# Prefer a Gitea-hosted node:20-alpine so docker build does not HEAD registry-1.docker.io.
# Order: local Gitea tag -> pull Gitea -> local Docker Hub tag -> pull Hub (retries) -> tag/push Gitea.
# ASCII only: Windows PowerShell 5.1 + act_runner mis-parses backtick escapes in this file.
param(
  [Parameter(Mandatory = $true)][string]$RegistryPrefix,
  [string]$OutFile = '.ci-node-image',
  [string]$HubImage = 'node:20-alpine'
)

$ErrorActionPreference = 'Continue'
$mirror = "$RegistryPrefix/node:20-alpine"
$nl = [char]10

function Test-Image([string]$Name) {
  docker image inspect $Name 2>&1 | Out-Null
  return ($LASTEXITCODE -eq 0)
}

function Invoke-Pull([string]$Name, [int]$Attempts) {
  for ($i = 1; $i -le $Attempts; $i++) {
    Write-Host "docker pull $Name (attempt $i/$Attempts)"
    docker pull $Name
    if ($LASTEXITCODE -eq 0) { return $true }
    if ($i -lt $Attempts) { Start-Sleep -Seconds (10 * $i) }
  }
  return $false
}

function Save-Choice([string]$Name) {
  $utf8 = New-Object System.Text.UTF8Encoding $false
  $path = Join-Path (Get-Location) $OutFile
  [System.IO.File]::WriteAllText($path, ($Name + $nl), $utf8)
  Write-Host "NODE_IMAGE=$Name"
}

if (Test-Image $mirror) {
  Write-Host "Using local $mirror"
  Save-Choice $mirror
  exit 0
}

if (Invoke-Pull $mirror 2) {
  Save-Choice $mirror
  exit 0
}

if (-not (Test-Image $HubImage)) {
  if (-not (Invoke-Pull $HubImage 5)) {
    Write-Host "Cannot pull $HubImage from Docker Hub (TLS timeout or blocked)."
    Write-Host "On the Windows runner, when Hub is reachable:"
    Write-Host "  docker pull $HubImage"
    Write-Host "  docker tag $HubImage $mirror"
    Write-Host "  docker push $mirror"
    Write-Host "Then re-run this workflow."
    exit 1
  }
}

Write-Host "Tagging $HubImage as $mirror"
docker tag $HubImage $mirror
if ($LASTEXITCODE -ne 0) { exit $LASTEXITCODE }

docker push $mirror
if ($LASTEXITCODE -ne 0) {
  Write-Host "Could not push $mirror - docker build will use the local tag (legacy builder)."
  $flag = Join-Path (Get-Location) '.ci-use-legacy-builder'
  New-Item -ItemType File -Path $flag -Force | Out-Null
}

Save-Choice $mirror
exit 0