[CmdletBinding()]
Param(
    [Parameter(Mandatory=$False)]
    [array]$ComputerName,
    [Parameter(Mandatory=$False)]
    [switch]$RunningProcesses,
    [Parameter(Mandatory=$False)]
    [switch]$ComputerInfo,
    [Parameter(Mandatory=$False)]
    [switch]$Updates,
    [Parameter(Mandatory=$False)]
    [switch]$LocalUsers,
    [Parameter(Mandatory=$False)]
    [switch]$DomainUsers,
    [Parameter(Mandatory=$False)]
    [switch]$Services
)

function getRunningProcesses {
    if ($ComputerName) {
        $procs = Get-Process -ComputerName $ComputerName -Credential CSC443\DSU
    } else {
        $procs = Get-Process
    }

    $procs | Export-Csv -Path "running-processes.csv" -Delimiter ","
}

function getComputerInfo {
    if ($ComputerName) {
        $os   = Get-WmiObject -ComputerName $ComputerName -Class Win32_OperatingSystem -Credential CSC443\DSU
        $proc = Get-WmiObject -ComputerName $ComputerName -Class Win32_Processor -Credential CSC443\DSU
        $mem  = Get-WmiObject -ComputerName $ComputerName -Class Win32_PhysicalMemory -Credential CSC443\DSU
    } else {
        $os   = Get-WmiObject -Class Win32_OperatingSystem
        $proc = Get-WmiObject -Class Win32_Processor
        $mem  = Get-WmiObject -Class Win32_PhysicalMemory
    }
    $os   | Export-Csv -Path "os.csv" -Delimiter ","
    $proc | Export-Csv -Path "processor.csv" -Delimiter ","
    $mem  | Export-Csv -Path "memory.csv" -Delimiter ","
}

function getUpdates {
    # could use Invoke-Expression "wmic qfe list"  for wmi
    if ($ComputerName) {
        $upds = Get-Hotfix -ComputerName $ComputerName -Credential CSC443\DSU
    } else {
        $upds = Get-HotFix
    }
    $upds | Export-Csv -Path "updates.csv" -Delimiter ","
}

function getLocalUsers {
    if ($ComputerName) {
        $users = Get-ADUser -Filter * -SearchBase "DC=csc443,DC=lan" -ComputerName $ComputerName -Credential CSC443\DSU
    } else {
        $users = Get-ADUser -Filter * -SearchBase "DC=csc443,DC=lan"
    }
    $users | Export-Csv -Path "local-users.csv" -Delimiter ","
}

function getDomainUsers {
    if ($ComputerName) {
        $users = Get-ADUser -Filter * -SearchBase "DC=DomainDnsZones,DC=csc443,DC=lan" -ComputerName $ComputerName -Credential CSC443\DSU
    } else {
        $users = Get-ADUser -Filter * -SearchBase "DC=DomainDnsZones,DC=csc443,DC=lan"
    }
    $users | Export-Csv -Path "domain-users.csv" -Delimiter ","
}

function getServices {
    if ($ComputerName) {
        $svcs = Get-Service -ComputerName $ComputerName | Where-Object {$_.Status -eq "Running"} -Credential CSC443\DSU
    } else {
        $svcs = Get-Service | Where-Object {$_.Status -eq "Running"}
    }
    $svcs | Export-Csv -Path "services.csv" -Delimiter ","
}

#Import-Module ActiveDirectory

function run  {
    if ($ComputerName) {
        Write-Output "Gathering Information for: $($ComputerName -join ", ")"
    }

    if ($RunningProcesses) { getRunningProcesses }
    if ($ComputerInfo) { getComputerInfo }
    if ($Updates) { getUpdates }
    if ($LocalUsers) { getLocalUsers }
    if ($DomainUsers) { getDomainUsers }
    if ($Services) { getServices }

    Write-Output "Done!"
}

run