class DiagnosticViewModel : FirefoxAddinManager.ObservableBase {

    [System.Collections.ObjectModel.ObservableCollection[PolicyCheckModel]] $PolicyChecks
    [System.Windows.Input.ICommand] $RunCheckCommand
    [System.Windows.Input.ICommand] $FixSelectedCommand
    [System.Windows.Input.ICommand] $FixAllErrorsCommand
    [System.Windows.Input.ICommand] $OpenAboutPoliciesCommand
    [System.Windows.Input.ICommand] $ImportRegCommand

    hidden [PolicyCheckModel] $_selectedCheck = $null
    hidden [string]           $_statusMessage  = ""
    hidden [bool]             $_isIntuneManaged = $false

    [PolicyCheckModel] $SelectedCheck {
        get { return $this._selectedCheck }
        set { $this._selectedCheck = $value; $this.OnPropertyChanged("SelectedCheck") }
    }

    [string] $StatusMessage {
        get { return $this._statusMessage }
        set { $this._statusMessage = $value; $this.OnPropertyChanged("StatusMessage") }
    }

    [bool] $IsIntuneManaged {
        get { return $this._isIntuneManaged }
        set { $this._isIntuneManaged = $value; $this.OnPropertyChanged("IsIntuneManaged") }
    }

    DiagnosticViewModel() {
        $this.PolicyChecks    = [System.Collections.ObjectModel.ObservableCollection[PolicyCheckModel]]::new()
        $this.IsIntuneManaged = [FirefoxService]::IsIntuneManaged()
        $this._InitCommands()
    }

    hidden [void] _InitCommands() {
        $vm = $this

        $this.RunCheckCommand = [FirefoxAddinManager.RelayCommand]::new({
            $vm.PolicyChecks.Clear()
            [PolicyService]::RunChecks() | ForEach-Object { $vm.PolicyChecks.Add($_) }
            $errors = ($vm.PolicyChecks | Where-Object { $_.Status -eq "FEHLER" }).Count
            $vm.StatusMessage = if ($errors -gt 0) { "$errors Fehler gefunden." } else { "Keine Fehler gefunden." }
        }, { $true })

        $this.FixSelectedCommand = [FirefoxAddinManager.RelayCommand]::new({
            if (-not $vm.SelectedCheck) { return }
            if (-not [FirefoxService]::IsAdmin()) {
                [System.Windows.MessageBox]::Show("Administratorrechte erforderlich.", "Kein Admin", "OK", "Warning")
                return
            }
            [PolicyService]::FixError($vm.SelectedCheck)
            $vm.RunCheckCommand.Execute($null)
            $vm.StatusMessage = "Korrektur angewendet. Firefox neu starten."
        }, { return $null -ne $this.SelectedCheck -and $this.SelectedCheck.Status -eq "FEHLER" })

        $this.FixAllErrorsCommand = [FirefoxAddinManager.RelayCommand]::new({
            if (-not [FirefoxService]::IsAdmin()) {
                [System.Windows.MessageBox]::Show("Administratorrechte erforderlich.", "Kein Admin", "OK", "Warning")
                return
            }
            $errors = $vm.PolicyChecks | Where-Object { $_.Status -eq "FEHLER" }
            foreach ($e in $errors) { [PolicyService]::FixError($e) }
            $vm.RunCheckCommand.Execute($null)
            $vm.StatusMessage = "$($errors.Count) Fehler behoben. Firefox neu starten."
        }, { return ($this.PolicyChecks | Where-Object { $_.Status -eq "FEHLER" }).Count -gt 0 })

        $this.OpenAboutPoliciesCommand = [FirefoxAddinManager.RelayCommand]::new({
            try { Start-Process "firefox" "about:policies" }
            catch { [System.Windows.MessageBox]::Show("Firefox konnte nicht gestartet werden.", "Fehler", "OK", "Error") }
        }, { $true })

        $this.ImportRegCommand = [FirefoxAddinManager.RelayCommand]::new({
            if (-not [FirefoxService]::IsAdmin()) {
                [System.Windows.MessageBox]::Show("Administratorrechte erforderlich.", "Kein Admin", "OK", "Warning")
                return
            }
            $dlg = New-Object Microsoft.Win32.OpenFileDialog
            $dlg.Filter = "Registry-Datei (*.reg)|*.reg"
            if (-not $dlg.ShowDialog()) { return }

            $lines = Get-Content $dlg.FileName -Encoding Unicode -ErrorAction SilentlyContinue
            if (-not $lines) { $lines = Get-Content $dlg.FileName -Encoding UTF8 -ErrorAction SilentlyContinue }

            $currentKey = $null; $applied = 0; $skipped = 0
            foreach ($line in $lines) {
                $line = $line.Trim()
                if ($line -eq "" -or $line.StartsWith(";") -or $line.StartsWith("Windows")) { continue }
                if ($line -match '^\[(.+)\]$') {
                    $rawKey = $Matches[1]
                    if ($rawKey -match 'SOFTWARE\\Policies\\Mozilla\\Firefox') {
                        $currentKey = $rawKey -replace '^HKEY_LOCAL_MACHINE','HKLM:' -replace '^HKEY_CURRENT_USER','HKCU:'
                    } else { $currentKey = $null; $skipped++ }
                    continue
                }
                if (-not $currentKey) { continue }
                if ($line -match '^"(.+)"=dword:(.+)$') {
                    if (-not (Test-Path $currentKey)) { New-Item -Path $currentKey -Force | Out-Null }
                    Set-ItemProperty $currentKey -Name $Matches[1] -Value ([Convert]::ToInt32($Matches[2],16)) -Type DWord
                    $applied++
                } elseif ($line -match '^"(.+)"="(.*)"$') {
                    if (-not (Test-Path $currentKey)) { New-Item -Path $currentKey -Force | Out-Null }
                    Set-ItemProperty $currentKey -Name $Matches[1] -Value ($Matches[2] -replace '\\"','"') -Type String
                    $applied++
                } elseif ($line -match '^"-(.+)"$') {
                    Remove-ItemProperty $currentKey -Name $Matches[1] -ErrorAction SilentlyContinue
                    $applied++
                }
            }
            $vm.RunCheckCommand.Execute($null)
            $vm.StatusMessage = "REG-Import: $applied Werte gesetzt, $skipped Keys uebersprungen. Firefox neu starten."
        }, { $true })
    }
}