watch-proxy.ps1

$ErrorActionPreference = "Stop"

$Root = Split-Path -Parent $MyInvocation.MyCommand.Path

if (-not $env:PORT) {
  $env:PORT = "8787"
}

if ((-not $env:UPSTREAM_ORIGIN) -or ($env:UPSTREAM_ORIGIN -eq "http://y3.ainiaini.xyz")) {
  $env:UPSTREAM_ORIGIN = "https://api.finalval.com"
}

$Port = [int]$env:PORT
$IntervalRaw = if ($env:WATCHDOG_INTERVAL_SECONDS) { $env:WATCHDOG_INTERVAL_SECONDS } else { "5" }
$IntervalSeconds = [int]$IntervalRaw
$ProxyPidFile = Join-Path $Root ".proxy.pid"
$WatchdogPidFile = Join-Path $Root ".watchdog.pid"
$WatchdogLog = Join-Path $Root "watchdog.log"
$StartScript = Join-Path $Root "start-proxy.ps1"

function Write-Log {
  param([string]$Message)
  $line = "[{0}] {1}" -f ([DateTime]::Now.ToString("yyyy-MM-dd HH:mm:ss")), $Message
  Add-Content -LiteralPath $WatchdogLog -Value $line -Encoding UTF8
}

function Get-ListeningPid {
  $conn = Get-NetTCPConnection -LocalAddress 127.0.0.1 -LocalPort $Port -State Listen -ErrorAction SilentlyContinue | Select-Object -First 1
  if ($conn) { return [int]$conn.OwningProcess }
  return 0
}

function Is-ProcessAlive {
  param([int]$TargetPid)
  if ($TargetPid -le 0) { return $false }
  return [bool](Get-Process -Id $TargetPid -ErrorAction SilentlyContinue)
}

function Read-PidFile {
  param([string]$Path)
  if (-not (Test-Path $Path)) { return 0 }
  try {
    return [int](Get-Content -LiteralPath $Path -ErrorAction Stop)
  } catch {
    return 0
  }
}

Set-Content -LiteralPath $WatchdogPidFile -Value $PID -Encoding ASCII
Write-Log "watchdog started on port $Port"

while ($true) {
  try {
    $proxyPid = Read-PidFile $ProxyPidFile
    $listeningPid = Get-ListeningPid

    if ($proxyPid -gt 0 -and -not (Is-ProcessAlive $proxyPid)) {
      Remove-Item -LiteralPath $ProxyPidFile -Force -ErrorAction SilentlyContinue
      Write-Log "removed stale proxy pid file ($proxyPid)"
      $proxyPid = 0
    }

    if ($listeningPid -gt 0) {
      if ($proxyPid -le 0 -or $proxyPid -ne $listeningPid) {
        Set-Content -LiteralPath $ProxyPidFile -Value $listeningPid -Encoding ASCII
      }
    } else {
      Write-Log "proxy not listening, starting"
      try {
        $output = & powershell.exe -NoProfile -ExecutionPolicy Bypass -File $StartScript 2>&1
        foreach ($line in $output) {
          Write-Log ([string]$line)
        }
      } catch {
        Write-Log ("start failed: " + $_.Exception.Message)
      }
    }
  } catch {
    Write-Log ("watchdog loop error: " + $_.Exception.Message)
  }

  Start-Sleep -Seconds $IntervalSeconds
}