using System;
using Avalonia;
using Avalonia.Controls;
using Project_Periodensystem.Model;
using Project_Periodensystem.Persistence;
using Project_Periodensystem.Controller;

namespace Project_Periodensystem.View
{
    /// <summary>
    /// Navigation Service Implementation im View-Layer
    /// Implementiert INavigationService Interface vom Controller
    /// SAUBERE TRENNUNG: Controller definiert WAS, View definiert WIE
    /// </summary>
    public class NavigationService : INavigationService
    {
        private readonly MainWindow _mainWindow;
        private PeriodensystemController? _dataController;

        /// <summary>
        /// Konstruktor
        /// </summary>
        public NavigationService(MainWindow mainWindow)
        {
            _mainWindow = mainWindow ?? throw new ArgumentNullException(nameof(mainWindow));
            Logger.Log("NavigationService initialisiert - saubere Interface-Trennung");
        }
        
        /// <summary>
        /// Data Controller setzen (löst zirkuläre Abhängigkeit)
        /// </summary>
        public void SetDataController(PeriodensystemController dataController)
        {
            _dataController = dataController ?? throw new ArgumentNullException(nameof(dataController));
        }

        /// <summary>
        /// Navigation zum Periodensystem (Interface Implementation)
        /// </summary>
        public void NavigateToPeriodicTable()
        {
            try
            {
                if (_dataController == null)
                {
                    Logger.LogError("DataController nicht gesetzt");
                    return;
                }
                
                var periodicTablePage = new PeriodicTablePage();
                periodicTablePage.SetController(_dataController);
                
                var mainContent = _mainWindow.FindControl<ContentControl>("MainContent");
                if (mainContent != null)
                {
                    mainContent.Content = periodicTablePage;
                    Logger.Log("NavigationService: Navigation zum Periodensystem");
                }
                else
                {
                    Logger.LogError("MainContent Control nicht gefunden");
                }
            }
            catch (Exception ex)
            {
                Logger.LogException(ex, "NavigateToPeriodicTable");
            }
        }

        /// <summary>
        /// Navigation zur About-Seite (Interface Implementation)
        /// </summary>
        public void NavigateToAbout()
        {
            try
            {
                if (_dataController == null)
                {
                    Logger.LogError("DataController nicht gesetzt");
                    return;
                }
                
                var aboutPage = new AboutPage();
                aboutPage.SetController(_dataController);
                
                var mainContent = _mainWindow.FindControl<ContentControl>("MainContent");
                if (mainContent != null)
                {
                    mainContent.Content = aboutPage;
                    Logger.Log("NavigationService: Navigation zu About");
                }
                else
                {
                    Logger.LogError("MainContent Control nicht gefunden");
                }
            }
            catch (Exception ex)
            {
                Logger.LogException(ex, "NavigateToAbout");
            }
        }

        /// <summary>
        /// Navigation zur Landing Page (Interface Implementation)
        /// </summary>
        public void NavigateToLanding()
        {
            try
            {
                if (_dataController == null)
                {
                    Logger.LogError("DataController nicht gesetzt");
                    return;
                }
                
                var landingPage = new LandingPage();
                landingPage.SetController(_dataController);
                
                var mainContent = _mainWindow.FindControl<ContentControl>("MainContent");
                if (mainContent != null)
                {
                    mainContent.Content = landingPage;
                    Logger.Log("NavigationService: Navigation zur Landing Page");
                }
                else
                {
                    Logger.LogError("MainContent Control nicht gefunden");
                }
            }
            catch (Exception ex)
            {
                Logger.LogException(ex, "NavigateToLanding");
            }
        }

        /// <summary>
        /// Theme-Wechsel (Interface Implementation)
        /// </summary>
        public void ToggleTheme()
        {
            try
            {
                var app = Application.Current;
                if (app != null)
                {
                    var currentTheme = app.ActualThemeVariant;
                    var newTheme = currentTheme == Avalonia.Styling.ThemeVariant.Dark 
                        ? Avalonia.Styling.ThemeVariant.Light 
                        : Avalonia.Styling.ThemeVariant.Dark;
                    
                    app.RequestedThemeVariant = newTheme;
                    
                    // Settings speichern
                    var settings = new AppSettings
                    {
                        LastTheme = newTheme.ToString() ?? "Dark",
                        LastUsed = DateTime.Now,
                        PreferredLanguage = "German"
                    };
                    DataManager.SaveSettings(settings);
                    
                    Logger.Log($"NavigationService: Theme gewechselt zu {newTheme}");
                }
            }
            catch (Exception ex)
            {
                Logger.LogException(ex, "ToggleTheme");
            }
        }

        /// <summary>
        /// Export-Bestätigung anzeigen (Interface Implementation)
        /// </summary>
        public void ShowExportConfirmation()
        {
            try
            {
                Logger.Log("NavigationService: Export-Bestätigung angezeigt");
                // Hier könnte ein Dialog oder Notification angezeigt werden
            }
            catch (Exception ex)
            {
                Logger.LogException(ex, "ShowExportConfirmation");
            }
        }
    }
}