using System;
using System.Runtime.InteropServices;
using System.Windows.Forms;

namespace grapher.Models.Mouse
{
    public class MouseWatcher
    {
        #region External
        /// <summary>
        /// Enumeration containing HID usage page flags.
        /// </summary>
        public enum HIDUsagePage : ushort
        {
            /// <summary>Unknown usage page.</summary>
            Undefined = 0x00,
            /// <summary>Generic desktop controls.</summary>
            Generic = 0x01,
            /// <summary>Simulation controls.</summary>
            Simulation = 0x02,
            /// <summary>Virtual reality controls.</summary>
            VR = 0x03,
            /// <summary>Sports controls.</summary>
            Sport = 0x04,
            /// <summary>Games controls.</summary>
            Game = 0x05,
            /// <summary>Keyboard controls.</summary>
            Keyboard = 0x07,
            /// <summary>LED controls.</summary>
            LED = 0x08,
            /// <summary>Button.</summary>
            Button = 0x09,
            /// <summary>Ordinal.</summary>
            Ordinal = 0x0A,
            /// <summary>Telephony.</summary>
            Telephony = 0x0B,
            /// <summary>Consumer.</summary>
            Consumer = 0x0C,
            /// <summary>Digitizer.</summary>
            Digitizer = 0x0D,
            /// <summary>Physical interface device.</summary>
            PID = 0x0F,
            /// <summary>Unicode.</summary>
            Unicode = 0x10,
            /// <summary>Alphanumeric display.</summary>
            AlphaNumeric = 0x14,
            /// <summary>Medical instruments.</summary>
            Medical = 0x40,
            /// <summary>Monitor page 0.</summary>
            MonitorPage0 = 0x80,
            /// <summary>Monitor page 1.</summary>
            MonitorPage1 = 0x81,
            /// <summary>Monitor page 2.</summary>
            MonitorPage2 = 0x82,
            /// <summary>Monitor page 3.</summary>
            MonitorPage3 = 0x83,
            /// <summary>Power page 0.</summary>
            PowerPage0 = 0x84,
            /// <summary>Power page 1.</summary>
            PowerPage1 = 0x85,
            /// <summary>Power page 2.</summary>
            PowerPage2 = 0x86,
            /// <summary>Power page 3.</summary>
            PowerPage3 = 0x87,
            /// <summary>Bar code scanner.</summary>
            BarCode = 0x8C,
            /// <summary>Scale page.</summary>
            Scale = 0x8D,
            /// <summary>Magnetic strip reading devices.</summary>
            MSR = 0x8E
        }

        /// <summary>
        /// Enumeration containing the HID usage values.
        /// </summary>
        public enum HIDUsage : ushort
        {
            /// <summary></summary>
            Pointer = 0x01,
            /// <summary></summary>
            Mouse = 0x02,
            /// <summary></summary>
            Joystick = 0x04,
            /// <summary></summary>
            Gamepad = 0x05,
            /// <summary></summary>
            Keyboard = 0x06,
            /// <summary></summary>
            Keypad = 0x07,
            /// <summary></summary>
            SystemControl = 0x80,
            /// <summary></summary>
            X = 0x30,
            /// <summary></summary>
            Y = 0x31,
            /// <summary></summary>
            Z = 0x32,
            /// <summary></summary>
            RelativeX = 0x33,
            /// <summary></summary>    
            RelativeY = 0x34,
            /// <summary></summary>
            RelativeZ = 0x35,
            /// <summary></summary>
            Slider = 0x36,
            /// <summary></summary>
            Dial = 0x37,
            /// <summary></summary>
            Wheel = 0x38,
            /// <summary></summary>
            HatSwitch = 0x39,
            /// <summary></summary>
            CountedBuffer = 0x3A,
            /// <summary></summary>
            ByteCount = 0x3B,
            /// <summary></summary>
            MotionWakeup = 0x3C,
            /// <summary></summary>
            VX = 0x40,
            /// <summary></summary>
            VY = 0x41,
            /// <summary></summary>
            VZ = 0x42,
            /// <summary></summary>
            VBRX = 0x43,
            /// <summary></summary>
            VBRY = 0x44,
            /// <summary></summary>
            VBRZ = 0x45,
            /// <summary></summary>
            VNO = 0x46,
            /// <summary></summary>
            SystemControlPower = 0x81,
            /// <summary></summary>
            SystemControlSleep = 0x82,
            /// <summary></summary>
            SystemControlWake = 0x83,
            /// <summary></summary>
            SystemControlContextMenu = 0x84,
            /// <summary></summary>
            SystemControlMainMenu = 0x85,
            /// <summary></summary>
            SystemControlApplicationMenu = 0x86,
            /// <summary></summary>
            SystemControlHelpMenu = 0x87,
            /// <summary></summary>
            SystemControlMenuExit = 0x88,
            /// <summary></summary>
            SystemControlMenuSelect = 0x89,
            /// <summary></summary>
            SystemControlMenuRight = 0x8A,
            /// <summary></summary>
            SystemControlMenuLeft = 0x8B,
            /// <summary></summary>
            SystemControlMenuUp = 0x8C,
            /// <summary></summary>
            SystemControlMenuDown = 0x8D,
            /// <summary></summary>
            KeyboardNoEvent = 0x00,
            /// <summary></summary>
            KeyboardRollover = 0x01,
            /// <summary></summary>
            KeyboardPostFail = 0x02,
            /// <summary></summary>
            KeyboardUndefined = 0x03,
            /// <summary></summary>
            KeyboardaA = 0x04,
            /// <summary></summary>
            KeyboardzZ = 0x1D,
            /// <summary></summary>
            Keyboard1 = 0x1E,
            /// <summary></summary>
            Keyboard0 = 0x27,
            /// <summary></summary>
            KeyboardLeftControl = 0xE0,
            /// <summary></summary>
            KeyboardLeftShift = 0xE1,
            /// <summary></summary>
            KeyboardLeftALT = 0xE2,
            /// <summary></summary>
            KeyboardLeftGUI = 0xE3,
            /// <summary></summary>
            KeyboardRightControl = 0xE4,
            /// <summary></summary>
            KeyboardRightShift = 0xE5,
            /// <summary></summary>
            KeyboardRightALT = 0xE6,
            /// <summary></summary>
            KeyboardRightGUI = 0xE7,
            /// <summary></summary>
            KeyboardScrollLock = 0x47,
            /// <summary></summary>
            KeyboardNumLock = 0x53,
            /// <summary></summary>
            KeyboardCapsLock = 0x39,
            /// <summary></summary>
            KeyboardF1 = 0x3A,
            /// <summary></summary>
            KeyboardF12 = 0x45,
            /// <summary></summary>
            KeyboardReturn = 0x28,
            /// <summary></summary>
            KeyboardEscape = 0x29,
            /// <summary></summary>
            KeyboardDelete = 0x2A,
            /// <summary></summary>
            KeyboardPrintScreen = 0x46,
            /// <summary></summary>
            LEDNumLock = 0x01,
            /// <summary></summary>
            LEDCapsLock = 0x02,
            /// <summary></summary>
            LEDScrollLock = 0x03,
            /// <summary></summary>
            LEDCompose = 0x04,
            /// <summary></summary>
            LEDKana = 0x05,
            /// <summary></summary>
            LEDPower = 0x06,
            /// <summary></summary>
            LEDShift = 0x07,
            /// <summary></summary>
            LEDDoNotDisturb = 0x08,
            /// <summary></summary>
            LEDMute = 0x09,
            /// <summary></summary>
            LEDToneEnable = 0x0A,
            /// <summary></summary>
            LEDHighCutFilter = 0x0B,
            /// <summary></summary>
            LEDLowCutFilter = 0x0C,
            /// <summary></summary>
            LEDEqualizerEnable = 0x0D,
            /// <summary></summary>
            LEDSoundFieldOn = 0x0E,
            /// <summary></summary>
            LEDSurroundFieldOn = 0x0F,
            /// <summary></summary>
            LEDRepeat = 0x10,
            /// <summary></summary>
            LEDStereo = 0x11,
            /// <summary></summary>
            LEDSamplingRateDirect = 0x12,
            /// <summary></summary>
            LEDSpinning = 0x13,
            /// <summary></summary>
            LEDCAV = 0x14,
            /// <summary></summary>
            LEDCLV = 0x15,
            /// <summary></summary>
            LEDRecordingFormatDet = 0x16,
            /// <summary></summary>
            LEDOffHook = 0x17,
            /// <summary></summary>
            LEDRing = 0x18,
            /// <summary></summary>
            LEDMessageWaiting = 0x19,
            /// <summary></summary>
            LEDDataMode = 0x1A,
            /// <summary></summary>
            LEDBatteryOperation = 0x1B,
            /// <summary></summary>
            LEDBatteryOK = 0x1C,
            /// <summary></summary>
            LEDBatteryLow = 0x1D,
            /// <summary></summary>
            LEDSpeaker = 0x1E,
            /// <summary></summary>
            LEDHeadset = 0x1F,
            /// <summary></summary>
            LEDHold = 0x20,
            /// <summary></summary>
            LEDMicrophone = 0x21,
            /// <summary></summary>
            LEDCoverage = 0x22,
            /// <summary></summary>
            LEDNightMode = 0x23,
            /// <summary></summary>
            LEDSendCalls = 0x24,
            /// <summary></summary>
            LEDCallPickup = 0x25,
            /// <summary></summary>
            LEDConference = 0x26,
            /// <summary></summary>
            LEDStandBy = 0x27,
            /// <summary></summary>
            LEDCameraOn = 0x28,
            /// <summary></summary>
            LEDCameraOff = 0x29,
            /// <summary></summary>    
            LEDOnLine = 0x2A,
            /// <summary></summary>
            LEDOffLine = 0x2B,
            /// <summary></summary>
            LEDBusy = 0x2C,
            /// <summary></summary>
            LEDReady = 0x2D,
            /// <summary></summary>
            LEDPaperOut = 0x2E,
            /// <summary></summary>
            LEDPaperJam = 0x2F,
            /// <summary></summary>
            LEDRemote = 0x30,
            /// <summary></summary>
            LEDForward = 0x31,
            /// <summary></summary>
            LEDReverse = 0x32,
            /// <summary></summary>
            LEDStop = 0x33,
            /// <summary></summary>
            LEDRewind = 0x34,
            /// <summary></summary>
            LEDFastForward = 0x35,
            /// <summary></summary>
            LEDPlay = 0x36,
            /// <summary></summary>
            LEDPause = 0x37,
            /// <summary></summary>
            LEDRecord = 0x38,
            /// <summary></summary>
            LEDError = 0x39,
            /// <summary></summary>
            LEDSelectedIndicator = 0x3A,
            /// <summary></summary>
            LEDInUseIndicator = 0x3B,
            /// <summary></summary>
            LEDMultiModeIndicator = 0x3C,
            /// <summary></summary>
            LEDIndicatorOn = 0x3D,
            /// <summary></summary>
            LEDIndicatorFlash = 0x3E,
            /// <summary></summary>
            LEDIndicatorSlowBlink = 0x3F,
            /// <summary></summary>
            LEDIndicatorFastBlink = 0x40,
            /// <summary></summary>
            LEDIndicatorOff = 0x41,
            /// <summary></summary>
            LEDFlashOnTime = 0x42,
            /// <summary></summary>
            LEDSlowBlinkOnTime = 0x43,
            /// <summary></summary>
            LEDSlowBlinkOffTime = 0x44,
            /// <summary></summary>
            LEDFastBlinkOnTime = 0x45,
            /// <summary></summary>
            LEDFastBlinkOffTime = 0x46,
            /// <summary></summary>
            LEDIndicatorColor = 0x47,
            /// <summary></summary>
            LEDRed = 0x48,
            /// <summary></summary>
            LEDGreen = 0x49,
            /// <summary></summary>
            LEDAmber = 0x4A,
            /// <summary></summary>
            LEDGenericIndicator = 0x3B,
            /// <summary></summary>
            TelephonyPhone = 0x01,
            /// <summary></summary>
            TelephonyAnsweringMachine = 0x02,
            /// <summary></summary>
            TelephonyMessageControls = 0x03,
            /// <summary></summary>
            TelephonyHandset = 0x04,
            /// <summary></summary>
            TelephonyHeadset = 0x05,
            /// <summary></summary>
            TelephonyKeypad = 0x06,
            /// <summary></summary>
            TelephonyProgrammableButton = 0x07,
            /// <summary></summary>
            SimulationRudder = 0xBA,
            /// <summary></summary>
            SimulationThrottle = 0xBB
        }

        /// <summary>Enumeration containing flags for a raw input device.</summary>
        [Flags()]
        public enum RawInputDeviceFlags
        {
            /// <summary>No flags.</summary>
            None = 0,
            /// <summary>If set, this removes the top level collection from the inclusion list. This tells the operating system to stop reading from a device which matches the top level collection.</summary>
            Remove = 0x00000001,
            /// <summary>If set, this specifies the top level collections to exclude when reading a complete usage page. This flag only affects a TLC whose usage page is already specified with PageOnly.</summary>
            Exclude = 0x00000010,
            /// <summary>If set, this specifies all devices whose top level collection is from the specified usUsagePage. Note that Usage must be zero. To exclude a particular top level collection, use Exclude.</summary>
            PageOnly = 0x00000020,
            /// <summary>If set, this prevents any devices specified by UsagePage or Usage from generating legacy messages. This is only for the mouse and keyboard.</summary>
            NoLegacy = 0x00000030,
            /// <summary>If set, this enables the caller to receive the input even when the caller is not in the foreground. Note that WindowHandle must be specified.</summary>
            InputSink = 0x00000100,
            /// <summary>If set, the mouse button click does not activate the other window.</summary>
            CaptureMouse = 0x00000200,
            /// <summary>If set, the application-defined keyboard device hotkeys are not handled. However, the system hotkeys; for example, ALT+TAB and CTRL+ALT+DEL, are still handled. By default, all keyboard hotkeys are handled. NoHotKeys can be specified even if NoLegacy is not specified and WindowHandle is NULL.</summary>
            NoHotKeys = 0x00000200,
            /// <summary>If set, application keys are handled.  NoLegacy must be specified.  Keyboard only.</summary>
            AppKeys = 0x00000400
        }

        /// <summary>Value type for raw input devices.</summary>
        [StructLayout(LayoutKind.Sequential)]
        public struct RAWINPUTDEVICE
        {
            /// <summary>Top level collection Usage page for the raw input device.</summary>
            public HIDUsagePage UsagePage;
            /// <summary>Top level collection Usage for the raw input device. </summary>
            public HIDUsage Usage;
            /// <summary>Mode flag that specifies how to interpret the information provided by UsagePage and Usage.</summary>
            public RawInputDeviceFlags Flags;
            /// <summary>Handle to the target device. If NULL, it follows the keyboard focus.</summary>
            public IntPtr WindowHandle;
        }

        /// <summary>
        /// Contains the raw input from a device.
        /// </summary>
        [StructLayout(LayoutKind.Sequential)]
        public struct RawInput
        {
            /// <summary>
            /// Header for the data.
            /// </summary>
            public RAWINPUTHEADER Header;
            public Union Data;
            [StructLayout(LayoutKind.Explicit)]
            public struct Union
            {
                /// <summary>
                /// Mouse raw input data.
                /// </summary>
                [FieldOffset(0)]
                public RawMouse Mouse;
                /// <summary>
                /// Keyboard raw input data.
                /// </summary>
                [FieldOffset(0)]
                public RawKeyboard Keyboard;
                /// <summary>
                /// HID raw input data.
                /// </summary>
                [FieldOffset(0)]
                public RawHID HID;
            }
        }

        /// <summary>
        /// Value type for raw input from a HID.
        /// </summary>    
        [StructLayout(LayoutKind.Sequential)]
        public struct RawHID
        {
            /// <summary>Size of the HID data in bytes.</summary>
            public int Size;
            /// <summary>Number of HID in Data.</summary>
            public int Count;
            /// <summary>Data for the HID.</summary>
            public IntPtr Data;
        }

        /// <summary>
        /// Value type for a raw input header.
        /// </summary>
        [StructLayout(LayoutKind.Sequential)]
        public struct RAWINPUTHEADER
        {
            /// <summary>Type of device the input is coming from.</summary>
            public RawInputType Type;
            /// <summary>Size of the packet of data.</summary>
            public int Size;
            /// <summary>Handle to the device sending the data.</summary>
            public IntPtr Device;
            /// <summary>wParam from the window message.</summary>
            public IntPtr wParam;
        }

        /// <summary>
        /// Enumeration containing the type device the raw input is coming from.
        /// </summary>
        public enum RawInputType
        {
            /// <summary>
            /// Mouse input.
            /// </summary>
            Mouse = 0,

            /// <summary>
            /// Keyboard input.
            /// </summary>
            Keyboard = 1,

            /// <summary>
            ///  Human interface device input.
            /// </summary>
            HID = 2,

            /// <summary>
            /// Another device that is not the keyboard or the mouse.
            /// </summary>
            Other = 3
        }

        /// <summary>
        /// Contains information about the state of the mouse.
        /// </summary>
        [StructLayout(LayoutKind.Sequential)]
        public struct RawMouse
        {
            /// <summary>
            /// The mouse state.
            /// </summary>
            public RawMouseFlags Flags;

            [StructLayout(LayoutKind.Explicit)]
            public struct Data
            {
                [FieldOffset(0)]
                public uint Buttons;
                /// <summary>
                /// If the mouse wheel is moved, this will contain the delta amount.
                /// </summary>
                [FieldOffset(2)]
                public ushort ButtonData;
                /// <summary>
                /// Flags for the event.
                /// </summary>
                [FieldOffset(0)]
                public RawMouseButtons ButtonFlags;
            }

            public Data _Data;

            /// <summary>
            /// Raw button data.
            /// </summary>
            public uint RawButtons;
            /// <summary>
            /// The motion in the X direction. This is signed relative motion or
            /// absolute motion, depending on the value of usFlags.
            /// </summary>
            public int LastX;
            /// <summary>
            /// The motion in the Y direction. This is signed relative motion or absolute motion,
            /// depending on the value of usFlags.
            /// </summary>
            public int LastY;
            /// <summary>
            /// The device-specific additional information for the event.
            /// </summary>
            public uint ExtraInformation;
        }

        /// <summary>
        /// Enumeration containing the flags for raw mouse data.
        /// </summary>
        [Flags()]
        public enum RawMouseFlags
            : ushort
        {
            /// <summary>Relative to the last position.</summary>
            MoveRelative = 0,
            /// <summary>Absolute positioning.</summary>
            MoveAbsolute = 1,
            /// <summary>Coordinate data is mapped to a virtual desktop.</summary>
            VirtualDesktop = 2,
            /// <summary>Attributes for the mouse have changed.</summary>
            AttributesChanged = 4
        }

        /// <summary>
        /// Enumeration containing the button data for raw mouse input.
        /// </summary>
        [Flags()]
        public enum RawMouseButtons
            : ushort
        {
            /// <summary>No button.</summary>
            None = 0,
            /// <summary>Left (button 1) down.</summary>
            LeftDown = 0x0001,
            /// <summary>Left (button 1) up.</summary>
            LeftUp = 0x0002,
            /// <summary>Right (button 2) down.</summary>
            RightDown = 0x0004,
            /// <summary>Right (button 2) up.</summary>
            RightUp = 0x0008,
            /// <summary>Middle (button 3) down.</summary>
            MiddleDown = 0x0010,
            /// <summary>Middle (button 3) up.</summary>
            MiddleUp = 0x0020,
            /// <summary>Button 4 down.</summary>
            Button4Down = 0x0040,
            /// <summary>Button 4 up.</summary>
            Button4Up = 0x0080,
            /// <summary>Button 5 down.</summary>
            Button5Down = 0x0100,
            /// <summary>Button 5 up.</summary>
            Button5Up = 0x0200,
            /// <summary>Mouse wheel moved.</summary>
            MouseWheel = 0x0400
        }

        /// <summary>
        /// Value type for raw input from a keyboard.
        /// </summary>    
        [StructLayout(LayoutKind.Sequential)]
        public struct RawKeyboard
        {
            /// <summary>Scan code for key depression.</summary>
            public short MakeCode;
            /// <summary>Scan code information.</summary>
            public RawKeyboardFlags Flags;
            /// <summary>Reserved.</summary>
            public short Reserved;
            /// <summary>Virtual key code.</summary>
            public ushort VirtualKey;
            /// <summary>Corresponding window message.</summary>
            public uint Message;
            /// <summary>Extra information.</summary>
            public int ExtraInformation;
        }

        /// <summary>
        /// Enumeration containing flags for raw keyboard input.
        /// </summary>
        [Flags]
        public enum RawKeyboardFlags : ushort
        {
            /// <summary></summary>
            KeyMake = 0,
            /// <summary></summary>
            KeyBreak = 1,
            /// <summary></summary>
            KeyE0 = 2,
            /// <summary></summary>
            KeyE1 = 4,
            /// <summary></summary>
            TerminalServerSetLED = 8,
            /// <summary></summary>
            TerminalServerShadow = 0x10,
            /// <summary></summary>
            TerminalServerVKPACKET = 0x20
        }

        /// <summary>
        /// Enumeration contanining the command types to issue.
        /// </summary>
        public enum RawInputCommand
        {
            /// <summary>
            /// Get input data.
            /// </summary>
            Input = 0x10000003,
            /// <summary>
            /// Get header data.
            /// </summary>
            Header = 0x10000005
        }

        [DllImport("user32.dll")]
        public static extern bool RegisterRawInputDevices([MarshalAs(UnmanagedType.LPArray, SizeParamIndex=0)] RAWINPUTDEVICE[] pRawInputDevices, int uiNumDevices, int cbSize);

        /// <summary>
        /// Function to retrieve raw input data.
        /// </summary>
        /// <param name="hRawInput">Handle to the raw input.</param>
        /// <param name="uiCommand">Command to issue when retrieving data.</param>
        /// <param name="pData">Raw input data.</param>
        /// <param name="pcbSize">Number of bytes in the array.</param>
        /// <param name="cbSizeHeader">Size of the header.</param>
        /// <returns>0 if successful if pData is null, otherwise number of bytes if pData is not null.</returns>
        [DllImport("user32.dll")]
        public static extern int GetRawInputData(IntPtr hRawInput, RawInputCommand uiCommand, out RawInput pData, ref int pcbSize, int cbSizeHeader);

        #endregion External

        #region Constructors

        public MouseWatcher(Form containingForm, Label display, AccelCharts accelCharts, Field pollRate)
        {
            ContainingForm = containingForm;
            Display = display;
            AccelCharts = accelCharts;
            PollRateField = pollRate;
            MouseData = new MouseData();

            RAWINPUTDEVICE device = new RAWINPUTDEVICE();
            device.WindowHandle = ContainingForm.Handle;
            device.UsagePage = HIDUsagePage.Generic;
            device.Usage = HIDUsage.Mouse;
            device.Flags = RawInputDeviceFlags.InputSink;

            RAWINPUTDEVICE[] devices = new RAWINPUTDEVICE[1];
            devices[0] = device;
            RegisterRawInputDevices(devices, 1, Marshal.SizeOf(typeof(RAWINPUTDEVICE)));
            PollTime = 1;
            PollRate = 1000;
        }

        #endregion Constructors

        #region Properties

        private Form ContainingForm { get; }

        private Label Display { get; }

        private AccelCharts AccelCharts { get; }

        private Field PollRateField { get; set; }

        private MouseData MouseData { get; }

        private double PollRate { get; set; }

        private double PollTime { get; set; }

        #endregion Properties

        #region Methods

        public void OnMouseMove(int x, int y, double timeInMs)
        {
            MouseData.Set(x,y);
            AccelCharts.MakeDots(x, y, timeInMs);
        }

        public void UpdateLastMove()
        {
            MouseData.Get(out var x, out var y);
            Display.Text = $"Last (x, y): ({x}, {y})";
        }

        public void ReadMouseMove(Message message)
        {
            RawInput rawInput = new RawInput();
            int outSize = 0;
            int size = Marshal.SizeOf(typeof(RawInput));

            outSize = GetRawInputData((IntPtr)message.LParam, RawInputCommand.Input, out rawInput, ref size, Marshal.SizeOf(typeof(RAWINPUTHEADER)));

            if (PollRateField.Data != PollRate)
            {
                PollRate = PollRateField.Data;
                PollTime = 1000 / PollRate;
            }

            if (rawInput.Data.Mouse.LastX != 0 || rawInput.Data.Mouse.LastY != 0)
            {
                OnMouseMove(rawInput.Data.Mouse.LastX, rawInput.Data.Mouse.LastY, PollTime);
            }

        }

        #endregion Methods
    }
}