// Copyright (c) 2012-2021 Wojciech Figat. All rights reserved.

#if PLATFORM_WINDOWS

#include "WindowsInput.h"
#include "WindowsWindow.h"
#include "Engine/Input/Input.h"
#include "Engine/Input/Mouse.h"
#include "Engine/Input/Keyboard.h"
#include "Engine/Input/Gamepad.h"
#include "Engine/Engine/Engine.h"
#include "Engine/Profiler/ProfilerCPU.h"
#include "../Win32/IncludeWindowsHeaders.h"

#define DIRECTINPUT_VERSION 0x0800
#include <xinput.h>

/// <summary>
/// Implementation of the keyboard device for Windows platform.
/// </summary>
/// <seealso cref="Keyboard" />
class WindowsKeyboard : public Keyboard
{
public:

    /// <summary>
    /// Initializes a new instance of the <see cref="WindowsKeyboard"/> class.
    /// </summary>
    explicit WindowsKeyboard()
        : Keyboard()
    {
    }

public:

    bool WndProc(Window* window, Windows::UINT msg, Windows::WPARAM wParam, Windows::LPARAM lParam);
};

/// <summary>
/// Implementation of the mouse device for Windows platform.
/// </summary>
/// <seealso cref="Mouse" />
class WindowsMouse : public Mouse
{
public:

    /// <summary>
    /// Initializes a new instance of the <see cref="WindowsMouse"/> class.
    /// </summary>
    explicit WindowsMouse()
        : Mouse()
    {
    }

public:

    bool WndProc(Window* window, Windows::UINT msg, Windows::WPARAM wParam, Windows::LPARAM lParam);

public:

    // [Mouse]
    void SetMousePosition(const Vector2& newPosition) final override
    {
        ::SetCursorPos(static_cast<int32>(newPosition.X), static_cast<int32>(newPosition.Y));

        OnMouseMoved(newPosition);
    }
};

/// <summary>
/// Implementation of the gamepad device for Windows platform.
/// </summary>
/// <seealso cref="Gamepad" />
class WindowsGamepad : public Gamepad
{
private:

    Windows::DWORD _userIndex;

public:

    /// <summary>
    /// Initializes a new instance of the <see cref="WindowsGamepad"/> class.
    /// </summary>
    /// <param name="userIndex">The user index.</param>
    explicit WindowsGamepad(Windows::DWORD userIndex);

    /// <summary>
    /// Finalizes an instance of the <see cref="WindowsGamepad"/> class.
    /// </summary>
    ~WindowsGamepad();

public:

    // [Gamepad]
    void SetVibration(const GamepadVibrationState& state) override;

protected:

    // [Gamepad]
    bool UpdateState() override;
};

namespace WindowsInputImpl
{
    float XInputLastUpdateTime = 0;
    bool XInputGamepads[XUSER_MAX_COUNT] = { false };
    WindowsMouse Mouse;
    WindowsKeyboard Keyboard;
}

void WindowsInput::Init()
{
    Input::Mouse = &WindowsInputImpl::Mouse;
    Input::Keyboard = &WindowsInputImpl::Keyboard;
}

void WindowsInput::Update()
{
    // Update every second
    const float time = (float)Platform::GetTimeSeconds();
    if (time - WindowsInputImpl::XInputLastUpdateTime < 1.0f)
        return;
    WindowsInputImpl::XInputLastUpdateTime = time;

    PROFILE_CPU_NAMED("Input.ScanGamepads");

    XINPUT_STATE state;
    for (DWORD i = 0; i < XUSER_MAX_COUNT; i++)
    {
        if (!WindowsInputImpl::XInputGamepads[i])
        {
            const DWORD result = XInputGetState(i, &state);
            if (result == ERROR_SUCCESS)
            {
                Input::Gamepads.Add(New<WindowsGamepad>(i));
                Input::OnGamepadsChanged();
            }
        }
    }
}

bool WindowsInput::WndProc(Window* window, Windows::UINT msg, Windows::WPARAM wParam, Windows::LPARAM lParam)
{
    if (WindowsInputImpl::Mouse.WndProc(window, msg, wParam, lParam))
        return true;
    if (WindowsInputImpl::Keyboard.WndProc(window, msg, wParam, lParam))
        return true;
    return false;
}

bool WindowsKeyboard::WndProc(Window* window, const Windows::UINT msg, Windows::WPARAM wParam, Windows::LPARAM lParam)
{
    bool result = false;

    // Handle keyboard related messages
    switch (msg)
    {
    case WM_CHAR:
    {
        OnCharInput(static_cast<Char>(wParam), window);
        result = true;
        break;
    }
    case WM_KEYDOWN:
    case WM_SYSKEYDOWN:
    {
        OnKeyDown(static_cast<KeyboardKeys>(wParam), window);
        result = true;
        break;
    }
    case WM_KEYUP:
    case WM_SYSKEYUP:
    {
        OnKeyUp(static_cast<KeyboardKeys>(wParam), window);
        result = true;
        break;
    }
    }

    return result;
}

bool WindowsMouse::WndProc(Window* window, const UINT msg, WPARAM wParam, LPARAM lParam)
{
    bool result = false;

    // Get mouse position in screen coordinates
    POINT p;
    p.x = static_cast<LONG>(WINDOWS_GET_X_LPARAM(lParam));
    p.y = static_cast<LONG>(WINDOWS_GET_Y_LPARAM(lParam));
    ::ClientToScreen(window->GetHWND(), &p);
    const auto mousePos = Vector2(static_cast<float>(p.x), static_cast<float>(p.y));

    // Handle mouse related messages
    switch (msg)
    {
    case WM_MOUSEMOVE:
    {
        OnMouseMove(mousePos, window);
        result = true;
        break;
    }
    case WM_MOUSELEAVE:
    {
        OnMouseLeave(window);
        result = true;
        break;
    }
    case WM_LBUTTONDOWN:
    {
        OnMouseDown(mousePos, MouseButton::Left, window);
        result = true;
        break;
    }
    case WM_RBUTTONDOWN:
    {
        OnMouseDown(mousePos, MouseButton::Right, window);
        result = true;
        break;
    }
    case WM_MBUTTONDOWN:
    {
        OnMouseDown(mousePos, MouseButton::Middle, window);
        result = true;
        break;
    }
    case WM_XBUTTONDOWN:
    {
        const auto button = (HIWORD(wParam) & XBUTTON1) ? MouseButton::Extended1 : MouseButton::Extended2;
        OnMouseDown(mousePos, button, window);
        result = true;
        break;
    }
    case WM_LBUTTONUP:
    {
        OnMouseUp(mousePos, MouseButton::Left, window);
        result = true;
        break;
    }
    case WM_RBUTTONUP:
    {
        OnMouseUp(mousePos, MouseButton::Right, window);
        result = true;
        break;
    }
    case WM_MBUTTONUP:
    {
        OnMouseUp(mousePos, MouseButton::Middle, window);
        result = true;
        break;
    }
    case WM_XBUTTONUP:
    {
        const auto button = (HIWORD(wParam) & XBUTTON1) ? MouseButton::Extended1 : MouseButton::Extended2;
        OnMouseUp(mousePos, button, window);
        result = true;
        break;
    }
    case WM_LBUTTONDBLCLK:
    {
        OnMouseDoubleClick(mousePos, MouseButton::Left, window);
        result = true;
        break;
    }
    case WM_RBUTTONDBLCLK:
    {
        OnMouseDoubleClick(mousePos, MouseButton::Right, window);
        result = true;
        break;
    }
    case WM_MBUTTONDBLCLK:
    {
        OnMouseDoubleClick(mousePos, MouseButton::Middle, window);
        result = true;
        break;
    }
    case WM_MOUSEWHEEL:
    {
        const short delta = GET_WHEEL_DELTA_WPARAM(wParam);
        if (delta != 0)
        {
            const float deltaNormalized = static_cast<float>(delta) / WHEEL_DELTA;
            // Use cached mouse position, the input pos is sometimes wrong in Win32
            OnMouseWheel(_state.MousePosition, deltaNormalized, window);
        }
        result = true;
        break;
    }
    }

    return result;
}

float NormalizeXInputAxis(const int16 axisVal)
{
    // Normalize [-32768..32767] -> [-1..1]
    const float norm = axisVal <= 0 ? 32768.0f : 32767.0f;
    return float(axisVal) / norm;
}

WindowsGamepad::WindowsGamepad(Windows::DWORD userIndex)
    : Gamepad(Guid(0, 0, 0, userIndex), TEXT("XInput Gamepad"))
    , _userIndex(userIndex)
{
    WindowsInputImpl::XInputGamepads[_userIndex] = true;
}

WindowsGamepad::~WindowsGamepad()
{
    WindowsInputImpl::XInputGamepads[_userIndex] = false;
}

void WindowsGamepad::SetVibration(const GamepadVibrationState& state)
{
    Gamepad::SetVibration(state);

    XINPUT_VIBRATION xInputVibration;
    const float leftMotor = Math::Saturate((state.LeftLarge + state.LeftSmall) * 0.5f);
    const float rightMotor = Math::Saturate((state.RightLarge + state.RightSmall) * 0.5f);
    xInputVibration.wLeftMotorSpeed = static_cast<WORD>(leftMotor * 65535.0f);
    xInputVibration.wRightMotorSpeed = static_cast<WORD>(rightMotor * 65535.0f);
    XInputSetState(_userIndex, &xInputVibration);
}

bool WindowsGamepad::UpdateState()
{
    // Gather XInput device state
    XINPUT_STATE inputState;
    if (XInputGetState(_userIndex, &inputState) != ERROR_SUCCESS)
    {
        return true;
    }

    // Process buttons state
    _state.Buttons[(int32)GamepadButton::A] = !!(inputState.Gamepad.wButtons & XINPUT_GAMEPAD_A);
    _state.Buttons[(int32)GamepadButton::B] = !!(inputState.Gamepad.wButtons & XINPUT_GAMEPAD_B);
    _state.Buttons[(int32)GamepadButton::X] = !!(inputState.Gamepad.wButtons & XINPUT_GAMEPAD_X);
    _state.Buttons[(int32)GamepadButton::Y] = !!(inputState.Gamepad.wButtons & XINPUT_GAMEPAD_Y);
    _state.Buttons[(int32)GamepadButton::LeftShoulder] = !!(inputState.Gamepad.wButtons & XINPUT_GAMEPAD_LEFT_SHOULDER);
    _state.Buttons[(int32)GamepadButton::RightShoulder] = !!(inputState.Gamepad.wButtons & XINPUT_GAMEPAD_RIGHT_SHOULDER);
    _state.Buttons[(int32)GamepadButton::Back] = !!(inputState.Gamepad.wButtons & XINPUT_GAMEPAD_BACK);
    _state.Buttons[(int32)GamepadButton::Start] = !!(inputState.Gamepad.wButtons & XINPUT_GAMEPAD_START);
    _state.Buttons[(int32)GamepadButton::LeftThumb] = !!(inputState.Gamepad.wButtons & XINPUT_GAMEPAD_LEFT_THUMB);
    _state.Buttons[(int32)GamepadButton::RightThumb] = !!(inputState.Gamepad.wButtons & XINPUT_GAMEPAD_RIGHT_THUMB);
    _state.Buttons[(int32)GamepadButton::LeftTrigger] = inputState.Gamepad.bLeftTrigger > XINPUT_GAMEPAD_TRIGGER_THRESHOLD;
    _state.Buttons[(int32)GamepadButton::RightTrigger] = inputState.Gamepad.bRightTrigger > XINPUT_GAMEPAD_TRIGGER_THRESHOLD;
    _state.Buttons[(int32)GamepadButton::DPadUp] = !!(inputState.Gamepad.wButtons & XINPUT_GAMEPAD_DPAD_UP);
    _state.Buttons[(int32)GamepadButton::DPadDown] = !!(inputState.Gamepad.wButtons & XINPUT_GAMEPAD_DPAD_DOWN);
    _state.Buttons[(int32)GamepadButton::DPadLeft] = !!(inputState.Gamepad.wButtons & XINPUT_GAMEPAD_DPAD_LEFT);
    _state.Buttons[(int32)GamepadButton::DPadRight] = !!(inputState.Gamepad.wButtons & XINPUT_GAMEPAD_DPAD_RIGHT);
    _state.Buttons[(int32)GamepadButton::LeftStickUp] = inputState.Gamepad.sThumbLY > XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE;
    _state.Buttons[(int32)GamepadButton::LeftStickDown] = inputState.Gamepad.sThumbLY < -XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE;
    _state.Buttons[(int32)GamepadButton::LeftStickLeft] = inputState.Gamepad.sThumbLX < -XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE;
    _state.Buttons[(int32)GamepadButton::LeftStickRight] = inputState.Gamepad.sThumbLX > XINPUT_GAMEPAD_LEFT_THUMB_DEADZONE;
    _state.Buttons[(int32)GamepadButton::RightStickUp] = inputState.Gamepad.sThumbRY > XINPUT_GAMEPAD_RIGHT_THUMB_DEADZONE;
    _state.Buttons[(int32)GamepadButton::RightStickDown] = inputState.Gamepad.sThumbRY < -XINPUT_GAMEPAD_RIGHT_THUMB_DEADZONE;
    _state.Buttons[(int32)GamepadButton::RightStickLeft] = inputState.Gamepad.sThumbRX < -XINPUT_GAMEPAD_RIGHT_THUMB_DEADZONE;
    _state.Buttons[(int32)GamepadButton::RightStickRight] = inputState.Gamepad.sThumbRX > XINPUT_GAMEPAD_RIGHT_THUMB_DEADZONE;

    // Process axes state
    _state.Axis[(int32)GamepadAxis::LeftStickX] = NormalizeXInputAxis(inputState.Gamepad.sThumbLX);
    _state.Axis[(int32)GamepadAxis::LeftStickY] = NormalizeXInputAxis(inputState.Gamepad.sThumbLY);
    _state.Axis[(int32)GamepadAxis::RightStickX] = NormalizeXInputAxis(inputState.Gamepad.sThumbRX);
    _state.Axis[(int32)GamepadAxis::RightStickY] = NormalizeXInputAxis(inputState.Gamepad.sThumbRY);
    _state.Axis[(int32)GamepadAxis::LeftTrigger] = inputState.Gamepad.bLeftTrigger / 255.0f;
    _state.Axis[(int32)GamepadAxis::RightTrigger] = inputState.Gamepad.bRightTrigger / 255.0f;

    return false;
}

#endif