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
{
    // ── KI-Unterstützung (4.5.9) ──────────────────────────────────────────────

    [ObservableProperty] private bool   _aiEnabled;
    [ObservableProperty] private string _aiUsername = "";
    [ObservableProperty] private string _aiPassword = "";
    [ObservableProperty] private string _aiLoginError = "";
    [ObservableProperty] private bool   _aiIsLoggedIn;
    [ObservableProperty] private string _aiBalanceDisplay = "";

    // ── KI-Unterstützung: Laden / Anmelden / Abmelden ────────────────────────

    private void LoadAiSettings()
    {
        AiEnabled = _aiSettings.Enabled;
        AiUsername = _aiSettings.Username;
        AiIsLoggedIn = _aiSettings.IsLoggedIn;
        if (AiIsLoggedIn) _ = RefreshAiBalance();
    }

    partial void OnAiEnabledChanged(bool value) => _aiSettings.SetEnabled(value);

    private async Task RefreshAiBalance()
    {
        var token = _aiSettings.GetToken();
        if (token is null) return;
        try
        {
            var balance = await _aiPlanning.GetBalanceAsync(token);
            AiBalanceDisplay = $"Guthaben: {balance:0.00} €";
        }
        catch (AiBackendException ex) { AiBalanceDisplay = ex.Message; }
    }

    [RelayCommand]
    private async Task AiLogin()
    {
        AiLoginError = "";
        var valid = true;
        if (string.IsNullOrWhiteSpace(AiUsername)) { AiLoginError = "Benutzername erforderlich."; valid = false; }
        if (string.IsNullOrWhiteSpace(AiPassword)) { AiLoginError = "Passwort erforderlich."; valid = false; }
        if (!valid) return;

        try
        {
            var token = await _aiPlanning.LoginAsync(AiUsername, AiPassword);
            _aiSettings.SetCredentialsAndToken(AiUsername, token);
            AiPassword = "";
            AiIsLoggedIn = true;
            await RefreshAiBalance();
        }
        catch (AiBackendException ex) { AiLoginError = ex.Message; }
    }

    [RelayCommand]
    private void AiLogout()
    {
        _aiSettings.Logout();
        AiIsLoggedIn = false;
        AiBalanceDisplay = "";
    }
}