#requires -version 2
#CompareFolder.ps1
# Compares the contents of two folders.
# Usage:
#   CompareFolder.ps1 "<Known Good Folder>" "<Folder to Check>"
# Created by sylver_dragon (reddit.com) 9/21/2010
# Version History:
#   0.1 - File Creation (sylver_dragon) 9/21/2010
#   1.0 - Script functional (sylver_dragon) 9/21/2010
Param(
  [switch]$Recurse,
  [switch]$Repair,
  [switch]$RemoveExtras,
  [Parameter(Position=0, Mandatory=$true)]
    [string]$KnownGood = $(throw "Please provide the Known Good folder"),
  [Parameter(Position=1, Mandatory=$true)]
    [string]$CheckFolder = $(throw "Please provide the folder to check"),
  [Parameter(Position=2, Mandatory=$false)]
    [string]$ReportLocation = (Get-Location).Path + "CompareFolderReport_" + (Get-Date).ToFileTime() + ".xml"
  )

$ErrorActionPreference = "Stop"

function MD5Hash($sFileName)
{
  $inFile = New-Object System.IO.StreamReader($sFileName)
  $Crypto = [System.Security.Cryptography.MD5]::Create()
  $hashArray = $Crypto.ComputeHash($inFile.BaseStream)
  $inFile.Close()
  foreach ($byte in $hashArray) { $rtn += “{0:X2}” -f $byte}
  return $rtn
}

# ********** Main Function **********
# Check for both folders existance
if(!(test-path $KnownGood))
{
  throw "Unable to connect to $KnownGood, Please check the folder and try again"
}
if(!(test-path $CheckFolder))
{
  throw "Unable to connect to $CheckFolder, Please check the folder and try again"
}

# Make sure that both paths end with a backslash
if($KnownGood[-1] -ne "\")
{
  $KnownGood += "\"
}
if($CheckFolder[-1] -ne "\")
{
  $CheckFolder += "\"
}

# Get the file lists
if($Recurse)
{
  $GoodList = Get-ChildItem -Recurse $KnownGood | Where{$_.PSIsContainer -eq $false} | ForEach{$_.FullName -replace $KnownGood.replace("\","\\").replace("$","\$"),""}
  $CheckList = Get-ChildItem -Recurse $CheckFolder | Where{$_.PSIsContainer -eq $false} | ForEach{$_.FullName -replace $CheckFolder.replace("\","\\").replace("$","\$"),""}
}
else
{
  $GoodList = Get-ChildItem $KnownGood | Where{$_.PSIsContainer -eq $false} | ForEach{$_.Name}
  $CheckList = Get-ChildItem $CheckFolder | Where{$_.PSIsContainer -eq $false} | ForEach{$_.Name}
}

# Build the report framework and add the settings
$xmlReport = new-object System.xml.xmlDataDocument
$xeRoot =  $xmlReport.CreateElement("report")
$result = $xmlReport.AppendChild($xeRoot)
$xeSettings = $xmlReport.CreateElement("settings")
$xeSettings.SetAttribute("KnownGood",$KnownGood)
$xeSettings.SetAttribute("CheckFolder",$CheckFolder)
$xeSettings.SetAttribute("Recurse",$Recurse)
$xeSettings.SetAttribute("Repair",$Repair)
$xeSettings.SetAttribute("Runtime",(Get-Date).ToString())
$result = $xeRoot.AppendChild($xeSettings)
$xeMissing = $xmlReport.CreateElement("missing")
$result = $xeRoot.AppendChild($xeMissing)
$xeExtra = $xmlReport.CreateElement("extra")
$result = $xeRoot.AppendChild($xeExtra)
$xeMismatch = $xmlReport.CreateElement("mismatch")
$result = $xeRoot.AppendChild($xeMismatch)
$xeMatch = $xmlReport.CreateElement("match")
$result = $xeRoot.AppendChild($xeMatch)
$xeErrors = $xmlReport.CreateElement("errors")
$result = $xeRoot.AppendChild($xeErrors)

ForEach($sFile in $GoodList)
{
  if($CheckList -contains $sFile)
  {
    $GoodFullName = $KnownGood + $sFile
    $CheckFullName = $CheckFolder + $sFile
    $GoodHash = MD5Hash($GoodFullName)
    $CheckHash = MD5Hash($CheckFullName)
    if($CheckHash -eq $GoodHash) # Handles matches
    {
      $xeFile = $xmlReport.CreateElement("file")
      $xeFile.SetAttribute("Name",$sFile)
      $result = $xeMatch.AppendChild($xeFile)
    }
    else # Handles mismatches
    {
      $xeFile = $xmlReport.CreateElement("file")
      $xeFile.SetAttribute("Name",$sFile)
      $xeFile.SetAttribute("GoodHash",$GoodHash)
      $xeFile.SetAttribute("CheckHash",$CheckHash)
      if($Repair)
      {
        Copy-Item $GoodFullName $CheckFullName
        $ReCheckHash = MD5Hash($CheckFullName)
        if($ReCheckHash -ne $GoodHash)
        {
          $xeFile.SetAttribute("repaired",$false)
          $xeError = $xmlReport.CreateElement("error")
          $xeError.SetAttribute("type","Mismatch Repair")
          $xeError.SetAttribute("filename",$sFile)
          $xeError.SetAttribute("GoodHash",$GoodHash)
          $xeError.SetAttribute("CheckHash",$CheckHash)
          $xeError.SetAttribute("ReCheckHash",$ReCheckHash)
          $result = $xeErrors.AppendChild($xeError)
        }
        else
        {
          $xeFile.SetAttribute("repaired",$true)
        }
      }
      else
      {
        $xeFile.SetAttribute("repaired",$false)
      }
      $result = $xeMismatch.AppendChild($xeFile)
    }
  }
  else # handles missing
  {
    $xeFile = $xmlReport.CreateElement("file")
    $xeFile.SetAttribute("name",$sFile)
    if($Repair)
    {
      $GoodFullName = $KnownGood + $sFile
      $CheckFullName = $CheckFolder + $sFile
      $sFullPath = ""
      For($i = 0;$i -lt ($CheckFullName.split("\").length) - 1;$i++)
      {
        $sFullPath += ($CheckFullName.split("\"))[$i] + "\"
      }
      if(!(test-path $sFullPath))
      {
        $result = New-Item -Type Directory -Path $sFullPath
      }
      Copy-Item $GoodFullName $CheckFullName
      $GoodHash = MD5Hash($GoodFullName)
      $ReCheckHash = MD5Hash($CheckFullName)
      if($ReCheckHash -ne $GoodHash)
      {
        $xeFile.SetAttribute("repaired",$false)
        $xeError = $xmlReport.CreateElement("error")
        $xeError.SetAttribute("type","Missing Repair")
        $xeError.SetAttribute("filename",$sFile)
        $xeError.SetAttribute("GoodHash",$GoodHash)
        $xeError.SetAttribute("ReCheckHash",$ReCheckHash)
        $result = $xeErrors.AppendChild($xeError)
      }
      else
      {
        $xeFile.SetAttribute("repaired",$true)
      }
    }
    else
    {
      $xeFile.SetAttribute("repaired",$false)
    }
    $result = $xeMissing.AppendChild($xeFile)
  }
}

ForEach($sFile in $CheckList)
{
  if(!($GoodList -contains $sFile)) # Handles extra files
  {
    $xeFile = $xmlReport.CreateElement("file")
    $xeFile.SetAttribute("name",$sFile)
    if($RemoveExtras)
    {
      $RemoveFile = $CheckFolder + $sFile
      Remove-Item $RemoveFile -Force
      $xeFile.SetAttribute("removed",$true)
    }
    else
    {
      $xeFile.SetAttribute("removed",$false)
    }
    $result = $xeExtra.AppendChild($xeFile)
  }
}

$xmlReport.Save($ReportLocation)