Deploy-WithProgress.ps1

param(
	[Parameter(Mandatory = $true)]
	[string]$Source,
	[Parameter(Mandatory = $true)]
	[string]$Destination
)

$global:appOfflineGistUrl = 'https://gist.githubusercontent.com/TomasBouda/176632ebcccaf684ea09231935f4d300/raw/ff6662b3131ed43fe206403b62ec2129fae81a83/App_offline.htm'

function Copy-WithProgress {
	[CmdletBinding()]
	param(
		[Parameter(Mandatory = $true, ValueFromPipelineByPropertyName = $true, Position = 0)]
		$Source,
		[Parameter(Mandatory = $true, ValueFromPipelineByPropertyName = $true)]
		$Destination
	)

	begin {
		$template = Invoke-RestMethod -Method GET -Uri $global:appOfflineGistUrl

		# Create App_offline.htm to gracefully take the website offline
		$template -replace '#progress#', 0 | Set-Content "$Destination\App_offline.htm"
	}
	process {
		$filelist = Get-ChildItem $Source -Recurse
	
		$total = $filelist.count
		$position = 0

		foreach ($file in $filelist) {
			$filename = $file.Fullname.Replace($Source, '')
			$destinationFile = $Destination + $filename

			Copy-Item $file.FullName -Destination $destinationFile -Force

			$position++
			$progress = [Math]::Round((($position / $total) * 100), 0)
			$template -replace '#progress#', $progress | Set-Content "$Destination\App_offline.htm"

			Write-Progress -Activity "Copying data from $Source to $Destination" -Status "Copying File $filename" -PercentComplete $progress
		}
	}
	end {
		Write-Debug "Removing App_offline.htm"

		# Remove App_offline.htm to finish the process and let users browse updated website
		Remove-Item "$Destination\App_offline.htm" -Force -ErrorAction SilentlyContinue

		Write-Debug "Copy-WithProgress"
	}
}

Copy-WithProgress -Source $Source -Destination $Destination