using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Threading;
using RGB.NET.Core;
using RGB.NET.Devices.Wooting.Enum;
using RGB.NET.Devices.Wooting.Generic;
using RGB.NET.Devices.Wooting.Keyboard;
using RGB.NET.Devices.Wooting.Keypad;
using RGB.NET.Devices.Wooting.Native;

namespace RGB.NET.Devices.Wooting;

/// <inheritdoc />
/// <summary>
/// Represents a device provider responsible for Wooting devices.
/// </summary>
public sealed class WootingDeviceProvider : AbstractRGBDeviceProvider
{
    #region Properties & Fields

    // ReSharper disable once InconsistentNaming
    private static readonly Lock _lock = new();

    private static WootingDeviceProvider? _instance;
    /// <summary>
    /// Gets the singleton <see cref="WootingDeviceProvider"/> instance.
    /// </summary>
    public static WootingDeviceProvider Instance
    {
        get
        {
            lock (_lock)
                return _instance ?? new WootingDeviceProvider();
        }
    }

    /// <summary>
    /// Gets a modifiable list of paths used to find the native SDK-dlls for x86 windows applications.
    /// The first match will be used.
    /// </summary>
    public static List<string> PossibleX86NativePathsWindows { get; } = ["x86/wooting-rgb-sdk.dll"];

    /// <summary>
    /// Gets a modifiable list of paths used to find the native SDK-dlls for x64 windows applications.
    /// The first match will be used.
    /// </summary>
    public static List<string> PossibleX64NativePathsWindows { get; } = ["x64/wooting-rgb-sdk64.dll"];

    /// <summary>
    /// Gets a modifiable list of paths used to find the native SDK-dlls for x64 linux applications.
    /// The first match will be used.
    /// </summary>
    public static List<string> PossibleNativePathsLinux { get; } = ["x64/libwooting-rgb-sdk.so"];

    /// <summary>
    /// Gets a modifiable list of paths used to find the native SDK-dlls for x64 MacOS applications.
    /// The first match will be used.
    /// </summary>
    // ReSharper disable once InconsistentNaming
    public static List<string> PossibleNativePathsMacOS { get; } = ["x64/libwooting-rgb-sdk.dylib"];

    #endregion

    #region Constructors

    /// <summary>
    /// Initializes a new instance of the <see cref="WootingDeviceProvider"/> class.
    /// </summary>
    /// <exception cref="InvalidOperationException">Thrown if this constructor is called even if there is already an instance of this class.</exception>
    public WootingDeviceProvider()
    {
        lock (_lock)
        {
            if (_instance != null) throw new InvalidOperationException($"There can be only one instance of type {nameof(WootingDeviceProvider)}");
            _instance = this;
        }
    }

    #endregion

    #region Methods

    /// <inheritdoc />
    protected override void InitializeSDK()
    {
        lock (_WootingSDK.SdkLock)
        {
            _WootingSDK.Reload();
        }
    }

    /// <inheritdoc />
    protected override IEnumerable<IRGBDevice> LoadDevices()
    {
        lock (_WootingSDK.SdkLock)
        {
            if (_WootingSDK.KeyboardConnected())
            {
                for (byte i = 0; i < _WootingSDK.GetDeviceCount(); i++)
                {
                    WootingUpdateQueue updateQueue = new(GetUpdateTrigger(), i);
                    _WootingSDK.SelectDevice(i);
                    _WootingDeviceInfo nativeDeviceInfo = (_WootingDeviceInfo)Marshal.PtrToStructure(_WootingSDK.GetDeviceInfo(), typeof(_WootingDeviceInfo))!;
                    
                    //Uwu non-rgb returns zero here.
                    if (nativeDeviceInfo.MaxLedIndex == 0)
                        continue;

                    yield return nativeDeviceInfo.DeviceType switch
                    {
                        WootingDeviceType.Keypad3Keys => new WootingKeypadRGBDevice(new WootingKeypadRGBDeviceInfo(nativeDeviceInfo, i), updateQueue),
                        _ => new WootingKeyboardRGBDevice(new WootingKeyboardRGBDeviceInfo(nativeDeviceInfo, i), updateQueue),
                    };
                }
            }
        }
    }

    /// <inheritdoc />
    protected override void Dispose(bool disposing)
    {
        lock (_lock)
        {
            base.Dispose(disposing);

            lock (_WootingSDK.SdkLock)
            {
                try { _WootingSDK.UnloadWootingSDK(); }
                catch { /* at least we tried */ }
            }

            _instance = null;
        }
    }

    #endregion
}