#requires -version 2.0

# Jeffery Hicks
# http://jdhitsolutions.com/blog
# follow on Twitter: http://twitter.com/JeffHicks
#
# Learn more Windows PowerShell with a copy of Windows PowerShell 2.0: TFM (SAPIEN Press 2010)
#
# "Those who forget to script are doomed to repeat their work."

#  ****************************************************************
#  * DO NOT USE IN A PRODUCTION ENVIRONMENT UNTIL YOU HAVE TESTED *
#  * THOROUGHLY IN A LAB ENVIRONMENT. USE AT YOUR OWN RISK.  IF   *
#  * YOU DO NOT UNDERSTAND WHAT THIS SCRIPT DOES OR HOW IT WORKS, *
#  * DO NOT USE IT OUTSIDE OF A SECURE, TEST SETTING.             *
#  ****************************************************************

Function New-WMIObject {

<#
.Synopsis
Create a custom WMI object from a hashtable of WMI classes and properties.
.Description
Connect to a computer and create a custom WMI object based on a hash table
of WMI Win32 classes and property names.
#>

[cmdletbinding()]

Param (
      [Parameter(Position=0,ValueFromPipeline=$True,
      HelpMessage="Enter a computername.")]
      [string[]]$computername=$env:computername,
      [Parameter(Position=1,ValueFromPipeline=$False,
      HelpMessage="Enter a hashtable of WMI classes and properties.",
      Mandatory=$True)]
      [hashtable]$hashtable
)

Begin {
     write-verbose "Starting $($myinvocation.mycommand)"
}#begin

Process {
 foreach ($computer in $computername) {
 #initialize property hash
     $properties=@{}
     write-verbose "Adding $($computer.toUpper()) to `$properties"
     $properties.Add("Computer",$($computer.toUpper()))
    foreach ($hash in $hashtable) {
        $classes=$hash.keys
        foreach ($class in $classes) {
            write-verbose "Getting $class information on $computer"
            $wmi=Get-WmiObject -Class $class -Property $hash.item($class) `
            -computername $computer
            #create array properties if $wmi returned more than one item
            if ($wmi.count -gt 1) {
                write-verbose "Multiple WMI objects returned"
                #initialize a temporary array
                $array=@()
                foreach ($object in $wmi) {
                    Write-Verbose "Adding $($object.__RELPATH)"
                    $array+=$object | select $hash.item($class)
                }#end foreach $object
                #add the array as a property value
                #strip off win32_ from the class name
                $parsed=$class.Substring($class.indexof("_")+1)
                $properties.Add($parsed,$array)
            }
            else {
                #add each property
                    foreach ($item in $hash.item($class)) {
                    write-verbose "Adding $item = $($wmi.($item))"
                    $properties.Add($item,$($wmi.($item)))
            }
            } #else
        } #foreach $class
    
    } #foreach $hash
    Write-Verbose "Creating custom object"
    New-Object PSObject -Property $properties
 } #foreach $computer
} #process

End {
 
 write-verbose "Ending $($myinvocation.mycommand)"
} #end
} #end function

#examples
#$a=@{win32_OperatingSystem="Caption","RegisteredUser","LastBootUpTime";
#win32_computersystem="Name","Manufacturer","Model";
#win32_bios="Version";
#win32_logicaldisk="DeviceId","Size","FreeSpace","DriveType"}
#$r="godot7","serenity" | new-wmiobject -hash $a 
#$r
#$r | select-object -property computer -expand logicaldisk | 
#where {$_.drivetype -eq 3} | format-table -GroupBy Computer -Property DeviceID,Size,FreeSpace