// ReSharper disable MemberCanBePrivate.Global
// ReSharper disable UnusedMember.Global

using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Runtime.InteropServices;
using RGB.NET.Core;
using RGB.NET.Core.Exceptions;
using RGB.NET.Devices.Corsair.Native;

namespace RGB.NET.Devices.Corsair
{
    /// <summary>
    /// Represents a device provider responsible for corsair (CUE) devices.
    /// </summary>
    public class CorsairDeviceProvider : IRGBDeviceProvider
    {
        #region Properties & Fields

        /// <summary>
        /// Gets the singleton <see cref="CorsairDeviceProvider"/> instance.
        /// </summary>
        public static CorsairDeviceProvider Instance { get; } = new CorsairDeviceProvider();

        /// <summary>
        /// Indicates if the SDK is initialized and ready to use.
        /// </summary>
        public bool IsInitialized { get; private set; }

        /// <summary>
        /// Gets the loaded architecture (x64/x86).
        /// </summary>
        public string LoadedArchitecture => _CUESDK.LoadedArchitecture;

        /// <summary>
        /// Gets the protocol details for the current SDK-connection.
        /// </summary>
        public CorsairProtocolDetails ProtocolDetails { get; private set; }

        /// <summary>
        /// Gets whether the application has exclusive access to the SDK or not.
        /// </summary>
        public bool HasExclusiveAccess { get; private set; }

        /// <summary>
        /// Gets the last error documented by CUE.
        /// </summary>
        public CorsairError LastError => _CUESDK.CorsairGetLastError();

        /// <inheritdoc />
        public IEnumerable<IRGBDevice> Devices { get; private set; }

        #endregion

        #region Constructors

        private CorsairDeviceProvider()
        { }

        #endregion

        #region Methods

        /// <inheritdoc />
        /// <exception cref="RGBDeviceException">Thrown if the SDK is already initialized or if the SDK is not compatible to CUE.</exception>
        /// <exception cref="CUEException">Thrown if the CUE-SDK provides an error.</exception>
        public bool Initialize(bool exclusiveAccessIfPossible = false, bool throwExceptions = false)
        {
            IsInitialized = false;

            try
            {
                _CUESDK.Reload();
            }
            catch
            {
                if (throwExceptions)
                    throw;
                else
                    return false;
            }

            ProtocolDetails = new CorsairProtocolDetails(_CUESDK.CorsairPerformProtocolHandshake());

            CorsairError error = LastError;
            if (error != CorsairError.Success)
            {
                Reset();
                if (throwExceptions)
                    throw new CUEException(error);
                else
                    return false;
            }

            if (ProtocolDetails.BreakingChanges)
            {
                Reset();
                if (throwExceptions)
                    throw new RGBDeviceException("The SDK currently used isn't compatible with the installed version of CUE.\r\n"
                                                 + $"CUE-Version: {ProtocolDetails.ServerVersion} (Protocol {ProtocolDetails.ServerProtocolVersion})\r\n"
                                                 + $"SDK-Version: {ProtocolDetails.SdkVersion} (Protocol {ProtocolDetails.SdkProtocolVersion})");
                else
                    return false;
            }

            if (exclusiveAccessIfPossible)
            {
                if (!_CUESDK.CorsairRequestControl(CorsairAccessMode.ExclusiveLightingControl))
                {
                    Reset();
                    if (throwExceptions)
                        throw new CUEException(LastError);
                    else
                        return false;
                }
                HasExclusiveAccess = true;
            }
            else
                HasExclusiveAccess = false;

            IList<IRGBDevice> devices = new List<IRGBDevice>();
            int deviceCount = _CUESDK.CorsairGetDeviceCount();
            for (int i = 0; i < deviceCount; i++)
            {
                _CorsairDeviceInfo nativeDeviceInfo =
                    (_CorsairDeviceInfo)Marshal.PtrToStructure(_CUESDK.CorsairGetDeviceInfo(i), typeof(_CorsairDeviceInfo));
                CorsairRGBDeviceInfo info = new CorsairRGBDeviceInfo(i, RGBDeviceType.Unknown, nativeDeviceInfo);
                if (!info.CapsMask.HasFlag(CorsairDeviceCaps.Lighting))
                    continue; // Everything that doesn't support lighting control is useless

                CorsairRGBDevice device;
                switch (info.CorsairDeviceType)
                {
                    case CorsairDeviceType.Keyboard:
                        device = new CorsairKeyboardRGBDevice(new CorsairKeyboardRGBDeviceInfo(i, nativeDeviceInfo));
                        break;
                    case CorsairDeviceType.Mouse:
                        device = new CorsairMouseRGBDevice(new CorsairMouseRGBDeviceInfo(i, nativeDeviceInfo));
                        break;
                    case CorsairDeviceType.Headset:
                        device = new CorsairHeadsetRGBDevice(new CorsairHeadsetRGBDeviceInfo(i, nativeDeviceInfo));
                        break;
                    case CorsairDeviceType.Mousemat:
                        device = new CorsairMousematRGBDevice(new CorsairMousematRGBDeviceInfo(i, nativeDeviceInfo));
                        break;
                    // ReSharper disable once RedundantCaseLabel
                    case CorsairDeviceType.Unknown:
                    default:
                        if (throwExceptions)
                            throw new RGBDeviceException("Unknown Device-Type");
                        else
                            continue;
                }

                try
                {
                    device.Initialize();
                }
                catch
                {
                    if (throwExceptions)
                        throw;
                    else
                        continue;
                }
                devices.Add(device);

                error = LastError;
                if (error != CorsairError.Success)
                {
                    Reset();
                    if (throwExceptions)
                        throw new CUEException(error);
                    else
                        return false;
                }
            }

            Devices = new ReadOnlyCollection<IRGBDevice>(devices);

            IsInitialized = true;

            return true;
        }

        /// <inheritdoc />
        public void ResetDevices()
        {
            if (IsInitialized)
                try
                {
                    _CUESDK.Reload();
                }
                catch
                {
                    // shit happens ...
                }
        }

        private void Reset()
        {
            ProtocolDetails = null;
            HasExclusiveAccess = false;
            Devices = null;
            IsInitialized = false;
        }

        #endregion
    }
}