// 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.Globalization;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using ManagedCommon;
using PowerDisplay.Common.Interfaces;
using PowerDisplay.Common.Models;
using WmiLight;
using Monitor = PowerDisplay.Common.Models.Monitor;

namespace PowerDisplay.Common.Drivers.WMI
{
    /// <summary>
    /// WMI monitor controller for controlling internal laptop displays.
    /// Rewritten to use WmiLight library for Native AOT compatibility.
    /// </summary>
    public partial class WmiController : IMonitorController, IDisposable
    {
        private const string WmiNamespace = @"root\WMI";
        private const string BrightnessQueryClass = "WmiMonitorBrightness";
        private const string BrightnessMethodClass = "WmiMonitorBrightnessMethods";
        private const string MonitorIdClass = "WmiMonitorID";

        // Common WMI error codes for classification
        private const int WbemENotFound = unchecked((int)0x80041002);
        private const int WbemEAccessDenied = unchecked((int)0x80041003);
        private const int WbemEProviderFailure = unchecked((int)0x80041004);
        private const int WbemEInvalidQuery = unchecked((int)0x80041017);
        private const int WmiFeatureNotSupported = 0x1068;

        private bool _disposed;

        /// <summary>
        /// Classifies WMI exceptions into user-friendly error messages.
        /// </summary>
        private static MonitorOperationResult ClassifyWmiError(WmiException ex, string operation)
        {
            var hresult = ex.HResult;

            return hresult switch
            {
                WbemENotFound => MonitorOperationResult.Failure($"WMI class not found during {operation}. This feature may not be supported on your system.", hresult),
                WbemEAccessDenied => MonitorOperationResult.Failure($"Access denied during {operation}. Administrator privileges may be required.", hresult),
                WbemEProviderFailure => MonitorOperationResult.Failure($"WMI provider failure during {operation}. The display driver may not support this feature.", hresult),
                WbemEInvalidQuery => MonitorOperationResult.Failure($"Invalid WMI query during {operation}. This is likely a bug.", hresult),
                WmiFeatureNotSupported => MonitorOperationResult.Failure($"WMI brightness control not supported on this system during {operation}.", hresult),
                _ => MonitorOperationResult.Failure($"WMI error during {operation}: {ex.Message}", hresult),
            };
        }

        /// <summary>
        /// Determines if the WMI error is expected for systems without WMI brightness support.
        /// </summary>
        private static bool IsExpectedUnsupportedError(WmiException ex)
        {
            return ex.HResult == WmiFeatureNotSupported || ex.HResult == WbemENotFound;
        }

        /// <summary>
        /// Escape special characters in WMI query strings.
        /// WMI requires backslashes and single quotes to be escaped in WHERE clauses.
        /// See: https://learn.microsoft.com/en-us/windows/win32/wmisdk/wql-sql-for-wmi
        /// </summary>
        /// <param name="value">The string value to escape.</param>
        /// <returns>The escaped string safe for use in WMI queries.</returns>
        private static string EscapeWmiString(string value)
        {
            if (string.IsNullOrEmpty(value))
            {
                return value;
            }

            // WMI requires backslashes and single quotes to be escaped in WHERE clauses
            // Backslash must be escaped first to avoid double-escaping the quote's backslash
            return value.Replace("\\", "\\\\").Replace("'", "\\'");
        }

        /// <summary>
        /// Extract hardware ID from WMI InstanceName.
        /// InstanceName format: "DISPLAY\BOE0900\4&amp;10fd3ab1&amp;0&amp;UID265988_0"
        /// Returns the second segment (e.g., "BOE0900") which is the manufacturer+product code.
        /// </summary>
        /// <param name="instanceName">The WMI InstanceName.</param>
        /// <returns>The hardware ID extracted from the InstanceName, or empty string if extraction fails.</returns>
        private static string ExtractHardwareIdFromInstanceName(string instanceName)
        {
            if (string.IsNullOrEmpty(instanceName))
            {
                return string.Empty;
            }

            // Split by backslash: ["DISPLAY", "BOE0900", "4&10fd3ab1&0&UID265988_0"]
            var parts = instanceName.Split('\\');
            if (parts.Length >= 2 && !string.IsNullOrEmpty(parts[1]))
            {
                // Return the second part (e.g., "BOE0900")
                return parts[1];
            }

            return string.Empty;
        }

        /// <summary>
        /// Get monitor number from MonitorDisplayInfo dictionary by matching HardwareId.
        /// Uses QueryDisplayConfig path index which matches Windows Display Settings "Identify" feature.
        /// </summary>
        /// <param name="hardwareId">The hardware ID to match (e.g., "LEN4038", "BOE0900").</param>
        /// <param name="monitorDisplayInfos">Dictionary of monitor display info from QueryDisplayConfig.</param>
        /// <returns>Monitor number (1-based) or 0 if not found.</returns>
        private static int GetMonitorNumberFromDisplayInfo(string hardwareId, Dictionary<string, Drivers.DDC.MonitorDisplayInfo> monitorDisplayInfos)
        {
            if (string.IsNullOrEmpty(hardwareId) || monitorDisplayInfos == null || monitorDisplayInfos.Count == 0)
            {
                return 0;
            }

            foreach (var kvp in monitorDisplayInfos)
            {
                if (!string.IsNullOrEmpty(kvp.Value.HardwareId) &&
                    kvp.Value.HardwareId.Equals(hardwareId, StringComparison.OrdinalIgnoreCase))
                {
                    Logger.LogDebug($"WMI: Matched HardwareId '{hardwareId}' to MonitorNumber {kvp.Value.MonitorNumber}");
                    return kvp.Value.MonitorNumber;
                }
            }

            Logger.LogWarning($"WMI: Could not find MonitorNumber for HardwareId '{hardwareId}'");
            return 0;
        }

        public string Name => "WMI Monitor Controller (WmiLight)";

        /// <summary>
        /// Check if the specified monitor can be controlled.
        /// Verifies the specific monitor exists in WMI by filtering on InstanceName.
        /// </summary>
        public async Task<bool> CanControlMonitorAsync(Monitor monitor, CancellationToken cancellationToken = default)
        {
            ArgumentNullException.ThrowIfNull(monitor);

            if (monitor.CommunicationMethod != "WMI")
            {
                return false;
            }

            // If no InstanceName, we can't verify the specific monitor
            if (string.IsNullOrEmpty(monitor.InstanceName))
            {
                return false;
            }

            return await Task.Run(
                () =>
                {
                    try
                    {
                        using var connection = new WmiConnection(WmiNamespace);

                        // Filter by InstanceName to verify this specific monitor exists
                        var escapedInstanceName = EscapeWmiString(monitor.InstanceName);
                        var query = $"SELECT InstanceName FROM {BrightnessQueryClass} WHERE InstanceName = '{escapedInstanceName}'";
                        var results = connection.CreateQuery(query).ToList();
                        return results.Count > 0;
                    }
                    catch (Exception ex)
                    {
                        Logger.LogWarning($"WMI CanControlMonitor check failed for '{monitor.InstanceName}': {ex.Message}");
                        return false;
                    }
                },
                cancellationToken);
        }

        /// <summary>
        /// Get monitor brightness
        /// </summary>
        public async Task<BrightnessInfo> GetBrightnessAsync(Monitor monitor, CancellationToken cancellationToken = default)
        {
            ArgumentNullException.ThrowIfNull(monitor);

            return await Task.Run(
                () =>
                {
                    try
                    {
                        using var connection = new WmiConnection(WmiNamespace);

                        // Filter by InstanceName to target the specific monitor
                        var escapedInstanceName = EscapeWmiString(monitor.InstanceName);
                        var query = $"SELECT CurrentBrightness FROM {BrightnessQueryClass} WHERE InstanceName = '{escapedInstanceName}'";
                        var results = connection.CreateQuery(query);

                        foreach (var obj in results)
                        {
                            var currentBrightness = obj.GetPropertyValue<byte>("CurrentBrightness");
                            return new BrightnessInfo(currentBrightness, 0, 100);
                        }

                        // No match found - monitor may have been disconnected
                        Logger.LogDebug($"WMI GetBrightness: No monitor found with InstanceName '{monitor.InstanceName}'");
                    }
                    catch (WmiException ex)
                    {
                        Logger.LogWarning($"WMI GetBrightness failed: {ex.Message} (HResult: 0x{ex.HResult:X})");
                    }
                    catch (Exception ex)
                    {
                        Logger.LogWarning($"WMI GetBrightness failed: {ex.Message}");
                    }

                    return BrightnessInfo.Invalid;
                },
                cancellationToken);
        }

        /// <summary>
        /// Set monitor brightness
        /// </summary>
        public async Task<MonitorOperationResult> SetBrightnessAsync(Monitor monitor, int brightness, CancellationToken cancellationToken = default)
        {
            ArgumentNullException.ThrowIfNull(monitor);

            // Validate brightness range
            brightness = Math.Clamp(brightness, 0, 100);

            return await Task.Run(
                () =>
                {
                    try
                    {
                        using var connection = new WmiConnection(WmiNamespace);

                        // Filter by InstanceName to target the specific monitor
                        var escapedInstanceName = EscapeWmiString(monitor.InstanceName);
                        var query = $"SELECT * FROM {BrightnessMethodClass} WHERE InstanceName = '{escapedInstanceName}'";
                        var results = connection.CreateQuery(query);

                        foreach (var obj in results)
                        {
                            // Call WmiSetBrightness method
                            // Parameters: Timeout (uint32), Brightness (uint8)
                            // Note: WmiLight requires string values for method parameters
                            using (WmiMethod method = obj.GetMethod("WmiSetBrightness"))
                            using (WmiMethodParameters inParams = method.CreateInParameters())
                            {
                                inParams.SetPropertyValue("Timeout", "0");
                                inParams.SetPropertyValue("Brightness", brightness.ToString(CultureInfo.InvariantCulture));

                                uint result = obj.ExecuteMethod<uint>(
                                    method,
                                    inParams,
                                    out WmiMethodParameters outParams);

                                // Check return value (0 indicates success)
                                if (result == 0)
                                {
                                    return MonitorOperationResult.Success();
                                }
                                else
                                {
                                    return MonitorOperationResult.Failure($"WMI method returned error code: {result}", (int)result);
                                }
                            }
                        }

                        // No match found - monitor may have been disconnected
                        Logger.LogWarning($"WMI SetBrightness: No monitor found with InstanceName '{monitor.InstanceName}'");
                        return MonitorOperationResult.Failure($"No WMI brightness method found for monitor '{monitor.InstanceName}'");
                    }
                    catch (UnauthorizedAccessException)
                    {
                        return MonitorOperationResult.Failure("Access denied. Administrator privileges may be required.", 5);
                    }
                    catch (WmiException ex)
                    {
                        return ClassifyWmiError(ex, "SetBrightness");
                    }
                    catch (Exception ex)
                    {
                        return MonitorOperationResult.Failure($"Unexpected error during SetBrightness: {ex.Message}");
                    }
                },
                cancellationToken);
        }

        /// <summary>
        /// Discover supported monitors
        /// </summary>
        public async Task<IEnumerable<Monitor>> DiscoverMonitorsAsync(CancellationToken cancellationToken = default)
        {
            return await Task.Run(
                () =>
                {
                var monitors = new List<Monitor>();

                try
                {
                    using var connection = new WmiConnection(WmiNamespace);

                    // First check if WMI brightness support is available
                    var brightnessQuery = $"SELECT * FROM {BrightnessQueryClass}";
                    var brightnessResults = connection.CreateQuery(brightnessQuery).ToList();

                    if (brightnessResults.Count == 0)
                    {
                        return monitors;
                    }

                    // Get monitor information
                    var idQuery = $"SELECT * FROM {MonitorIdClass}";
                    var idResults = connection.CreateQuery(idQuery).ToList();

                    var monitorInfos = new Dictionary<string, (string Name, string InstanceName)>();

                    foreach (var obj in idResults)
                    {
                        try
                        {
                            var instanceName = obj.GetPropertyValue<string>("InstanceName") ?? string.Empty;
                            var userFriendlyName = GetUserFriendlyName(obj) ?? "Internal Display";

                            if (!string.IsNullOrEmpty(instanceName))
                            {
                                monitorInfos[instanceName] = (userFriendlyName, instanceName);
                            }
                        }
                        catch (Exception ex)
                        {
                            // Skip problematic entries
                            Logger.LogDebug($"Failed to parse WMI monitor info: {ex.Message}");
                        }
                    }

                    // Get MonitorDisplayInfo from QueryDisplayConfig - this provides the correct monitor numbers
                    var monitorDisplayInfos = Drivers.DDC.DdcCiNative.GetAllMonitorDisplayInfo();

                    // Create monitor objects for each supported brightness instance
                    foreach (var obj in brightnessResults)
                    {
                        try
                        {
                            var instanceName = obj.GetPropertyValue<string>("InstanceName") ?? string.Empty;
                            var currentBrightness = obj.GetPropertyValue<byte>("CurrentBrightness");

                            var name = "Internal Display";
                            if (monitorInfos.TryGetValue(instanceName, out var info))
                            {
                                name = info.Name;
                            }

                            // Extract EdidId from InstanceName
                            // e.g., "DISPLAY\BOE0900\4&10fd3ab1&0&UID265988_0" -> "BOE0900"
                            var edidId = ExtractHardwareIdFromInstanceName(instanceName);

                            // Get MonitorNumber from QueryDisplayConfig by matching EdidId
                            // This matches Windows Display Settings "Identify" feature
                            int monitorNumber = GetMonitorNumberFromDisplayInfo(edidId, monitorDisplayInfos);

                            // Generate unique monitor Id: "WMI_{EdidId}_{MonitorNumber}"
                            string monitorId = !string.IsNullOrEmpty(edidId)
                                ? $"WMI_{edidId}_{monitorNumber}"
                                : $"WMI_Unknown_{monitorNumber}";

                            var monitor = new Monitor
                            {
                                Id = monitorId,
                                Name = name,
                                CurrentBrightness = currentBrightness,
                                MinBrightness = 0,
                                MaxBrightness = 100,
                                IsAvailable = true,
                                InstanceName = instanceName,
                                Capabilities = MonitorCapabilities.Brightness | MonitorCapabilities.Wmi,
                                ConnectionType = "Internal",
                                CommunicationMethod = "WMI",
                                Manufacturer = edidId.Length >= 3 ? edidId.Substring(0, 3) : "Internal",
                                SupportsColorTemperature = false,
                                MonitorNumber = monitorNumber,
                            };

                            monitors.Add(monitor);
                        }
                        catch (Exception ex)
                        {
                            // Skip problematic monitors
                            Logger.LogWarning($"Failed to create monitor from WMI data: {ex.Message}");
                        }
                    }
                }
                catch (WmiException ex)
                {
                    // Return empty list instead of throwing exception
                    Logger.LogError($"WMI DiscoverMonitors failed: {ex.Message} (HResult: 0x{ex.HResult:X})");
                }
                catch (Exception ex)
                {
                    Logger.LogError($"WMI DiscoverMonitors failed: {ex.Message}");
                }

                return monitors;
            },
                cancellationToken);
        }

        /// <summary>
        /// Get user-friendly name from WMI object.
        /// WmiMonitorID returns UserFriendlyName as a fixed-size uint16 array buffer,
        /// with UserFriendlyNameLength indicating the actual character count.
        /// </summary>
        private static string? GetUserFriendlyName(WmiObject monitorObject)
        {
            try
            {
                var userFriendlyName = monitorObject.GetPropertyValue<ushort[]>("UserFriendlyName");
                var nameLength = monitorObject.GetPropertyValue<ushort>("UserFriendlyNameLength");

                if (userFriendlyName != null && nameLength > 0 && nameLength <= userFriendlyName.Length)
                {
                    // Use UserFriendlyNameLength to extract only valid characters
                    var chars = userFriendlyName
                        .Take(nameLength)
                        .Select(c => (char)c)
                        .ToArray();

                    if (chars.Length > 0)
                    {
                        return new string(chars).Trim();
                    }
                }
            }
            catch (Exception ex)
            {
                Logger.LogDebug($"Failed to parse UserFriendlyName: {ex.Message}");
            }

            return null;
        }

        /// <summary>
        /// Check WMI service availability
        /// </summary>
        public static bool IsWmiAvailable()
        {
            try
            {
                using var connection = new WmiConnection(WmiNamespace);
                var query = $"SELECT * FROM {BrightnessQueryClass}";
                var results = connection.CreateQuery(query).ToList();
                return results.Count > 0;
            }
            catch (WmiException ex) when (IsExpectedUnsupportedError(ex))
            {
                // Expected on systems without WMI brightness support (desktops, some laptops)
                Logger.LogInfo("WMI brightness control not supported on this system (expected for desktops)");
                return false;
            }
            catch (WmiException ex)
            {
                // Unexpected WMI error - log with details for debugging
                Logger.LogWarning($"WMI availability check failed: {ex.Message} (HResult: 0x{ex.HResult:X})");
                return false;
            }
            catch (Exception ex)
            {
                // Unexpected non-WMI error
                Logger.LogDebug($"WMI availability check failed: {ex.Message}");
                return false;
            }
        }

        // Extended features not supported by WMI
        public Task<MonitorOperationResult> SetContrastAsync(Monitor monitor, int contrast, CancellationToken cancellationToken = default)
        {
            return Task.FromResult(MonitorOperationResult.Failure("Contrast control not supported via WMI"));
        }

        public Task<MonitorOperationResult> SetVolumeAsync(Monitor monitor, int volume, CancellationToken cancellationToken = default)
        {
            return Task.FromResult(MonitorOperationResult.Failure("Volume control not supported via WMI"));
        }

        public Task<BrightnessInfo> GetColorTemperatureAsync(Monitor monitor, CancellationToken cancellationToken = default)
        {
            return Task.FromResult(BrightnessInfo.Invalid);
        }

        public Task<MonitorOperationResult> SetColorTemperatureAsync(Monitor monitor, int colorTemperature, CancellationToken cancellationToken = default)
        {
            return Task.FromResult(MonitorOperationResult.Failure("Color temperature control not supported via WMI"));
        }

        public Task<BrightnessInfo> GetInputSourceAsync(Monitor monitor, CancellationToken cancellationToken = default)
        {
            // Input source switching not supported for internal displays
            return Task.FromResult(BrightnessInfo.Invalid);
        }

        public Task<MonitorOperationResult> SetInputSourceAsync(Monitor monitor, int inputSource, CancellationToken cancellationToken = default)
        {
            // Input source switching not supported for internal displays
            return Task.FromResult(MonitorOperationResult.Failure("Input source switching not supported via WMI"));
        }

        public Task<string> GetCapabilitiesStringAsync(Monitor monitor, CancellationToken cancellationToken = default)
        {
            return Task.FromResult(string.Empty);
        }

        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        protected virtual void Dispose(bool disposing)
        {
            if (!_disposed && disposing)
            {
                // WmiLight objects are automatically cleaned up, no specific cleanup needed here
                _disposed = true;
            }
        }
    }
}