copylocaltos3.ps1

param (
    [string]$from = $(get-location).ToString(),
    [string]$to = "selectcs-backup",
    [switch]$mirror 
 )

#$DebugPreference = "Continue"

#todo:if no parameters, then show instructions 
#todo:mirror option into own function 
#todo:aws details need to be in the environment.
#todo:Copy from & copy to to use the same script. Maybe put it into a module. 


import-module "C:\Program Files (x86)\AWS Tools\PowerShell\AWSPowerShell\AWSPowerShell.psd1"
add-type -assemblyName "System.Web"

$blocksize = (1024*1024*5)
$startblocks = (1024*1024*16)
$AccessKeyId = (get-item env:aws-access-key-id -erroraction ignore).value 
$AccessKeySecret = (get-item env:aws-access-key-secret -erroraction ignore).value 

if ( !($AccessKeyId) -or !($AccessKeySecret)) {
	$ok = ($AccessKeyId) -or ($AccessKeySecret)
	Write-Host "AWS Access keys have not been created."
	Write-Host "==================================================================="
	Write-Host "To run this script you must create two environment variables called"
	Write-Host "aws-access-key-id and aws-access-key-secret"
	Write-Host "--"
	break
} 


# Regions: us-east-1, us-west-2, us-west-1, eu-west-1, ap-southeast-1
$region = "eu-west-1"   


$backupFrom = $from
$backupTo = $to 

$backupFrom  = $backupFrom.ToLower()
$BackupTo  = $BackupTo.ToLower()
if ($backupFrom[-1] -ne "\") { $backupFrom += "\" }
$bucket = $BackupTo.Split(":")[0]
$s3folder = $BackupTo.Split(":")[1]

if (!($s3folder)) {
    $s3folder = $env:COMPUTERNAME + "/"
    $s3folder += $(get-location).ToString() + "/"
    $s3folder = $s3folder.replace("\\","/").replace(":\","/").replace("\","/") 
    $s3folder = $s3folder.ToLower()
}

$s3folder = $s3folder.ToLower().replace("\" , "/")
if ($s3folder[-1] -ne "/") { $s3folder += "/" }

$msg="Copying files from $backupFrom to $BackupTo" 
Write-Host $msg
Write-Host "-"
Write-Host "Bucket: $bucket"
write-Host "Mirror: $mirror"
Write-Host "S3 Folder: $s3folder"
Write-Host ("=" * $msg.Length)

$md5 = new-object -TypeName System.Security.Cryptography.MD5CryptoServiceProvider

function AmazonEtagHashForFile($filename) {
    $lines = 0
    [byte[]] $binHash = @()

    $reader = [System.IO.File]::Open($filename,"OPEN","READ")
	
	if ((Get-Item $filename).length -gt $startblocks) {
		$buf = new-object byte[] $blocksize
		while (($read_len = $reader.Read($buf,0,$buf.length)) -ne 0){
			$lines   += 1
			$binHash += $md5.ComputeHash($buf,0,$read_len)
		}
		$binHash=$md5.ComputeHash( $binHash )
	}
	else {
	    $lines   = 1
		$binHash += $md5.ComputeHash($reader)
	}

    $reader.Close()
    
	$hash = [System.BitConverter]::ToString( $binHash )
    $hash = $hash.Replace("-","").ToLower()

    if ($lines -gt 1) {
        $hash = $hash + "-$lines"
    }

    return $hash
}

function s3NameToLocalName($file) {
	$file = $file.replace($s3Folder,"")
	$file = $file.replace("/" , "\")
	$file = [System.Web.HttpUtility]::UrlDecode($file) 
	$file = $backupFrom + $file 
	
	return $file 
}

function s3BackupFile($file) {
	if (!$file.PSIsContainer) {
		
		$fromFile = $file.fullname.ToLower()
		$tofile = $file.fullname.ToLower()
		
		$tofile = $tofile.replace($backupfrom,"")
        $tofile = $tofile.replace("\" , "/")
        $tofile = [System.Web.HttpUtility]::UrlEncode($tofile) 
        $tofile = $tofile.replace("%2f" , "/")
		$tofile = $s3folder + $tofile
		
		$s3file = (Get-S3Object -BucketName $bucket -Key $tofile)
		if ($s3file -eq $null) {
			Write-Host "$fromFile  -> $tofile (New File)" 
			Write-S3Object -BucketName $bucket -File $fromfile -Key $tofile
			return 
		}
		
		$hash = AmazonEtagHashForFile($fromFile)
		$etag =$s3file[0].etag.Replace('"',"")

		if ($etag -ne $hash) {
			Write-Host("$fromFile  -> $tofile (Different)" )
			Write-S3Object -BucketName $bucket -File $fromfile -Key $tofile
		}
	}
}


Set-AWSCredentials -AccessKey $AccessKeyId -SecretKey $AccessKeySecret
Set-DefaultAWSRegion $region

#Mirroring....
if ($mirror) {
	do {
		$s3files = (Get-S3Object -Marker $marker -MaxKeys $maxkeys -BucketName $bucket -KeyPrefix $s3Folder )
		$s3files | Foreach-Object{
			$marker = $_.key
			$LocalFile = (s3NameToLocalName $_.key)
			if (!(Test-Path $LocalFile)) {
				$DeleteAmazonFile = $_.key
			    Write-Host ("Deleting... $DeleteAmazonFile")
				$response = Remove-S3Object -BucketName $bucket -Key $DeleteAmazonFile -Force
			}
		}
	} while ($s3files.length -eq $maxkeys)
}


#now we restore
$files = Get-ChildItem $BackupFrom -Recurse
$files | Foreach-Object{
    s3BackupFile $_ 
}

Write-Host("..")