# DevFlow 自宿主换装脚本 v3
# 流程: 等旧进程退出并探测句柄释放, 静默安装, 按构建产物哈希校验且失败重试一次, 交互用户可见重启, 结束自清理
$ErrorActionPreference = 'Stop'
$installer = 'E:\wk-lab\devflow\target\release\bundle\nsis\devflow_0.1.0_x64-setup.exe'
$target    = 'C:\Users\23780\AppData\Local\devflow\devflow.exe'
$builtExe  = 'E:\wk-lab\devflow\target\release\devflow.exe'
$log       = 'E:\wk-lab\devflow\swap-install.log'
$lockFile  = 'E:\wk-lab\devflow\swap-install.lock'

# 构建产物哈希是唯一强基准; 产物缺失时退化为与安装前快照比对的弱校验
$hashWant = $null
if (Test-Path $builtExe) { $hashWant = (Get-FileHash $builtExe -Algorithm SHA256).Hash }

# 0. SYSTEM 上下文转投用户会话
$who = whoami
if ($who -like '*SYSTEM*') {
    $loggedUser = (Get-CimInstance Win32_ComputerSystem).UserName
    if ($loggedUser) {
        $action  = New-ScheduledTaskAction -Execute 'powershell.exe' -Argument "-NoProfile -ExecutionPolicy Bypass -WindowStyle Hidden -File `"$PSCommandPath`""
        $principal = New-ScheduledTaskPrincipal -UserId $loggedUser -LogonType Interactive
        Register-ScheduledTask -TaskName 'DevFlowSwapUser' -Action $action -Principal $principal -Force | Out-Null
        Start-ScheduledTask -TaskName 'DevFlowSwapUser'
        # 锁由重入脚本创建删除, 是其存活的可靠信号; 按 task State 等有 Ready 竞态且超时会腰斩换装
        $deadline = (Get-Date).AddSeconds(30)
        while (-not (Test-Path $lockFile) -and (Get-Date) -lt $deadline) { Start-Sleep -Seconds 1 }
        $deadline = (Get-Date).AddSeconds(300)
        while ((Test-Path $lockFile) -and (Get-Date) -lt $deadline) { Start-Sleep -Seconds 2 }
        Unregister-ScheduledTask -TaskName 'DevFlowSwapUser' -Confirm:$false -ErrorAction SilentlyContinue
    } else {
        "[FAIL] SYSTEM context and no logged-on user found" | Out-File $log -Encoding utf8
    }
    Unregister-ScheduledTask -TaskName 'DevFlowSwapInstall' -Confirm:$false -ErrorAction SilentlyContinue
    exit 0
}

if (Test-Path $lockFile) {
    $lockAge = (Get-Date) - (Get-Item $lockFile).LastWriteTime
    if ($lockAge.TotalMinutes -lt 5) { exit 0 }
}
New-Item $lockFile -Force | Out-Null

# 独占打开目标 exe 成功即旧句柄已释放; Windows 文件锁延迟释放会让 NSIS 静默伪成功
function Wait-HandleReleased {
    if (-not (Test-Path $target)) { return $true }
    $deadline = (Get-Date).AddSeconds(30)
    while ((Get-Date) -lt $deadline) {
        try {
            $fs = [IO.File]::Open($target, 'Open', 'ReadWrite', 'None')
            $fs.Close()
            "[$(Get-Date -Format 'HH:mm:ss')] handle released" | Add-Content $log
            return $true
        } catch {
            Start-Sleep -Milliseconds 500
        }
    }
    "[$(Get-Date -Format 'HH:mm:ss')] handle wait timeout, continue" | Add-Content $log
    return $false
}

# 静默安装并校验新 exe, 返回换装是否成功
function Invoke-SwapInstall {
    param([string]$Attempt)
    $p = Start-Process $installer -ArgumentList '/S' -Wait -PassThru
    "[$(Get-Date -Format 'HH:mm:ss')] installer exit=$($p.ExitCode) (attempt $Attempt)" | Add-Content $log
    if ($p.ExitCode -ne 0) { return $false }
    if (-not (Test-Path $target)) {
        "[$(Get-Date -Format 'HH:mm:ss')] FAIL: target missing after install" | Add-Content $log
        return $false
    }
    $afterHash = (Get-FileHash $target -Algorithm SHA256).Hash
    $afterSize = (Get-Item $target).Length
    "[$(Get-Date -Format 'HH:mm:ss')] installed size=$afterSize hash=$($afterHash.Substring(0, 12))" | Add-Content $log
    if ($hashWant) {
        if ($afterHash -ne $hashWant) { return $false }
    } else {
        "[$(Get-Date -Format 'HH:mm:ss')] weak check: built exe absent, compare with pre-install hash" | Add-Content $log
        if ($afterHash -eq $before.hash) { return $false }
    }
    return $true
}

try {
    "[$(Get-Date -Format 'HH:mm:ss')] swap start (user=$(whoami))" | Out-File $log -Encoding utf8
    if ($hashWant) {
        "[$(Get-Date -Format 'HH:mm:ss')] verify baseline: built exe hash=$($hashWant.Substring(0, 12))" | Add-Content $log
    } else {
        "[$(Get-Date -Format 'HH:mm:ss')] verify baseline: weak check (built exe absent)" | Add-Content $log
    }

    # 1. 等旧进程退出(最多 30s), 超时强杀
    $deadline = (Get-Date).AddSeconds(30)
    while ((Get-Date) -lt $deadline) {
        if (-not (Get-Process devflow -ErrorAction SilentlyContinue)) { break }
        Start-Sleep -Milliseconds 500
    }
    Get-Process devflow -ErrorAction SilentlyContinue | Stop-Process -Force
    Start-Sleep -Seconds 2
    "[$(Get-Date -Format 'HH:mm:ss')] old process stopped" | Add-Content $log

    # 2. 探测句柄释放
    Wait-HandleReleased | Out-Null

    # 3. 安装前快照, 供弱校验与前后比对
    $before = @{ hash = 'absent'; size = 0 }
    if (Test-Path $target) {
        $before.hash = (Get-FileHash $target -Algorithm SHA256).Hash
        $before.size = (Get-Item $target).Length
    }
    $beforeHashShort = $before.hash
    if ($beforeHashShort.Length -gt 12) { $beforeHashShort = $beforeHashShort.Substring(0, 12) }
    "[$(Get-Date -Format 'HH:mm:ss')] before size=$($before.size) hash=$beforeHashShort" | Add-Content $log

    # 4. 静默安装 + 校验, 校验失败重试一次
    if (Invoke-SwapInstall 'first') {
        "[$(Get-Date -Format 'HH:mm:ss')] verify pass (first attempt)" | Add-Content $log
    } else {
        "[$(Get-Date -Format 'HH:mm:ss')] verify fail, retry once" | Add-Content $log
        Wait-HandleReleased | Out-Null
        if (Invoke-SwapInstall 'retry') {
            "[$(Get-Date -Format 'HH:mm:ss')] verify pass (retry)" | Add-Content $log
        } else {
            "[$(Get-Date -Format 'HH:mm:ss')] FAIL: verify failed twice" | Add-Content $log
            exit 1
        }
    }

    # 5. 重启并验证; GUI 必须起在交互用户会话才可见
    Start-Process $target
    Start-Sleep -Seconds 5
    $proc = Get-Process devflow -ErrorAction SilentlyContinue | Select-Object -First 1
    if ($proc) {
        "[$(Get-Date -Format 'HH:mm:ss')] OK: restarted pid=$($proc.Id)" | Add-Content $log
        exit 0
    }

    # SYSTEM 会话直启的 GUI 不可见, 转投交互登录用户名下的一次性计划任务
    $explorer = Get-CimInstance Win32_Process -Filter "Name='explorer.exe'" | Select-Object -First 1
    if ($explorer) {
        $o = Invoke-CimMethod -InputObject $explorer -MethodName GetOwner
        $user = "$($o.Domain)\$($o.User)"
        try {
            $action    = New-ScheduledTaskAction -Execute $target
            $principal = New-ScheduledTaskPrincipal -UserId $user -LogonType Interactive
            Register-ScheduledTask -TaskName 'DevFlowStartOnce' -Action $action -Principal $principal -Force -ErrorAction Stop | Out-Null
            Start-ScheduledTask -TaskName 'DevFlowStartOnce'
            Start-Sleep -Seconds 5
        } catch {
            "[$(Get-Date -Format 'HH:mm:ss')] start task error: $($_.Exception.Message)" | Add-Content $log
        } finally {
            Unregister-ScheduledTask -TaskName 'DevFlowStartOnce' -Confirm:$false -ErrorAction SilentlyContinue
        }
        $proc = Get-Process devflow -ErrorAction SilentlyContinue | Select-Object -First 1
        if ($proc) {
            "[$(Get-Date -Format 'HH:mm:ss')] OK: restarted as $user pid=$($proc.Id)" | Add-Content $log
            exit 0
        }
    }

    # 仍无进程, 落标记等人工拉起
    Set-Content -Path 'E:\wk-lab\devflow\swap-need-start.flag' -Value (Get-Date -Format o)
    "[$(Get-Date -Format 'HH:mm:ss')] FAIL: need manual start" | Add-Content $log
    exit 1
}
finally {
    Remove-Item $lockFile -ErrorAction SilentlyContinue
    Unregister-ScheduledTask -TaskName 'DevFlowSwapInstall' -Confirm:$false -ErrorAction SilentlyContinue
}