#region License
//
// WinRawJoystick.cs
//
// Author:
//       Stefanos A. <stapostol@gmail.com>
//
// Copyright (c) 2014 Stefanos Apostolopoulos
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//
#endregion

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Text;
using OpenTK.Input;
using OpenTK.Platform.Common;

namespace OpenTK.Platform.Windows
{
    class WinRawJoystick : IJoystickDriver2
    {
        class Device
        {
            public IntPtr Handle;
            JoystickCapabilities Capabilities;
            JoystickState State;
            Guid Guid;

            readonly Dictionary<int, JoystickAxis> axes =
                new Dictionary<int,JoystickAxis>();
            readonly Dictionary<int, JoystickButton> buttons =
                new Dictionary<int, JoystickButton>();
            readonly Dictionary<int, JoystickHat> hats =
                new Dictionary<int, JoystickHat>();

            #region Constructors

            public Device(IntPtr handle, Guid guid)
            {
                Handle = handle;
                Guid = guid;
            }

            #endregion

            #region Public Members

            public void ClearButtons()
            {
                State.ClearButtons();
            }

            public void SetAxis(HIDPage page, short usage, short value)
            {
                JoystickAxis axis = GetAxis(page, usage);
                State.SetAxis(axis, value);
            }

            public void SetButton(HIDPage page, short usage, bool value)
            {
                JoystickButton button = GetButton(page, usage);
                State.SetButton(button, value);
            }

            public void SetHat(HIDPage page, short usage, HatPosition pos)
            {
                JoystickHat hat = GetHat(page, usage);
                State.SetHat(hat, new JoystickHatState(pos));
            }

            public void SetConnected(bool value)
            {
                Capabilities.SetIsConnected(value);
                State.SetIsConnected(value);
            }

            public JoystickCapabilities GetCapabilities()
            {
                Capabilities = new JoystickCapabilities(
                    axes.Count, buttons.Count, hats.Count,
                    Capabilities.IsConnected);
                return Capabilities;
            }

            internal void SetCapabilities(JoystickCapabilities caps)
            {
                Capabilities = caps;
            }

            public Guid GetGuid()
            {
                return Guid;
            }

            public JoystickState GetState()
            {
                return State;
            }

            #endregion

            #region Private Members

            static int MakeKey(HIDPage page, short usage)
            {
                return ((ushort)page << 16) | unchecked((ushort)usage);
            }

            JoystickAxis GetAxis(HIDPage page, short usage)
            {
                int key = MakeKey(page, usage);
                if (!axes.ContainsKey(key))
                {
                    axes.Add(key, JoystickAxis.Axis0 + axes.Count);
                }
                return axes[key];
            }

            JoystickButton GetButton(HIDPage page, short usage)
            {
                int key = MakeKey(page, usage);
                if (!buttons.ContainsKey(key))
                {
                    buttons.Add(key, JoystickButton.Button0 + buttons.Count);
                }
                return buttons[key];
            }

            JoystickHat GetHat(HIDPage page, short usage)
            {
                int key = MakeKey(page, usage);
                if (!hats.ContainsKey(key))
                {
                    hats.Add(key, JoystickHat.Hat0 + hats.Count);
                }
                return hats[key];
            }

            #endregion
        }

        // Defines which types of HID devices we are interested in
        readonly RawInputDevice[] DeviceTypes;

        readonly IntPtr Window;
        readonly object UpdateLock = new object();
        readonly DeviceCollection<Device> Devices = new DeviceCollection<Device>();

        byte[] HIDData = new byte[1024];
        byte[] PreparsedData = new byte[1024];
        HidProtocolValueCaps[] AxisCaps = new HidProtocolValueCaps[4];
        HidProtocolButtonCaps[] ButtonCaps = new HidProtocolButtonCaps[4];
        HidProtocolData[] DataBuffer = new HidProtocolData[16];

        public WinRawJoystick(IntPtr window)
        {
            Debug.WriteLine("Using WinRawJoystick.");
            Debug.Indent();

            if (window == IntPtr.Zero)
                throw new ArgumentNullException("window");

            Window = window;
            DeviceTypes = new RawInputDevice[]
            {
                new RawInputDevice(HIDUsageGD.Joystick, RawInputDeviceFlags.DEVNOTIFY | RawInputDeviceFlags.EXINPUTSINK, window),
                new RawInputDevice(HIDUsageGD.GamePad, RawInputDeviceFlags.DEVNOTIFY | RawInputDeviceFlags.EXINPUTSINK, window),
            };

            if (!Functions.RegisterRawInputDevices(DeviceTypes, DeviceTypes.Length, API.RawInputDeviceSize))
            {
                Debug.Print("[Warning] Raw input registration failed with error: {0}.",
                    Marshal.GetLastWin32Error());
            }
            else
            {
                Debug.Print("[WinRawJoystick] Registered for raw input");
            }

            RefreshDevices();

            Debug.Unindent();
        }

        #region Public Members

        public void RefreshDevices()
        {
            // Mark all devices as disconnected. We will check which of those
            // are connected below.
            foreach (var device in Devices)
            {
                device.SetConnected(false);
            }

            // Discover joystick devices
            foreach (RawInputDeviceList dev in WinRawInput.GetDeviceList())
            {
                // Skip non-joystick devices
                if (dev.Type != RawInputDeviceType.HID)
                    continue;

                IntPtr handle = dev.Device;
                Guid guid = GetDeviceGuid(handle);
                //long hardware_id = guid.GetHashCode();
                long hardware_id = handle.ToInt64();

                Device device = Devices.FromHardwareId(hardware_id);
                if (device != null)
                {
                    // We have already opened this device, mark it as connected
                    device.SetConnected(true);
                }
                else
                {
                    device = new Device(handle, guid);

                    // This is a new device, query its capabilities and add it
                    // to the device list
                    QueryDeviceCaps(device);

                    device.SetConnected(true);
                    Devices.Add(hardware_id, device);

                    Debug.Print("[{0}] Connected joystick {1} ({2})",
                        GetType().Name, device.GetGuid(), device.GetCapabilities());
                }
            }
        }

        public unsafe bool ProcessEvent(IntPtr raw)
        {
            // Query the size of the raw HID data buffer
            int size = 0;
            Functions.GetRawInputData(raw, GetRawInputDataEnum.INPUT, IntPtr.Zero, ref size, RawInputHeader.SizeInBytes);
            if (size > HIDData.Length)
            {
                Array.Resize(ref HIDData, size);
            }

            // Retrieve the raw HID data buffer
            if (Functions.GetRawInputData(raw, HIDData) > 0)
            {
                fixed (byte* pdata = HIDData)
                {
                    RawInput* rin = (RawInput*)pdata;

                    IntPtr handle = rin->Header.Device;
                    Device stick = GetDevice(handle);
                    if (stick == null)
                    {
                        Debug.Print("[WinRawJoystick] Unknown device {0}", handle);
                        return false;
                    }

                    if (!GetPreparsedData(handle, ref PreparsedData))
                    {
                        return false;
                    }

                    // Detect which axes / buttons are contained in this report
                    HidProtocolCaps caps;
                    int axis_caps_count;
                    int button_caps_count;
                    if (!GetDeviceCaps(PreparsedData, out caps,
                        ref AxisCaps, out axis_caps_count,
                        ref ButtonCaps, out button_caps_count))
                    {
                        return false;
                    }

                    // Query current state
                    // Allocate enough storage to hold the data of the current report
                    int report_count = HidProtocol.MaxDataListLength(HidProtocolReportType.Input, PreparsedData);
                    if (report_count == 0)
                    {
                        Debug.Print("[WinRawJoystick] HidProtocol.MaxDataListLength() failed with {0}",
                            Marshal.GetLastWin32Error());
                        return false;
                    }

                    // Fill the data buffer
                    if (DataBuffer.Length < report_count)
                    {
                        Array.Resize(ref DataBuffer, report_count);
                    }

                    /*
                    if (HidProtocol.GetData(HidProtocolReportType.Input,
                        DataBuffer, ref size, PreparsedData,
                        new IntPtr((void*)&rin->Data.HID.RawData),
                        rin->Data.HID.Size) != HidProtocolStatus.Success)
                    {
                        Debug.Print("[WinRawJoystick] HidProtocol.GetData() failed with {0}",
                            Marshal.GetLastWin32Error());
                        return false;
                    }
                    */

                    UpdateButtons(rin, stick, button_caps_count);

                    //UpdateAxes(stick, caps, AxisCaps, axis_caps_count, DataBuffer, size);
                    return true;
                }
            }

            return false;
        }

        unsafe void UpdateButtons(RawInput* rin, Device stick, int button_caps_count)
        {
            stick.ClearButtons();

            for (int i = 0; i < button_caps_count; i++)
            {
                short* usage_list = stackalloc short[(int)JoystickButton.Last];
                int usage_length = (int)JoystickButton.Last;
                HIDPage page = ButtonCaps[i].UsagePage;

                HidProtocolStatus status = HidProtocol.GetUsages(
                    HidProtocolReportType.Input,
                    page, 0, usage_list, ref usage_length,
                    PreparsedData,
                    new IntPtr((void*)&rin->Data.HID.RawData),
                    rin->Data.HID.Size);

                if (status != HidProtocolStatus.Success)
                {
                    Debug.Print("[WinRawJoystick] HidProtocol.GetUsages() failed with {0}",
                        Marshal.GetLastWin32Error());
                    continue;
                }

                for (int j = 0; j < usage_length; j++)
                {
                    stick.SetButton(page, *(usage_list + j), true);
                }
            }
        }

        #endregion

        #region Private Members

        static bool GetPreparsedData(IntPtr handle, ref byte[] prepared_data)
        {
            // Query the size of the _HIDP_PREPARSED_DATA structure for this event.
            int preparsed_size = 0;
            Functions.GetRawInputDeviceInfo(handle, RawInputDeviceInfoEnum.PREPARSEDDATA,
                IntPtr.Zero, ref preparsed_size);
            if (preparsed_size == 0)
            {
                Debug.Print("[WinRawJoystick] Functions.GetRawInputDeviceInfo(PARSEDDATA) failed with {0}",
                    Marshal.GetLastWin32Error());
                return false;
            }

            // Allocate space for _HIDP_PREPARSED_DATA.
            // This is an untyped blob of data.
            if (prepared_data.Length < preparsed_size)
            {
                Array.Resize(ref prepared_data, preparsed_size);
            }

            if (Functions.GetRawInputDeviceInfo(handle, RawInputDeviceInfoEnum.PREPARSEDDATA,
                prepared_data, ref preparsed_size) < 0)
            {
                Debug.Print("[WinRawJoystick] Functions.GetRawInputDeviceInfo(PARSEDDATA) failed with {0}",
                    Marshal.GetLastWin32Error());
                return false;
            }

            return true;
        }

        void QueryDeviceCaps(Device stick)
        {
            HidProtocolCaps caps;
            int axis_count;
            int button_count;

            // Discovered elements
            int axes = 0;
            int dpads = 0;
            int buttons = 0;

            if (GetPreparsedData(stick.Handle, ref PreparsedData) &&
                GetDeviceCaps(PreparsedData, out caps,
                    ref AxisCaps, out axis_count,
                    ref ButtonCaps, out button_count))
            {
                for (int i = 0; i < axis_count; i++)
                {
                    if (AxisCaps[i].IsRange)
                    {
                        Debug.Print("[WinRawJoystick] Range axis elements not implemented.");
                        continue;
                    }

                    HIDPage page = AxisCaps[i].UsagePage;
                    switch (page)
                    {
                        case HIDPage.GenericDesktop:
                            switch ((HIDUsageGD)AxisCaps[i].NotRange.Usage)
                            {
                                case HIDUsageGD.X:
                                case HIDUsageGD.Y:
                                case HIDUsageGD.Z:
                                case HIDUsageGD.Rx:
                                case HIDUsageGD.Ry:
                                case HIDUsageGD.Rz:
                                case HIDUsageGD.Slider:
                                case HIDUsageGD.Dial:
                                case HIDUsageGD.Wheel:
                                    stick.SetAxis(page, AxisCaps[i].NotRange.Usage, 0);
                                    break;

                                case HIDUsageGD.Hatswitch:
                                    stick.SetHat(page, AxisCaps[i].NotRange.Usage, HatPosition.Centered);
                                    break;
                            }
                            break;

                        case HIDPage.Simulation:
                            switch ((HIDUsageSim)AxisCaps[i].NotRange.Usage)
                            {
                                case HIDUsageSim.Rudder:
                                case HIDUsageSim.Throttle:
                                    stick.SetAxis(page, AxisCaps[i].NotRange.Usage, 0);
                                    break;
                            }
                            break;
                    }
                }

                for (int i = 0; i < button_count; i++)
                {
                    bool is_range = ButtonCaps[i].IsRange;
                    HIDPage page = ButtonCaps[i].UsagePage;
                    switch (page)
                    {
                        case HIDPage.Button:
                            if (is_range)
                            {
                                for (short usage = ButtonCaps[i].Range.UsageMin; usage < ButtonCaps[i].Range.UsageMax; usage++)
                                {
                                    buttons++;
                                    stick.SetButton(page, usage, false);
                                }
                            }
                            else
                            {
                                buttons++;
                                stick.SetButton(page, ButtonCaps[i].NotRange.Usage, false);
                            }
                            break;

                        default:
                            Debug.Print("[WinRawJoystick] Unknown HIDPage {0} for button.", page);
                            break;
                    }
                }
            }

            stick.SetCapabilities(new JoystickCapabilities(axes, buttons, dpads, true));
        }

        static bool GetDeviceCaps(byte[] preparsed_data, out HidProtocolCaps caps,
            ref HidProtocolValueCaps[] axis_caps, out int axis_caps_count,
            ref HidProtocolButtonCaps[] button_caps, out int button_caps_count)
        {
            axis_caps_count = 0;
            button_caps_count = 0;

            // Query joystick capabilities
            caps = new HidProtocolCaps();
            if (HidProtocol.GetCaps(preparsed_data, ref caps) != HidProtocolStatus.Success)
            {
                Debug.Print("[WinRawJoystick] HidProtocol.GetCaps() failed with {0}",
                    Marshal.GetLastWin32Error());
                return false;
            }

            // Make sure our caps arrays are big enough
            if (axis_caps.Length < caps.NumberInputValueCaps)
            {
                Array.Resize(ref axis_caps, caps.NumberInputValueCaps);
            }
            if (button_caps.Length < caps.NumberInputButtonCaps)
            {
                Array.Resize(ref button_caps, caps.NumberInputButtonCaps);
            }

            // Axis capabilities
            ushort axis_count = (ushort)axis_caps.Length;
            if (HidProtocol.GetValueCaps(HidProtocolReportType.Input,
                axis_caps, ref axis_count, preparsed_data) !=
                HidProtocolStatus.Success)
            {
                Debug.Print("[WinRawJoystick] HidProtocol.GetValueCaps() failed with {0}",
                    Marshal.GetLastWin32Error());
                return false;
            }
            axis_caps_count = (int)axis_count;

            // Button capabilities
            ushort button_count = (ushort)button_caps.Length;
            if (HidProtocol.GetButtonCaps(HidProtocolReportType.Input,
                button_caps, ref button_count, preparsed_data) !=
                HidProtocolStatus.Success)
            {
                Debug.Print("[WinRawJoystick] HidProtocol.GetButtonCaps() failed with {0}",
                    Marshal.GetLastWin32Error());
                return false;
            }
            button_caps_count = (int)button_count;

            return true;
        }

        // Retrieves the GUID of a device, which is stored
        // in the last part of the DEVICENAME string
        Guid GetDeviceGuid(IntPtr handle)
        {
            Guid guid = new Guid();

            unsafe
            {
                // Find out how much memory we need to allocate
                // for the DEVICENAME string
                int size = 0;
                if (Functions.GetRawInputDeviceInfo(handle, RawInputDeviceInfoEnum.DEVICENAME, IntPtr.Zero, ref size) < 0 || size == 0)
                {
                    Debug.Print("[WinRawJoystick] Functions.GetRawInputDeviceInfo(DEVICENAME) failed with error {0}",
                        Marshal.GetLastWin32Error());
                    return guid;
                }

                // Allocate memory and retrieve the DEVICENAME string
                sbyte* pname = stackalloc sbyte[size + 1];
                if (Functions.GetRawInputDeviceInfo(handle, RawInputDeviceInfoEnum.DEVICENAME, (IntPtr)pname, ref size) < 0)
                {
                    Debug.Print("[WinRawJoystick] Functions.GetRawInputDeviceInfo(DEVICENAME) failed with error {0}",
                        Marshal.GetLastWin32Error());
                    return guid;
                }

                // Convert the buffer to a .Net string, and split it into parts
                string name = new string(pname);
                if (String.IsNullOrEmpty(name))
                {
                    Debug.Print("[WinRawJoystick] Failed to construct device name");
                    return guid;
                }

                // The GUID is stored in the last part of the string
                string[] parts = name.Split('#');
                if (parts.Length > 3)
                {
                    guid = new Guid(parts[3]);
                }
            }

            return guid;
        }

        static void UpdateAxes(Device stick, HidProtocolCaps caps, HidProtocolValueCaps[] axes, int axes_count, HidProtocolData[] data)
        {
            // Use the data indices in the axis and button caps arrays to
            // access the data buffer we just filled.
            for (int i = 0; i < axes_count; i++)
            {
                if (!axes[i].IsRange)
                {
                    int index = axes[i].NotRange.DataIndex;
                    if (index < 0 || index >= caps.NumberInputValueCaps)
                    {
                        // Should never happen
                        Debug.Print("[WinRawJoystick] Error: DataIndex out of range");
                        continue;
                    }

                    if (data[index].DataIndex != i)
                    {
                        // Should also never happen
                        Debug.Print("[WinRawJoystick] DataIndex != index ({0} != {1})",
                            data[index].DataIndex, i);
                        continue;
                    }

                    short value = (short)HidHelper.ScaleValue(data[i].RawValue,
                        axes[i].LogicalMin, axes[i].LogicalMax,
                        short.MinValue, short.MaxValue);

                    stick.SetAxis(axes[i].UsagePage, axes[i].NotRange.Usage, value);
                }
                else
                {
                    // Todo: fall back to HidProtocol.GetLinkCollectionNodes
                }
            }
        }

        Device GetDevice(IntPtr handle)
        {
            long hardware_id = handle.ToInt64();
            bool is_device_known = false;

            lock (UpdateLock)
            {
                is_device_known = Devices.FromHardwareId(hardware_id) != null;
            }

            if (!is_device_known)
            {
                RefreshDevices();
            }

            lock (UpdateLock)
            {
                return Devices.FromHardwareId(hardware_id);
            }
        }

        bool IsValid(int index)
        {
            return Devices.FromIndex(index) != null;
        }

        #endregion

        #region IJoystickDriver2 Members

        public JoystickState GetState(int index)
        {
            lock (UpdateLock)
            {
                if (IsValid(index))
                {
                    return Devices.FromIndex(index).GetState();
                }
                return new JoystickState();
            }
        }

        public JoystickCapabilities GetCapabilities(int index)
        {
            lock (UpdateLock)
            {
                if (IsValid(index))
                {
                    return Devices.FromIndex(index).GetCapabilities();
                }
                return new JoystickCapabilities();
            }
        }

        public Guid GetGuid(int index)
        {
            lock (UpdateLock)
            {
                if (IsValid(index))
                {
                    return Devices.FromIndex(index).GetGuid();
                }
                return new Guid();
            }
        }

        #endregion
    }
}