using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;

namespace CredentialsPrompt
{
    internal class CredentialsPromptHelper
    {
        [DllImport("ole32.dll")]
        internal static extern void CoTaskMemFree(IntPtr ptr);

        [DllImport("credui.dll", CharSet = CharSet.Unicode)]
        internal static extern uint CredUIPromptForWindowsCredentials(ref CREDUI_INFO notUsedHere,
            int authError,
            ref uint authPackage,
            IntPtr InAuthBuffer,
            uint InAuthBufferSize,
            out IntPtr refOutAuthBuffer,
            out uint refOutAuthBufferSize,
            ref bool fSave,
            PromptForWindowsCredentialsFlags flags);

        [DllImport("credui.dll", CharSet = CharSet.Auto)]
        internal static extern bool CredUnPackAuthenticationBuffer(int dwFlags,
            IntPtr pAuthBuffer,
            uint cbAuthBuffer,
            StringBuilder pszUserName,
            ref int pcchMaxUserName,
            StringBuilder pszDomainName,
            ref int pcchMaxDomainname,
            StringBuilder pszPassword,
            ref int pcchMaxPassword);

        [DllImport("user32.dll")]
        internal static extern IntPtr CreateDesktop(string lpszDesktop,
            IntPtr lpszDevice,
            IntPtr pDevmode,
            int dwFlags,
            uint dwDesiredAccess,
            IntPtr lpsa);

        [DllImport("user32.dll")]
        internal static extern bool SwitchDesktop(IntPtr hDesktop);

        [DllImport("user32.dll")]
        internal static extern bool CloseDesktop(IntPtr handle);

        [DllImport("user32.dll")]
        internal static extern bool SetThreadDesktop(IntPtr hDesktop);

        [DllImport("user32.dll")]
        internal static extern IntPtr GetThreadDesktop(int dwThreadId);

        [DllImport("kernel32.dll")]
        internal static extern int GetCurrentThreadId();

        internal enum DESKTOP_ACCESS : uint
        {
            DESKTOP_NONE = 0,
            DESKTOP_READOBJECTS = 0x0001,
            DESKTOP_CREATEWINDOW = 0x0002,
            DESKTOP_CREATEMENU = 0x0004,
            DESKTOP_HOOKCONTROL = 0x0008,
            DESKTOP_JOURNALRECORD = 0x0010,
            DESKTOP_JOURNALPLAYBACK = 0x0020,
            DESKTOP_ENUMERATE = 0x0040,
            DESKTOP_WRITEOBJECTS = 0x0080,
            DESKTOP_SWITCHDESKTOP = 0x0100,

            GENERIC_ALL = (DESKTOP_READOBJECTS | DESKTOP_CREATEWINDOW | DESKTOP_CREATEMENU |
                            DESKTOP_HOOKCONTROL | DESKTOP_JOURNALRECORD | DESKTOP_JOURNALPLAYBACK |
                            DESKTOP_ENUMERATE | DESKTOP_WRITEOBJECTS | DESKTOP_SWITCHDESKTOP)
        }


        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
        internal struct CREDUI_INFO
        {
            public int cbSize;
            public IntPtr hwndParent;
            public string pszMessageText;
            public string pszCaptionText;
            public IntPtr hbmBanner;
        }

        [Flags]
        internal enum PromptForWindowsCredentialsFlags
        {
            /// <summary>
            /// The caller is requesting that the credential provider return the user name and password in plain text.
            /// This value cannot be combined with SECURE_PROMPT.
            /// </summary>
            CREDUIWIN_GENERIC = 0x1,
            /// <summary>
            /// The Save check box is displayed in the dialog box.
            /// </summary>
            CREDUIWIN_CHECKBOX = 0x2,
            /// <summary>
            /// Only credential providers that support the authentication package specified by the authPackage parameter should be enumerated.
            /// This value cannot be combined with CREDUIWIN_IN_CRED_ONLY.
            /// </summary>
            CREDUIWIN_AUTHPACKAGE_ONLY = 0x10,
            /// <summary>
            /// Only the credentials specified by the InAuthBuffer parameter for the authentication package specified by the authPackage parameter should be enumerated.
            /// If this flag is set, and the InAuthBuffer parameter is NULL, the function fails.
            /// This value cannot be combined with CREDUIWIN_AUTHPACKAGE_ONLY.
            /// </summary>
            CREDUIWIN_IN_CRED_ONLY = 0x20,
            /// <summary>
            /// Credential providers should enumerate only administrators. This value is intended for User Account Control (UAC) purposes only. We recommend that external callers not set this flag.
            /// </summary>
            CREDUIWIN_ENUMERATE_ADMINS = 0x100,
            /// <summary>
            /// Only the incoming credentials for the authentication package specified by the authPackage parameter should be enumerated.
            /// </summary>
            CREDUIWIN_ENUMERATE_CURRENT_USER = 0x200,
            /// <summary>
            /// The credential dialog box should be displayed on the secure desktop. This value cannot be combined with CREDUIWIN_GENERIC.
            /// Windows Vista: This value is not supported until Windows Vista with SP1.
            /// </summary>
            CREDUIWIN_SECURE_PROMPT = 0x1000,
            /// <summary>
            /// The credential provider should align the credential BLOB pointed to by the refOutAuthBuffer parameter to a 32-bit boundary, even if the provider is running on a 64-bit system.
            /// </summary>
            CREDUIWIN_PACK_32_WOW = 0x10000000,
        }
    }
}

public class Credentials
    {
        public string Username { get; set; }
        public string Password { get; set; }
    }