• Waits up to two hours for backup to complete, if script starts while backup is still running (Looking for BACKUP_RUNNING file)
  
• Determines the proper incremental and base backup files from the current day, based on filenames
  
• Existing downloaded backup files are checked and not re-downloaded if they are present in the backup location and have the correct filesize (especially useful so that base backup files don't have to be downloaded every night, since they are only created once a week)
  
• Existing downloads with mismatched filesizes (likely incomplete downloads) are deleted and re-downloaded
• Daily Incremental backup is downloaded and the dependent base backup is also downloaded.
• Backups older than the user-defined age are automatically deleted. Base backups are kept until no saved incremental backups are dependent on them.
  
• Sends an email to user-defined address if any errors are encountered
• Notes in error email if the BACKUP_RUNNING file is from the previous day, indicating that the backup process may have gotten stuck
• Logs are saved in the script folder as well as being copied to the backup location
  

$BackupLocation = "\\server.address.or.ip\FolderShare\" #Destination for backups to be downloaded to (Can also be a local path)
$ServerPath = "kace.domain.com" #Your KACE Server Address
$FTPUser = "kbftp" #User for KACE FTP server (Can only be kbftp)
$FTPPass = "getbxf" #Password for KACE FTP server (getbxf is default, but can be changed at Settings>Security Settings>New FTP user password
$DaystoRetain = 30 #Days of backups to retain on the desitnation location. Backups older than 30 days will be automatically deleted.

$EmailUser = "domain\username" #Username for email account to send error emails from (Recommend using service account)
$EmailFrom = "serviceaccount@domain.com" #Email address for the selected account
$EmailPass = ConvertTo-SecureString "P@Ssw0rD" -AsPlainText -Force #Password for email account for sending error emails
$EmailTo = "serveradmin@domain.com" #Email which will recieve error emails
$PSEmailServer = "smtp.domain.com" #SMTP server for sending error emails

#------------------------------------------------------------------------------------

$cred = new-object -typename System.Management.Automation.PSCredential `
         -argumentlist $EmailUser, $EmailPass


function Write-Logline ($String){"[ "+(Get-Date).ToString()+" ]	"+$String | Out-File $LogfilePath -encoding ASCII -append}
function Write-Logline-Blank (){"" | Out-File $LogfilePath -encoding ASCII -append}

function get-DiskFreeSpaceEx{ 
    [cmdletbinding()] 
    param( 
        [parameter(mandatory=$true,position=0,ValueFromPipeLine=$true)] 
        [validatescript({(Test-Path $_ -IsValid)})] 
        [string]$path, 
        [parameter(mandatory=$false,position=1)] 
        [string]$unit="byte" 
    ) 
     
    begin{ 
        switch($unit){ 
            "byte" {$unitval = 1;break} 
            "kb" {$unitval = 1kb;break} 
            "mb" {$unitval = 1mb;break} 
            "gb" {$unitval = 1gb;break} 
            "tb" {$unitval = 1tb;break} 
            "pb" {$unitval = 1pb;break} 
            default {$unitval = 1;break} 
        } 
         
        $typeDefinition = @' 
[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)] 
[return: MarshalAs(UnmanagedType.Bool)] 
public static extern bool GetDiskFreeSpaceEx(string lpDirectoryName, 
    out ulong lpFreeBytesAvailable, 
    out ulong lpTotalNumberOfBytes, 
    out ulong lpTotalNumberOfFreeBytes); 
'@ 
     
    } 
    process{ 
        $freeBytesAvail = New-Object System.UInt64 
        $totalNoBytes = New-Object System.UInt64 
        $totalNoFreeBytes = New-Object System.UInt64 
         
        $type = Add-Type -MemberDefinition $typeDefinition -Name Win32Utils -Namespace GetDiskFreeSpaceEx -PassThru 
         
        $result = $type::GetDiskFreeSpaceEx($path,([ref]$freeBytesAvail),([ref]$totalNoBytes),([ref]$totalNoFreeBytes)) 
         
        $freeBytes = {if($result){$freeBytesAvail/$unitval}else{"N/A"}}.invoke()[0] 
        $totalBytes = {if($result){$totalNoBytes/$unitval}else{"N/A"}}.invoke()[0] 
        $totalFreeBytes = {if($result){$totalNoFreeBytes/$unitval}else{"N/A"}}.invoke()[0] 
         
        #New-Object PSObject -Property @{ 
        #    Success = $result 
        #    Path = $path 
        #    "Free`($unit`)" = $freeBytes 
        #    "total`($unit`)" = $totalBytes 
        #    "totalFree`($unit`)" = $totalFreeBytes 
        #}
		Return $freeBytes
    }  
}  

function Get-FTPModDate ($Source,$UserName,$password) 
{ 
	# Create a FTPWebRequest object to handle the connection to the ftp server 
    $ftprequest = [System.Net.FtpWebRequest]::create($Source) 
    # set the request's network credentials for an authenticated connection 
    $ftprequest.Credentials = 
        New-Object System.Net.NetworkCredential($username,$password) 
    $ftprequest.Method = [System.Net.WebRequestMethods+Ftp]::GetDateTimestamp 
    $ftprequest.UseBinary = $true 
    $ftprequest.KeepAlive = $false 
     
	try
		{
			# send the ftp request to the server 
			$ftpresponse = $ftprequest.GetResponse()
			$ModDate = $ftpresponse.LastModified.Date
			$today = Get-Date -displayhint date
			$DateDiff = New-TimeSpan $ModDate $today
			If($DateDiff.Days -lt 1){
				$Status = "Backup is Still Running. Pausing for 15 minutes..."
			}
			Else {
				$Status = "Backup File present, but it is from previous day. BACKUP PROCESS LIKELY STUCK. Pausing for 15 minutes..."
			}
			$ftpresponse.Close()
		}
		catch [System.Net.WebException]
		{
			#Write-Logline $_.Exception.ToString()
			$Status = "Y"
		}
    Return $Status 
}
function Get-FTPDirList ($Source,$UserName,$password) 
{ 
	# Create a FTPWebRequest object to handle the connection to the ftp server 
    $ftprequest = [System.Net.FtpWebRequest]::create($Source) 
    # set the request's network credentials for an authenticated connection 
    $ftprequest.Credentials = 
        New-Object System.Net.NetworkCredential($username,$password) 
    $ftprequest.Method = [System.Net.WebRequestMethods+Ftp]::ListDirectory 
    $ftprequest.UseBinary = $true 
    $ftprequest.KeepAlive = $false
	# send the ftp request to the server 
	$ftpresponse = $ftprequest.GetResponse()
	$stream = $ftpresponse.GetResponseStream()
	$buffer = new-object System.Byte[] 1024 
	$encoding = new-object System.Text.AsciiEncoding 

	$outputBuffer = "" 
	$foundMore = $false 

	## Read all the data available from the stream, writing it to the 
	## output buffer when done. 
	do 
	{ 
		## Allow data to buffer for a bit 
		start-sleep -m 1000 

		## Read what data is available 
		$foundmore = $false 
		$stream.ReadTimeout = 500

		do 
		{ 
			try 
			{ 
				$read = $stream.Read($buffer, 0, 1024) 

				if($read -gt 0) 
				{ 
					$foundmore = $true 
					$outputBuffer += ($encoding.GetString($buffer, 0, $read))
				} 
			} catch { $foundMore = $false; $read = 0 } 
		} while($read -gt 0) 
	} while($foundmore)

	$ftpresponse.Close()
	Return $outputBuffer
	
}
function Get-FTPFilesize ($DestFolder,$ServerPath,$Filename,$UserName,$Password)
{ 
	$DestFreeSpace = get-DiskFreeSpaceEx $DestFolder -unit bytes
	#Write-Logline "Destination free space: $DestFreeSpace"
	$destfilepath = $DestFolder+$Filename
	$Source = "ftp://"+$ServerPath+"/"+$Filename
	
	#Write-Logline "Testing $Source and $destfilepath"
	
	# Create a FTPWebRequest object to handle the connection to the ftp server 
	$ftprequest = [System.Net.FtpWebRequest]::create($Source) 
	 
	# set the request's network credentials for an authenticated connection 
	$ftprequest.Credentials = 
		New-Object System.Net.NetworkCredential($username,$password) 
	 
	$ftprequest.Method = [System.Net.WebRequestMethods+Ftp]::GetFileSize 
	$ftprequest.UseBinary = $true 
	$ftprequest.KeepAlive = $false 
	 
	# send the ftp request to the server 
	$ftpresponse = $ftprequest.GetResponse() 

	$SourceSize = $ftpresponse.ContentLength
	$ftpresponse.Close()
	
	#Write-Logline "Source size: $SourceSize"
	
	$TestPath = Test-Path $destfilepath
	#Write-Logline $TestPath
			
	If((Test-Path $destfilepath) -eq $true) {

		$destfile = Get-Item $destfilepath
		$destfilesize = $destfile.length
		If ($SourceSize -eq $destfilesize) {
			#Destination file is present and sizes match, which is a pretty good indication that the transfer was successful.
			Return $true
		}
		Else {
			If(($DestFreeSpace+$destfilesize) -lt $SourceSize) {
				Goto-Error-Exit "NOT ENOUGH FREE SPACE FOR BACKUP. BACKUP OF FILE $FileName WAS ABORTED."
			}
			Else {
				#Destination file is present, but sizes don't match. This must be a failed or corrupt transfer, so we'll have to delete and retry.
				$SourceSizeGB = [string] ([math]::round($SourceSize/1024/1024/1024,2))
				$SourceSize = [string] $SourceSize
				Write-Logline "$Filename is present on backup location, but sizes don't match. Deleting failed transfer."
				Write-Logline "Size of [$Filename] to download: $SourceSizeGB GB ($SourceSize bytes)"
				Write-Logline "Sufficient free space on destination ($DestFreeSpace bytes)"
				Remove-Item $destfile
				Return $false
			}
		}
	}
	Else {
		If($DestFreeSpace -lt $SourceSize) {
			Goto-Error-Exit "NOT ENOUGH FREE SPACE FOR BACKUP. BACKUP OF FILE $FileName WAS ABORTED."
		}
		Else {
			#Destination File not yet present
			$SourceSizeGB = [string] ([math]::round($SourceSize/1024/1024/1024,2))
			$SourceSize = [string] $SourceSize
			Write-Logline "Size of [$Filename] to download: $SourceSizeGB GB ($SourceSize bytes)"
			Write-Logline "Sufficient free space on destination ($DestFreeSpace bytes)"
			Return $false
		}
	}
}

function Get-FTPFile ($DestFolder,$ServerPath,$Filename,$UserName,$FTPpassword) 
    { 
    $target = $DestFolder+$Filename
	$Source = "ftp://"+$ServerPath+"/"+$Filename
    # Create a FTPWebRequest object to handle the connection to the ftp server 
    $ftprequest = [System.Net.FtpWebRequest]::create($Source) 
     
    # set the request's network credentials for an authenticated connection 
    $ftprequest.Credentials = 
        New-Object System.Net.NetworkCredential($username,$FTPpassword) 
     
    $ftprequest.Method = [System.Net.WebRequestMethods+Ftp]::DownloadFile 
    $ftprequest.UseBinary = $true 
    $ftprequest.KeepAlive = $false 
     
    # send the ftp request to the server 
    $ftpresponse = $ftprequest.GetResponse() 
     
    # get a download stream from the server response 
    $responsestream = $ftpresponse.GetResponseStream() 
     
    # create the target file on the local system and the download buffer 
    $targetfile = New-Object IO.FileStream ($Target,[IO.FileMode]::Create) 
    [byte[]]$readbuffer = New-Object byte[] 1024 
     
    # loop through the download stream and send the data to the target file 
    do{ 
        $readlength = $responsestream.Read($readbuffer,0,1024) 
        $targetfile.Write($readbuffer,0,$readlength) 
    } 
    while ($readlength -ne 0) 
     
    $targetfile.close() 
    }
	
function Send-Error-Email ($ErrorText) {
	Write-Logline "$ErrCt error(s) were encountered. Sending Error email."
	$LogContents = [IO.File]::ReadAllText($LogfilePath)
	$LogContentsHTML = $LogContents -Replace "`n", "</br>"
	$Body = "Hello KACE Team,</br><h3>The backup process for server <font color=""blue"">$ServerPath</font> encountered an error.</h3></br><h4>Error text:</h4>$ErrorText</br></br><h4>Full Logs:</h4>$LogContentsHTML</br></br>"
	#$Body += $LogContents
	echo $ErrCt
	$Subjectvar = "Backup Log, Error Count: $ErrCt"
	$Subject = [string] $Subjectvar
	Send-MailMessage -To $EmailTo -from $EmailFrom -Subject $Subject -BodyAsHtml $Body -Port 587 -Priority: High
}
	
function Goto-Error-Exit ($ErrorString) {
	Write-Logline "Encountered Fatal Error. Sending Error Email and exiting."
	Write-Logline $ErrorString
	Send-Error-Email $ErrorString
	#Copy log file to network/backup share
	if ( -not ( Test-Path $BackupLocation"Logs" -PathType Container )) { 
		New-Item -Path $BackupLocation"Logs" -ItemType directory
	}
	Copy-Item $LogfilePath $BackupLocation"Logs"
	exit 1
}

#-------------------------------------------------------------------------------------
#-------------------------------------------------------------------------------------
#-----------------------------------MAIN STARTS HERE----------------------------------
#-------------------------------------------------------------------------------------
#-------------------------------------------------------------------------------------

$ErrCt = 0
$CurDir = Split-Path $MyInvocation.MyCommand.Path
$CurDate = (get-date).tostring("yyyyMMdd")
$CurTime = (get-date).tostring("HHmmss")

$LogsPath = $CurDir + "\Logs\"
$LogfileName = $CurDate + "_backuplog.txt"
if ( -not ( Test-Path $LogsPath -PathType Container )) { 
	New-Item -Path $LogsPath -ItemType directory
}
$LogfilePath = $LogsPath + $LogfileName
$LogFileExists = Test-Path $LogfilePath
If ($LogFileExists -eq $True) {
	$LogfileName = $CurDate + "_" + $CurTime + "_backuplog.txt"
	$LogfilePath = $LogsPath + $LogfileName
}

Write-Logline "Backing up $ServerPath to $BackupLocation"

$Count=0
Do {
	$BackupComplete = Get-FTPModDate "ftp://$serverpath/BACKUP_RUNNING" $FTPUser $FTPpass
	If ($BackupComplete -eq "Y") {
		Write-Logline "-->Onboard backup appears complete. Proceeding with offload."
		$BackupStillRunning = $false
	}
	Else {
		#Backup isn't complete, so we'll pause for 15 minutes to try and wait for it to finish. Writing the status we recieved from the Get-FTPModDate function to the log.
		Write-Logline $BackupComplete
		Start-Sleep -s 900
		$BackupStillRunning = $true
		$Count += 1
	}
} while($BackupStillRunning -and $Count -lt 8)
$Count=0
Do {
$FileList = Get-FTPDirList "ftp://$ServerPath" $FTPUser $FTPpass
$Count+=1
} while($FileList -eq "" -and $Count -lt 2)
If($FileList -eq "") {
	$ErrCt+=1
	Goto-Error-Exit "Unable to retrieve file list from FTP server."
}
$IncrPattern = ".+_k1_incr.*"+$CurDate+".tgz"
$FileList -match $IncrPattern
$IncrFile = $matches[0]
echo "Incremental File: $IncrFile"
Write-Logline-Blank
Write-Logline "Incremental File to Download:	[$IncrFile]"
$BaseDate = $IncrFile.substring(0,8)
$BasePattern = $BaseDate+"_k1_base_.*tgz"
$FileList -match $BasePattern
$BaseFile = $matches[0]
echo "Base File: $BaseFile"
Write-Logline "Base File to Download:		[$BaseFile]"
$Count=0
#Check for (properly sized) existing Incremental File
If ($IncrFile -ne "") {
	$TestIncr = Get-FTPFilesize $BackupLocation $ServerPath $IncrFile $FTPuser $FTPpass
	If (-not ($TestIncr)) {
		Do {
			Write-Logline "Copying $IncrFile to $BackupLocation"
			Get-FTPFile $BackupLocation $ServerPath $IncrFile $FTPuser $FTPpass
			$TestIncr = Get-FTPFilesize $BackupLocation $ServerPath $IncrFile $FTPuser $FTPpass
			$Count+=1
		} Until($TestIncr -or $Count -gt 2)
		If (-not ($TestIncr)) {
			$ErrCt+=1
			Write-Logline "Copying of Incremental file [$IncrFile] FAILED."
			$ErrorText+= "Copying of Incremental file [$IncrFile] FAILED."
		}
	}
	ELSE {
		Write-Logline "Incremental File [$IncrFile] is already present and sizes match."
	}
}
Else {
	$ErrCt+=1
	$ErrorText += "Could not identify Incremental Backup for today."
}
$Count=0
#Check for (properly sized) existing BASE File
If ($BaseFile -ne "") {
	$TestBase = Get-FTPFilesize $BackupLocation $ServerPath $BaseFile $FTPuser $FTPpass
	If (-not $TestBase) {
		Do {
			Write-Logline "Copying $BaseFile to $BackupLocation"
			Get-FTPFile $BackupLocation $ServerPath $BaseFile $FTPuser $FTPpass
			$TestBase = Get-FTPFilesize $BackupLocation $ServerPath $BaseFile $FTPuser $FTPpass
			$Count+=1
		} Until($TestBase -or $Count -gt 2)
		If (-not $TestBase) {
			$ErrCt+=1
			Write-Logline "Copying of Base file [$BaseFile] FAILED."
			$ErrorText+= "Copying of Base file [$BaseFile] FAILED."
		}
	}
	ELSE {
		Write-Logline "Base File [$BaseFile] is already present and sizes match."
	}
}
Else {
	$ErrCt+=1
	$ErrorText += "Could not identify Base Backup for today's backup."
}
Write-Logline-Blank

#Now we delete old backups from the destination backup directory
$Subtract = "-"+$DaystoRetain
$MinDate = (Get-Date).AddDays($Subtract)
#$CurDate = (get-date).tostring("yyyyMMdd")
Get-ChildItem $BackupLocation -Filter *.tgz | `
Foreach-Object{
	$Filename = $_.Name
	If($Filename -like "*_k1_incr_*") {
		$FileDate = $Filename.substring($Filename.Length-8,2)+"/"+$Filename.substring($Filename.Length-6,2)+"/"+$Filename.substring($Filename.Length-12,4)
		$FormattedFileDate = [datetime] $FileDate
		echo "Filename: $Filename"
		echo "FileDate: $FileDate"
		$DateDiff = New-TimeSpan $MinDate $FormattedFileDate
		If ($DateDiff.Days -gt -1) {
			echo " File is still new enough. Keeping Incremental file dated "$Filename.substring(0,8)
			$BaseFilesKeep += $Filename.substring(0,8)+"|"
		}
		Else {
			echo "FILE IS TOO OLD. Deleting [$Filename]"
			Remove-Item $_.FullName
			$DeletedIncrFile = $true
		}
    }
	Else {
		echo "$Filename is not an incremental backup."
	}

}
echo "Base Files to keep: $BaseFilesKeep"
Get-ChildItem $BackupLocation -Filter *.tgz | `
Foreach-Object{
	$Filename = $_.Name
	If($Filename -like "*_k1_base_*") {
		$FileDate = $Filename.substring(0,8)
		If ($BaseFilesKeep -like "*$FileDate*") {
			echo "Keeping Base File [$Filename]"
		}
		Else {
			Write-Logline "Base file no longer needed by any Incremental backups. Deleting [$Filename]"
			Remove-Item $_.FullName
			$DeletedBaseFile = $true
		}
    }
	Else {
		echo "$Filename is not a base backup."
	}

}

If($DeletedIncrFile -ne $true -and $DeletedBaseFile -ne $true){
	Write-Logline "No old backups were found/deleted."
}
If($ErrCt -gt 0){
	Send-Error-Email $ErrorText
}

#Copy log file to network/backup share
if ( -not ( Test-Path $BackupLocation"Logs" -PathType Container )) { 
	New-Item -Path $BackupLocation"Logs" -ItemType directory
}
Copy-Item $LogfilePath $BackupLocation"Logs"