<#
#>

param
(
# Computer to wake up
    [Alias("Computer")]
    [String]
    $targetComputer = "",
# Skip RDP connectivity readiness check
    [Alias("Check", "Readiness")]
    [Switch]
    $ConnectivityCheck = $false,
# RDP connectivity readiness check timeout
    [Int]
    $Timeout = 300
)

function exitError($errMessage, $PSItem, $exitCode = 1)
{
    if ( [String]::IsNullOrEmpty($errMessage))
    {
        Write-Host -ForegroundColor Red "`n`rABNORMAL EXIT: exitError function called without exit message!`n`r"
        exit 99
    }
    Write-Host -ForegroundColor Red "`r`nERROR: ${errMessage}."
    if ($PSItem)
    {
        Write-Host -ForegroundColor Red "`r`nAdditional information:`r`n$PSItem"
    }
    Write-Host
    Exit $exitCode
}

$wolModuleName = "wol-magicPacket"
$wolDatabase = "WOLDatabase.xml"

# exit on error if Send-MagicPacket module is not loaded
if (!(Get-Module -Name $wolModuleName))
{
    try
    {
        Import-Module -Name $wolModuleName -ErrorAction Stop
    }
    catch
    {
        $errMessage = "Unable to load '$wolModuleName'"
        exitError $errMessage $PSItem
    }
}

# exit if database cannot be found/read
if (!(Test-Path -Path $wolDatabase -PathType Leaf))
{
    $errMessage = "Unable to find or read Wake-On-LAN database file ($wolDatabase)"
    exitError $errMessage
}

# get target computer name if not already specified
if ( [String]::IsNullOrWhiteSpace($targetComputer))
{
    do
    {
        $targetComputer = Read-Host -Prompt 'Computer to wake-up'
    } while ( [String]::IsNullOrWhiteSpace($targetComputer))
}
Write-Host

# read database and assemble list of target computers
[xml]$db = Get-Content -Path $wolDatabase
$broadcastIP = $db.WOLDatabase.Configuration.BroadcastAddress
$port = $db.WOLDatabase.Configuration.Port
$dnsSuffix = $db.WOLDatabase.Configuration.DnsSuffix
$targetComputers = [System.Collections.Generic.List[PSObject]]::new()
$db.WOLDatabase.Computers.Computer | Where-Object { $_.name -match "$targetComputer" } | ForEach-Object { $targetComputers.Add($_) }
$removeFromTargetComputers = [System.Collections.Generic.List[String]]::new()

# exit if nothing to do (i.e. empty targetComputers list)
if ($targetComputers.Count -eq 0)
{
    Write-Host -ForegroundColor Yellow "No computers found matching '$targetComputer'. Nothing to do.`r`n"
    exit 0
}

# send WOL magic packets
$targetComputers | ForEach-Object {
    $wolError = @()
    $name = $_.name
    $friendlyName = $_.friendlyName
    if ( [String]::IsNullOrWhiteSpace($friendlyName))
    {
        Write-Host "Processing request to wake-up '$name'... " -NoNewline
    }
    else
    {
        Write-Host "Processing request to wake-up '$friendlyName'... " -NoNewline
    }

    # send magic packet
    $_.mac | Send-MagicPacket -BroadcastIP $broadcastIP -Port $port -ErrorAction SilentlyContinue -ErrorVariable +wolError
    if ($wolError.Count -eq 0)
    {
        Write-Host -ForegroundColor Green "[OK]"
    }
    else
    {
        Write-Host -ForegroundColor Red "[ERROR]"
        $removeFromTargetComputers.Add($name)
    }
}

# remove computers from targetComputers if WOL packet was not successfully sent
$removeFromTargetComputers | ForEach-Object {
    $removeName = $_
    $targetComputers.Remove(($targetComputers | Where-Object { $_.name -eq $removeName })) | Out-Null
}

# process RDP readiness check
$targetComputers

Exit 0