
    NAME: Out-Rainbow
    AUTHOR: Jeffery Hicks
    VERSION: 1.0
    LASTEDIT: 01/21/2011
    
    Learn more with a copy of Windows PowerShell 2.0: TFM (SAPIEN Press 2010)
    
   .Link
http://jdhitsolutions.com/blog/2011/01/friday-fun-out-rainbow/
    
    .Link
    Write-Host
    .Inputs
    Strings
    
    .Outputs
    None
#>

Param (
  [Parameter(Position=0,Mandatory=$False,HelpMessage="Enter a message to display.",
  ValueFromPipeline=$True)]
  [string[]]$Message,
  
  [Parameter(Mandatory=$False,ValueFromPipeline=$False)]
  [ValidateSet("Black","DarkMagenta","DarkRed","DarkBlue",
    "DarkGreen","DarkCyan","DarkYellow","Red",
    "Blue","Green","Cyan","Magenta","Yellow",
    "DarkGray","Gray","White")]
  [string]$Background=$Host.UI.RawUI.BackGroundColor
  )
  
Begin
{
    #measure the $Message variable. A value of 0 means it was piped in
    #and a value greater than 0 means it as passed as a parameter
    #This has an affect on the processed output.
    if (($message | measure-object).Count -eq 0)
    {
        Write-Verbose "Pipelined input"
        $Pipelined=$True
    }
    
    #define the array of valid colors
    $AllColors=@(
    "Black","DarkMagenta","DarkRed","DarkBlue",
    "DarkGreen","DarkCyan","DarkYellow","Red",
    "Blue","Green","Cyan","Magenta","Yellow",
    "DarkGray","Gray","White"
    )
    
    Write-Verbose "Omitting $($host.ui.RawUI.Backgroundcolor) from color array"
    
    #filter out the current background color
    $colors=$AllColors | Where {$_ -ne $host.ui.RawUI.Backgroundcolor}
    
    #Check if -Background was called and if the value is different than the current
    #background.
    
    if ($Background -ne $Host.UI.RawUI.BackgroundColor)
    {
        #save current color
        $SavedBGColor=$Host.UI.RawUI.BackgroundColor
        #set background color
        $Host.UI.RawUI.BackgroundColor=$Background
        #need to clear the host for this to work properly
        Clear-Host
        Write-Verbose "Changed background color ro $Background"
    }
} #close Begin

Process 
{
    ForEach ($m in $Message) {
        Write-Verbose "Splitting message $m"
        #split the line into a word array
        $arr=$m.Split()
        Write-Verbose "Now have $($arr.count) words"
        
        for ($i=0;$i -lt $arr.count;$i++) 
        {
            #write each word followed by a space. Don't insert a new line
            Write-Host "$($arr[$i]) " -foregroundcolor $colors[(Get-Random -Min 0 -max ($colors.count-1))] -NoNewline       
        } #for
                  
         if (-Not $Pipelined)
         {
            #if not pipelined input then add a carriage retrun
            Write-host `r        
          }
    } #foreach
    
    #add a carriage return after each processed object
    write-host `r
    
    } #close Process

End
{
    #change the background color back if there is a saved color
    if ($SavedBGColor) 
    {
        Write-Verbose "Returning background color to $SavedBGColor"
        $host.UI.RawUI.BackgroundColor=$SavedBGColor
    }
    #write a carriage return for visual clarity
   Write-Host `r
   Write-Verbose "We've reached the end of the rainbow" 
} #close End

} #end function