// This Source Code Form is subject to the terms of the MIT License.
// If a copy of the MIT was not distributed with this file, You can obtain one at https://opensource.org/licenses/MIT.
// Copyright (C) Leszek Pomianowski and WPF UI Contributors.
// All Rights Reserved.

using System.Reflection;
using System.Windows.Media;

using WPFluent.Appearance;

namespace WPFluent.Gallery.ViewModels.Pages;

public sealed partial class SettingsViewModel() : ViewModel
{
    private bool _isInitialized = false;

    [ObservableProperty]
    private string _appVersion = string.Empty;

    [ObservableProperty]
    private ThemeType _currentApplicationTheme = ThemeType.Unknow;

    public override void OnNavigatedTo()
    {
        if (!_isInitialized)
        {
            InitializeViewModel();
        }
    }

    partial void OnCurrentApplicationThemeChanged(ThemeType oldValue, ThemeType newValue)
    {
        ThemeManager.ChangeAppTheme(newValue);
    }


    private void InitializeViewModel()
    {
        CurrentApplicationTheme = ThemeManager.GetAppTheme();
        AppVersion = $"{GetAssemblyVersion()}";

        ThemeManager.Changed += OnThemeChanged;

        _isInitialized = true;
    }

    private void OnThemeChanged(ThemeType currentApplicationTheme, Color systemAccent)
    {
        // Update the theme if it has been changed elsewhere than in the settings.
        if (CurrentApplicationTheme != currentApplicationTheme)
        {
            CurrentApplicationTheme = currentApplicationTheme;
        }
    }

    private static string GetAssemblyVersion()
    {
        return Assembly.GetExecutingAssembly().GetName().Version?.ToString() ?? string.Empty;
    }
}