SettingsWindow.cs

using System;
using System.Globalization;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Media;

namespace DesktopNest
{
    /// <summary>
    /// On-demand settings window.  API keys are written directly to Windows
    /// Credential Manager through SecretStore and are never copied into AppSettings.
    /// </summary>
    public sealed class SettingsWindow : Window
    {
        private const string OpenAiProvider = "openai";
        private const string DeepSeekProvider = "deepseek";
        private const string OpenAiDefaultModel = "gpt-5.6-luna";
        private const string DeepSeekDefaultModel = "deepseek-v4-flash";

        private readonly AppSettings _settings;
        private CheckBox _startupCheckBox;
        private CheckBox _takeoverCheckBox;
        private CheckBox _aiCheckBox;
        private Slider _opacitySlider;
        private TextBlock _opacityValue;
        private ComboBox _providerComboBox;
        private TextBox _modelTextBox;
        private PasswordBox _apiKeyPasswordBox;
        private TextBlock _keyStatusText;
        private Button _saveKeyButton;
        private Button _deleteKeyButton;
        private bool _initializing;
        private string _previousProvider;
        private bool _openAiHasKey;
        private bool _deepSeekHasKey;

        public SettingsWindow(AppSettings settings)
        {
            if (settings == null)
            {
                throw new ArgumentNullException("settings");
            }

            _settings = settings;
            _settings.EnsureDefaults();

            Title = "拾光桌面设置";
            Width = 540;
            Height = 650;
            MinWidth = 500;
            MinHeight = 590;
            WindowStartupLocation = WindowStartupLocation.CenterScreen;
            WindowStyle = WindowStyle.ToolWindow;
            ResizeMode = ResizeMode.CanResize;
            ShowInTaskbar = false;
            Background = CreateBrush(Color.FromRgb(19, 27, 39));
            Foreground = CreateBrush(Color.FromRgb(232, 238, 247));
            FontFamily = new FontFamily("Microsoft YaHei UI");
            SnapsToDevicePixels = true;
            UseLayoutRounding = true;

            Content = BuildContent();
            LoadValues();
        }

        public event EventHandler SettingsApplied;

        private UIElement BuildContent()
        {
            Grid page = new Grid { Margin = new Thickness(24, 20, 24, 18) };
            page.RowDefinitions.Add(new RowDefinition { Height = new GridLength(1, GridUnitType.Star) });
            page.RowDefinitions.Add(new RowDefinition { Height = GridLength.Auto });

            ScrollViewer scrollViewer = new ScrollViewer
            {
                VerticalScrollBarVisibility = ScrollBarVisibility.Auto,
                HorizontalScrollBarVisibility = ScrollBarVisibility.Disabled
            };
            Grid.SetRow(scrollViewer, 0);
            page.Children.Add(scrollViewer);

            StackPanel content = new StackPanel { Margin = new Thickness(0, 0, 8, 4) };
            scrollViewer.Content = content;

            TextBlock heading = new TextBlock
            {
                Text = "桌面整理设置",
                FontSize = 23,
                FontWeight = FontWeights.SemiBold,
                Foreground = Brushes.White,
                Margin = new Thickness(0, 0, 0, 3)
            };
            content.Children.Add(heading);

            TextBlock introduction = new TextBlock
            {
                Text = "保持常驻逻辑轻量；只有桌面文件发生新增、重命名或减少时才触发分类。",
                FontSize = 12,
                Foreground = CreateBrush(Color.FromRgb(167, 180, 198)),
                TextWrapping = TextWrapping.Wrap,
                Margin = new Thickness(0, 0, 0, 18)
            };
            content.Children.Add(introduction);

            content.Children.Add(CreateSectionTitle("常规"));
            _startupCheckBox = CreateCheckBox("开机自动启动拾光桌面");
            content.Children.Add(_startupCheckBox);

            _takeoverCheckBox = CreateCheckBox("接管 Windows 桌面图标显示");
            _takeoverCheckBox.ToolTip = "关闭软件或取消此选项后可恢复系统桌面图标；不会删除桌面文件。";
            content.Children.Add(_takeoverCheckBox);

            Grid opacityRow = new Grid { Margin = new Thickness(0, 8, 0, 18) };
            opacityRow.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(116) });
            opacityRow.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(1, GridUnitType.Star) });
            opacityRow.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(46) });
            content.Children.Add(opacityRow);

            TextBlock opacityLabel = CreateLabel("收纳盒透明度");
            opacityRow.Children.Add(opacityLabel);

            _opacitySlider = new Slider
            {
                Minimum = 0.38,
                Maximum = 0.92,
                SmallChange = 0.02,
                LargeChange = 0.1,
                Margin = new Thickness(4, 0, 10, 0),
                VerticalAlignment = VerticalAlignment.Center
            };
            _opacitySlider.ValueChanged += delegate
            {
                if (_opacityValue != null)
                {
                    _opacityValue.Text = Math.Round(_opacitySlider.Value * 100.0).ToString(CultureInfo.InvariantCulture) + "%";
                }
            };
            Grid.SetColumn(_opacitySlider, 1);
            opacityRow.Children.Add(_opacitySlider);

            _opacityValue = new TextBlock
            {
                Foreground = Brushes.White,
                FontFamily = new FontFamily("Segoe UI"),
                FontSize = 12,
                TextAlignment = TextAlignment.Right,
                VerticalAlignment = VerticalAlignment.Center
            };
            Grid.SetColumn(_opacityValue, 2);
            opacityRow.Children.Add(_opacityValue);

            content.Children.Add(CreateSectionTitle("AI 自动归类"));
            _aiCheckBox = CreateCheckBox("启用 AI 辅助识别（仅在桌面内容变化时调用）");
            _aiCheckBox.Checked += delegate { UpdateAiControlsEnabled(); };
            _aiCheckBox.Unchecked += delegate { UpdateAiControlsEnabled(); };
            content.Children.Add(_aiCheckBox);

            Grid providerRow = CreateFormRow("提供方");
            _providerComboBox = new ComboBox
            {
                Height = 30,
                VerticalContentAlignment = VerticalAlignment.Center
            };
            _providerComboBox.Items.Add(new ProviderOption(OpenAiProvider, "OpenAI"));
            _providerComboBox.Items.Add(new ProviderOption(DeepSeekProvider, "DeepSeek"));
            _providerComboBox.SelectionChanged += OnProviderSelectionChanged;
            Grid.SetColumn(_providerComboBox, 1);
            providerRow.Children.Add(_providerComboBox);
            content.Children.Add(providerRow);

            Grid modelRow = CreateFormRow("模型");
            _modelTextBox = new TextBox
            {
                Height = 30,
                Padding = new Thickness(7, 4, 7, 4),
                VerticalContentAlignment = VerticalAlignment.Center
            };
            Grid.SetColumn(_modelTextBox, 1);
            modelRow.Children.Add(_modelTextBox);
            content.Children.Add(modelRow);

            TextBlock modelHint = new TextBlock
            {
                Text = "默认使用小模型完成文件名分类；可填写账户中可用的兼容模型。",
                Foreground = CreateBrush(Color.FromRgb(151, 166, 186)),
                FontSize = 11,
                TextWrapping = TextWrapping.Wrap,
                Margin = new Thickness(116, -2, 0, 9)
            };
            content.Children.Add(modelHint);

            Grid keyRow = CreateFormRow("API 密钥");
            keyRow.ColumnDefinitions[1].Width = new GridLength(1, GridUnitType.Star);
            _apiKeyPasswordBox = new PasswordBox
            {
                Height = 30,
                Padding = new Thickness(7, 4, 7, 4),
                VerticalContentAlignment = VerticalAlignment.Center,
                ToolTip = "密钥不会显示或写入 settings.xml"
            };
            _apiKeyPasswordBox.PasswordChanged += delegate { UpdateKeyButtons(); };
            Grid.SetColumn(_apiKeyPasswordBox, 1);
            keyRow.Children.Add(_apiKeyPasswordBox);
            content.Children.Add(keyRow);

            Grid keyActions = new Grid { Margin = new Thickness(116, 1, 0, 8) };
            keyActions.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(1, GridUnitType.Star) });
            keyActions.ColumnDefinitions.Add(new ColumnDefinition { Width = GridLength.Auto });
            keyActions.ColumnDefinitions.Add(new ColumnDefinition { Width = GridLength.Auto });
            content.Children.Add(keyActions);

            _keyStatusText = new TextBlock
            {
                Foreground = CreateBrush(Color.FromRgb(154, 210, 190)),
                FontSize = 11,
                VerticalAlignment = VerticalAlignment.Center,
                TextTrimming = TextTrimming.CharacterEllipsis
            };
            keyActions.Children.Add(_keyStatusText);

            _saveKeyButton = CreateActionButton("保存密钥", true);
            _saveKeyButton.Margin = new Thickness(8, 0, 0, 0);
            _saveKeyButton.Click += SaveKey;
            Grid.SetColumn(_saveKeyButton, 1);
            keyActions.Children.Add(_saveKeyButton);

            _deleteKeyButton = CreateActionButton("删除", false);
            _deleteKeyButton.Margin = new Thickness(7, 0, 0, 0);
            _deleteKeyButton.Click += DeleteKey;
            Grid.SetColumn(_deleteKeyButton, 2);
            keyActions.Children.Add(_deleteKeyButton);

            Border privacy = new Border
            {
                Background = CreateBrush(Color.FromArgb(105, 39, 54, 73)),
                BorderBrush = CreateBrush(Color.FromArgb(80, 126, 150, 180)),
                BorderThickness = new Thickness(1),
                CornerRadius = new CornerRadius(7),
                Padding = new Thickness(11, 9, 11, 9),
                Margin = new Thickness(0, 7, 0, 10)
            };
            privacy.Child = new TextBlock
            {
                Text = "隐私说明：AI 分类仅上传文件名和扩展名，不读取或上传文件内容。密钥保存在 Windows 凭据管理器中；也可使用 OPENAI_API_KEY 或 DEEPSEEK_API_KEY 环境变量。",
                Foreground = CreateBrush(Color.FromRgb(190, 203, 220)),
                FontSize = 11,
                LineHeight = 18,
                TextWrapping = TextWrapping.Wrap
            };
            content.Children.Add(privacy);

            Grid footer = new Grid { Margin = new Thickness(0, 14, 8, 0) };
            footer.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(1, GridUnitType.Star) });
            footer.ColumnDefinitions.Add(new ColumnDefinition { Width = GridLength.Auto });
            footer.ColumnDefinitions.Add(new ColumnDefinition { Width = GridLength.Auto });
            Grid.SetRow(footer, 1);
            page.Children.Add(footer);

            Button cancelButton = CreateFooterButton("取消", false);
            cancelButton.Click += delegate { CloseWithResult(false); };
            Grid.SetColumn(cancelButton, 1);
            footer.Children.Add(cancelButton);

            Button applyButton = CreateFooterButton("保存设置", true);
            applyButton.Margin = new Thickness(9, 0, 0, 0);
            applyButton.Click += ApplySettings;
            Grid.SetColumn(applyButton, 2);
            footer.Children.Add(applyButton);

            return page;
        }

        private void LoadValues()
        {
            _openAiHasKey = TryHasKey(OpenAiProvider);
            _deepSeekHasKey = TryHasKey(DeepSeekProvider);
            _initializing = true;
            try
            {
                _startupCheckBox.IsChecked = _settings.StartWithWindows;
                _takeoverCheckBox.IsChecked = _settings.TakeOverDesktopIcons;
                _opacitySlider.Value = Math.Max(_opacitySlider.Minimum,
                    Math.Min(_opacitySlider.Maximum, _settings.BoxOpacity));
                _opacityValue.Text = Math.Round(_opacitySlider.Value * 100.0).ToString(CultureInfo.InvariantCulture) + "%";
                _aiCheckBox.IsChecked = _settings.AiEnabled;

                string provider = NormalizeProvider(_settings.AiProvider);
                _providerComboBox.SelectedIndex = provider == DeepSeekProvider ? 1 : 0;
                _previousProvider = provider;
                _modelTextBox.Text = String.IsNullOrWhiteSpace(_settings.AiModel)
                    ? GetDefaultModel(provider)
                    : _settings.AiModel.Trim();
            }
            finally
            {
                _initializing = false;
            }

            UpdateAiControlsEnabled();
            UpdateKeyStatus();
            UpdateKeyButtons();
        }

        private void OnProviderSelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            string provider = GetSelectedProvider();
            if (!_initializing)
            {
                string currentModel = _modelTextBox.Text == null ? String.Empty : _modelTextBox.Text.Trim();
                if (currentModel.Length == 0 ||
                    String.Equals(currentModel, GetDefaultModel(_previousProvider), StringComparison.OrdinalIgnoreCase))
                {
                    _modelTextBox.Text = GetDefaultModel(provider);
                }
            }
            _previousProvider = provider;
            if (_keyStatusText != null)
            {
                UpdateKeyStatus();
                UpdateKeyButtons();
            }
        }

        private void UpdateAiControlsEnabled()
        {
            bool enabled = _aiCheckBox != null && _aiCheckBox.IsChecked == true;
            if (_providerComboBox != null)
            {
                _providerComboBox.IsEnabled = enabled;
                _modelTextBox.IsEnabled = enabled;
                _apiKeyPasswordBox.IsEnabled = enabled;
                UpdateKeyButtons();
            }
        }

        private void UpdateKeyButtons()
        {
            if (_saveKeyButton == null || _providerComboBox == null)
            {
                return;
            }
            bool aiEnabled = _aiCheckBox != null && _aiCheckBox.IsChecked == true;
            _saveKeyButton.IsEnabled = aiEnabled &&
                _apiKeyPasswordBox != null &&
                !String.IsNullOrWhiteSpace(_apiKeyPasswordBox.Password);
            _deleteKeyButton.IsEnabled = aiEnabled && GetCachedHasKey(GetSelectedProvider());
        }

        private void UpdateKeyStatus()
        {
            if (_keyStatusText == null || _providerComboBox == null)
            {
                return;
            }
            bool hasKey = GetCachedHasKey(GetSelectedProvider());
            _keyStatusText.Text = hasKey ? "已配置密钥" : "尚未配置";
            _keyStatusText.Foreground = hasKey
                ? CreateBrush(Color.FromRgb(133, 214, 181))
                : CreateBrush(Color.FromRgb(173, 183, 198));
        }

        private void SaveKey(object sender, RoutedEventArgs e)
        {
            string key = _apiKeyPasswordBox.Password == null
                ? String.Empty
                : _apiKeyPasswordBox.Password.Trim();
            if (key.Length == 0)
            {
                return;
            }

            try
            {
                SecretStore.SaveKey(GetSelectedProvider(), key);
                SetCachedHasKey(GetSelectedProvider(), true);
                _apiKeyPasswordBox.Clear();
                UpdateKeyStatus();
                UpdateKeyButtons();
                MessageBox.Show(this, "API 密钥已安全保存到 Windows 凭据管理器。",
                    "拾光桌面", MessageBoxButton.OK, MessageBoxImage.Information);
            }
            catch (Exception ex)
            {
                MessageBox.Show(this, "无法保存 API 密钥：\n" + ex.Message,
                    "拾光桌面", MessageBoxButton.OK, MessageBoxImage.Warning);
            }
        }

        private void DeleteKey(object sender, RoutedEventArgs e)
        {
            MessageBoxResult result = MessageBox.Show(this,
                "删除当前提供方保存在 Windows 凭据管理器中的密钥？",
                "拾光桌面", MessageBoxButton.YesNo, MessageBoxImage.Question);
            if (result != MessageBoxResult.Yes)
            {
                return;
            }

            try
            {
                SecretStore.DeleteKey(GetSelectedProvider());
                // An environment variable takes precedence over the credential
                // just deleted, so re-check rather than assuming no key exists.
                SetCachedHasKey(GetSelectedProvider(), TryHasKey(GetSelectedProvider()));
                _apiKeyPasswordBox.Clear();
                UpdateKeyStatus();
                UpdateKeyButtons();
            }
            catch (Exception ex)
            {
                MessageBox.Show(this, "无法删除 API 密钥：\n" + ex.Message,
                    "拾光桌面", MessageBoxButton.OK, MessageBoxImage.Warning);
            }
        }

        private void ApplySettings(object sender, RoutedEventArgs e)
        {
            string provider = GetSelectedProvider();
            string model = _modelTextBox.Text == null ? String.Empty : _modelTextBox.Text.Trim();
            if (model.Length == 0)
            {
                model = GetDefaultModel(provider);
            }
            if (!AppSettings.IsValidModelName(model))
            {
                MessageBox.Show(this, "模型名称不能超过 128 个字符，也不能包含控制字符。",
                    "拾光桌面", MessageBoxButton.OK, MessageBoxImage.Warning);
                _modelTextBox.Focus();
                return;
            }

            string pendingKey = _apiKeyPasswordBox.Password == null
                ? String.Empty
                : _apiKeyPasswordBox.Password.Trim();
            if (pendingKey.Length > 0)
            {
                try
                {
                    SecretStore.SaveKey(provider, pendingKey);
                    SetCachedHasKey(provider, true);
                    _apiKeyPasswordBox.Clear();
                }
                catch (Exception ex)
                {
                    MessageBox.Show(this, "无法保存 API 密钥：\n" + ex.Message,
                        "拾光桌面", MessageBoxButton.OK, MessageBoxImage.Warning);
                    return;
                }
            }

            _settings.StartWithWindows = _startupCheckBox.IsChecked == true;
            _settings.TakeOverDesktopIcons = _takeoverCheckBox.IsChecked == true;
            _settings.BoxOpacity = Math.Max(0.38, Math.Min(0.92, _opacitySlider.Value));
            _settings.AiEnabled = _aiCheckBox.IsChecked == true;
            _settings.AiProvider = provider;
            _settings.AiModel = model;
            _settings.EnsureDefaults();

            EventHandler handler = SettingsApplied;
            if (handler != null)
            {
                handler(this, EventArgs.Empty);
            }
            CloseWithResult(true);
        }

        private void CloseWithResult(bool result)
        {
            try
            {
                DialogResult = result;
            }
            catch (InvalidOperationException)
            {
                Close();
            }
        }

        private string GetSelectedProvider()
        {
            ProviderOption option = _providerComboBox == null
                ? null
                : _providerComboBox.SelectedItem as ProviderOption;
            return option == null ? OpenAiProvider : option.Id;
        }

        private static string NormalizeProvider(string provider)
        {
            return String.Equals(provider, DeepSeekProvider, StringComparison.OrdinalIgnoreCase)
                ? DeepSeekProvider
                : OpenAiProvider;
        }

        private static string GetDefaultModel(string provider)
        {
            return String.Equals(provider, DeepSeekProvider, StringComparison.OrdinalIgnoreCase)
                ? DeepSeekDefaultModel
                : OpenAiDefaultModel;
        }

        private bool GetCachedHasKey(string provider)
        {
            return String.Equals(provider, DeepSeekProvider, StringComparison.OrdinalIgnoreCase)
                ? _deepSeekHasKey
                : _openAiHasKey;
        }

        private void SetCachedHasKey(string provider, bool value)
        {
            if (String.Equals(provider, DeepSeekProvider, StringComparison.OrdinalIgnoreCase))
            {
                _deepSeekHasKey = value;
            }
            else
            {
                _openAiHasKey = value;
            }
        }

        private static bool TryHasKey(string provider)
        {
            try
            {
                return SecretStore.HasKey(provider);
            }
            catch
            {
                return false;
            }
        }

        private static TextBlock CreateSectionTitle(string text)
        {
            return new TextBlock
            {
                Text = text,
                Foreground = CreateBrush(Color.FromRgb(115, 220, 202)),
                FontSize = 12,
                FontWeight = FontWeights.SemiBold,
                Margin = new Thickness(0, 0, 0, 8)
            };
        }

        private static CheckBox CreateCheckBox(string text)
        {
            return new CheckBox
            {
                Content = text,
                Foreground = CreateBrush(Color.FromRgb(224, 232, 242)),
                FontSize = 12,
                Margin = new Thickness(0, 3, 0, 8),
                VerticalContentAlignment = VerticalAlignment.Center
            };
        }

        private static Grid CreateFormRow(string label)
        {
            Grid row = new Grid { Margin = new Thickness(0, 4, 0, 7) };
            row.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(116) });
            row.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(1, GridUnitType.Star) });
            row.Children.Add(CreateLabel(label));
            return row;
        }

        private static TextBlock CreateLabel(string text)
        {
            return new TextBlock
            {
                Text = text,
                Foreground = CreateBrush(Color.FromRgb(204, 214, 228)),
                FontSize = 12,
                VerticalAlignment = VerticalAlignment.Center
            };
        }

        private static Button CreateActionButton(string text, bool accent)
        {
            return new Button
            {
                Content = text,
                Height = 27,
                MinWidth = 58,
                Padding = new Thickness(9, 2, 9, 2),
                BorderThickness = new Thickness(1),
                BorderBrush = accent
                    ? CreateBrush(Color.FromRgb(80, 206, 188))
                    : CreateBrush(Color.FromRgb(92, 109, 132)),
                Background = accent
                    ? CreateBrush(Color.FromRgb(39, 143, 132))
                    : CreateBrush(Color.FromRgb(39, 50, 66)),
                Foreground = Brushes.White,
                FontSize = 11,
                Cursor = Cursors.Hand
            };
        }

        private static Button CreateFooterButton(string text, bool accent)
        {
            Button button = CreateActionButton(text, accent);
            button.Height = 34;
            button.MinWidth = accent ? 92 : 74;
            button.FontSize = 12;
            return button;
        }

        private static SolidColorBrush CreateBrush(Color color)
        {
            SolidColorBrush brush = new SolidColorBrush(color);
            if (brush.CanFreeze)
            {
                brush.Freeze();
            }
            return brush;
        }

        private sealed class ProviderOption
        {
            public ProviderOption(string id, string name)
            {
                Id = id;
                Name = name;
            }

            public string Id { get; private set; }

            public string Name { get; private set; }

            public override string ToString()
            {
                return Name;
            }
        }
    }
}