<#
.SYNOPSIS
	pull-repos.ps1 [<parent-dir>]
.DESCRIPTION
	Pulls updates for all Git repositories under the current/given directory (including submodules).
.EXAMPLE
	PS> .\pull-repos.ps1 C:\MyRepos
.NOTES
	Author: Markus Fleschutz · License: CC0
.LINK
	https://github.com/fleschutz/PowerShell
#>

param([string]$ParentDir = "$PWD")

try {
	$StopWatch = [system.diagnostics.stopwatch]::startNew()

	if (-not(test-path "$ParentDir" -pathType container)) { throw "Can't access directory: $ParentDir" }

	$Null = (git --version)
	if ($lastExitCode -ne "0") { throw "Can't execute 'git' - make sure Git is installed and available" }

	$Folders = (get-childItem "$ParentDir" -attributes Directory)
	$FolderCount = $Folders.Count
	$ParentDirName = (get-item "$ParentDir").Name
	"Found $FolderCount subfolders in 📂$ParentDirName..."

	[int]$Step = 1
	foreach ($Folder in $Folders) {
		$FolderName = (get-item "$Folder").Name
		"🢃 Pulling 📂$FolderName ($Step/$FolderCount)..."

		& git -C "$Folder" pull --recurse-submodules --jobs=4
		if ($lastExitCode -ne "0") { write-warning "'git pull' on 📂$FolderName failed" }

		& git -C "$Folder" submodule update --init --recursive
		if ($lastExitCode -ne "0") { throw "'git submodule update' failed" }

		$Step++
	}

	[int]$Elapsed = $StopWatch.Elapsed.TotalSeconds
	"✔️ pulled $FolderCount Git repositories at 📂$ParentDirName in $Elapsed sec"
	exit 0
} catch {
	write-error "⚠️ Error in line $($_.InvocationInfo.ScriptLineNumber): $($Error[0])"
	exit 1
}