# Compare-PSObject
#
# Better compare of two PSObjects based on the values of all properties
# Compares alle properties of all objects as strings
#
# 20220605 - Initial Version Frank Carius www.msxfaq.de
# 20231106 - Erweiterung auf Pipelineunterstützung

[CmdletBinding()]
param (
	[Parameter(Mandatory=$true,ValueFromPipeline=$true)]
    $ReferenceObject,
    $DifferenceObject,
	$Properties,
	[string]$headerproperty = $null,
	[switch]$ExludeEqual ,
	[switch]$ExcludeDifferent = $false
)

begin{
	Write-Verbose "Compare-PSObject: START Begin"
	$objectlist=@()
}

process {
	Write-Verbose "Compare-PSObject: START Process"
	if ($null -eq $DifferenceObject) {
		Write-Verbose "Loading objects from pipeline"
		$objectlist += $ReferenceObject
	}
	else {
		Write-Verbose "Loading objects from parameters"
		$objectlist += $ReferenceObject
		$objectlist += $DifferenceObject
	}
}

end {
	Write-Verbose "Compare-PSObject: START end"
	Write-Verbose "ObjectCount: $($objectlist.count)"
	if ($objectlist.count -gt 2) {
		Write-Warning "Only comparing the first two objects"
	}
	[hashtable]$propertylist=@{}
	if ($null -eq $Properties) {
		Write-Verbose " Collecting Properties"
		$count=0
		foreach ($object in $objectlist) {
			$count++
			Write-Verbose "  Collect Properties of Object $($count)"
			$object | get-member -Type property | ForEach-Object {
				if (!$propertylist.ContainsKey($_.name)){
					Write-Verbose "Add Property $($_.name)"
					$propertylist[$_.name]="1"
				}
			}
		}
	}
	else {
		Write-Verbose "Use given Properties"
		foreach ($property in $Properties) {
			$propertylist[$property]="1"
		}
	}
	Write-Verbose "Total Properties to compare $($propertylist.count)"

	[array]$result=@()
	foreach ($property in $propertylist.keys) {
		Write-Verbose "Compare $($property)"
		$resultline = New-Object -TypeName PSCustomObject
		$resultline | Add-Member -MemberType NoteProperty -Name "Property" -Value $property
		$count=0
		$property0 = [string]($objectlist[0].$property)
		$property1 = [string]($objectlist[1].$property)

		if ($property0 -eq $property1) {
			$resultline | Add-Member -MemberType NoteProperty -Name SideIndicator -Value "=="
		}
		elseif ((!$property0) -and ($property1)) {
			$resultline | Add-Member -MemberType NoteProperty -Name SideIndicator -Value "<-"
		}
		elseif (($property0) -and (!$property1)) {
			$resultline | Add-Member -MemberType NoteProperty -Name SideIndicator -Value "->"
		}
		else {
			$resultline | Add-Member -MemberType NoteProperty -Name SideIndicator -Value "<>"
		}
		foreach ($object in $objectlist) {
			$count++
			if ($headerproperty) {
				$resultline | Add-Member -MemberType NoteProperty -Name $object.$headerproperty -Value $object.$property
			}
			else {
				$resultline | Add-Member -MemberType NoteProperty -Name $count -Value $object.$property
			}
		}
		if ($ExcludeDifferent -and ($resultline."SideIndicator" -ne "==")) {
			Write-Verbose "ExludeDifferent"
		}
		if ($ExludeEqual -and $resultline."SideIndicator" -eq "==") {
			Write-Verbose "ExludeEqual"
		}
		else {
			Write-Verbose "AddLine $($resultline.Property)"
			$result+=$resultline
		}
	}
	$result
	Write-Verbose "Compare-PSObject: END"
}