<#
    float-window.ps1 -- DSH 悬浮窗原生壳 (Windows only)

    一个由我们自己进程拥有的无边框顶层窗口，内嵌 WebView2 (Chromium)：
      * 始终置顶 / 固定位置 (pin) / 锁定尺寸 (lock) 三个可开关状态
      * 拖动移动、右下角拖动改变尺寸、自适应布局、全屏切换
      * SetWindowDisplayAffinity(WDA_EXCLUDEFROMCAPTURE) -> 从截屏里彻底消失
      * 位置/尺寸/开关状态记忆；透明度（CSS + 窗口级 alpha 双通道）
      * 与页面通过 WebView2 的 postMessage 桥通信 (见 shell/ui.html)

    用法:
      powershell -File shell\float-window.ps1
      powershell -File shell\float-window.ps1 -NoExclude -Opacity 1.0   # 调试: 允许被截图
#>
[CmdletBinding()]
param(
    [string]$Lib,               # WebView2 SDK 目录, 默认 <repo>\shell\lib
    [string]$UiFile,            # 浮窗 UI 文件, 默认 <repo>\shell\ui.html
    [string]$DshHome,           # DSH 主目录, 默认 $env:DSH_HOME 或 ~\.dsh
    [double]$Opacity = 0.92,
    [ValidateSet('opaque', 'translucent', 'acrylic', 'mica', 'blur')]
    [string]$Backdrop = 'opaque',
    [switch]$NoExclude,         # 调试用: 关闭截图排除
    [switch]$NoTopMost,
    [string]$Action             # 命令行下发的动作: pin|sizeLock|topmost|fullscreen|hide|show|close
)

$ErrorActionPreference = 'Stop'
$ProgressPreference = 'SilentlyContinue'
Add-Type -AssemblyName System.Windows.Forms, System.Drawing

$root = Split-Path -Parent (Split-Path -Parent $MyInvocation.MyCommand.Path)
if (-not $Lib) { $Lib = Join-Path $root 'shell\lib' }
if (-not $UiFile) { $UiFile = Join-Path $root 'shell\ui.html' }
if (-not $DshHome) { $DshHome = if ($env:DSH_HOME) { $env:DSH_HOME } else { Join-Path $env:USERPROFILE '.dsh' } }

# 插件写出的 endpoint.json 永远在 DSH 主目录下（只读）
$endpointFile = Join-Path (Join-Path $DshHome 'float-window') 'endpoint.json'

# 自己的状态和 WebView2 用户数据目录需要可写；被沙箱限制时自动降级
function Test-Writable([string]$Dir) {
    try {
        New-Item -ItemType Directory -Force -Path $Dir | Out-Null
        $probe = Join-Path $Dir '.write-probe'
        Set-Content -Path $probe -Value 'x' -ErrorAction Stop
        Remove-Item $probe -Force
        return $true
    } catch { return $false }
}
$stateDir = $null
foreach ($cand in @((Join-Path $DshHome 'float-window'), (Join-Path $env:LOCALAPPDATA 'dsh-float-window'), (Join-Path $root '.runtime'))) {
    if (Test-Writable $cand) { $stateDir = $cand; break }
}
if (-not $stateDir) { throw 'no writable state directory' }
$stateFile = Join-Path $stateDir 'window.json'
$logFile = Join-Path $stateDir 'float-window.log'
function Log([string]$Msg) {
    try { Add-Content -Path $logFile -Value ("{0} {1}" -f (Get-Date -Format 'HH:mm:ss.fff'), $Msg) -Encoding UTF8 } catch {}
    Write-Host "[float] $Msg"
}
Log "start lib=$Lib ui=$UiFile stateDir=$stateDir endpoint=$endpointFile exclude=$(-not $NoExclude) topmost=$(-not $NoTopMost)"

# 单实例：必须在建窗口之前判定
# 单实例：已在运行时，把动作写进 command.json 交给它执行，然后自己退出
$mutexName = 'DSHFloatWindow'
$alreadyRunning = $false
try { $null = [System.Threading.Mutex]::OpenExisting($mutexName); $alreadyRunning = $true } catch { $alreadyRunning = $false }
$commandFile = Join-Path $stateDir 'command.json'
$aliveFile = Join-Path $stateDir 'alive.json'
# 文件桥：插件每秒写 snapshot.json（桌面壳 HTTP 网关 403，浮窗只能走文件）
$snapshotFile = Join-Path $DshHome 'float-window\snapshot.json'
$outboxFile = Join-Path $DshHome 'float-window\outbox.json'
if ($alreadyRunning) {
    if ($Action) {
        try {
            @{ cmd = $Action; at = (Get-Date).ToString('o') } | ConvertTo-Json | Set-Content -Path $commandFile -Encoding UTF8
            Log "handed action '$Action' to the running instance"
        } catch { Log "command write failed: $($_.Exception.Message)" }
    } else { Log 'another instance is running; exiting' }
    exit 0
}

$createdNew = $false
$mutex = New-Object System.Threading.Mutex($true, $mutexName, [ref]$createdNew)
if (-not $createdNew) { Log 'another instance is running; exiting'; exit 0 }
Log 'mutex ok'

# ---------------------------------------------------------------- native interop
Add-Type -Namespace DshFloat -Name Native -MemberDefinition @'
[DllImport("user32.dll")] public static extern bool ReleaseCapture();
[DllImport("user32.dll")] public static extern IntPtr SendMessage(IntPtr hWnd, int Msg, IntPtr wParam, IntPtr lParam);
[DllImport("user32.dll")] public static extern bool SetWindowDisplayAffinity(IntPtr hWnd, uint dwAffinity);
[DllImport("user32.dll")] public static extern int SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong);
[DllImport("user32.dll")] public static extern int GetWindowLong(IntPtr hWnd, int nIndex);
[DllImport("user32.dll")] public static extern bool SetLayeredWindowAttributes(IntPtr hWnd, uint crKey, byte bAlpha, uint dwFlags);
'@

# ---------------------------------------------------------------- WebView2 加载
# 本机 PowerShell 用 LoadFrom 加载 WebView2 SDK 会报 0x80131515, 改从字节加载
function Import-AssemblyFromBytes([string]$Path) {
    if (-not (Test-Path $Path)) { throw "missing assembly: $Path (先跑 tools\setup-webview2.ps1)" }
    [void][System.Reflection.Assembly]::Load([System.IO.File]::ReadAllBytes($Path))
}
Import-AssemblyFromBytes (Join-Path $Lib 'Microsoft.Web.WebView2.Core.dll')
Import-AssemblyFromBytes (Join-Path $Lib 'Microsoft.Web.WebView2.WinForms.dll')
# 原生 loader 走 P/Invoke, 靠 PATH 找到
$env:PATH = "$Lib;$env:PATH"
Log 'webview2 assemblies loaded'

# ---------------------------------------------------------------- 窗体类（边缘缩放 + 云母/亚克力背景）
# 无边框窗口默认没有可拖拽的边框：用 WM_NCHITTEST 在四周 8px 边环上返回 HT* 代码，
# 让系统自己完成缩放（比从页面 postMessage 触发可靠得多）。玻璃模式下抑制 WinForms
# 擦背景，把客户区让给 DWM 的系统背景（Mica / Acrylic）绘制。
Add-Type -ReferencedAssemblies System.Windows.Forms, System.Drawing, System.Runtime.InteropServices -TypeDefinition @'
using System;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Windows.Forms;

namespace DshFloat
{
    public class FloatForm : Form
    {
        public int BorderSize = 8;
        public bool AllowResize = true;
        public int BackdropMode = 0;   // 0=opaque 1=mica 2=acrylic 3=blur

        [StructLayout(LayoutKind.Sequential)] struct MARGINS { public int l, r, t, b; }
        [StructLayout(LayoutKind.Sequential)] struct ACCENTPOLICY { public int State, Flags, GradientColor, AnimationId; }
        [StructLayout(LayoutKind.Sequential)] struct WINCOMPDATA { public int Attrib; public IntPtr Data; public int Size; }

        [DllImport("dwmapi.dll")] static extern int DwmSetWindowAttribute(IntPtr h, int attr, ref int val, int size);
        [DllImport("dwmapi.dll")] static extern int DwmGetWindowAttribute(IntPtr h, int attr, out int val, int size);
        [DllImport("dwmapi.dll")] static extern int DwmExtendFrameIntoClientArea(IntPtr h, ref MARGINS m);
        [DllImport("user32.dll")] static extern int SetWindowCompositionAttribute(IntPtr h, ref WINCOMPDATA d);

        public string ApplyBackdrop(int mode)
        {
            BackdropMode = mode;
            int type = mode == 1 ? 2 : (mode == 2 ? 3 : 0);   // DWMSBT_MAINWINDOW / TRANSIENTWINDOW / AUTO
            int hr = DwmSetWindowAttribute(Handle, 38, ref type, 4);   // DWMWA_SYSTEMBACKDROP_TYPE
            int got = -1;
            int hrGet = DwmGetWindowAttribute(Handle, 38, out got, 4);
            bool effective = mode == 0 ? true : (hr == 0 && hrGet == 0 && got == type);
            // 关键 1：**不再**把客户区扩展成"玻璃"（真机上会让 8px 边环与 WebView2 露出白底）
            // 关键 2：**不要**再用 SetWindowCompositionAttribute 的 ACCENT_ENABLE_ACRYLICBLURBEHIND，
            //         那是 Win10 时代的未文档化做法，Win11 上会把窗口变成纯黑（实测 PrintWindow 全黑）。
            // 现在窗口始终由应用自己画深色，系统背景只当装饰，"霜化"观感交给页面自己的半透明。
            MARGINS m = new MARGINS();
            DwmExtendFrameIntoClientArea(Handle, ref m);
            Invalidate(true);
            return "mode=" + mode + " hr=" + hr + " got=" + got + " effective=" + effective;
        }

        void SetAccent(int state, int color)
        {
            ACCENTPOLICY acc = new ACCENTPOLICY();
            acc.State = state; acc.Flags = 2; acc.GradientColor = color; acc.AnimationId = 0;
            int size = Marshal.SizeOf(acc);
            IntPtr p = Marshal.AllocHGlobal(size);
            Marshal.StructureToPtr(acc, p, false);
            WINCOMPDATA d = new WINCOMPDATA();
            d.Attrib = 19; d.Data = p; d.Size = size;   // WCA_ACCENT_POLICY
            SetWindowCompositionAttribute(Handle, ref d);
            Marshal.FreeHGlobal(p);
        }

        // 始终由应用自己画背景（深色）：玻璃模式下 DWM 若没生效也不会露出白底
        protected override void OnPaintBackground(PaintEventArgs e)
        {
            base.OnPaintBackground(e);
        }

        protected override void WndProc(ref Message m)
        {
            const int WM_NCHITTEST = 0x84;
            if (m.Msg == WM_NCHITTEST && AllowResize)
            {
                long lp = m.LParam.ToInt64();
                Point p = PointToClient(new Point((short)(lp & 0xFFFF), (short)((lp >> 16) & 0xFFFF)));
                int b = BorderSize;
                bool l = p.X <= b, r = p.X >= ClientSize.Width - b;
                bool t = p.Y <= b, bo = p.Y >= ClientSize.Height - b;
                int hit = 0;
                if (t && l) hit = 13; else if (t && r) hit = 14;
                else if (bo && l) hit = 16; else if (bo && r) hit = 17;
                else if (l) hit = 10; else if (r) hit = 11;
                else if (t) hit = 12; else if (bo) hit = 15;
                if (hit != 0) { m.Result = (IntPtr)hit; return; }
            }
            base.WndProc(ref m);
        }
    }
}
'@
Log 'floatform type ok'

# ---------------------------------------------------------------- 状态与默认值
$WS_EX_LAYERED = 0x80000
$WDA_EXCLUDEFROMCAPTURE = 0x11
$SWP_NOMOVE = 0x2; $SWP_NOSIZE = 0x1

$script:state = [ordered]@{
    x = -1; y = -1; w = 420; h = 720
    topmost = (-not $NoTopMost)
    posLock = $false
    sizeLock = $false
    opacity = $Opacity
    exclude = $true          # 默认抓屏隐身；-NoExclude 只在运行时覆盖，绝不落盘成默认值
    scale = 1.0
    fullscreen = $false
    backdrop = if ($Backdrop) { $Backdrop } else { 'opaque' }
}
if (Test-Path $stateFile) {
    try {
        $saved = Get-Content $stateFile -Raw | ConvertFrom-Json
        foreach ($k in @($saved.PSObject.Properties.Name)) { if ($script:state.Contains($k)) { $script:state[$k] = $saved.$k } }
        if ($NoTopMost) { $script:state.topmost = $false }
        if ($NoExclude) { $script:state.exclude = $false }
        $script:state.opacity = $Opacity
        $script:state.fullscreen = $false
    } catch { Write-Warning "state file ignored: $($_.Exception.Message)" }
}
# -NoExclude 只是本次运行的调试开关，不允许被写回状态文件（否则以后默认就不隐身了）
$script:persistExclude = [bool]$script:state.exclude

function Save-State {
    try {
        $out = [ordered]@{}
        foreach ($k in $script:state.Keys) { $out[$k] = $script:state[$k] }
        if ($NoExclude) { $out.exclude = $script:persistExclude }
        ($out | ConvertTo-Json -Depth 3) | Set-Content -Path $stateFile -Encoding UTF8
    } catch {}
}

# ---------------------------------------------------------------- 窗口
$form = New-Object DshFloat.FloatForm
$form.Text = 'DSH 悬浮窗'
$form.FormBorderStyle = 'None'
$form.StartPosition = 'Manual'
$form.ShowInTaskbar = $true
$form.MinimumSize = New-Object System.Drawing.Size(260, 240)
$form.BackColor = [System.Drawing.Color]::FromArgb(15, 17, 21)
$form.TopMost = [bool]$script:state.topmost
$form.KeyPreview = $true
# 8px 边环留给系统做缩放命中测试，WebView2 只铺在里面
$form.Padding = New-Object System.Windows.Forms.Padding(8, 8, 8, 8)

$scr = [System.Windows.Forms.Screen]::PrimaryScreen.WorkingArea
if ($script:state.x -lt 0 -or $script:state.y -lt 0) {
    $script:state.x = $scr.Right - [int]$script:state.w - 24
    $script:state.y = $scr.Top + 24
}
$form.Bounds = New-Object System.Drawing.Rectangle(
    [int]$script:state.x, [int]$script:state.y, [int]$script:state.w, [int]$script:state.h)
# 高 DPI 下 WinForms 会把逻辑尺寸放大，这里按真实尺寸把窗口夹回屏幕内
if ($form.Right -gt $scr.Right) { $form.Left = [Math]::Max($scr.Left, $scr.Right - $form.Width - 12) }
if ($form.Bottom -gt $scr.Bottom) { $form.Top = [Math]::Max($scr.Top, $scr.Bottom - $form.Height - 12) }
if ($form.Left -lt $scr.Left) { $form.Left = $scr.Left + 12 }
if ($form.Top -lt $scr.Top) { $form.Top = $scr.Top + 12 }

$wv = New-Object Microsoft.Web.WebView2.WinForms.WebView2
$wv.Dock = 'Fill'
$form.Controls.Add($wv)

function Send-ToPage([hashtable]$Msg) {
    if ($wv.CoreWebView2) {
        try { $wv.CoreWebView2.PostWebMessageAsJson(($Msg | ConvertTo-Json -Depth 6 -Compress)) } catch {}
    }
}

function Apply-Opacity([double]$value) {
    $script:state.opacity = [Math]::Round([Math]::Max(0.25, [Math]::Min(1.0, $value)), 2)
    # 观感透明度由页面 CSS 的 --alpha 决定；只有「半透明」模式才额外给整窗 alpha
    if ($script:state.backdrop -eq 'translucent') { Set-WindowAlpha $script:state.opacity } else { Set-WindowAlpha 1.0 }
}

function Apply-Exclude {
    # 0x11 = WDA_EXCLUDEFROMCAPTURE: 窗口从所有抓屏 API 里彻底消失(实测有效)
    $aff = if ($script:state.exclude) { $WDA_EXCLUDEFROMCAPTURE } else { 0 }
    [void][DshFloat.Native]::SetWindowDisplayAffinity($form.Handle, $aff)
}

function Apply-Backdrop([string]$Mode) {
    if (-not $Mode) { $Mode = 'opaque' }
    # 真机结论：这台机器上任何"窗口级"的系统背景（DWM 系统背景类型 / Win10 亚克力 /
    # 把客户区扩展成玻璃）都会让 WebView2 内容变黑、8px 边环露白底（用户原话"边框有白色的框"）。
    # 所以窗口**永远**保持应用自己绘制的深色，"背景效果"只作为页面侧的半透明/霜化观感，
    # 页面 alpha 由不透明度滑杆控制。
    $script:state.backdrop = $Mode
    if ($wv.CoreWebView2) {
        try { $wv.DefaultBackgroundColor = [System.Drawing.Color]::FromArgb(255, 15, 17, 21) } catch { }
    }
    Set-WindowAlpha 1.0
    Log "backdrop $Mode (page-level only)"
    Push-State
}

# 页面 -> 宿主：写 outbox.json（UTF-8 无 BOM，宿主侧 JSON.parse 才吃得下）
function Write-Outbox([hashtable]$Msg) {
    try {
        $Msg.at = (Get-Date).ToString('o')
        $json = $Msg | ConvertTo-Json -Compress
        [System.IO.File]::WriteAllText($outboxFile, $json, (New-Object System.Text.UTF8Encoding($false)))
        Log "outbox $($Msg.cmd) ($($json.Length)B)"
    } catch { Log "outbox write failed: $($_.Exception.Message)" }
}

function Set-WindowAlpha([double]$value) {
    $alpha = [byte][Math]::Round([Math]::Max(0.05, [Math]::Min(1.0, $value)) * 255)
    $style = [DshFloat.Native]::GetWindowLong($form.Handle, -20)
    if ($value -lt 1.0) {
        [void][DshFloat.Native]::SetWindowLong($form.Handle, -20, $style -bor $WS_EX_LAYERED)
        [void][DshFloat.Native]::SetLayeredWindowAttributes($form.Handle, 0, $alpha, 0x2)
    } else {
        [void][DshFloat.Native]::SetWindowLong($form.Handle, -20, $style -band (-bnot $WS_EX_LAYERED))
    }
}

function Push-State {
    Send-ToPage @{
        type = 'state'
        state = @{
            topmost = [bool]$script:state.topmost
            posLock = [bool]$script:state.posLock
            sizeLock = [bool]$script:state.sizeLock
            opacity = [double]$script:state.opacity
            exclude = [bool]$script:state.exclude
            scale = [double]$script:state.scale
            backdrop = [string]$script:state.backdrop
            fullscreen = [bool]$script:state.fullscreen
            w = $form.Width; h = $form.Height
        }
    }
}

function Toggle-Fullscreen {
    if ($script:state.fullscreen) {
        $b = $script:savedBounds
        if ($b) { $form.Bounds = $b }
        $script:state.fullscreen = $false
    } else {
        $script:savedBounds = $form.Bounds
        $form.WindowState = 'Normal'
        $form.Bounds = [System.Windows.Forms.Screen]::FromHandle($form.Handle).Bounds
        $script:state.fullscreen = $true
    }
    Push-State
}

function Send-Endpoint {
    $payload = @{ type = 'endpoint'; baseUrl = $null; token = $null }
    if (Test-Path $endpointFile) {
        try {
            $ep = Get-Content $endpointFile -Raw | ConvertFrom-Json
            $payload.baseUrl = $ep.baseUrl; $payload.token = $ep.token
        } catch { Log "endpoint parse failed: $($_.Exception.Message)" }
    }
    Log "push endpoint -> $($payload.baseUrl)"
    Send-ToPage $payload
}

# ---------------------------------------------------------------- 页面消息处理
$onWebMessage = {
    # 参数不能叫 $args —— 那是 PowerShell 的自动变量，会被整个事件参数数组占住，
    # 于是 TryGetWebMessageAsString 找不到（实测：页面全部按钮失效、ready 握手丢失）。
    param($s, $e)
    try {
        $msg = $e.TryGetWebMessageAsString()
        if (-not $msg) { $msg = $e.WebMessageAsJson }
        $m = $msg | ConvertFrom-Json
    } catch { Log "webmessage parse failed: $($_.Exception.Message)"; return }
    if ($m.cmd -and $m.cmd -ne 'drag' -and $m.cmd -ne 'resize') { Log "page cmd: $($m.cmd)" }
    switch ($m.cmd) {
        'ready'      { Push-State; Send-Endpoint }
        'drag'       { if (-not $script:state.posLock) { [void][DshFloat.Native]::ReleaseCapture(); [void][DshFloat.Native]::SendMessage($form.Handle, 0xA1, [IntPtr]2, [IntPtr]::Zero) } }
        'resize'     { if (-not $script:state.sizeLock) { [void][DshFloat.Native]::ReleaseCapture(); [void][DshFloat.Native]::SendMessage($form.Handle, 0xA1, [IntPtr]17, [IntPtr]::Zero) } }
        'close'      { $form.Close() }
        'minimize'   { $form.WindowState = 'Minimized' }
        'fullscreen' { Toggle-Fullscreen }
        'topmost'    { $script:state.topmost = -not $script:state.topmost; $form.TopMost = [bool]$script:state.topmost; Save-State; Push-State }
        'posLock'    { $script:state.posLock = -not $script:state.posLock; Save-State; Push-State }
        'sizeLock'   { $script:state.sizeLock = -not $script:state.sizeLock; $form.AllowResize = -not $script:state.sizeLock; Save-State; Push-State }
        'exclude'    { $script:state.exclude = -not $script:state.exclude; Apply-Exclude; Save-State; Push-State }
        'opacity'    { Apply-Opacity ([double]$m.value); Save-State; Push-State }
        'backdrop'   { Apply-Backdrop ([string]$m.value); Save-State; Push-State }
        'scale'      { $script:state.scale = [double]$m.value; $wv.ZoomFactor = [double]$m.value; Save-State; Push-State }
        'reload'     { $wv.Reload() }
        'chat'       { Write-Outbox @{ cmd = 'chat'; text = [string]$m.text } }
        'watch'      { Write-Outbox @{ cmd = 'watch'; sessionId = [string]$m.sessionId } }
        'newSession' { Write-Outbox @{ cmd = 'session'; action = 'create' } }
        'openExternal' { if ($m.url -match '^https?://') { Start-Process $m.url } }
    }
}
# ---------------------------------------------------------------- 外部命令 / 心跳
function Invoke-Cmd([string]$c) {
    switch ($c) {
        'close' { $form.Close() }
        'pin' { $script:state.posLock = -not $script:state.posLock; Save-State; Push-State }
        'sizeLock' { $script:state.sizeLock = -not $script:state.sizeLock; $form.AllowResize = -not $script:state.sizeLock; Save-State; Push-State }
        'topmost' { $script:state.topmost = -not $script:state.topmost; $form.TopMost = [bool]$script:state.topmost; Save-State; Push-State }
        'fullscreen' { Toggle-Fullscreen }
        'hide' { Send-ToPage @{ type = 'cmd'; cmd = 'hide' } }
        'show' { $form.Show(); $form.Activate(); Send-ToPage @{ type = 'cmd'; cmd = 'show' } }
        'open' { if (-not $form.Visible) { $form.Show() }; $form.Activate(); $form.BringToFront(); Send-ToPage @{ type = 'cmd'; cmd = 'show' } }
        default { Send-ToPage @{ type = 'cmd'; cmd = $c } }
    }
}

$script:lastEndpointText = ''
$script:lastCommandText = ''
$script:lastSnapshotText = ''
$timer = New-Object System.Windows.Forms.Timer
$timer.Interval = 700
$timer.Add_Tick({
        # endpoint.json 变了（DSH 重启 / 换端口）就重新告诉页面
        try {
            if (Test-Path $endpointFile) {
                $t = Get-Content $endpointFile -Raw
                if ($t -ne $script:lastEndpointText) { $script:lastEndpointText = $t; Send-Endpoint }
            }
        } catch {}
        # 文件桥：宿主每秒写 snapshot.json（桌面壳的 HTTP 网关会 403，浮窗只能走文件）
        # 必须显式按 UTF-8 读：PS 5.1 的 Get-Content -Raw 会按 GBK 解码，中文摘要会破坏 JSON
        try {
            if (Test-Path $snapshotFile) {
                $s = [System.IO.File]::ReadAllText($snapshotFile, [System.Text.Encoding]::UTF8)
                if ($s -and $s -ne $script:lastSnapshotText) {
                    $script:lastSnapshotText = $s
                    Send-ToPage @{ type = 'snapshot'; data = ($s | ConvertFrom-Json) }
                }
            }
        } catch { Log "snapshot error: $($_.Exception.Message)" }
        # 插件/命令行下发的动作
        try {
            if (Test-Path $commandFile) {
                $c = Get-Content $commandFile -Raw -ErrorAction SilentlyContinue
                if ($c -and $c -ne $script:lastCommandText) {
                    $script:lastCommandText = $c
                    Remove-Item $commandFile -Force -ErrorAction SilentlyContinue
                    $cmd = ($c | ConvertFrom-Json).cmd
                    Log "external cmd: $cmd"
                    Invoke-Cmd $cmd
                }
            }
        } catch { Log "cmd error: $($_.Exception.Message)" }
        # 心跳，宿主据此判断浮窗是否还活着
        try { @{ pid = $PID; at = (Get-Date).ToString('o') } | ConvertTo-Json | Set-Content -Path $aliveFile -Encoding UTF8 } catch {}
    })
$timer.Start()

# WebView2 初始化是异步的：绝不能在 UI 线程上阻塞等待（会死锁），改为事件驱动
$onWvReady = {
    param($sender, $e)
    if (-not $e.IsSuccess) { Log "WV2 init failed: $($e.InitializationException)"; return }
    Log 'corewebview2 ready'
    $s = $wv.CoreWebView2.Settings
    $s.AreDefaultContextMenusEnabled = $false
    $s.IsStatusBarEnabled = $false
    $s.AreBrowserAcceleratorKeysEnabled = $false
    $s.IsZoomControlEnabled = $true
    $s.AreDevToolsEnabled = $false
    $wv.CoreWebView2.add_WebMessageReceived($onWebMessage)
    $wv.CoreWebView2.SetVirtualHostNameToFolderMapping('dshfloat.local', $root, 1)
    Apply-Backdrop $script:state.backdrop
    Apply-Opacity $script:state.opacity
    $wv.CoreWebView2.Navigate("file:///$(($UiFile -replace '\\','/'))")
    Log "navigated to $UiFile"
    Push-State
}
$wv.add_CoreWebView2InitializationCompleted($onWvReady)
$form.Add_Shown({
        Log 'form shown'
        $form.AllowResize = -not $script:state.sizeLock
        try {
            $udf = Join-Path $stateDir 'webview2'
            New-Item -ItemType Directory -Force -Path $udf | Out-Null
            Log "creating WebView2 env at $udf"
            # 参数顺序是 (browserExecutableFolder, userDataFolder, options)
            $wvEnv = [Microsoft.Web.WebView2.Core.CoreWebView2Environment]::CreateAsync($null, $udf, $null).GetAwaiter().GetResult()
            Log "env ok browser=$($wvEnv.BrowserVersionString)"
            [void]$wv.EnsureCoreWebView2Async($wvEnv)
            Log 'EnsureCoreWebView2Async started'
        } catch {
            Log "WV2 ERROR: $($_.Exception.Message)"
        }
        try { Apply-Exclude; $wv.ZoomFactor = [double]$script:state.scale } catch { Log "apply ERROR: $($_.Exception.Message)" }
    })

$form.Add_ResizeEnd({ if (-not $script:state.fullscreen) { $script:state.w = $form.Width; $script:state.h = $form.Height; Save-State; Push-State } })
$form.Add_Move({ if (-not $script:state.fullscreen -and $form.WindowState -eq 'Normal') { $script:state.x = $form.Left; $script:state.y = $form.Top } })
$form.Add_FormClosing({ Save-State })
$form.Add_KeyDown({
        param($s, $e)
        if ($e.KeyCode -eq [System.Windows.Forms.Keys]::F11) { Toggle-Fullscreen }
        if ($e.KeyCode -eq [System.Windows.Forms.Keys]::Escape -and $script:state.fullscreen) { Toggle-Fullscreen }
    })

# 单实例已在上方处理

[void]$form.Show()
[System.Windows.Forms.Application]::Run($form)
$mutex.ReleaseMutex()