using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;
using LehrerApp.Core.Interfaces;
using LehrerApp.Core.Models;
using LehrerApp.Core.Services;
using LehrerApp.Data;
using LehrerApp.Desktop.Services;
using LehrerApp.Desktop.ViewModels.Planning;
using LehrerApp.Sync;
using LehrerApp.Sync.Crypto;
using System.Collections.ObjectModel;
using System.Globalization;
using System.Security.Cryptography;
using System.Text.Json;
using System.Text.Json.Serialization;

namespace LehrerApp.Desktop.ViewModels.Settings;

public partial class SettingsViewModel
{
    // ── Sicherheit: App-Sperre nach Inaktivität (13.3.5) ─────────────────────

    [ObservableProperty] private bool   _appLockEnabled;
    [ObservableProperty] private int    _appLockTimeoutMinutes = 10;
    [ObservableProperty] private string _appLockNewPassword        = "";
    [ObservableProperty] private string _appLockNewPasswordConfirm = "";
    [ObservableProperty] private string _appLockPasswordError      = "";
    [ObservableProperty] private string _appLockStatus             = "";

    public bool AppLockHasPassword => _appLock.HasPassword;

    /// Vom Code-Behind gesetzt: aktualisiert den laufenden Inaktivitäts-Timer sofort,
    /// ohne dass die App neu gestartet werden muss.
    public Action? OnAppLockChanged { get; set; }

    // ── App-Sperre: Speichern ─────────────────────────────────────────────────

    [RelayCommand]
    private void SaveAppLockSettings()
    {
        AppLockPasswordError = "";
        var valid = true;
        var wantsNewPassword = !string.IsNullOrWhiteSpace(AppLockNewPassword) || !string.IsNullOrWhiteSpace(AppLockNewPasswordConfirm);

        if (AppLockEnabled && !_appLock.HasPassword && !wantsNewPassword)
        {
            AppLockPasswordError = "Bitte ein Passwort für die App-Sperre festlegen.";
            valid = false;
        }
        else if (wantsNewPassword)
        {
            if (AppLockNewPassword != AppLockNewPasswordConfirm)
            {
                AppLockPasswordError = "Passwörter stimmen nicht überein.";
                valid = false;
            }
            else if (AppLockNewPassword.Length < 4)
            {
                AppLockPasswordError = "Mindestens 4 Zeichen.";
                valid = false;
            }
        }

        if (!valid) return;

        if (wantsNewPassword) _appLock.SetPassword(AppLockNewPassword.Trim());
        _appLock.Configure(AppLockEnabled, AppLockTimeoutMinutes);

        AppLockNewPassword = ""; AppLockNewPasswordConfirm = "";
        OnPropertyChanged(nameof(AppLockHasPassword));
        AppLockStatus = "Gespeichert.";
        OnAppLockChanged?.Invoke();
    }
}