<#
.SYNOPSIS
	Checks the given XML file for validity
.DESCRIPTION
	check-xml-file [<file>]
.EXAMPLE
	PS> ./check-xml-file myfile.xml
	✔️ XML file is valid
.NOTES
	Author: Markus Fleschutz · License: CC0
.LINK
	https://github.com/fleschutz/PowerShell
#>

param([string]$file = "")

try {
	if ($file -eq "" ) { $file = read-host "Enter path to XML file" }

	$XmlFile = Get-Item $file
	
	$script:ErrorCount = 0
	
	# Perform the XSD Validation
	$ReaderSettings = New-Object -TypeName System.Xml.XmlReaderSettings
	$ReaderSettings.ValidationType = [System.Xml.ValidationType]::Schema
	$ReaderSettings.ValidationFlags = [System.Xml.Schema.XmlSchemaValidationFlags]::ProcessInlineSchema -bor [System.Xml.Schema.XmlSchemaValidationFlags]::ProcessSchemaLocation
	$ReaderSettings.add_ValidationEventHandler({ $script:ErrorCount++ })
	$Reader = [System.Xml.XmlReader]::Create($XmlFile.FullName, $ReaderSettings)
	while ($Reader.Read()) { }
	$Reader.Close()
	
	if ($script:ErrorCount -gt 0) {
		write-warning "Invalid XML file"
		exit 1
	} 

	"✔️ XML file is valid"
	exit 0 # success
} catch {
	"⚠️ Error: $($Error[0]) ($($MyInvocation.MyCommand.Name):$($_.InvocationInfo.ScriptLineNumber))"
	exit 1
}