using System;
using System.Runtime.InteropServices;

// ReSharper disable InconsistentNaming

namespace VAR.ScreenAutomation.Code
{
    public static class Mouse
    {
        public enum MouseButtons
        {
            Left,
            Middle,
            Right
        }

        public static void SetButton(MouseButtons button, bool down)
        {
            INPUT input = new INPUT
            {
                Type = INPUT_MOUSE
            };
            input.Data.Mouse.X = 0;
            input.Data.Mouse.Y = 0;
            if (button == MouseButtons.Left)
            {
                input.Data.Mouse.Flags = down ? MOUSEEVENTF_LEFTDOWN : MOUSEEVENTF_LEFTUP;
            }

            if (button == MouseButtons.Middle)
            {
                input.Data.Mouse.Flags = down ? MOUSEEVENTF_MIDDLEDOWN : MOUSEEVENTF_MIDDLEUP;
            }

            if (button == MouseButtons.Right)
            {
                input.Data.Mouse.Flags = down ? MOUSEEVENTF_RIGHTDOWN : MOUSEEVENTF_RIGHTUP;
            }

            INPUT[] inputs = new INPUT[] { input };
            if (SendInput(1, inputs, Marshal.SizeOf(typeof(INPUT))) == 0)
                throw new Exception();
        }

        public static void Click(MouseButtons button)
        {
            SetButton(button, true);
            System.Threading.Thread.Sleep(500);
            SetButton(button, false);
        }

        public static void GetPosition(out UInt32 x, out UInt32 y)
        {
            GetCursorPos(out POINT lpPoint);
            x = lpPoint.X;
            y = lpPoint.Y;
        }

        public static void SetPosition(UInt32 x, UInt32 y)
        {
            SetCursorPos(x, y);
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct INPUT
        {
            public uint Type;
            public MOUSEKEYBDHARDWAREINPUT Data;
        }

        public const int INPUT_MOUSE = 0;
        public const int INPUT_KEYBOARD = 1;
        public const int INPUT_HARDWARE = 2;

        /// <summary>
        /// http://social.msdn.microsoft.com/Forums/en/csharplanguage/thread/f0e82d6e-4999-4d22-b3d3-32b25f61fb2a
        /// </summary>
        [StructLayout(LayoutKind.Explicit)]
        public struct MOUSEKEYBDHARDWAREINPUT
        {
            [FieldOffset(0)] public HARDWAREINPUT Hardware;

            [FieldOffset(0)] public KEYBDINPUT Keyboard;

            [FieldOffset(0)] public MOUSEINPUT Mouse;
        }

        /// <summary>
        /// http://msdn.microsoft.com/en-us/library/windows/desktop/ms646310(v=vs.85).aspx
        /// </summary>
        [StructLayout(LayoutKind.Sequential)]
        public struct HARDWAREINPUT
        {
            public uint Msg;
            public ushort ParamL;
            public ushort ParamH;
        }

        /// <summary>
        /// http://msdn.microsoft.com/en-us/library/windows/desktop/ms646310(v=vs.85).aspx
        /// </summary>
        [StructLayout(LayoutKind.Sequential)]
        public struct KEYBDINPUT
        {
            public ushort Vk;
            public ushort Scan;
            public uint Flags;
            public uint Time;
            public IntPtr ExtraInfo;
        }

        /// <summary>
        /// http://social.msdn.microsoft.com/forums/en-US/netfxbcl/thread/2abc6be8-c593-4686-93d2-89785232dacd
        /// https://msdn.microsoft.com/es-es/library/windows/desktop/ms646273%28v=vs.85%29.aspx
        /// </summary>
        [StructLayout(LayoutKind.Sequential)]
        public struct MOUSEINPUT
        {
            public int X;
            public int Y;
            public uint MouseData;
            public uint Flags;
            public uint Time;
            public IntPtr ExtraInfo;
        }

        public const int MOUSEEVENTD_XBUTTON1 = 0x0001;
        public const int MOUSEEVENTD_XBUTTON2 = 0x0002;

        public const uint MOUSEEVENTF_ABSOLUTE = 0x8000;
        public const uint MOUSEEVENTF_HWHEEL = 0x01000;
        public const uint MOUSEEVENTF_MOVE = 0x0001;
        public const uint MOUSEEVENTF_MOVE_NOCOALESCE = 0x2000;
        public const uint MOUSEEVENTF_LEFTDOWN = 0x0002;
        public const uint MOUSEEVENTF_LEFTUP = 0x0004;
        public const uint MOUSEEVENTF_RIGHTDOWN = 0x0008;
        public const uint MOUSEEVENTF_RIGHTUP = 0x0010;
        public const uint MOUSEEVENTF_MIDDLEDOWN = 0x0020;
        public const uint MOUSEEVENTF_MIDDLEUP = 0x0040;
        public const uint MOUSEEVENTF_VIRTUALDESK = 0x4000;
        public const uint MOUSEEVENTF_WHEEL = 0x0800;
        public const uint MOUSEEVENTF_XDOWN = 0x0080;
        public const uint MOUSEEVENTF_XUP = 0x0100;

        [DllImport("User32.dll")]
        public static extern int SendInput(int nInputs, INPUT[] pInputs, int cbSize);


        /// <summary>
        /// Struct representing a point.
        /// </summary>
        [StructLayout(LayoutKind.Sequential)]
        public struct POINT
        {
            public UInt32 X;
            public UInt32 Y;
        }

        /// <summary>
        /// Retrieves the cursor's position, in screen coordinates.
        /// </summary>
        /// <see>See MSDN documentation for further information.</see>
        [DllImport("user32.dll")]
        public static extern bool GetCursorPos(out POINT lpPoint);

        [DllImport("User32.dll")]
        public static extern Boolean SetCursorPos(UInt32 x, UInt32 y);
    }
}