using System.Drawing;
using System.Runtime.InteropServices;
using System.Text;

namespace XFEExtension.NetCore.InputSimulator;

/// <summary>
/// 模拟用户输入
/// </summary>
public static partial class InputSimulator
{
    #region DLL引用
    [LibraryImport("user32.dll", SetLastError = true)]
    private static partial void keybd_event(byte bVk, byte bScan, uint dwFlags, IntPtr dwExtraInfo);
    [LibraryImport("user32.dll")]
    private static partial void mouse_event(uint dwFlags, int dx, int dy, int dwData, IntPtr dwExtraInfo);
    [LibraryImport("user32.dll")]
    private static partial int GetSystemMetrics(int nIndex);
    [LibraryImport("user32.dll")]
    private static partial void SetCursorPos(int x, int y);
    [LibraryImport("user32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static partial bool GetCursorPos(out Point lpPoint);
    [LibraryImport("user32.dll")]
    private static partial IntPtr GetDC(IntPtr hWnd);
    [LibraryImport("user32.dll")]
    private static partial int ReleaseDC(IntPtr hWnd, IntPtr hDC);
    [LibraryImport("user32.dll")]
    private static partial int GetDpiForWindow(IntPtr hWnd);
    [LibraryImport("user32.dll")]
    private static partial short GetAsyncKeyState(int vKey);
    [LibraryImport("user32.dll")]
    private static partial IntPtr GetDesktopWindow();
    [LibraryImport("gdi32.dll")]
    private static partial int GetDeviceCaps(IntPtr hdc, int nIndex);
    #endregion
    #region 常量
    private const int KEYEVENTF_KEYDOWN = 0x0000; // 按键按下
    private const int KEYEVENTF_KEYUP = 0x0002; // 按键松开
    private const uint MOUSEEVENTF_MOVE = 0x0001; // 鼠标移动
    private const uint MOUSEEVENTF_LEFTDOWN = 0x0002; // 鼠标左键按下
    private const uint MOUSEEVENTF_LEFTUP = 0x0004; // 鼠标左键松开
    private const uint MOUSEEVENTF_RIGHTDOWN = 0x0008; // 鼠标右键按下
    private const uint MOUSEEVENTF_RIGHTUP = 0x0010; // 鼠标右键松开
    private const uint MOUSEEVENTF_MIDDOWN = 0x0020; // 鼠标中键按下
    private const uint MOUSEEVENTF_MIDUP = 0x0040; // 鼠标中键松开
    private const uint MOUSEEVENTF_WHEEL = 0x0800; // 鼠标滚轮
    private const int VK_LBUTTON = 0x01; // 检测鼠标左键
    private const int VK_RBUTTON = 0x02; // 检测鼠标右键
    private const int VK_MBUTTON = 0x04; // 检测鼠标中键
    private const int SM_CXSCREEN = 0; // 屏幕宽度
    private const int SM_CYSCREEN = 1; // 屏幕高度
    private const int HORZRES = 8;
    private const int VERTRES = 10;
    private const int LOGPIXELSX = 88;
    private const int LOGPIXELSY = 90;
    private const int DESKTOPVERTRES = 117;
    private const int DESKTOPHORZRES = 118;
    #endregion
    #region 键盘方法
    /// <summary>
    /// 按住某个按键
    /// </summary>
    /// <param name="key">按键</param>
    public static void KeyDown(char key)
    {
        byte keyCode = (byte)key;
        keybd_event(keyCode, 0, KEYEVENTF_KEYDOWN, IntPtr.Zero);
    }
    /// <summary>
    /// 松开某个按键
    /// </summary>
    /// <param name="key">按键</param>
    public static void KeyUp(char key)
    {
        byte keyCode = (byte)key;
        keybd_event(keyCode, 0, KEYEVENTF_KEYUP, IntPtr.Zero);
    }
    /// <summary>
    /// 按下某个按键
    /// </summary>
    /// <remarks>
    /// 如果需要输入一组按键，请使用<see cref="InputKeys(string)"/>
    /// </remarks>
    /// <param name="key">按键</param>
    public static void PressKey(char key)
    {
        byte keyCode = (byte)key;
        keybd_event(keyCode, 0, KEYEVENTF_KEYDOWN, IntPtr.Zero);
        keybd_event(keyCode, 0, KEYEVENTF_KEYUP, IntPtr.Zero);
    }
    /// <summary>
    /// 按下某个按键
    /// </summary>
    /// <remarks>
    /// 如果需要输入一组按键，请使用<see cref="InputKeys(string)"/>
    /// </remarks>
    /// <param name="key">按键</param>
    /// <param name="holdTime">按下时间</param>
    public static async Task PressKeyAsync(char key, int holdTime)
    {
        byte keyCode = (byte)key;
        keybd_event(keyCode, 0, KEYEVENTF_KEYDOWN, IntPtr.Zero);
        await Task.Delay(holdTime);
        keybd_event(keyCode, 0, KEYEVENTF_KEYUP, IntPtr.Zero);
    }
    /// <summary>
    /// 输入一组按键
    /// </summary>
    /// <remarks>
    /// 如果需要输入延迟，请使用<see cref="InputKeysAsync(string, int, int)"/>
    /// </remarks>
    /// <param name="keys">待输入按键</param>
    public static void InputKeys(string keys)
    {
        foreach (var key in keys.Select(key => key.ToString()))
        {
            if (key.Equals(key, StringComparison.CurrentCultureIgnoreCase))
            {
                keybd_event(0x10, 0, KEYEVENTF_KEYDOWN, IntPtr.Zero);
                keybd_event(Encoding.ASCII.GetBytes(key).FirstOrDefault(), 0, KEYEVENTF_KEYDOWN, IntPtr.Zero);
                keybd_event(Encoding.ASCII.GetBytes(key).FirstOrDefault(), 0, KEYEVENTF_KEYUP, IntPtr.Zero);
                keybd_event(0x10, 0, KEYEVENTF_KEYUP, IntPtr.Zero);
            }
            else
            {
                keybd_event(Encoding.ASCII.GetBytes(key.ToUpper()).FirstOrDefault(), 0, KEYEVENTF_KEYDOWN, IntPtr.Zero);
                keybd_event(Encoding.ASCII.GetBytes(key.ToUpper()).FirstOrDefault(), 0, KEYEVENTF_KEYUP, IntPtr.Zero);
            }
        }
    }
    /// <summary>
    /// 输入一组按键
    /// </summary>
    /// <param name="keys">待输入按键</param>
    /// <param name="holdTime">每个按键按住的时间</param>
    /// <param name="delay">按键间延迟</param>
    /// <returns></returns>
    public static async Task InputKeysAsync(string keys, int holdTime = 0, int delay = 0)
    {
        foreach (var key in keys.Select(key => key.ToString()))
        {
            if (key.Equals(key, StringComparison.CurrentCultureIgnoreCase))
            {
                keybd_event(0x10, 0, KEYEVENTF_KEYDOWN, IntPtr.Zero);
                keybd_event(Encoding.ASCII.GetBytes(key).FirstOrDefault(), 0, KEYEVENTF_KEYDOWN, IntPtr.Zero);
                await Task.Delay(holdTime);
                keybd_event(Encoding.ASCII.GetBytes(key).FirstOrDefault(), 0, KEYEVENTF_KEYUP, IntPtr.Zero);
                keybd_event(0x10, 0, KEYEVENTF_KEYUP, IntPtr.Zero);
            }
            else
            {
                keybd_event(Encoding.ASCII.GetBytes(key.ToUpper()).FirstOrDefault(), 0, KEYEVENTF_KEYDOWN, IntPtr.Zero);
                await Task.Delay(holdTime);
                keybd_event(Encoding.ASCII.GetBytes(key.ToUpper()).FirstOrDefault(), 0, KEYEVENTF_KEYUP, IntPtr.Zero);
            }
            await Task.Delay(delay);
        }
    }
    #endregion
    #region 鼠标方法
    /// <summary>
    /// 相对移动
    /// </summary>
    /// <remarks>
    /// 如果需要绝对移动请使用<see cref="LocateTo(int, int)"/>方法
    /// </remarks>
    /// <param name="x">X偏移</param>
    /// <param name="y">Y偏移</param>
    public static void MouseMove(int x, int y)
    {
        mouse_event(MOUSEEVENTF_MOVE, x, y, 0, IntPtr.Zero);
    }
    /// <summary>
    /// 将鼠标定位至
    /// </summary>
    /// <remarks>
    /// 如果需要相对移动请使用<see cref="MouseMove(int, int)"/>方法
    /// </remarks>
    /// <param name="x">X坐标</param>
    /// <param name="y">Y坐标</param>
    public static void LocateTo(int x, int y)
    {
        SetCursorPos(x, y);
    }
    /// <summary>
    /// 将鼠标定位至
    /// </summary>
    /// <remarks>
    /// 如果需要相对移动请使用<see cref="MouseMove(int, int)"/>方法
    /// </remarks>
    /// <param name="point">定位到的位置</param>
    public static void LocateTo(Point point)
    {
        LocateTo(point.X, point.Y);
    }
    /// <summary>
    /// 将鼠标定位至
    /// </summary>
    /// <remarks>
    /// 如果需要相对移动请使用<see cref="MouseMove(int, int)"/>方法
    /// </remarks>
    /// <param name="screenPosition">屏幕空间位置</param>
    public static void LocateTo(ScreenPosition screenPosition)
    {
        switch (screenPosition)
        {
            case ScreenPosition.TopLeft:
                LocateTo(0, 0);
                break;
            case ScreenPosition.TopRight:
                LocateTo(GetScreenSize().Width - 1, 0);
                break;
            case ScreenPosition.Top:
                LocateTo(GetScreenSize().Width / 2, 0);
                break;
            case ScreenPosition.Left:
                LocateTo(0, GetScreenSize().Height / 2);
                break;
            case ScreenPosition.Right:
                LocateTo(GetScreenSize().Width - 1, GetScreenSize().Height / 2);
                break;
            case ScreenPosition.Center:
                LocateTo(GetScreenSize().Width / 2, GetScreenSize().Height / 2);
                break;
            case ScreenPosition.BottomLeft:
                LocateTo(0, GetScreenSize().Height - 1);
                break;
            case ScreenPosition.Bottom:
                LocateTo(GetScreenSize().Width / 2, GetScreenSize().Height - 1);
                break;
            case ScreenPosition.BottomRight:
                LocateTo(GetScreenSize().Width - 1, GetScreenSize().Height - 1);
                break;
            default:
                break;
        }
    }
    /// <summary>
    /// 模拟鼠标点击
    /// </summary>
    /// <param name="mouseButton">鼠标按键</param>
    public static void MouseClick(MouseButton mouseButton)
    {
        switch (mouseButton)
        {
            case MouseButton.Left:
                mouse_event(MOUSEEVENTF_LEFTDOWN, GetMousePosition().X, GetMousePosition().Y, 0, IntPtr.Zero);
                mouse_event(MOUSEEVENTF_LEFTUP, GetMousePosition().X, GetMousePosition().Y, 0, IntPtr.Zero);
                break;
            case MouseButton.Right:
                mouse_event(MOUSEEVENTF_RIGHTDOWN, GetMousePosition().X, GetMousePosition().Y, 0, IntPtr.Zero);
                mouse_event(MOUSEEVENTF_RIGHTUP, GetMousePosition().X, GetMousePosition().Y, 0, IntPtr.Zero);
                break;
            case MouseButton.Middle:
                mouse_event(MOUSEEVENTF_MIDDOWN, GetMousePosition().X, GetMousePosition().Y, 0, IntPtr.Zero);
                mouse_event(MOUSEEVENTF_MIDUP, GetMousePosition().X, GetMousePosition().Y, 0, IntPtr.Zero);
                break;
            default:
                break;
        }
    }
    /// <summary>
    /// 模拟鼠标点击
    /// </summary>
    /// <param name="mouseButton">鼠标按键</param>
    /// <param name="holdTime">鼠标按键按住时间</param>
    public static async Task MouseClickAsync(MouseButton mouseButton, int holdTime)
    {
        switch (mouseButton)
        {
            case MouseButton.Left:
                mouse_event(MOUSEEVENTF_LEFTDOWN, GetMousePosition().X, GetMousePosition().Y, 0, IntPtr.Zero);
                await Task.Delay(holdTime);
                mouse_event(MOUSEEVENTF_LEFTUP, GetMousePosition().X, GetMousePosition().Y, 0, IntPtr.Zero);
                break;
            case MouseButton.Right:
                mouse_event(MOUSEEVENTF_RIGHTDOWN, GetMousePosition().X, GetMousePosition().Y, 0, IntPtr.Zero);
                await Task.Delay(holdTime);
                mouse_event(MOUSEEVENTF_RIGHTUP, GetMousePosition().X, GetMousePosition().Y, 0, IntPtr.Zero);
                break;
            case MouseButton.Middle:
                mouse_event(MOUSEEVENTF_MIDDOWN, GetMousePosition().X, GetMousePosition().Y, 0, IntPtr.Zero);
                await Task.Delay(holdTime);
                mouse_event(MOUSEEVENTF_MIDUP, GetMousePosition().X, GetMousePosition().Y, 0, IntPtr.Zero);
                break;
            default:
                break;
        }
    }
    /// <summary>
    /// 鼠标滚轮滚动
    /// </summary>
    /// <param name="length">滚动长度，负为向下滚动</param>
    public static void MouseWhellRoll(int length)
    {
        mouse_event(MOUSEEVENTF_WHEEL, GetMousePosition().X, GetMousePosition().Y, length, IntPtr.Zero);
    }
    /// <summary>
    /// 检查鼠标是否按下
    /// </summary>
    /// <param name="button">鼠标按键</param>
    /// <returns>是否被按下</returns>
    public static bool GetMouseDown(MouseButton button) => button switch
    {
        MouseButton.Left => (GetAsyncKeyState(VK_LBUTTON) & 0x8000) != 0,
        MouseButton.Right => (GetAsyncKeyState(VK_RBUTTON) & 0x8000) != 0,
        MouseButton.Middle => (GetAsyncKeyState(VK_MBUTTON) & 0x8000) != 0,
        _ => false
    };
    #endregion
    #region 系统信息获取方法
    /// <summary>
    /// 获取屏幕的宽高
    /// </summary>
    /// <returns>屏幕宽高</returns>
    public static Size GetScreenSize()
    {
        return new Size(GetSystemMetrics(SM_CXSCREEN), GetSystemMetrics(SM_CYSCREEN));
    }
    /// <summary>
    /// 获取屏幕的绝对宽高
    /// </summary>
    /// <returns></returns>
    public static Size GetAbsoluteScreenSize()
    {
        var hdc = GetDC(GetDesktopWindow());
        int nWidth = GetDeviceCaps(hdc, DESKTOPHORZRES);
        int nHeight = GetDeviceCaps(hdc, DESKTOPVERTRES);
        _ = ReleaseDC(IntPtr.Zero, hdc);
        return new Size(nWidth, nHeight);
    }
    /// <summary>
    /// 获取鼠标的当前位置
    /// </summary>
    /// <returns>鼠标位置</returns>
    public static Point GetMousePosition()
    {
        GetCursorPos(out Point point);
        return point;
    }
    /// <summary>
    /// 获取鼠标位置相对于屏幕大小的百分比
    /// </summary>
    /// <returns>百分比，0-1之间(X, Y)</returns>
    public static (double X, double Y) GetMousePointRelatively()
    {
        GetCursorPos(out Point point);
        return ((double)point.X / (GetSystemMetrics(SM_CXSCREEN) - 1), (double)point.Y / (GetSystemMetrics(SM_CYSCREEN) - 1));
    }
    /// <summary>
    /// 获取当前缩放倍率
    /// </summary>
    /// <returns></returns>
    public static double GetScalingFactorForWindow()
    {
        return GetAbsoluteScreenSize().Width / GetScreenSize().Width;
    }
    /// <summary>
    /// 获取当前窗口的缩放倍率
    /// </summary>
    /// <param name="hWnd">窗口句柄</param>
    /// <returns></returns>
    public static double GetScalingFactorForWindow(nint hWnd)
    {
        var hDC = GetDC(hWnd);
        var dpi = GetDpiForWindow(hWnd);
        _ = ReleaseDC(hWnd, hDC);
        return dpi / 96.0f;
    }
    #endregion
}