using anjianjingling.Native;
using System.Diagnostics;
using System.Text;

namespace anjianjingling.Window
{
    public record WindowInfo(IntPtr Handle, string Title);

    /// <summary>
    /// 系统级窗口管理：枚举、查找、激活、启动程序、后台消息投递。
    /// </summary>
    public sealed class WindowManager
    {
        /// <summary>启动外部程序或打开文件。</summary>
        public void Launch(string path, string? arguments = null)
        {
            var psi = new ProcessStartInfo
            {
                FileName = path,
                UseShellExecute = true
            };
            if (!string.IsNullOrWhiteSpace(arguments)) psi.Arguments = arguments;
            Process.Start(psi);
        }

        /// <summary>枚举所有可见且有标题的顶层窗口。</summary>
        public List<WindowInfo> GetWindows()
        {
            var list = new List<WindowInfo>();
            Win32.EnumWindows((h, _) =>
            {
                if (Win32.IsWindowVisible(h))
                {
                    int len = Win32.GetWindowTextLength(h);
                    if (len > 0)
                    {
                        var sb = new StringBuilder(len + 1);
                        Win32.GetWindowText(h, sb, sb.Capacity);
                        var title = sb.ToString().Trim();
                        if (title.Length > 0) list.Add(new WindowInfo(h, title));
                    }
                }
                return true;
            }, IntPtr.Zero);
            return list;
        }

        /// <summary>按标题关键字（包含匹配，不区分大小写）查找窗口。</summary>
        public IntPtr FindByTitle(string keyword)
        {
            foreach (var w in GetWindows())
            {
                if (w.Title.Contains(keyword, StringComparison.OrdinalIgnoreCase))
                    return w.Handle;
            }
            return IntPtr.Zero;
        }

        /// <summary>激活窗口并前置（最小化则恢复，使用 AttachThreadInput 解决前台锁定）。</summary>
        public bool Activate(IntPtr hWnd)
        {
            if (hWnd == IntPtr.Zero) return false;
            if (Win32.IsIconic(hWnd)) Win32.ShowWindow(hWnd, Win32.SW_RESTORE);

            uint foregroundThread = Win32.GetWindowThreadProcessId(Win32.GetForegroundWindow(), out _);
            uint currentThread = Win32.GetCurrentThreadId();

            if (foregroundThread != currentThread)
            {
                Win32.AttachThreadInput(currentThread, foregroundThread, true);
                Win32.SetForegroundWindow(hWnd);
                Win32.AttachThreadInput(currentThread, foregroundThread, false);
            }
            else
            {
                Win32.SetForegroundWindow(hWnd);
            }
            return true;
        }

        /// <summary>按标题激活。</summary>
        public bool ActivateByTitle(string keyword)
        {
            var h = FindByTitle(keyword);
            return h != IntPtr.Zero && Activate(h);
        }

        /// <summary>获取窗口屏幕矩形。</summary>
        public Rectangle? GetBounds(IntPtr hWnd)
        {
            if (Win32.GetWindowRect(hWnd, out var r))
                return new Rectangle(r.Left, r.Top, r.Width, r.Height);
            return null;
        }

        /// <summary>
        /// 后台点击：向窗口句柄 PostMessage 发送鼠标按下/弹起（客户区坐标），不抢焦点。
        /// 注意：对 DirectX/自绘程序可能无效。
        /// </summary>
        public void PostClick(IntPtr hWnd, int clientX, int clientY, bool right = false)
        {
            var lp = Win32.MakeLParam(clientX, clientY);
            uint down = right ? Win32.WM_RBUTTONDOWN : Win32.WM_LBUTTONDOWN;
            uint up = right ? Win32.WM_RBUTTONUP : Win32.WM_LBUTTONUP;
            Win32.PostMessage(hWnd, down, Win32.MK_LBUTTON, lp);
            Thread.Sleep(60);
            Win32.PostMessage(hWnd, up, IntPtr.Zero, lp);
        }
    }
}