// Mozilla Public License 2.0
// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// Copyright (C) LibreHardwareMonitor and Contributors
// All Rights Reserved

using System;
using System.Runtime.InteropServices;
using LibreHardwareMonitor.Interop;

namespace LibreHardwareMonitor.Hardware.Storage
{
    internal class NVMeWindows : INVMeDrive
    {
        //windows generic driver nvme access

        public SafeHandle Identify(StorageInfo storageInfo)
        {
            return IdentifyDevice(storageInfo);
        }

        public bool IdentifyController(SafeHandle hDevice, out Kernel32.NVME_IDENTIFY_CONTROLLER_DATA data)
        {
            data = Kernel32.CreateStruct<Kernel32.NVME_IDENTIFY_CONTROLLER_DATA>();
            if (hDevice == null || hDevice.IsInvalid)
                return false;

            bool result = false;
            Kernel32.STORAGE_QUERY_BUFFER nptwb = Kernel32.CreateStruct<Kernel32.STORAGE_QUERY_BUFFER>();
            nptwb.ProtocolSpecific.ProtocolType = Kernel32.STORAGE_PROTOCOL_TYPE.ProtocolTypeNvme;
            nptwb.ProtocolSpecific.DataType = (uint)Kernel32.STORAGE_PROTOCOL_NVME_DATA_TYPE.NVMeDataTypeIdentify;
            nptwb.ProtocolSpecific.ProtocolDataOffset = (uint)Marshal.SizeOf<Kernel32.STORAGE_PROTOCOL_SPECIFIC_DATA>();
            nptwb.ProtocolSpecific.ProtocolDataLength = (uint)nptwb.Buffer.Length;
            nptwb.PropertyId = Kernel32.STORAGE_PROPERTY_ID.StorageAdapterProtocolSpecificProperty;
            nptwb.QueryType = Kernel32.STORAGE_QUERY_TYPE.PropertyStandardQuery;

            int length = Marshal.SizeOf<Kernel32.STORAGE_QUERY_BUFFER>();
            IntPtr buffer = Marshal.AllocHGlobal(length);
            Marshal.StructureToPtr(nptwb, buffer, false);
            bool validTransfer = Kernel32.DeviceIoControl(hDevice, Kernel32.IOCTL.IOCTL_STORAGE_QUERY_PROPERTY, buffer, length, buffer, length, out _, IntPtr.Zero);
            if (validTransfer)
            {
                //map NVME_IDENTIFY_CONTROLLER_DATA to nptwb.Buffer
                var offset = Marshal.OffsetOf<Kernel32.STORAGE_QUERY_BUFFER>(nameof(Kernel32.STORAGE_QUERY_BUFFER.Buffer));
                var newPtr = IntPtr.Add(buffer, offset.ToInt32());
                var item = Marshal.PtrToStructure<Kernel32.NVME_IDENTIFY_CONTROLLER_DATA>(newPtr);
                data = item;
                Marshal.FreeHGlobal(buffer);
                result = true;
            }
            else
            {
                Marshal.FreeHGlobal(buffer);
            }

            return result;
        }

        public bool HealthInfoLog(SafeHandle hDevice, out Kernel32.NVME_HEALTH_INFO_LOG data)
        {
            data = Kernel32.CreateStruct<Kernel32.NVME_HEALTH_INFO_LOG>();
            if (hDevice == null || hDevice.IsInvalid)
                return false;

            bool result = false;
            Kernel32.STORAGE_QUERY_BUFFER nptwb = Kernel32.CreateStruct<Kernel32.STORAGE_QUERY_BUFFER>();
            nptwb.ProtocolSpecific.ProtocolType = Kernel32.STORAGE_PROTOCOL_TYPE.ProtocolTypeNvme;
            nptwb.ProtocolSpecific.DataType = (uint)Kernel32.STORAGE_PROTOCOL_NVME_DATA_TYPE.NVMeDataTypeLogPage;
            nptwb.ProtocolSpecific.ProtocolDataRequestValue = (uint)Kernel32.NVME_LOG_PAGES.NVME_LOG_PAGE_HEALTH_INFO;
            nptwb.ProtocolSpecific.ProtocolDataOffset = (uint)Marshal.SizeOf<Kernel32.STORAGE_PROTOCOL_SPECIFIC_DATA>();
            nptwb.ProtocolSpecific.ProtocolDataLength = (uint)nptwb.Buffer.Length;
            nptwb.PropertyId = Kernel32.STORAGE_PROPERTY_ID.StorageAdapterProtocolSpecificProperty;
            nptwb.QueryType = Kernel32.STORAGE_QUERY_TYPE.PropertyStandardQuery;

            int length = Marshal.SizeOf<Kernel32.STORAGE_QUERY_BUFFER>();
            IntPtr buffer = Marshal.AllocHGlobal(length);
            Marshal.StructureToPtr(nptwb, buffer, false);
            bool validTransfer = Kernel32.DeviceIoControl(hDevice, Kernel32.IOCTL.IOCTL_STORAGE_QUERY_PROPERTY, buffer, length, buffer, length, out _, IntPtr.Zero);
            if (validTransfer)
            {
                //map NVME_HEALTH_INFO_LOG to nptwb.Buffer
                var offset = Marshal.OffsetOf<Kernel32.STORAGE_QUERY_BUFFER>(nameof(Kernel32.STORAGE_QUERY_BUFFER.Buffer));
                var newPtr = IntPtr.Add(buffer, offset.ToInt32());
                var item = Marshal.PtrToStructure<Kernel32.NVME_HEALTH_INFO_LOG>(newPtr);
                data = item;
                Marshal.FreeHGlobal(buffer);
                result = true;
            }
            else
            {
                Marshal.FreeHGlobal(buffer);
            }

            return result;
        }

        public static SafeHandle IdentifyDevice(StorageInfo storageInfo)
        {
            var handle = Kernel32.OpenDevice(storageInfo.DeviceId);
            if (handle == null || handle.IsInvalid)
                return null;


            Kernel32.STORAGE_QUERY_BUFFER nptwb = Kernel32.CreateStruct<Kernel32.STORAGE_QUERY_BUFFER>();
            nptwb.ProtocolSpecific.ProtocolType = Kernel32.STORAGE_PROTOCOL_TYPE.ProtocolTypeNvme;
            nptwb.ProtocolSpecific.DataType = (uint)Kernel32.STORAGE_PROTOCOL_NVME_DATA_TYPE.NVMeDataTypeIdentify;
            nptwb.ProtocolSpecific.ProtocolDataOffset = (uint)Marshal.SizeOf<Kernel32.STORAGE_PROTOCOL_SPECIFIC_DATA>();
            nptwb.ProtocolSpecific.ProtocolDataLength = (uint)nptwb.Buffer.Length;
            nptwb.PropertyId = Kernel32.STORAGE_PROPERTY_ID.StorageAdapterProtocolSpecificProperty;
            nptwb.QueryType = Kernel32.STORAGE_QUERY_TYPE.PropertyStandardQuery;

            int length = Marshal.SizeOf<Kernel32.STORAGE_QUERY_BUFFER>();
            IntPtr buffer = Marshal.AllocHGlobal(length);
            Marshal.StructureToPtr(nptwb, buffer, false);
            bool validTransfer = Kernel32.DeviceIoControl(handle, Kernel32.IOCTL.IOCTL_STORAGE_QUERY_PROPERTY, buffer, length, buffer, length, out _, IntPtr.Zero);
            if (validTransfer)
            {
                Marshal.FreeHGlobal(buffer);
            }
            else
            {
                Marshal.FreeHGlobal(buffer);
                handle.Close();
                handle = null;
            }

            return handle;
        }
    }
}