<#
.SYNOPSIS
    Windows-Installer für den Newt-Client.
    Features: Winget.pro, NSSM-Service, Turbo-BITS, Log-Rotation, Auto-Cleanup.
#>
param([string]$mode = "install")

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

# 2. Konfiguration
$Repo = "fosrl/newt"
$InstallDir = "C:\Program Files\me-msp-newt"
$ServiceName = "MAIEREDV-Managed-Site-Client"
$Symlink = "$InstallDir\newt_latest.exe"
$UpdaterTaskName = "MAIEREDV-Newt-Updater"
$GiteaUrl = "https://me-gitea.maieredv.cloud/manuel.maier/update-install-newt/raw/branch/main/install_newt-msp-site-win_v2.1.ps1"

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

# 3. Umgebung vorbereiten
function Prepare-Environment {
    if (!(Get-Command winget -ErrorAction SilentlyContinue)) {
        Write-Log "Winget fehlt. Installiere via winget.pro..." "Cyan"
        try {
            Invoke-RestMethod -Uri "https://winget.pro/install.ps1" | Invoke-Expression
            $env:Path = [System.Environment]::GetEnvironmentVariable("Path","Machine") + ";" + [System.Environment]::GetEnvironmentVariable("Path","User")
        } catch {
            Write-Log "FEHLER: Winget Installation fehlgeschlagen." "Red"; exit 1
        }
    }

    if (!(Get-Command nssm -ErrorAction SilentlyContinue)) {
        Write-Log "NSSM wird via Winget bereitgestellt..." "Cyan"
        winget install nssm --silent --accept-package-agreements --accept-source-agreements | Out-Null
        $env:Path = [System.Environment]::GetEnvironmentVariable("Path","Machine") + ";" + [System.Environment]::GetEnvironmentVariable("Path","User")
    }
}

function Get-LatestVersion {
    try {
        $url = "https://api.github.com/repos/${Repo}/releases/latest"
        $json = Invoke-RestMethod -Uri $url -UseBasicParsing
        return $json.tag_name
    } catch {
        Write-Log "FEHLER: GitHub API nicht erreichbar." "Red"; exit 1
    }
}

# 4. Download & Cleanup
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 -ItemType Directory -Path $InstallDir -Force | Out-Null }
    
    if (!(Test-Path $Target)) {
        Write-Log "Downloade Version $VersionOnly..." "Cyan"
        try {
            Start-BitsTransfer -Source $Url -Destination $Target -Priority Foreground -ErrorAction Stop
        } catch {
            Write-Log "BITS fehlgeschlagen. Versuche Web-Fallback..." "Yellow"
            Invoke-WebRequest -Uri $Url -OutFile $Target -UseBasicParsing
        }
    }

    $Service = Get-Service $ServiceName -ErrorAction SilentlyContinue
    $WasRunning = $Service -and $Service.Status -eq 'Running'

    if ($WasRunning) {
        Write-Log "Stoppe Dienst für Datei-Update..." "Yellow"
        Stop-Service $ServiceName -Force
    }

    try {
        Copy-Item -Path $Target -Destination $Symlink -Force
        Write-Log "newt_latest.exe aktualisiert." "Green"
    } catch {
        Write-Log "FEHLER: Datei blockiert." "Red"
    }

    if ($WasRunning) {
        Start-Service $ServiceName
        Write-Log "Dienst wieder gestartet." "Green"
    }

    # Cleanup: Behalte die neuesten 2 Versionen
    $OldVersions = Get-ChildItem -Path $InstallDir -Filter "newt_*.exe" | 
                   Where-Object { $_.Name -ne "newt_latest.exe" } | 
                   Sort-Object LastWriteTime -Descending | 
                   Select-Object -Skip 2
    foreach ($file in $OldVersions) { Remove-Item $file.FullName -Force }
}

function Setup-Service {
    if (!(Get-Service $ServiceName -ErrorAction SilentlyContinue)) {
        Write-Log "--- Dienst-Konfiguration ---" "Yellow"
        $PangolinID = Read-Host "Bitte Pangolin ID eingeben"
        $PangolinSecret = Read-Host "Bitte Secret eingeben"
        $PangolinEndpoint = Read-Host "Bitte Endpoint eingeben"

        $ArgList = "--id ${PangolinID} --secret ${PangolinSecret} --endpoint ${PangolinEndpoint}"
        
        & nssm install $ServiceName "$Symlink" $ArgList
        & nssm set $ServiceName Description "MAIEREDV Managed Site Client"
        & nssm set $ServiceName AppExit Default Restart
        & nssm set $ServiceName AppRestartDelay 5000
        
        $LogFile = "${InstallDir}\newt_service.log"
        & 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
        
        Start-Service $ServiceName
        Write-Log "Dienst gestartet." "Green"
    }
}

function Setup-UpdaterTask {
    $ActionScript = "[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; `$s = (New-Object System.Net.WebClient).DownloadString('$GiteaUrl'); `$b = [scriptblock]::Create(`$s); & `$b -mode update"
    $Action = New-ScheduledTaskAction -Execute "powershell.exe" -Argument "-NoProfile -ExecutionPolicy Bypass -Command `"$ActionScript`""
    $Trigger = New-ScheduledTaskTrigger -Daily -At 3am
    $Principal = New-ScheduledTaskPrincipal -UserId "SYSTEM" -LogonType ServiceAccount -RunLevel Highest

    Register-ScheduledTask -Action $Action -Trigger $Trigger -Principal $Principal -TaskName $UpdaterTaskName -Force | Out-Null
    Write-Log "Update-Task (03:00 Uhr) registriert." "Green"
}

# --- Main ---
Prepare-Environment

switch ($mode) {
    "install" {
        $v = Get-LatestVersion
        Download-Newt $v
        Setup-Service
        Setup-UpdaterTask
        Write-Log "Installation abgeschlossen!" "Green"
    }
    "update" {
        $v = Get-LatestVersion
        $vOnly = $v.TrimStart('v')
        $TargetVersionPath = "${InstallDir}\newt_${vOnly}.exe"

        $NeedsUpdate = $false
        if (!(Test-Path $TargetVersionPath)) {
            $NeedsUpdate = $true
        } elseif (Test-Path $Symlink) {
            $HashLatest = (Get-FileHash $Symlink).Hash
            $HashTarget = (Get-FileHash $TargetVersionPath).Hash
            if ($HashLatest -ne $HashTarget) { $NeedsUpdate = $true }
        } else { $NeedsUpdate = $true }

        if ($NeedsUpdate) {
            Download-Newt $v
            Write-Log "Update auf $v erledigt." "Green"
        } else {
            Write-Log "System aktuell ($vOnly)." "Cyan"
            if ((Get-Service $ServiceName).Status -ne 'Running') { Start-Service $ServiceName }
        }
    }
    "uninstall" {
        Write-Log "Deinstallation..." "Yellow"
        if (Get-Service $ServiceName -ErrorAction SilentlyContinue) {
            Stop-Service $ServiceName -Force -ErrorAction SilentlyContinue
            & nssm remove $ServiceName confirm
        }
        Unregister-ScheduledTask -TaskName $UpdaterTaskName -Confirm:$false -ErrorAction SilentlyContinue
        Write-Log "Alles entfernt." "Green"
    }
}