using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;
namespace DS4Control
{
    class InputMethods
    {
        private static INPUT[] sendInputs = new INPUT[2]; // will allow for keyboard + mouse/tablet input within one SendInput call, or two mouse events
        private static object lockob = new object();
        public static void MoveCursorBy(int x, int y)
        {
            lock (lockob)
            {
                if (x != 0 || y != 0)
                {
                    sendInputs[0].Type = INPUT_MOUSE;
                    sendInputs[0].Data.Mouse.ExtraInfo = IntPtr.Zero;
                    sendInputs[0].Data.Mouse.Flags = MOUSEEVENTF_MOVE;
                    sendInputs[0].Data.Mouse.MouseData = 0;
                    sendInputs[0].Data.Mouse.Time = 0;
                    sendInputs[0].Data.Mouse.X = x;
                    sendInputs[0].Data.Mouse.Y = y;
                    uint result = SendInput(1, sendInputs, Marshal.SizeOf(sendInputs[0]));
                }
            }
        }

        public static void MouseWheel(int vertical, int horizontal)
        {
            lock (lockob)
            {
                uint inputs = 0;
                if (vertical != 0)
                {
                    sendInputs[inputs].Type = INPUT_MOUSE;
                    sendInputs[inputs].Data.Mouse.ExtraInfo = IntPtr.Zero;
                    sendInputs[inputs].Data.Mouse.Flags = MOUSEEVENTF_WHEEL;
                    sendInputs[inputs].Data.Mouse.MouseData = (uint)vertical;
                    sendInputs[inputs].Data.Mouse.Time = 0;
                    sendInputs[inputs].Data.Mouse.X = 0;
                    sendInputs[inputs].Data.Mouse.Y = 0;
                    inputs++;
                }
                if (horizontal != 0)
                {
                    sendInputs[inputs].Type = INPUT_MOUSE;
                    sendInputs[inputs].Data.Mouse.ExtraInfo = IntPtr.Zero;
                    sendInputs[inputs].Data.Mouse.Flags = MOUSEEVENTF_HWHEEL;
                    sendInputs[inputs].Data.Mouse.MouseData = (uint)horizontal;
                    sendInputs[inputs].Data.Mouse.Time = 0;
                    sendInputs[inputs].Data.Mouse.X = 0;
                    sendInputs[inputs].Data.Mouse.Y = 0;
                    inputs++;
                }
                SendInput(inputs, sendInputs, (int)inputs * Marshal.SizeOf(sendInputs[0]));
            }
        }

        public static void MouseEvent(uint mouseButton)
        {
            lock (lockob)
            {
                sendInputs[0].Type = INPUT_MOUSE;
                sendInputs[0].Data.Mouse.ExtraInfo = IntPtr.Zero;
                sendInputs[0].Data.Mouse.Flags = mouseButton;
                sendInputs[0].Data.Mouse.MouseData = 0;
                sendInputs[0].Data.Mouse.Time = 0;
                sendInputs[0].Data.Mouse.X = 0;
                sendInputs[0].Data.Mouse.Y = 0;
                uint result = SendInput(1, sendInputs, Marshal.SizeOf(sendInputs[0]));
            }
        }

        public static void performLeftClick()
        {
            lock (lockob)
            {
                sendInputs[0].Type = INPUT_MOUSE;
                sendInputs[0].Data.Mouse.ExtraInfo = IntPtr.Zero;
                sendInputs[0].Data.Mouse.Flags = 0;
                sendInputs[0].Data.Mouse.Flags |= MOUSEEVENTF_LEFTDOWN | MOUSEEVENTF_LEFTUP;
                sendInputs[0].Data.Mouse.MouseData = 0;
                sendInputs[0].Data.Mouse.Time = 0;
                sendInputs[0].Data.Mouse.X = 0;
                sendInputs[0].Data.Mouse.Y = 0;
                uint result = SendInput(1, sendInputs, Marshal.SizeOf(sendInputs[0]));
            }
        }

        public static void performRightClick()
        {
            lock (lockob)
            {
                sendInputs[0].Type = INPUT_MOUSE;
                sendInputs[0].Data.Mouse.ExtraInfo = IntPtr.Zero;
                sendInputs[0].Data.Mouse.Flags = 0;
                sendInputs[0].Data.Mouse.Flags |= MOUSEEVENTF_RIGHTDOWN | MOUSEEVENTF_RIGHTUP;
                sendInputs[0].Data.Mouse.MouseData = 0;
                sendInputs[0].Data.Mouse.Time = 0;
                sendInputs[0].Data.Mouse.X = 0;
                sendInputs[0].Data.Mouse.Y = 0;
                uint result = SendInput(1, sendInputs, Marshal.SizeOf(sendInputs[0]));
            }
        }

        public static void performMiddleClick()
        {
            lock (lockob)
            {
                sendInputs[0].Type = INPUT_MOUSE;
                sendInputs[0].Data.Mouse.ExtraInfo = IntPtr.Zero;
                sendInputs[0].Data.Mouse.Flags = 0;
                sendInputs[0].Data.Mouse.Flags |= MOUSEEVENTF_MIDDLEDOWN | MOUSEEVENTF_MIDDLEUP;
                sendInputs[0].Data.Mouse.MouseData = 0;
                sendInputs[0].Data.Mouse.Time = 0;
                sendInputs[0].Data.Mouse.X = 0;
                sendInputs[0].Data.Mouse.Y = 0;
                uint result = SendInput(1, sendInputs, Marshal.SizeOf(sendInputs[0]));
            }
        }

        public static void performSCKeyPress(ushort key)
        {
            lock (lockob)
            {
                sendInputs[0].Type = INPUT_KEYBOARD;
                sendInputs[0].Data.Keyboard.ExtraInfo = IntPtr.Zero;
                sendInputs[0].Data.Keyboard.Flags = KEYEVENTF_SCANCODE;
                sendInputs[0].Data.Keyboard.Scan = MapVirtualKey(key, MAPVK_VK_TO_VSC); ;
                sendInputs[0].Data.Keyboard.Time = 0;
                sendInputs[0].Data.Keyboard.Vk = key;
                uint result = SendInput(1, sendInputs, Marshal.SizeOf(sendInputs[0]));
            }
        }

        public static void performKeyPress(ushort key)
        {
            lock (lockob)
            {
                sendInputs[0].Type = INPUT_KEYBOARD;
                sendInputs[0].Data.Keyboard.ExtraInfo = IntPtr.Zero;
                sendInputs[0].Data.Keyboard.Flags = 0;
                sendInputs[0].Data.Keyboard.Scan = 0;
                sendInputs[0].Data.Keyboard.Time = 0;
                sendInputs[0].Data.Keyboard.Vk = key;
                uint result = SendInput(1, sendInputs, Marshal.SizeOf(sendInputs[0]));
            }
        }

        public static void performSCKeyRelease(ushort key)
        {
            lock (lockob)
            {
                sendInputs[0].Type = INPUT_KEYBOARD;
                sendInputs[0].Data.Keyboard.ExtraInfo = IntPtr.Zero;
                sendInputs[0].Data.Keyboard.Flags = KEYEVENTF_SCANCODE | KEYEVENTF_KEYUP;
                sendInputs[0].Data.Keyboard.Scan = MapVirtualKey(key, MAPVK_VK_TO_VSC);
                sendInputs[0].Data.Keyboard.Time = 0;
                sendInputs[0].Data.Keyboard.Vk = key;
                uint result = SendInput(1, sendInputs, Marshal.SizeOf(sendInputs[0]));
            }
        }

        public static void performKeyRelease(ushort key)
        {
            lock (lockob)
            {
                sendInputs[0].Type = INPUT_KEYBOARD;
                sendInputs[0].Data.Keyboard.ExtraInfo = IntPtr.Zero;
                sendInputs[0].Data.Keyboard.Flags = KEYEVENTF_KEYUP;
                sendInputs[0].Data.Keyboard.Scan = 0;
                sendInputs[0].Data.Keyboard.Time = 0;
                sendInputs[0].Data.Keyboard.Vk = key;
                uint result = SendInput(1, sendInputs, Marshal.SizeOf(sendInputs[0]));
            }
        }

        /// <summary>
        /// http://msdn.microsoft.com/en-us/library/windows/desktop/ms646270(v=vs.85).aspx
        /// </summary>
        [StructLayout(LayoutKind.Sequential)]
        internal struct INPUT
        {
            public uint Type;
            public MOUSEKEYBDHARDWAREINPUT Data;
        }
        internal const uint INPUT_MOUSE = 0, INPUT_KEYBOARD = 1, INPUT_HARDWARE = 2;

        /// <summary>
        /// http://social.msdn.microsoft.com/Forums/en/csharplanguage/thread/f0e82d6e-4999-4d22-b3d3-32b25f61fb2a
        /// </summary>
        [StructLayout(LayoutKind.Explicit)]
        internal 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)]
        internal 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)]
        internal 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
        /// </summary>
        [StructLayout(LayoutKind.Sequential)]
        internal struct MOUSEINPUT
        {
            public int X;
            public int Y;
            public uint MouseData;
            public uint Flags;
            public uint Time;
            public IntPtr ExtraInfo;
        }

        internal const uint MOUSEEVENTF_MOVE = 1, // just apply X/Y (delta due to not setting absolute flag)
            MOUSEEVENTF_LEFTDOWN = 2, MOUSEEVENTF_LEFTUP = 4,
            MOUSEEVENTF_RIGHTDOWN = 8, MOUSEEVENTF_RIGHTUP = 16,
            MOUSEEVENTF_MIDDLEDOWN = 32, MOUSEEVENTF_MIDDLEUP = 64,
            KEYEVENTF_KEYUP = 2, MOUSEEVENTF_WHEEL = 0x0800, MOUSEEVENTF_HWHEEL = 0x1000,
            KEYEVENTF_SCANCODE = 0x0008, MAPVK_VK_TO_VSC = 0;

        [DllImport("user32.dll", SetLastError = true)]
        private static extern uint SendInput(uint numberOfInputs, INPUT[] inputs, int sizeOfInputs);
        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        private static extern ushort MapVirtualKey(uint uCode, uint uMapType);
    }
}