File Deployer with Anti-package generator and automatic rollback

Function Deployer-Prepare {
    Param($source,$target,$anti)

    # Pre-validations
    $sourceExists = Test-Path $source
    if ($sourceExists -eq $false){
        Write-Output "Source directory is wrong - $source"
        return $false
    }
    $targetExists = Test-Path $target
    if ($targetExists -eq $false){
        Write-Output "Target directory is wrong - $target"
        return $false
    }
    $sourceFolder = Get-Item $source 
    $targetFolder = Get-Item $target 

    # Build Anti
    # Create or get antiFolder
    $antiExists = Test-Path $anti
    if ($antiExists -eq $false){
        $antiFolder = New-Item $anti -ItemType Directory
    }
    else {
        $antiFolder = Get-Item $anti
    }

    # Loop thru Source to create anti
    Write-Output "Create Anti-package on $anti"


    $sourceFolderChild = Get-ChildItem $sourceFolder -Recurse
    Foreach($sourceEntry in $sourceFolderChild) {
        $relativePath = $($sourceEntry.FullName).Replace($source,"")
        $antiPath = "$anti$relativePath"
        $antiEntryExists = Test-Path $antiPath
        $targetPath = "$target$relativePath"
        $targetEntryExists = Test-Path $targetPath
        #$antiEntry = Get-Item $antiPath

        if ($targetEntryExists -eq $false) {
            # If file is not on target - its a new file - should be *.delete on anti
            Copy-Item $sourceEntry.FullName -Destination $antiPath
            $antiEntry = Get-Item $antiPath
            $antiEntryName = $antiEntry.Name;
            $antiEntry = Rename-Item $antiEntry -NewName "$($antiEntryName).delete"
        }
        else {
            # Copy from target to Anti
            $targetEntry = Get-Item $targetPath
            $antiEntry = Copy-Item $targetEntry -Destination $antiPath
        }
    }

    Write-Output "Anti-package created on $anti"
    Write-Output "To deploy -> Deployer-Run 'c:\sourcepath' -target 'c:\targetpath' "
    Write-Output "To rollback -> Deployer-Rollback 'c:\targetpath' -anti 'c:\antipath' "
}

Function Deployer-Run {
    Param($source,$target)

    # Pre-validations
    $sourceExists = Test-Path $source
    if ($sourceExists -eq $false){
        Write-Output "Source directory is wrong - $source"
        return $false
    }
    $targetExists = Test-Path $target
    if ($targetExists -eq $false){
        Write-Output "Target directory is wrong - $target"
        return $false
    }
    $sourceFolder = Get-Item $source 
    $targetFolder = Get-Item $target 

    Write-Output "Deploy start - from: '$source' to '$target'"

    $sourceFolderChild = Get-ChildItem $sourceFolder -Recurse
    Foreach($sourceEntry in $sourceFolderChild) {
        $relativePath = $($sourceEntry.FullName).Replace($source,"")
        $targetPath = "$target$relativePath"

        Copy-Item $sourceEntry.FullName -Destination $targetPath -Force
        Write-Output "Copied: $targetPath"
    }
        
    Write-Output "Deploy finished"
    Write-Output "To rollback -> Deployer-Rollback 'c:\targetpath' -anti 'c:\antipath' "
}

Function Deployer-Rollback {
    Param($target,$anti)

    # Pre-validations
    $antiExists = Test-Path $anti
    if ($antiExists -eq $false){
        Write-Output "Anti-package directory is wrong - $anti"
        return $false
    }
    $targetExists = Test-Path $target
    if ($targetExists -eq $false){
        Write-Output "Target directory is wrong - $target"
        return $false
    }
    $antiFolder = Get-Item $anti 
    $targetFolder = Get-Item $target 

    # Undo
    $antiFolderChild = Get-ChildItem $antiFolder -Recurse
    Foreach($antiEntry in $antiFolderChild) {
        $relativePath = $($antiEntry.FullName).Replace($anti,"")
        $targetPath = "$target$relativePath"

        $isDelete = $($relativePath).EndsWith(".delete")
        if ($isDelete){
            # Delete from target
            $targetPath = $targetPath.Replace(".delete","")
            Remove-Item $targetPath -Force
            Write-Output "Deleted: $targetPath"
        }
        else {
            # Copy from anti to target
            Copy-Item $antiEntry.FullName -Destination $targetPath -Force
            Write-Output "Rolled back: $targetPath"
        }
    }

}