<#
.SYNOPSIS
    v2.7 - Brutal-Rename-Strategy & Immediate Kill.
#>
param([string]$mode = "install")

[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
[Console]::OutputEncoding = [System.Text.Encoding]::UTF8

$Repo = "fosrl/newt"
$InstallDir = "C:\Program Files\me-msp-newt"
$ServiceName = "MAIEREDV-Managed-Site-Client"
$Symlink = "$InstallDir\newt_latest.exe"
$LogFile = "$InstallDir\newt_service.log"
$GiteaUrl = "https://me-gitea.maieredv.cloud/manuel.maier/update-install-newt/raw/branch/main/install_newt-msp-site-win_v2.ps1"

function Write-Log($msg, $color = "White") { 
    Write-Host "[$(Get-Date -Format 'HH:mm:ss')] $msg" -ForegroundColor $color 
}

function Download-Newt {
    param($FullVersion)
    $ArchSuffix = if ([Environment]::Is64BitOperatingSystem) { "windows_amd64.exe" } else { "windows_386.exe" }
    $VersionOnly = $FullVersion.TrimStart('v')
    $Url = "https://github.com/${Repo}/releases/download/${VersionOnly}/newt_${ArchSuffix}"
    $Target = "${InstallDir}\newt_${VersionOnly}.exe"

    if (!(Test-Path $InstallDir)) { New-Item $InstallDir -ItemType Directory -Force | Out-Null }
    
    if (!(Test-Path $Target)) {
        Write-Log "Download $VersionOnly..." "Cyan"
        try { Start-BitsTransfer $Url $Target -Priority Foreground -ErrorAction Stop }
        catch { Invoke-WebRequest $Url -OutFile $Target -UseBasicParsing }
    }

    Write-Log "Erzwinge Dateizugriff..." "Yellow"
    
    # 1. Dienst sofort hart auf Eis legen
    if (Get-Service $ServiceName -ErrorAction SilentlyContinue) {
        Set-Service $ServiceName -StartupType Disabled
        Stop-Service $ServiceName -Force -ErrorAction SilentlyContinue
    }

    # 2. Sofort-Kill ohne langes Warten
    Write-Log "Sende Taskkill..." "Red"
    taskkill.exe /F /T /IM "newt*" 2>$null
    Start-Sleep -Seconds 2

    # 3. DER RENAME-TRICK (Die Brechstange)
    # Wir versuchen nicht zu loeschen, wir schieben die Leiche einfach zur Seite
    if (Test-Path $Symlink) {
        $DeadFile = "$Symlink.zombie_" + (Get-Date -Format "yyyyMMdd_HHmmss")
        try {
            # Move-Item auf derselben Partition klappt oft trotz Lock!
            Move-Item -Path $Symlink -Destination $DeadFile -Force -ErrorAction Stop
            Write-Log "Pfad freigemacht (Zombie verschoben)." "Green"
        } catch {
            Write-Log "Dateisperre extrem hartnaeckig. Versuche drueberzukopieren..." "Yellow"
        }
    }

    # 4. Neue Datei platzieren
    try {
        Copy-Item -Path $Target -Destination $Symlink -Force -ErrorAction Stop
        Write-Log "Update erfolgreich eingespielt." "Green"
    } catch {
        Write-Log "KRITISCH: Update fehlgeschlagen. Datei wird vom Kernel blockiert." "Red"
        Write-Log "Bitte den Server bei Gelegenheit neu starten." "Yellow"
    }

    # Dienst wieder reaktivieren
    Set-Service $ServiceName -StartupType Automatic
    Start-Service $ServiceName -ErrorAction SilentlyContinue
}

# --- Restliche Funktionen (Setup-Service, Setup-Task etc.) ---
function Setup-Service {
    if (!(Get-Service $ServiceName -ErrorAction SilentlyContinue)) {
        Write-Log "Setup Dienst..." "Yellow"
        $PangolinID = Read-Host "ID"; $PangolinSecret = Read-Host "Secret"; $PangolinEndpoint = Read-Host "Endpoint"
        $ArgList = "--id ${PangolinID} --secret ${PangolinSecret} --endpoint ${PangolinEndpoint}"
        & nssm install $ServiceName "$Symlink" $ArgList
    }
    & nssm set $ServiceName AppStdout "$LogFile"
    & nssm set $ServiceName AppStderr "$LogFile"
    & nssm set $ServiceName AppRotateFiles 1
    & nssm set $ServiceName AppRotateOnline 1
    & nssm set $ServiceName AppRotateBytes 10485760
}

function Setup-Task {
    $IexCmd = "[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; iex ((New-Object System.Net.WebClient).DownloadString('$GiteaUrl'))"
    $Action = New-ScheduledTaskAction -Execute "powershell.exe" -Argument "-NoProfile -ExecutionPolicy Bypass -Command `"$IexCmd`""
    $Trigger = New-ScheduledTaskTrigger -Daily -At 3am
    $Principal = New-ScheduledTaskPrincipal -UserId "SYSTEM" -LogonType ServiceAccount -RunLevel Highest
    Register-ScheduledTask -Action $Action -Trigger $Trigger -Principal $Principal -TaskName "MAIEREDV-Newt-Updater" -Force | Out-Null
}

# --- Main ---
if (!(Get-Command nssm -ErrorAction SilentlyContinue)) {
    if (!(Get-Command winget -ErrorAction SilentlyContinue)) { try { irm winget.pro | iex } catch {} }
    winget install nssm --silent --accept-package-agreements --accept-source-agreements | Out-Null
    $env:Path = [System.Environment]::GetEnvironmentVariable("Path","Machine") + ";" + [System.Environment]::GetEnvironmentVariable("Path","User")
}

if (!(Test-Path $Symlink) -or ($mode -eq "install")) {
    $v = (Invoke-RestMethod "https://api.github.com/repos/${Repo}/releases/latest").tag_name
    Download-Newt $v; Setup-Service; Setup-Task
    Write-Log "Installation fertig!" "Green"
}
elseif ($mode -eq "update" -or (Test-Path $Symlink)) {
    $v = (Invoke-RestMethod "https://api.github.com/repos/${Repo}/releases/latest").tag_name
    $vO = $v.TrimStart('v')
    if (!(Test-Path "${InstallDir}\newt_${vO}.exe")) {
        Download-Newt $v
    } else {
        Write-Log "System aktuell." "Cyan"
        Setup-Service
        if ((Get-Service $ServiceName).Status.value__ -ne 4) { Start-Service $ServiceName }
    }
}
elseif ($mode -eq "uninstall") {
    taskkill.exe /F /T /IM "newt*" 2>$null
    if (Get-Service $ServiceName -ErrorAction SilentlyContinue) {
        Stop-Service $ServiceName -Force -ErrorAction SilentlyContinue
        & nssm remove $ServiceName confirm
    }
    Unregister-ScheduledTask "MAIEREDV-Newt-Updater" -Confirm:$false -ErrorAction SilentlyContinue
}