# 后台启动/停止网页预览服务器 (无 PowerShell 窗口)
# 用法:
#   powershell -NoProfile -ExecutionPolicy Bypass -File tools\serve-web-bg.ps1            # 后台启动
#   powershell -NoProfile -ExecutionPolicy Bypass -File tools\serve-web-bg.ps1 -Stop      # 停止
#   powershell -NoProfile -ExecutionPolicy Bypass -File tools\serve-web-bg.ps1 -Status    # 查看状态
#   ... -Root release\web_2026.09 -Port 8080                                              # 指定目录/端口
#
# 原理: 用 Start-Process -WindowStyle Hidden 启动 serve-web.ps1, 并把 PID + 参数写入
#       .serve-web.pid 文件, 便于 -Stop / -Status 定位。
param(
  [string]$Root = '',
  [int]$Port = 8080,
  [switch]$Stop,
  [switch]$Status
)

$projRoot = Split-Path $PSScriptRoot -Parent
$pidFile = Join-Path $projRoot '.serve-web.pid'
# 相对路径按【项目根】转绝对 —— Start-Process 启动的子进程工作目录不确定,
# 传相对路径会被解析到别处; 也不能依赖 Get-Location (调用方可能在任意目录)。
# 注意 1: PowerShell 变量名【大小写不敏感】, 不能同时用 $root 和 $Root (会互相覆盖),
#         故项目根变量取名 $projRoot。
# 注意 2: Join-Path 只做拼接不做 .. 归约, 必须再用 GetFullPath 规范化。
if ([string]::IsNullOrWhiteSpace($Root)) { $Root = 'release\web_2026.09' }
if (-not [System.IO.Path]::IsPathRooted($Root)) { $Root = Join-Path $projRoot $Root }
$Root = [System.IO.Path]::GetFullPath($Root)
if (-not (Test-Path $Root)) { Write-Output ("目录不存在: " + $Root); exit 1 }
$script = Join-Path $PSScriptRoot 'serve-web.ps1'

function Get-Running {
  # 用命令行匹配定位服务进程 (比只靠 PID 文件更可靠: 窗口关过/崩溃后 PID 会失效)
  Get-CimInstance Win32_Process -Filter "Name='powershell.exe'" -ErrorAction SilentlyContinue |
    Where-Object { $_.CommandLine -like '*serve-web.ps1*' }
}

if ($Stop) {
  $procs = Get-Running
  if (-not $procs) { Write-Output '服务未在运行'; if (Test-Path $pidFile) { Remove-Item $pidFile -Force }; exit 0 }
  foreach ($p in $procs) {
    Write-Output ("停止 serve-web (PID " + $p.ProcessId + ")")
    Stop-Process -Id $p.ProcessId -Force -ErrorAction SilentlyContinue
  }
  if (Test-Path $pidFile) { Remove-Item $pidFile -Force }
  exit 0
}

if ($Status) {
  $procs = Get-Running
  if ($procs) { Write-Output ("运行中: " + ($procs.ProcessId -join ', ')) }
  else { Write-Output '未运行' }
  try {
    $code = (Invoke-WebRequest -Uri ("http://localhost:" + $Port + "/index.html") -UseBasicParsing -TimeoutSec 3).StatusCode
    Write-Output ("HTTP " + $code + "  http://localhost:" + $Port)
  } catch { Write-Output ("HTTP 不可达  http://localhost:" + $Port) }
  exit 0
}

# 启动前先清理已在跑的, 避免端口占用/多份实例
$old = Get-Running
if ($old) {
  Write-Output ("已有实例, 先停止: " + ($old.ProcessId -join ', '))
  foreach ($p in $old) { Stop-Process -Id $p.ProcessId -Force -ErrorAction SilentlyContinue }
  Start-Sleep -Seconds 2
}

# -WindowStyle Hidden: 不弹 PowerShell 窗口; 进程随本脚本退出继续运行
# 注: 变量名不用 $args (PowerShell 自动变量, 赋值有副作用)
$srvArgs = @('-NoProfile', '-ExecutionPolicy', 'Bypass', '-File', $script, '-Root', $Root, '-Port', $Port)
$p = Start-Process -FilePath 'powershell' -ArgumentList $srvArgs -WindowStyle Hidden -PassThru
Set-Content -Path $pidFile -Value $p.Id -Encoding ascii

Start-Sleep -Seconds 4
try {
  $code = (Invoke-WebRequest -Uri ("http://localhost:" + $Port + "/index.html") -UseBasicParsing -TimeoutSec 5).StatusCode
  Write-Output ("已后台启动 (PID " + $p.Id + ")  HTTP " + $code + "  http://localhost:" + $Port)
  Write-Output ("目录: " + $Root)
  Write-Output "停止: tools\serve-web-bg.ps1 -Stop"
} catch {
  Write-Output ("启动后探测失败, 请检查目录/端口: " + $Root)
  exit 1
}