// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT license.

using System;
using System.Runtime.InteropServices;

namespace Microsoft.ClearScript.Util
{
    [StructLayout(LayoutKind.Sequential)]
    internal struct SystemInfo
    {
        public ushort ProcessorArchitecture;
        public ushort Reserved;
        public uint PageSize;
        public IntPtr MinimumApplicationAddress;
        public IntPtr MaximumApplicationAddress;
        public IntPtr ActiveProcessorMask;
        public uint NumberOfProcessors;
        public uint ProcessorType;
        public uint AllocationGranularity;
        public ushort ProcessorLevel;
        public ushort ProcessorRevision;
    }

    internal static class NativeMethods
    {
        [DllImport("kernel32", ExactSpelling = true, SetLastError = true)]
        public static extern IntPtr LoadLibraryW(
            [In] [MarshalAs(UnmanagedType.LPWStr)] string path
        );

        [DllImport("kernel32.dll", SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        public static extern bool FreeLibrary(
            [In] IntPtr hLibrary
        );

        [DllImport("ole32.dll", ExactSpelling = true)]
        public static extern uint CLSIDFromProgID(
            [In] [MarshalAs(UnmanagedType.LPWStr)] string progID,
            [Out] out Guid clsid
        );

        [DllImport("ole32.dll", ExactSpelling = true)]
        public static extern uint CoCreateInstance(
            [In] ref Guid clsid,
            [In] IntPtr pOuter,
            [In] uint clsContext,
            [In] ref Guid iid,
            [Out] out IntPtr pInterface
        );

        [DllImport("oleaut32.dll", ExactSpelling = true)]
        public static extern void VariantInit(
            [In] IntPtr pVariant
        );

        [DllImport("oleaut32.dll", ExactSpelling = true)]
        public static extern uint VariantClear(
            [In] IntPtr pVariant
        );

        [DllImport("kernel32.dll", SetLastError = true)]
        public static extern IntPtr HeapCreate(
            [In] uint options,
            [In] UIntPtr initialSize,
            [In] UIntPtr maximumSize
        );

        [DllImport("kernel32.dll", SetLastError = false)]
        public static extern IntPtr HeapAlloc(
            [In] IntPtr hHeap,
            [In] uint flags,
            [In] UIntPtr size
        );

        [DllImport("kernel32.dll", SetLastError = true)]
        public static extern bool HeapFree(
            [In] IntPtr hHeap,
            [In] uint flags,
            [In] IntPtr pBlock
        );

        [DllImport("kernel32.dll", SetLastError = true)]
        public static extern bool HeapDestroy(
            [In] IntPtr hHeap
        );

        [DllImport("kernel32.dll", SetLastError = true)]
        public static extern bool VirtualProtect(
            [In] IntPtr pBlock,
            [In] UIntPtr size,
            [In] uint newProtect,
            [Out] out uint oldProtect
        );

        [DllImport("kernel32.dll", SetLastError = false)]
        public static extern void GetSystemInfo(
            [Out] out SystemInfo info
        );

        [DllImport("kernel32.dll")]
        public static extern void GetNativeSystemInfo(
            [Out] out SystemInfo info
        );
    }
}