using System;
using System.Runtime.InteropServices;

namespace PluginListener
{
    public class WinAPI_Interop
    {
        public static IntPtr WTS_CURRENT_SERVER_HANDLE = IntPtr.Zero;
        /// <summary>
        /// 服务程序执行消息提示,前台MessageBox.Show
        /// </summary>
        /// <param name="message">消息内容</param>
        /// <param name="title">标题</param>
        public static void ShowServiceMessage(string message, string title)
        {
            int resp = 0;
            WTSSendMessage(WTS_CURRENT_SERVER_HANDLE, WTSGetActiveConsoleSessionId(), title, title.Length, message, message.Length, 0, 0, out resp, false);
        }

        [DllImport("kernel32.dll", SetLastError = true)]
        public static extern int WTSGetActiveConsoleSessionId();

        [DllImport("wtsapi32.dll", SetLastError = true)]
        public static extern bool WTSSendMessage(IntPtr hServer, int SessionId, String pTitle, int TitleLength, String pMessage, int MessageLength, int Style, int Timeout, out int pResponse, bool bWait);
        #region P/Invoke WTS APIs
        private enum WTS_CONNECTSTATE_CLASS
        {
            WTSActive,
            WTSConnected,
            WTSConnectQuery,
            WTSShadow,
            WTSDisconnected,
            WTSIdle,
            WTSListen,
            WTSReset,
            WTSDown,
            WTSInit
        }

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
        private struct WTS_SESSION_INFO
        {
            public UInt32 SessionID;
            public string pWinStationName;
            public WTS_CONNECTSTATE_CLASS State;
        }

        [DllImport("WTSAPI32.DLL", SetLastError = true, CharSet = CharSet.Auto)]
        static extern bool WTSEnumerateSessions(
            IntPtr hServer,
            [MarshalAs(UnmanagedType.U4)] UInt32 Reserved,
            [MarshalAs(UnmanagedType.U4)] UInt32 Version,
            ref IntPtr ppSessionInfo,
            [MarshalAs(UnmanagedType.U4)] ref UInt32 pSessionInfoCount
            );

        [DllImport("WTSAPI32.DLL", SetLastError = true, CharSet = CharSet.Auto)]
        static extern void WTSFreeMemory(IntPtr pMemory);

        [DllImport("WTSAPI32.DLL", SetLastError = true, CharSet = CharSet.Auto)]
        static extern bool WTSQueryUserToken(UInt32 sessionId, out IntPtr Token);
        #endregion

        #region P/Invoke CreateProcessAsUser
        /// <summary> 
        /// Struct, Enum and P/Invoke Declarations for CreateProcessAsUser. 
        /// </summary> 
        ///  

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
        struct STARTUPINFO
        {
            public Int32 cb;
            public string lpReserved;
            public string lpDesktop;
            public string lpTitle;
            public Int32 dwX;
            public Int32 dwY;
            public Int32 dwXSize;
            public Int32 dwYSize;
            public Int32 dwXCountChars;
            public Int32 dwYCountChars;
            public Int32 dwFillAttribute;
            public Int32 dwFlags;
            public Int16 wShowWindow;
            public Int16 cbReserved2;
            public IntPtr lpReserved2;
            public IntPtr hStdInput;
            public IntPtr hStdOutput;
            public IntPtr hStdError;
        }

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
        struct PROCESS_INFORMATION
        {
            public IntPtr hProcess;
            public IntPtr hThread;
            public int dwProcessId;
            public int dwThreadId;
        }

        /// <summary>
        /// 以当前登录的windows用户(角色权限)运行指定程序进程
        /// </summary>
        /// <param name="hToken"></param>
        /// <param name="lpApplicationName">指定程序(全路径)</param>
        /// <param name="lpCommandLine">参数</param>
        /// <param name="lpProcessAttributes">进程属性</param>
        /// <param name="lpThreadAttributes">线程属性</param>
        /// <param name="bInheritHandles"></param>
        /// <param name="dwCreationFlags"></param>
        /// <param name="lpEnvironment"></param>
        /// <param name="lpCurrentDirectory"></param>
        /// <param name="lpStartupInfo">程序启动属性</param>
        /// <param name="lpProcessInformation">最后返回的进程信息</param>
        /// <returns>是否调用成功</returns>
        [DllImport("ADVAPI32.DLL", SetLastError = true, CharSet = CharSet.Auto)]
        static extern bool CreateProcessAsUser(IntPtr hToken, string lpApplicationName, string lpCommandLine, IntPtr lpProcessAttributes, IntPtr lpThreadAttributes,
                                                      bool bInheritHandles, uint dwCreationFlags, string lpEnvironment, string lpCurrentDirectory,
                                                      ref STARTUPINFO lpStartupInfo, out PROCESS_INFORMATION lpProcessInformation);

        [DllImport("KERNEL32.DLL", SetLastError = true, CharSet = CharSet.Auto)]
        static extern bool CloseHandle(IntPtr hHandle);
        #endregion

        /// <summary>
        /// 以当前登录系统的用户角色权限启动指定的进程
        /// </summary>
        /// <param name="ChildProcName">指定的进程(全路径)</param>
        public static void CreateProcess(string ChildProcName)
        {
            IntPtr ppSessionInfo = IntPtr.Zero;
            UInt32 SessionCount = 0;
            if (WTSEnumerateSessions(
                                    (IntPtr)WTS_CURRENT_SERVER_HANDLE,  // Current RD Session Host Server handle would be zero. 
                                    0,  // This reserved parameter must be zero. 
                                    1,  // The version of the enumeration request must be 1. 
                                    ref ppSessionInfo, // This would point to an array of session info. 
                                    ref SessionCount  // This would indicate the length of the above array.
                                    ))
            {
                for (int nCount = 0; nCount < SessionCount; nCount++)
                {
                    WTS_SESSION_INFO tSessionInfo = (WTS_SESSION_INFO)Marshal.PtrToStructure(ppSessionInfo + nCount * Marshal.SizeOf(typeof(WTS_SESSION_INFO)), typeof(WTS_SESSION_INFO));
                    if (WTS_CONNECTSTATE_CLASS.WTSActive == tSessionInfo.State)
                    {
                        IntPtr hToken = IntPtr.Zero;
                        if (WTSQueryUserToken(tSessionInfo.SessionID, out hToken))
                        {
                            PROCESS_INFORMATION tProcessInfo;
                            STARTUPINFO tStartUpInfo = new STARTUPINFO();
                            tStartUpInfo.cb = Marshal.SizeOf(typeof(STARTUPINFO));
                            bool ChildProcStarted = CreateProcessAsUser(
                                                                        hToken,             // Token of the logged-on user. 
                                                                        ChildProcName,      // Name of the process to be started. 
                                                                        null,               // Any command line arguments to be passed. 
                                                                        IntPtr.Zero,        // Default Process' attributes. 
                                                                        IntPtr.Zero,        // Default Thread's attributes. 
                                                                        false,              // Does NOT inherit parent's handles. 
                                                                        0,                  // No any specific creation flag. 
                                                                        null,               // Default environment path. 
                                                                        null,               // Default current directory. 
                                                                        ref tStartUpInfo,   // Process Startup Info.  
                                                                        out tProcessInfo    // Process information to be returned. 
                                                     );
                            if (ChildProcStarted)
                            {
                                CloseHandle(tProcessInfo.hThread);
                                CloseHandle(tProcessInfo.hProcess);
                            }
                            else
                            {
                                ShowServiceMessage("CreateProcessAsUser失败", "CreateProcess");
                            }
                            CloseHandle(hToken);
                            break;
                        }
                    }
                }
                WTSFreeMemory(ppSessionInfo);
            }
        }
    }
}