param(
  [switch]$Build,
  [int]$BackupRetention = 0,
  [string]$SshUser = "y2keui",
  [string]$SshHost = "comtropy.synology.me",
  [int]$SshPort = 50022,
  [string]$SshKey = "$env:USERPROFILE\.ssh\nas_msix_ed25519",
  [string]$RemoteRoot = "/volume1/web",
  [string]$SiteName = "heros_web"
)

$ErrorActionPreference = "Stop"
Set-StrictMode -Version Latest

function Assert-Command {
  param([string]$Name)
  if (-not (Get-Command $Name -ErrorAction SilentlyContinue)) {
    throw "Required command not found: $Name"
  }
}

function Quote-Sh {
  param([string]$Value)
  return "'" + ($Value -replace "'", "'\''") + "'"
}

function Get-ObjectPropertyValue {
  param(
    [object]$Object,
    [string]$Name
  )
  if ($null -eq $Object) {
    return $null
  }
  $property = $Object.PSObject.Properties[$Name]
  if ($null -eq $property) {
    return $null
  }
  return $property.Value
}

function Test-ReleaseManifestRenderingGate {
  param([object]$Manifest)
  $renderingGate = Get-ObjectPropertyValue $Manifest "renderingGate"
  $viewport = Get-ObjectPropertyValue $renderingGate "viewport"
  return (
    (Get-ObjectPropertyValue $renderingGate "requiredRenderer") -eq "webgl" -and
    (Get-ObjectPropertyValue $renderingGate "compatibilityRenderer") -eq "canvas" -and
    (Get-ObjectPropertyValue $viewport "width") -eq 1920 -and
    (Get-ObjectPropertyValue $viewport "height") -eq 1080 -and
    (Get-ObjectPropertyValue $viewport "deviceScaleFactor") -eq 1
  )
}

Assert-Command "ssh"
Assert-Command "scp"
Assert-Command "git"

if ($Build) {
  Assert-Command "pnpm"
  pnpm build
  if ($LASTEXITCODE -ne 0) {
    throw "pnpm build failed with exit code $LASTEXITCODE"
  }
}

$dist = Join-Path (Get-Location) "dist"
$index = Join-Path $dist "index.html"
$assets = Join-Path $dist "assets"

if (-not (Test-Path $index -PathType Leaf)) {
  throw "Missing dist/index.html. Run pnpm build first or pass -Build."
}

if (-not (Test-Path $assets -PathType Container)) {
  throw "Missing dist/assets. Run pnpm build first or pass -Build."
}

if ($BackupRetention -lt 0) {
  throw "BackupRetention must be 0 or greater."
}

$timestamp = Get-Date -Format "yyyyMMddHHmmss"
$fullCommit = (git rev-parse HEAD).Trim()
$commit = (git rev-parse --short=8 HEAD).Trim()
$qaVersion = if ($env:PUBLIC_QA_VERSION) { $env:PUBLIC_QA_VERSION } else { "deploy-$timestamp" }
$releaseManifestPath = Join-Path $dist "release-manifest.json"
$writeReleaseManifest = $true
if (Test-Path $releaseManifestPath -PathType Leaf) {
  try {
    $existingReleaseManifest = Get-Content -LiteralPath $releaseManifestPath -Raw | ConvertFrom-Json
    if ($existingReleaseManifest.app -ne "heros_web") {
      throw "Existing release manifest has unexpected app '$($existingReleaseManifest.app)'."
    }
    if (
      $existingReleaseManifest.commit -eq $fullCommit -and
      (Test-ReleaseManifestRenderingGate $existingReleaseManifest)
    ) {
      $writeReleaseManifest = $false
      Write-Host "Using existing $releaseManifestPath for $commit"
    } elseif ($existingReleaseManifest.commit -eq $fullCommit) {
      Write-Host "Replacing incomplete $releaseManifestPath for $commit"
    } else {
      Write-Host "Replacing stale $releaseManifestPath commit $($existingReleaseManifest.commit) with $commit"
    }
  } catch {
    throw "Invalid existing release manifest at $releaseManifestPath. $_"
  }
}
if ($writeReleaseManifest) {
  $releaseManifestJson = @{
    app = "heros_web"
    commit = $fullCommit
    shortCommit = $commit
    qaVersion = $qaVersion
    generatedAt = (Get-Date).ToUniversalTime().ToString("o")
    renderingGate = @{
      requiredRenderer = "webgl"
      compatibilityRenderer = "canvas"
      viewport = @{
        width = 1920
        height = 1080
        deviceScaleFactor = 1
      }
    }
  } | ConvertTo-Json -Depth 4
  $utf8NoBom = New-Object System.Text.UTF8Encoding $false
  [System.IO.File]::WriteAllText($releaseManifestPath, "$releaseManifestJson`n", $utf8NoBom)
  Write-Host "Wrote $releaseManifestPath for $commit ($qaVersion)"
}

$userHost = "$SshUser@$SshHost"
$remoteTemp = "$RemoteRoot/.$($SiteName)_deploy_$timestamp"
$remotePrevious = "$RemoteRoot/.$($SiteName)_previous_$timestamp"
$remoteBackup = "$RemoteRoot/$SiteName.backup-$timestamp-$commit"

$quotedRemoteRoot = Quote-Sh $RemoteRoot
$quotedSiteName = Quote-Sh $SiteName
$quotedTemp = Quote-Sh $remoteTemp
$quotedPrevious = Quote-Sh $remotePrevious
$quotedBackup = Quote-Sh $remoteBackup
$retention = $BackupRetention

$prepareRemote = @"
set -e
remote_root=$quotedRemoteRoot
temp=$quotedTemp
site_name=$quotedSiteName
test -d "`$remote_root"
rm -rf -- "`$temp"
mkdir -p -- "`$temp"
printf 'Prepared %s/%s via %s\n' "`$remote_root" "`$site_name" "`$temp"
"@

ssh -o BatchMode=yes -o ConnectTimeout=8 -i $SshKey -p $SshPort $userHost $prepareRemote
if ($LASTEXITCODE -ne 0) {
  throw "Failed to prepare remote deploy directory."
}

scp -O -i $SshKey -P $SshPort -r "$dist\*" "$userHost`:$remoteTemp/"
if ($LASTEXITCODE -ne 0) {
  throw "Failed to upload dist to remote deploy directory."
}

$installRemote = @"
set -e
remote_root=$quotedRemoteRoot
site_name=$quotedSiteName
temp=$quotedTemp
previous=$quotedPrevious
backup=$quotedBackup
retention=$retention
site="`$remote_root/`$site_name"

test -f "`$temp/index.html"
test -d "`$temp/assets"
rm -rf -- "`$previous"

if [ -d "`$site" ]; then
  mv -- "`$site" "`$previous"
fi

if ! mv -- "`$temp" "`$site"; then
  if [ -d "`$previous" ]; then
    mv -- "`$previous" "`$site"
  fi
  exit 1
fi

chmod -R a+rX "`$site"

if [ -d "`$previous" ]; then
  if [ "`$retention" -gt 0 ]; then
    mv -- "`$previous" "`$backup"
  else
    rm -rf -- "`$previous"
  fi
fi

find "`$remote_root" -maxdepth 1 -type d \( -name ".`${site_name}_deploy_*" -o -name "`${site_name}_deploy_*" -o -name ".`${site_name}_previous_*" \) -exec rm -rf -- {} +

if [ "`$retention" -eq 0 ]; then
  find "`$remote_root" -maxdepth 1 -type d -name "`${site_name}.backup-*" -exec rm -rf -- {} +
else
  keep_count=`$retention
  find "`$remote_root" -maxdepth 1 -type d -name "`${site_name}.backup-*" -printf '%f\n' | sort -r | tail -n +`$((keep_count + 1)) | while IFS= read -r old_backup; do
    [ -n "`$old_backup" ] && rm -rf -- "`$remote_root/`$old_backup"
  done
fi

printf 'Deployed %s at %s\n' "`$site_name" "`$site"
printf 'Backup retention: %s\n' "`$retention"
printf 'Remaining site directories:\n'
find "`$remote_root" -maxdepth 1 -type d -name "*`${site_name}*" -printf '%f\n' | sort
"@

ssh -o BatchMode=yes -o ConnectTimeout=8 -i $SshKey -p $SshPort $userHost $installRemote
if ($LASTEXITCODE -ne 0) {
  throw "Failed to install remote deploy directory."
}