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 "'", "'\''") + "'"
}

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"
$commit = (git rev-parse --short=8 HEAD).Trim()
$userHost = "$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."
}