param(
  [ValidateSet('start', 'restart', 'stop', 'status')]
  [string]$Action = 'start'
)

$ErrorActionPreference = 'Stop'
$projectRoot = Split-Path -Parent $PSScriptRoot
$runtimeDir = Join-Path $projectRoot 'tmp'
$pidFile = Join-Path $runtimeDir 'dev.pid'

function Get-TrackedProcessId {
  if (-not (Test-Path -LiteralPath $pidFile)) {
    return $null
  }

  $value = (Get-Content -LiteralPath $pidFile -Raw).Trim()
  try {
    if ($value -match '^\d+$') {
      $processId = [int]$value
      $startTimeTicks = $null
    } else {
      $state = $value | ConvertFrom-Json
      $processId = [int]$state.pid
      $startTimeTicks = [long]$state.start_time_ticks
    }
  } catch {
    Remove-Item -LiteralPath $pidFile -Force
    return $null
  }

  $process = Get-Process -Id $processId -ErrorAction SilentlyContinue
  if (-not $process -or ($startTimeTicks -and $process.StartTime.ToUniversalTime().Ticks -ne $startTimeTicks)) {
    Remove-Item -LiteralPath $pidFile -Force
    return $null
  }

  return $processId
}

function Stop-TrackedProject {
  $processId = Get-TrackedProcessId
  if (-not $processId) {
    Write-Host 'No managed Delivery Desk process is running.' -ForegroundColor Yellow
    return
  }

  Write-Host "Stopping Delivery Desk process tree (PID $processId)..."
  & taskkill.exe /PID $processId /T /F | Out-Null
  Remove-Item -LiteralPath $pidFile -Force -ErrorAction SilentlyContinue
  Start-Sleep -Milliseconds 300
  Write-Host 'Delivery Desk stopped.' -ForegroundColor Green
}

function Test-Endpoint([string]$Url) {
  try {
    $response = Invoke-WebRequest -UseBasicParsing -Uri $Url -TimeoutSec 2
    return $response.StatusCode -eq 200
  } catch {
    return $false
  }
}

if ($Action -eq 'status') {
  $processId = Get-TrackedProcessId
  $frontendReady = Test-Endpoint 'http://127.0.0.1:5180/'
  $backendReady = Test-Endpoint 'http://127.0.0.1:3010/api/health'
  $processStatus = if ($processId) { "running (PID $processId)" } else { 'not managed' }
  $frontendStatus = if ($frontendReady) { 'ready' } else { 'unavailable' }
  $backendStatus = if ($backendReady) { 'ready' } else { 'unavailable' }
  Write-Host "Process: $processStatus"
  Write-Host "Frontend 5180: $frontendStatus"
  Write-Host "Backend 3010: $backendStatus"
  if ($frontendReady -and $backendReady) { exit 0 } else { exit 1 }
}

if ($Action -eq 'stop') {
  Stop-TrackedProject
  exit 0
}

$trackedProcessId = Get-TrackedProcessId
if ($trackedProcessId -and $Action -eq 'start') {
  Write-Host "Delivery Desk is already running (PID $trackedProcessId). Use pnpm dev:restart to restart it." -ForegroundColor Yellow
  exit 0
}

if ($Action -eq 'restart') {
  Stop-TrackedProject
}

$pnpm = Get-Command pnpm -ErrorAction Stop
New-Item -ItemType Directory -Path $runtimeDir -Force | Out-Null
$currentProcess = Get-Process -Id $PID
@{
  pid = $PID
  start_time_ticks = $currentProcess.StartTime.ToUniversalTime().Ticks
} | ConvertTo-Json -Compress | Set-Content -LiteralPath $pidFile -Encoding ascii -NoNewline
Set-Location -LiteralPath $projectRoot

Write-Host 'Starting Delivery Desk...' -ForegroundColor Cyan
Write-Host 'Frontend: http://localhost:5180  Backend: http://localhost:3010'
Write-Host 'Press Ctrl+C to stop.'

try {
  & $pnpm.Source dev
  exit $LASTEXITCODE
} finally {
  if ((Get-TrackedProcessId) -eq $PID) {
    Remove-Item -LiteralPath $pidFile -Force
  }
}