#Requires -version 2.0 

#You need to collect the user name, computer name, domain name, and the operating system information 
#from a number of computers. To make matters easier, you have decided to write the information to a 
#text file. The text file needs to be saved as an ASCII file, and not as Unicode. You should include 
#the date in which the information was gathered to determine reliability of the information.

#Design points
#	Extra points for a script that will work against a remote machine
#	Extra points for a script that will accept a Text file, CSV or other type of input of remote computer names
#	Extra points for adding useful help information and comments
#	Design points for clear easy to read code, and use of native Windows PowerShell cmdlets

Param (
 [string]$File="computers.txt",
 [string]$LogFile="ComputerReport.txt",
 [string]$ErrorLog="failed.txt",
 [Switch]$Append
 )
 
Set-StrictMode -Version 2

#Verify list of computers exists
If (Test-Path -Path $File)
{

    #if error log already exists, delete it so we get a new file
    if (Test-Path -Path $ErrorLog)
    {
        Remove-Item -Path $ErrorLog
    }
    #retrieve computer names filtering out any blank lines
    $Computers=Get-Content -Path $file | Where {$_}
    
    Write-Host "Gathering computer information. Please wait..." -ForegroundColor Cyan
    #initialize an array to hold computer information
    $data=@()
    
    #for each computer in the list
    Foreach ($Computer in $Computers) {
    
        #trim off any spaces
        $Computer=$Computer.Trim()
    
        #write the computername to the console as a status message
        Write-Host $Computer.toUpper() -ForegroundColor Cyan
    
        #ping the computer using Test-Connection. I'm saving the results to a variable
        #so that I can get the IP address. I set the ErrorAction preference to SilentlyContinue
        #to suppress error messages
        $ping=Test-Connection -ComputerName $Computer -Count 2 -ErrorAction "SilentlyContinue"
        if ($ping)
        {
            #if the computer is pingable get WMI information
            Try
            {    
                #attempt to retrieve WMI information and if there is an error catch it
                $OperatingSystem=Get-WmiObject -Class Win32_OperatingSystem -ComputerName $Computer -ErrorAction Stop
                $ComputerSystem=Get-WmiObject -Class Win32_ComputerSystem -ComputerName $Computer -ErrorAction Stop

                #only process if WMI queries were sucessful
                if ($OperatingSystem -AND $ComputerSystem)
                {
                    #create a custom object using a property hash table
                    #I'm including ServicePack information since that might come in handy
                    $data+=New-Object -TypeName PSObject -Property @{
                        User=$ComputerSystem.UserName
                        Commputer=$OperatingSystem.CSName
                        IPAddress=$ping[0].ipv4address.ToString()
                        Domain=$ComputerSystem.Domain
                        OS=$OperatingSystem.Caption
                        ServicePack=$OperatingSystem.ServicePackMajorVersion
                        Model=$ComputerSystem.Model
                        Reported=(Get-Date)
                    } 
                }
                else
                {
                    #otherwise record the failure in a log file
                    $Computer.ToUpper() | Add-Content -Path $ErrorLog
                }
            } #close Try
           
            Catch
            {
                Write-Warning "There was a problem retrieving information from $($Computer.ToUpper())"
                #write the exception message as a warning
                Write-Warning $_.Exception.Message
                #write the failed computername to a text file
                $computer.ToUpper() | Add-Content -Path $ErrorLog
            } #close Catch scriptblock
         } #if pingable
         else
         {
            #computer is not pingable
            $Computer.ToUpper() | Add-Content -Path $ErrorLog
         }
    } #foreach
    
     #measure how many computers were queried and save the count property to a variable
     $count=($data | measure-object).Count
     Write-Host "Successfully queried $Count computers." -ForegroundColor Cyan
     #write the WMI information to a log file if $data has anything in it
     if ($count -gt 0)
     {
        #if a file was specified then record information
        if ($LogFile -AND $Append)
        {
            $data | Out-File -FilePath $LogFile -Encoding ASCII -Append
        }
        else
        {
            $data | Out-File -FilePath $LogFile -Encoding ASCII 
        }
     } #if $count greater than 0
     
     Write-Host "See $LogFile for details and $ErrorLog for failed computers." -ForegroundColor Cyan
} #if file exisits

else 
{
    #Failed to verify text file of computers
    Write-Warning "Cannot find or verify $file."
}

#end of script