PowerToys/src/modules/powerdisplay/PowerDisplay/ViewModels/MonitorViewModel.cs

// Copyright (c) Microsoft Corporation
// The Microsoft Corporation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;
using ManagedCommon;
using Microsoft.UI.Dispatching;
using Microsoft.UI.Xaml;
using Microsoft.UI.Xaml.Controls;
using Microsoft.UI.Xaml.Controls.Primitives;
using Microsoft.UI.Xaml.Input;
using PowerDisplay.Common.Models;
using PowerDisplay.Common.Services;
using PowerDisplay.Configuration;
using PowerDisplay.Helpers;
using PowerDisplay.Models;
using Windows.System;
using DispatcherQueue = Microsoft.UI.Dispatching.DispatcherQueue;
using DispatcherQueueTimer = Microsoft.UI.Dispatching.DispatcherQueueTimer;
using Monitor = PowerDisplay.Common.Models.Monitor;

namespace PowerDisplay.ViewModels;

/// <summary>
/// ViewModel for individual monitor
/// </summary>
public partial class MonitorViewModel : ObservableObject, IDisposable
{
    private readonly Monitor _monitor;
    private readonly MonitorManager _monitorManager;
    private readonly MainViewModel? _mainViewModel;

    private int _brightness;
    private int _contrast;
    private int _volume;

    // Debounce timers — each user-driven setter restarts the matching timer so a drag
    // or held arrow key collapses into a single DDC/CI write once the user stops moving.
    // External / programmatic apply paths (SetBrightnessAsync etc.) bypass the setters
    // and therefore never schedule a debounced commit.
    private DispatcherQueueTimer? _brightnessCommitTimer;
    private DispatcherQueueTimer? _contrastCommitTimer;
    private DispatcherQueueTimer? _volumeCommitTimer;

    // Visibility settings (controlled by Settings UI)
    [ObservableProperty]
    [NotifyPropertyChangedFor(nameof(ShowBrightnessSlider))]
    public partial bool ShowBrightness { get; set; }

    [ObservableProperty]
    [NotifyPropertyChangedFor(nameof(HasAdvancedControls))]
    public partial bool ShowContrast { get; set; }

    [ObservableProperty]
    [NotifyPropertyChangedFor(nameof(HasAdvancedControls))]
    public partial bool ShowVolume { get; set; }

    [ObservableProperty]
    [NotifyPropertyChangedFor(nameof(ShowMoreButton))]
    [NotifyPropertyChangedFor(nameof(ShowSeparatorAfterInputSource))]
    public partial bool ShowInputSource { get; set; }

    [ObservableProperty]
    public partial bool ShowRotation { get; set; }

    private bool _showPowerState;

    /// <summary>
    /// Apply brightness with hardware update and state persistence.
    /// </summary>
    /// <param name="brightness">Brightness value (0-100)</param>
    public async Task SetBrightnessAsync(int brightness)
    {
        brightness = Math.Clamp(brightness, 0, 100);

        // Update UI state immediately
        if (_brightness != brightness)
        {
            _brightness = brightness;
            OnPropertyChanged(nameof(Brightness));
        }

        await ApplyPropertyToHardwareAsync(nameof(Brightness), brightness, _monitorManager.SetBrightnessAsync);
    }

    /// <summary>
    /// Apply contrast with hardware update and state persistence.
    /// </summary>
    public async Task SetContrastAsync(int contrast)
    {
        contrast = Math.Clamp(contrast, 0, 100);

        if (_contrast != contrast)
        {
            _contrast = contrast;
            OnPropertyChanged(nameof(Contrast));
        }

        await ApplyPropertyToHardwareAsync(nameof(Contrast), contrast, _monitorManager.SetContrastAsync);
    }

    /// <summary>
    /// Apply volume with hardware update and state persistence.
    /// </summary>
    public async Task SetVolumeAsync(int volume)
    {
        volume = Math.Clamp(volume, 0, 100);

        if (_volume != volume)
        {
            _volume = volume;
            OnPropertyChanged(nameof(Volume));
        }

        await ApplyPropertyToHardwareAsync(nameof(Volume), volume, _monitorManager.SetVolumeAsync);
    }

    private bool IsDiscreteValueSupported(byte vcpCode, int value)
    {
        var vcpInfo = VcpCapabilitiesInfo;
        if (vcpInfo == null ||
            !vcpInfo.SupportedVcpCodes.TryGetValue(vcpCode, out var codeInfo) ||
            !codeInfo.HasDiscreteValues ||
            !codeInfo.SupportedValues.Contains(value))
        {
            Logger.LogWarning($"[{Id}] VCP 0x{vcpCode:X2} value 0x{value:X2} not in reported supported values, skipping");
            return false;
        }

        return true;
    }

    /// <summary>
    /// Unified method to apply color temperature with hardware update and state persistence.
    /// Always immediate (no debouncing for discrete preset values).
    /// </summary>
    public async Task SetColorTemperatureAsync(int colorTemperature)
    {
        if (!IsDiscreteValueSupported(0x14, colorTemperature))
        {
            return;
        }

        try
        {
            var result = await _monitorManager.SetColorTemperatureAsync(Id, colorTemperature);

            if (result.IsSuccess)
            {
                _monitor.CurrentColorTemperature = colorTemperature;
                OnPropertyChanged(nameof(ColorTemperature));
                OnPropertyChanged(nameof(ColorTemperaturePresetName));

                // Refresh the color presets list to update IsSelected checkmarks in UI
                RefreshAvailableColorPresets();

                _mainViewModel?.SaveMonitorSettingDirect(_monitor.Id, nameof(ColorTemperature), colorTemperature);
            }
            else
            {
                Logger.LogWarning($"[{Id}] Failed to set color temperature: {result.ErrorMessage}");
            }
        }
        catch (Exception ex)
        {
            Logger.LogError($"[{Id}] Exception setting color temperature: {ex.Message}");
        }
    }

    /// <summary>
    /// Generic method to apply a monitor property to hardware and persist state.
    /// Consolidates common logic for brightness, contrast, and volume operations.
    /// </summary>
    /// <param name="propertyName">Name of the property being set (for logging and state persistence)</param>
    /// <param name="value">Value to apply</param>
    /// <param name="setAsyncFunc">Async function to call on MonitorManager</param>
    private async Task<bool> ApplyPropertyToHardwareAsync(
        string propertyName,
        int value,
        Func<string, int, CancellationToken, Task<MonitorOperationResult>> setAsyncFunc)
    {
        try
        {
            var result = await setAsyncFunc(Id, value, default);

            if (result.IsSuccess)
            {
                _mainViewModel?.SaveMonitorSettingDirect(_monitor.Id, propertyName, value);
                return true;
            }
            else
            {
                Logger.LogWarning($"[{Id}] Failed to set {propertyName.ToLowerInvariant()}: {result.ErrorMessage}");
            }
        }
        catch (Exception ex)
        {
            Logger.LogError($"[{Id}] Exception setting {propertyName.ToLowerInvariant()}: {ex.Message}");
        }

        return false;
    }

    // Property to access IsInteractionEnabled from parent ViewModel
    public bool IsInteractionEnabled => _mainViewModel?.IsInteractionEnabled ?? true;

    /// <summary>
    /// Gets the shared per-mouse-wheel-notch step for this monitor's sliders, proxied from the
    /// owning <see cref="MainViewModel"/>. Falls back to 5 if the owner is unavailable.
    /// </summary>
    public int MouseWheelIncrement => _mainViewModel?.MouseWheelIncrement ?? 5;

    public MonitorViewModel(Monitor monitor, MonitorManager monitorManager, MainViewModel mainViewModel)
    {
        _monitor = monitor;
        _monitorManager = monitorManager;
        _mainViewModel = mainViewModel;

        // Subscribe to MainViewModel property changes to update IsInteractionEnabled
        if (_mainViewModel != null)
        {
            _mainViewModel.PropertyChanged += OnMainViewModelPropertyChanged;
        }

        // Subscribe to underlying Monitor property changes (e.g., Orientation updates in mirror mode)
        _monitor.PropertyChanged += OnMonitorPropertyChanged;

        // Initialize Show properties for first-time detection. ApplyFeatureVisibility will
        // override these whenever settings.json has a saved entry for this monitor, so these
        // values only take effect for brand-new monitors (no persisted preference yet).
        // Mirror CreateMonitorInfo's defaults to keep the flyout and settings.json in sync:
        //   - Brightness / Contrast / Volume: enabled if the hardware advertises the VCP code.
        //   - InputSource / ColorTemperature / PowerState: always disabled by default (dangerous
        //     features); the user opts in via the Settings UI confirmation dialog.
        ShowBrightness = monitor.SupportsBrightness;
        ShowContrast = monitor.SupportsContrast;
        ShowVolume = monitor.SupportsVolume;
        ShowInputSource = false;
        _showPowerState = false;
        _showColorTemperature = false;

        // Initialize basic properties from monitor
        _brightness = monitor.CurrentBrightness;
        _contrast = monitor.CurrentContrast;
        _volume = monitor.CurrentVolume;
    }

    public string Id => _monitor.Id;

    public string Name => IsInternal
        ? ResourceLoaderInstance.ResourceLoader.GetString("BuiltInDisplayName")
        : _monitor.Name;

    /// <summary>
    /// Gets the monitor number from the underlying monitor model (Windows DISPLAY number)
    /// </summary>
    public int MonitorNumber => _monitor.MonitorNumber;

    /// <summary>
    /// Gets the GDI display source name used to match the Windows primary display.
    /// </summary>
    public string GdiDeviceName => _monitor.GdiDeviceName;

    /// <summary>
    /// Gets the display name - includes monitor number when multiple monitors exist.
    /// Follows the same logic as Settings UI's MonitorInfo.DisplayName for consistency.
    /// </summary>
    public string DisplayName
    {
        get
        {
            var monitorCount = _mainViewModel?.Monitors?.Count ?? 0;

            // Show monitor number only when there are multiple monitors and MonitorNumber is valid
            if (monitorCount > 1 && MonitorNumber > 0)
            {
                return $"{Name} {MonitorNumber}";
            }

            return Name;
        }
    }

    public string CommunicationMethod => _monitor.CommunicationMethod;

    public bool IsInternal => _monitor.CommunicationMethod == "WMI";

    public string? CapabilitiesRaw => _monitor.CapabilitiesRaw;

    public VcpCapabilities? VcpCapabilitiesInfo => _monitor.VcpCapabilitiesInfo;

    /// <summary>
    /// Gets the icon glyph based on communication method
    /// WMI monitors (laptop internal displays) use laptop icon, others use external monitor icon
    /// </summary>
    public string MonitorIconGlyph => _monitor.CommunicationMethod?.Contains("WMI", StringComparison.OrdinalIgnoreCase) == true
        ? AppConstants.UI.InternalMonitorGlyph // Laptop icon for WMI
        : AppConstants.UI.ExternalMonitorGlyph; // External monitor icon for DDC/CI and others

    // Advanced control display logic
    public bool HasAdvancedControls => ShowContrast || ShowVolume;

    /// <summary>
    /// Gets a value indicating whether this monitor supports contrast control via VCP 0x12
    /// </summary>
    public bool SupportsContrast => _monitor.SupportsContrast;

    public bool SupportsBrightness => _monitor.SupportsBrightness;

    /// <summary>
    /// Gets a value indicating whether discovery read a trustworthy current brightness.
    /// </summary>
    public bool HasValidBrightnessReading
        => _monitor.ReadValues.HasFlag(MonitorReadFlags.Brightness);

    /// <summary>
    /// Gets a value indicating whether this monitor's brightness is currently driven by linked
    /// mode rather than its own slider. True when the parent has link mode on, this monitor
    /// supports brightness, and the user has not excluded it. When true the per-card brightness
    /// row shows a disabled linked-mode hint — the "All Displays" master slider broadcasts the
    /// value instead.
    /// </summary>
    public bool IsBrightnessLinked => (_mainViewModel?.LinkedLevelsActive ?? false) && SupportsBrightness && !IsExcludedFromSync;

    /// <summary>
    /// Gets a value indicating whether the per-card brightness slider accepts input. Disabled both
    /// while the app is busy (<see cref="IsInteractionEnabled"/>) and while link mode owns this
    /// monitor's brightness (<see cref="IsBrightnessLinked"/>). Excluded monitors keep an active
    /// slider, so this is true for them whenever interaction is enabled.
    /// </summary>
    public bool IsBrightnessSliderEnabled => IsInteractionEnabled && !IsBrightnessLinked;

    public bool ShowBrightnessSlider => ShowBrightness && !IsBrightnessLinked;

    public bool ShowIncludedInSyncIcon => !IsExcludedFromSync;

    /// <summary>
    /// Gets or sets a value indicating whether this monitor is excluded from linked brightness.
    /// Backed by the parent's shared exclusion set (keyed by <see cref="Id"/>), so the state
    /// survives monitor-list rebuilds and is persisted to settings.json. An excluded monitor keeps
    /// its own independent brightness slider while link mode is on.
    /// </summary>
    public bool IsExcludedFromSync
    {
        get => _mainViewModel?.IsMonitorExcludedFromSync(Id) ?? false;
        set
        {
            if (IsExcludedFromSync != value)
            {
                _mainViewModel?.SetMonitorExcludedFromSync(Id, value);
                OnPropertyChanged();
                OnPropertyChanged(nameof(IsBrightnessLinked));
                OnPropertyChanged(nameof(IsBrightnessSliderEnabled));
                OnPropertyChanged(nameof(ShowBrightnessSlider));
                OnPropertyChanged(nameof(ShowIncludedInSyncIcon));
                OnPropertyChanged(nameof(SyncToggleToolTip));
            }
        }
    }

    /// <summary>
    /// Gets a value indicating whether the per-card exclude toggle is shown. Only relevant while
    /// link mode is on and the monitor supports brightness — otherwise exclusion has no effect.
    /// </summary>
    public bool ShowExcludeButton => (_mainViewModel?.LinkedLevelsActive ?? false) && SupportsBrightness;

    /// <summary>
    /// Gets the tooltip for the per-card linked-brightness toggle. The action reverses with the
    /// current exclusion state: linked monitors can be excluded, excluded monitors can be included.
    /// </summary>
    public string SyncToggleToolTip => ResourceLoaderInstance.ResourceLoader.GetString(
        IsExcludedFromSync ? "IncludeInSyncToggleToolTip" : "ExcludeFromSyncToggleToolTip");

    /// <summary>
    /// Gets a value indicating whether this monitor supports volume control via VCP 0x62
    /// </summary>
    public bool SupportsVolume => _monitor.SupportsVolume;

    /// <summary>
    /// Gets or sets a value indicating whether to show power state control in the More Button flyout.
    /// </summary>
    public bool ShowPowerState
    {
        get => _showPowerState && SupportsPowerState;
        set
        {
            if (_showPowerState != value)
            {
                _showPowerState = value;
                OnPropertyChanged();
                OnMoreButtonPropertiesChanged();
            }
        }
    }

    /// <summary>
    /// Gets a value indicating whether the More Button should be visible.
    /// Visible when at least one feature (InputSource or PowerState) is enabled.
    /// </summary>
    public bool ShowMoreButton => ShowInputSource || ShowPowerState;

    /// <summary>
    /// Gets a value indicating whether to show separator after Input Source section.
    /// Only shown when both InputSource and PowerState are visible.
    /// </summary>
    public bool ShowSeparatorAfterInputSource => ShowInputSource && ShowPowerState;

    /// <summary>
    /// Notifies property changes for More Button related properties.
    /// </summary>
    private void OnMoreButtonPropertiesChanged()
    {
        OnPropertyChanged(nameof(ShowMoreButton));
        OnPropertyChanged(nameof(ShowSeparatorAfterInputSource));
    }

    /// <summary>
    /// Gets the current rotation/orientation of the monitor (0=normal, 1=90°, 2=180°, 3=270°)
    /// </summary>
    public int CurrentRotation => _monitor.Orientation;

    /// <summary>
    /// Gets a value indicating whether the current rotation is 0° (normal/default).
    /// </summary>
    public bool IsRotation0 => CurrentRotation == 0;

    /// <summary>
    /// Gets a value indicating whether the current rotation is 90° (rotated right).
    /// </summary>
    public bool IsRotation1 => CurrentRotation == 1;

    /// <summary>
    /// Gets a value indicating whether the current rotation is 180° (inverted).
    /// </summary>
    public bool IsRotation2 => CurrentRotation == 2;

    /// <summary>
    /// Gets a value indicating whether the current rotation is 270° (rotated left).
    /// </summary>
    public bool IsRotation3 => CurrentRotation == 3;

    /// <summary>
    /// Gets or sets the selected rotation index for binding to a ComboBox.
    /// Maps directly to <see cref="CurrentRotation"/>: 0=Landscape, 1=Portrait, 2=Landscape (flipped), 3=Portrait (flipped).
    /// </summary>
    public int SelectedRotationIndex
    {
        get => CurrentRotation;
        set => _ = SetRotationAsync(value);
    }

    /// <summary>
    /// Set rotation/orientation for this monitor.
    /// Note: MonitorManager.SetRotationAsync will refresh all monitors' orientations after success,
    /// which triggers PropertyChanged through OnMonitorPropertyChanged - no manual notification needed here.
    /// </summary>
    /// <param name="orientation">Orientation: 0=normal, 1=90°, 2=180°, 3=270°</param>
    public async Task SetRotationAsync(int orientation)
    {
        // Validate orientation range (0=normal, 1=90°, 2=180°, 3=270°)
        if (orientation < 0 || orientation > 3)
        {
            return;
        }

        // If already at this orientation, do nothing
        if (CurrentRotation == orientation)
        {
            return;
        }

        try
        {
            var result = await _monitorManager.SetRotationAsync(Id, orientation);

            if (!result.IsSuccess)
            {
                Logger.LogWarning($"[{Id}] Failed to set rotation: {result.ErrorMessage}");
            }
        }
        catch (Exception ex)
        {
            Logger.LogError($"[{Id}] Exception setting rotation: {ex.Message}");
        }
    }

    public int Brightness
    {
        get => _brightness;
        set
        {
            if (_brightness != value)
            {
                _brightness = value;
                OnPropertyChanged();
                ScheduleCommit(ref _brightnessCommitTimer, () => SetBrightnessAsync(_brightness));
            }
        }
    }

    /// <summary>
    /// Update the brightness backing field and notify the UI without scheduling a per-VM commit
    /// or hardware write. Used by <c>MainViewModel.LinkedBrightness</c> to keep each linked
    /// monitor's stored brightness aligned with the master value, so it is correct if the
    /// monitor is later excluded or link mode is disabled. The master broadcast is the single
    /// source of hardware writes while link mode is on, so this path must not schedule its own
    /// debounced commit.
    /// </summary>
    public void UpdateBrightnessDisplay(int value)
    {
        value = Math.Clamp(value, 0, 100);
        if (_brightness != value)
        {
            _brightness = value;
            OnPropertyChanged(nameof(Brightness));
        }
    }

    /// <summary>
    /// Gets color temperature VCP preset value (from VCP code 0x14).
    /// Read-only in flyout UI - controlled via Settings UI.
    /// Returns the raw VCP value (e.g., 0x05 for 6500K).
    /// </summary>
    public int ColorTemperature => _monitor.CurrentColorTemperature;

    /// <summary>
    /// Gets human-readable color temperature preset name (e.g., "6500K", "sRGB")
    /// Uses custom mappings if available; falls back to built-in names if not.
    /// </summary>
    public string ColorTemperaturePresetName
    {
        get
        {
            var name = Common.Utils.VcpNames.GetValueName(0x14, _monitor.CurrentColorTemperature, _mainViewModel?.CustomVcpMappings, _monitor.Id);
            return name != null ? $"{name} (0x{_monitor.CurrentColorTemperature:X2})" : $"0x{_monitor.CurrentColorTemperature:X2}";
        }
    }

    /// <summary>
    /// Gets a value indicating whether this monitor supports color temperature via VCP 0x14
    /// </summary>
    public bool SupportsColorTemperature => _monitor.SupportsColorTemperature;

    private List<ColorTemperatureItem>? _availableColorPresets;
    private bool _showColorTemperature;

    /// <summary>
    /// Gets or sets a value indicating whether to show color temperature switcher (controlled by Settings UI, default false).
    /// </summary>
    public bool ShowColorTemperature
    {
        get => _showColorTemperature && SupportsColorTemperature;
        set
        {
            if (_showColorTemperature != value)
            {
                _showColorTemperature = value;
                OnPropertyChanged();
            }
        }
    }

    /// <summary>
    /// Gets available color temperature presets for this monitor
    /// </summary>
    public List<ColorTemperatureItem>? AvailableColorPresets
    {
        get
        {
            if (_availableColorPresets == null && SupportsColorTemperature)
            {
                RefreshAvailableColorPresets();
            }

            return _availableColorPresets;
        }
    }

    /// <summary>
    /// Refresh the list of available color temperature presets based on monitor capabilities.
    /// Only values explicitly reported in the capabilities string are exposed — no MCCS standard fallback.
    /// </summary>
    private void RefreshAvailableColorPresets()
    {
        var vcpInfo = VcpCapabilitiesInfo;
        if (!SupportsColorTemperature ||
            vcpInfo == null ||
            !vcpInfo.SupportedVcpCodes.TryGetValue(0x14, out var colorTempInfo) ||
            !colorTempInfo.HasDiscreteValues)
        {
            _availableColorPresets = null;
            OnPropertyChanged(nameof(AvailableColorPresets));
            return;
        }

        _availableColorPresets = colorTempInfo.SupportedValues.Select(value => new ColorTemperatureItem
        {
            VcpValue = value,
            DisplayName = Common.Utils.VcpNames.GetValueName(0x14, value, _mainViewModel?.CustomVcpMappings, _monitor.Id) is string n ? $"{n} (0x{value:X2})" : $"0x{value:X2}",
            IsSelected = value == _monitor.CurrentColorTemperature,
            MonitorId = _monitor.Id,
        }).ToList();

        OnPropertyChanged(nameof(AvailableColorPresets));
    }

    /// <summary>
    /// Gets a value indicating whether this monitor supports input source switching via VCP 0x60
    /// </summary>
    public bool SupportsInputSource => _monitor.SupportsInputSource;

    /// <summary>
    /// Gets current input source VCP value (from VCP code 0x60)
    /// </summary>
    public int CurrentInputSource => _monitor.CurrentInputSource;

    /// <summary>
    /// Gets human-readable current input source name (e.g., "HDMI-1", "DisplayPort-1")
    /// Uses custom mappings if available; falls back to built-in names if not.
    /// </summary>
    public string CurrentInputSourceName =>
        Common.Utils.VcpNames.GetValueName(0x60, _monitor.CurrentInputSource, _mainViewModel?.CustomVcpMappings, _monitor.Id)
        ?? $"Source 0x{_monitor.CurrentInputSource:X2}";

    private List<InputSourceItem>? _availableInputSources;

    /// <summary>
    /// Gets available input sources for this monitor
    /// </summary>
    public List<InputSourceItem>? AvailableInputSources
    {
        get
        {
            if (_availableInputSources == null && SupportsInputSource)
            {
                RefreshAvailableInputSources();
            }

            return _availableInputSources;
        }
    }

    /// <summary>
    /// Refresh the list of available input sources based on monitor capabilities
    /// </summary>
    private void RefreshAvailableInputSources()
    {
        var supportedSources = _monitor.SupportedInputSources;
        if (supportedSources == null || supportedSources.Count == 0)
        {
            _availableInputSources = null;
            return;
        }

        _availableInputSources = supportedSources.Select(value => new InputSourceItem
        {
            Value = value,
            Name = Common.Utils.VcpNames.GetValueName(0x60, value, _mainViewModel?.CustomVcpMappings, _monitor.Id) ?? $"Source 0x{value:X2}",
            SelectionVisibility = value == _monitor.CurrentInputSource ? Visibility.Visible : Visibility.Collapsed,
            MonitorId = _monitor.Id,
        }).ToList();

        OnPropertyChanged(nameof(AvailableInputSources));
    }

    /// <summary>
    /// Refresh custom VCP name displays after settings change.
    /// Called when CustomVcpMappings is updated from Settings UI.
    /// </summary>
    public void RefreshCustomVcpNames()
    {
        // Refresh color temperature names
        OnPropertyChanged(nameof(ColorTemperaturePresetName));
        _availableColorPresets = null;  // Force rebuild with new custom names
        OnPropertyChanged(nameof(AvailableColorPresets));

        // Refresh input source names
        OnPropertyChanged(nameof(CurrentInputSourceName));
        _availableInputSources = null;  // Force rebuild with new custom names
        OnPropertyChanged(nameof(AvailableInputSources));
    }

    /// <summary>
    /// Raise <see cref="PropertyChanged"/> for <see cref="MouseWheelIncrement"/> so per-monitor
    /// sliders pick up a new value after the user changes it in Settings. Called from
    /// <c>MainViewModel.ApplySettingsFromUI</c>.
    /// </summary>
    public void RefreshMouseWheelIncrement()
    {
        OnPropertyChanged(nameof(MouseWheelIncrement));
    }

    /// <summary>
    /// Set input source for this monitor
    /// </summary>
    public async Task SetInputSourceAsync(int inputSource)
    {
        if (!IsDiscreteValueSupported(0x60, inputSource))
        {
            return;
        }

        try
        {
            var result = await _monitorManager.SetInputSourceAsync(Id, inputSource);

            if (result.IsSuccess)
            {
                OnPropertyChanged(nameof(CurrentInputSource));
                OnPropertyChanged(nameof(CurrentInputSourceName));
                RefreshAvailableInputSources();
            }
            else
            {
                Logger.LogWarning($"[{Id}] Failed to set input source: {result.ErrorMessage}");
            }
        }
        catch (Exception ex)
        {
            Logger.LogError($"[{Id}] Exception setting input source: {ex.Message}");
        }
    }

    /// <summary>
    /// Command to set input source
    /// </summary>
    [RelayCommand]
    private async Task SetInputSource(int? source)
    {
        if (source.HasValue)
        {
            await SetInputSourceAsync(source.Value);
        }
    }

    /// <summary>
    /// Gets a value indicating whether this monitor supports power state control via VCP 0xD6
    /// </summary>
    public bool SupportsPowerState => _monitor.SupportsPowerState;

    private List<PowerStateItem>? _availablePowerStates;

    /// <summary>
    /// Gets available power states for this monitor.
    /// The current power state is shown as selected based on the monitor's actual state.
    /// </summary>
    public List<PowerStateItem>? AvailablePowerStates
    {
        get
        {
            if (_availablePowerStates == null && SupportsPowerState)
            {
                RefreshAvailablePowerStates();
            }

            return _availablePowerStates;
        }
    }

    /// <summary>
    /// Refresh the list of available power states based on monitor capabilities
    /// </summary>
    private void RefreshAvailablePowerStates()
    {
        var supportedStates = _monitor.SupportedPowerStates;
        if (supportedStates == null || supportedStates.Count == 0)
        {
            _availablePowerStates = null;
            return;
        }

        _availablePowerStates = supportedStates.Select(value => new PowerStateItem
        {
            Value = value,
            Name = Common.Utils.VcpNames.GetValueName(0xD6, value) ?? $"State 0x{value:X2}",
            IsSelected = value == _monitor.CurrentPowerState,
            MonitorId = _monitor.Id,
        }).ToList();

        OnPropertyChanged(nameof(AvailablePowerStates));
    }

    /// <summary>
    /// Set the monitor's power state via VCP 0xD6: On (0x01) wakes the display,
    /// Standby/Suspend/Off put it to sleep.
    /// </summary>
    public async Task SetPowerStateAsync(int powerState)
    {
        if (!IsDiscreteValueSupported(0xD6, powerState))
        {
            return;
        }

        try
        {
            var result = await _monitorManager.SetPowerStateAsync(Id, powerState);

            if (result.IsSuccess)
            {
                // Update the model's power state and refresh UI
                _monitor.CurrentPowerState = powerState;
                RefreshAvailablePowerStates();
            }
            else
            {
                Logger.LogWarning($"[{Id}] Failed to set power state: {result.ErrorMessage}");
            }
        }
        catch (Exception ex)
        {
            Logger.LogError($"[{Id}] Exception setting power state: {ex.Message}");
        }
    }

    public int Contrast
    {
        get => _contrast;
        set
        {
            if (_contrast != value)
            {
                _contrast = value;
                OnPropertyChanged();
                ScheduleCommit(ref _contrastCommitTimer, () => SetContrastAsync(_contrast));
            }
        }
    }

    public int Volume
    {
        get => _volume;
        set
        {
            if (_volume != value)
            {
                _volume = value;
                OnPropertyChanged();
                ScheduleCommit(ref _volumeCommitTimer, () => SetVolumeAsync(_volume));
            }
        }
    }

    [RelayCommand]
    private void SetBrightness(int? brightness)
    {
        if (brightness.HasValue)
        {
            Brightness = brightness.Value;
        }
    }

    [RelayCommand]
    private void SetContrast(int? contrast)
    {
        if (contrast.HasValue)
        {
            Contrast = contrast.Value;
        }
    }

    [RelayCommand]
    private void SetVolume(int? volume)
    {
        if (volume.HasValue)
        {
            Volume = volume.Value;
        }
    }

    private void OnMainViewModelPropertyChanged(object? sender, PropertyChangedEventArgs e)
    {
        if (e.PropertyName == nameof(MainViewModel.IsInteractionEnabled))
        {
            OnPropertyChanged(nameof(IsInteractionEnabled));
            OnPropertyChanged(nameof(IsBrightnessSliderEnabled));
        }
        else if (e.PropertyName == nameof(MainViewModel.HasMonitors))
        {
            // Monitor count changed, update display name to show/hide number suffix
            OnPropertyChanged(nameof(DisplayName));
        }
        else if (e.PropertyName == nameof(MainViewModel.LinkedLevelsActive))
        {
            // Link mode toggled — refresh the linked hint, exclude button, and slider state.
            OnPropertyChanged(nameof(IsBrightnessLinked));
            OnPropertyChanged(nameof(IsBrightnessSliderEnabled));
            OnPropertyChanged(nameof(ShowBrightnessSlider));
            OnPropertyChanged(nameof(ShowExcludeButton));
        }
    }

    private void OnMonitorPropertyChanged(object? sender, PropertyChangedEventArgs e)
    {
        // Forward Orientation changes from underlying Monitor to ViewModel properties
        // This is important for mirror mode where MonitorManager.RefreshAllOrientations()
        // updates multiple monitors sharing the same GdiDeviceName
        if (e.PropertyName == nameof(Monitor.Orientation))
        {
            OnPropertyChanged(nameof(CurrentRotation));
            OnPropertyChanged(nameof(IsRotation0));
            OnPropertyChanged(nameof(IsRotation1));
            OnPropertyChanged(nameof(IsRotation2));
            OnPropertyChanged(nameof(IsRotation3));
            OnPropertyChanged(nameof(SelectedRotationIndex));
        }
    }

    // Slider commit handlers — debounced via ScheduleCommit. The setters store the
    // value, raise PropertyChanged, and (re)start a per-metric DispatcherQueueTimer
    // that fires the hardware write once the user stops moving. The commit closure
    // reads the latest field at fire-time so intermediate values are coalesced.
    private void ScheduleCommit(ref DispatcherQueueTimer? timer, Func<Task> commit)
    {
        SliderCommitScheduler.Schedule(ref timer, DispatcherQueue.GetForCurrentThread(), commit);
    }

    // Rotation button handlers — one per orientation to avoid Tag string parsing
    public async void HandleRotation0Click(object sender, RoutedEventArgs e) => await CommitRotationClickAsync(0);

    public async void HandleRotation1Click(object sender, RoutedEventArgs e) => await CommitRotationClickAsync(1);

    public async void HandleRotation2Click(object sender, RoutedEventArgs e) => await CommitRotationClickAsync(2);

    public async void HandleRotation3Click(object sender, RoutedEventArgs e) => await CommitRotationClickAsync(3);

    private async Task CommitRotationClickAsync(int orientation)
    {
        if (CurrentRotation == orientation)
        {
            // Force-notify to restore the ToggleButton checked state
            // (ToggleButton auto-unchecks on click; OneWay binding only re-pushes on change)
            OnPropertyChanged(nameof(IsRotation0));
            OnPropertyChanged(nameof(IsRotation1));
            OnPropertyChanged(nameof(IsRotation2));
            OnPropertyChanged(nameof(IsRotation3));
            return;
        }

        await SetRotationAsync(orientation);
    }

    // ListView selection handlers
    public async void HandleColorTemperatureSelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        if (sender is not ListView listView || listView.SelectedItem is not ColorTemperatureItem item)
        {
            return;
        }

        await SetColorTemperatureAsync(item.VcpValue);
        listView.SelectedItem = null;
    }

    public async void HandleInputSourceSelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        if (sender is not ListView listView || listView.SelectedItem is not InputSourceItem item)
        {
            return;
        }

        await SetInputSourceAsync(item.Value);
    }

    public async void HandlePowerStateSelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        if (sender is not ListView listView || listView.SelectedItem is not PowerStateItem item)
        {
            return;
        }

        // Send the selected state straight to the hardware. Selecting On (0x01) wakes a
        // sleeping monitor: DDC/CI stays reachable in Standby/Suspend/Off(DPM), so the
        // write turns the panel back on (Off(Hard)/0x05 may still need a physical wake).
        await SetPowerStateAsync(item.Value);
    }

    public void Dispose()
    {
        // Drop any pending debounced commits — if we're being disposed the monitor is
        // gone (unplug/refresh) or the app is shutting down, so a hardware write would
        // race a half-torn-down MonitorManager.
        _brightnessCommitTimer?.Stop();
        _contrastCommitTimer?.Stop();
        _volumeCommitTimer?.Stop();

        // Unsubscribe from MainViewModel events
        if (_mainViewModel != null)
        {
            _mainViewModel.PropertyChanged -= OnMainViewModelPropertyChanged;
        }

        // Unsubscribe from underlying Monitor events
        _monitor.PropertyChanged -= OnMonitorPropertyChanged;

        GC.SuppressFinalize(this);
    }
}