$ErrorActionPreference = 'Continue'
$testLog = 'C:\Apache24\htdocs\.codex_tmp\airmax_gateway_ab_test.log'
$protonClient = 'C:\Program Files\Proton\VPN\v5.1.5\ProtonVPN.Client.exe'
$protonDirectory = Split-Path -Parent $protonClient
$interfaceIndex = 14
$temporaryPrefixes = @('10.30.99.22/32', '10.30.99.25/32')

function Write-TestLog([string]$message) {
    Add-Content -LiteralPath $testLog -Value (('{0} {1}' -f (Get-Date -Format 'yyyy-MM-dd HH:mm:ss.fff'), $message)) -Encoding UTF8
}

function Test-DevicePair([string]$label) {
    $timeoutMs = 20000
    $started = [System.Diagnostics.Stopwatch]::StartNew()
    $checks = @(
        [pscustomobject]@{ Host = '10.30.99.22'; Port = 80; Client = [System.Net.Sockets.TcpClient]::new(); Async = $null },
        [pscustomobject]@{ Host = '10.30.99.25'; Port = 443; Client = [System.Net.Sockets.TcpClient]::new(); Async = $null }
    )
    foreach ($check in $checks) {
        $check.Async = $check.Client.BeginConnect($check.Host, $check.Port, $null, $null)
    }
    foreach ($check in $checks) {
        $connected = $false
        $errorText = ''
        try {
            $remaining = [Math]::Max(0, $timeoutMs - [int]$started.ElapsedMilliseconds)
            if ($check.Async.AsyncWaitHandle.WaitOne($remaining)) {
                $check.Client.EndConnect($check.Async)
                $connected = $check.Client.Connected
            } else {
                $errorText = 'timeout'
            }
        } catch {
            $errorText = $_.Exception.GetBaseException().Message
        } finally {
            $check.Client.Close()
        }
        Write-TestLog ("TCP $label host=$($check.Host) port=$($check.Port) connected=$connected elapsed_ms=$($started.ElapsedMilliseconds) error=$errorText")
    }
    $started.Stop()
}

Set-Content -LiteralPath $testLog -Value '' -Encoding UTF8
Write-TestLog 'BEGIN gateway A/B test'

try {
    Get-Process -Name 'ProtonVPN.Client' -ErrorAction SilentlyContinue | Stop-Process -Force -ErrorAction SilentlyContinue
    Start-Sleep -Milliseconds 750
    Stop-Service -Name 'ProtonVPN Service' -Force -ErrorAction Continue
    Start-Sleep -Seconds 2

    $service = Get-Service -Name 'ProtonVPN Service' -ErrorAction SilentlyContinue
    $protonDefault = Get-NetRoute -InterfaceAlias 'ProTUN' -DestinationPrefix '0.0.0.0/0' -ErrorAction SilentlyContinue
    Write-TestLog "PROTON service=$($service.Status) default_route=$([bool]$protonDefault)"

    $baseRoute = Get-NetRoute -DestinationPrefix '10.30.99.0/24' -InterfaceIndex $interfaceIndex -ErrorAction SilentlyContinue
    Write-TestLog ("BASE_ROUTE next_hop=" + (($baseRoute.NextHop | Select-Object -Unique) -join ','))
    Test-DevicePair 'via-51'

    foreach ($prefix in $temporaryPrefixes) {
        New-NetRoute -DestinationPrefix $prefix -InterfaceIndex $interfaceIndex -NextHop '10.30.98.50' -RouteMetric 1 -PolicyStore ActiveStore -ErrorAction Stop | Out-Null
    }
    Write-TestLog 'TEMP_ROUTES via 10.30.98.50 installed'
    Test-DevicePair 'via-50'
}
catch {
    Write-TestLog ("ERROR " + $_.Exception.GetBaseException().Message)
}
finally {
    foreach ($prefix in $temporaryPrefixes) {
        Get-NetRoute -DestinationPrefix $prefix -InterfaceIndex $interfaceIndex -ErrorAction SilentlyContinue |
            Where-Object { $_.NextHop -eq '10.30.98.50' } |
            Remove-NetRoute -Confirm:$false -ErrorAction SilentlyContinue
    }
    Write-TestLog 'TEMP_ROUTES removed'

    Start-Service -Name 'ProtonVPN Service' -ErrorAction Continue
    Start-Sleep -Seconds 2
    if (Test-Path -LiteralPath $protonClient) {
        Start-Process -FilePath $protonClient -WorkingDirectory $protonDirectory -WindowStyle Hidden
    }
    Start-Sleep -Seconds 12
    $finalService = Get-Service -Name 'ProtonVPN Service' -ErrorAction SilentlyContinue
    $finalClient = Get-Process -Name 'ProtonVPN.Client' -ErrorAction SilentlyContinue
    Write-TestLog "RESTORED service=$($finalService.Status) client=$([bool]$finalClient)"
    Write-TestLog 'END gateway A/B test'
}