<#
.SYNTAX       check-xml-file [<file>]
.DESCRIPTION  checks the given XML file for validity
.LINK         https://github.com/fleschutz/PowerShell
.NOTES        Author: Markus Fleschutz / License: CC0
#>

param($File = "")

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

try {
	$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
	} 
	write-host -foregroundColor green "OK - XML file is valid"
	exit 0
} catch {
	write-error "⚠️ Error in line $($_.InvocationInfo.ScriptLineNumber): $($Error[0])"
	exit 1
}