using System;
using System.Runtime.InteropServices;
using UnityEngine;

namespace Chiva.Toolkit.Function.NoBorder
{
    /// <summary>
    /// 系统工具类
    /// </summary>
    public class WindowsTools
    {
        /// <summary>
        /// 获取应用对应进程句柄
        /// </summary>
        private static IntPtr ProcessHandle;

        #region 方法
        /// <summary>
        /// 获取顶层窗口的句柄，不搜索子窗口
        /// </summary>
        /// <param name="lpClassName">类名</param>
        /// <param name="lpWindowName">窗口名</param>
        /// <returns></returns>
        [DllImport("user32.dll")]
        private static extern IntPtr FindWindow(string lpClassName, string lpWindowName);

        /// <summary>
        /// 设置指定窗口的显示状态
        /// </summary>
        /// <param name="hwnd"></param>
        /// <param name="nCmdShow"></param>
        /// <returns></returns>
        [DllImport("user32.dll")]
        public static extern bool ShowWindow(IntPtr hwnd, int nCmdShow);

        /// <summary>
        /// 获取一个前台窗口的句柄（用户当前工作的窗口）
        /// </summary>
        /// <returns></returns>
        [DllImport("user32.dll")]
        private static extern IntPtr GetForegroundWindow();

        /// <summary>
        /// 用来改变指定窗口的属性
        /// </summary>
        /// <param name="hwnd">窗口句柄及间接给出的窗口所属的类</param>
        /// <param name="nIndex">将设定的大于等于0的偏移值</param>
        /// <param name="dwNewLong">替换值</param>
        /// <returns></returns>
        [DllImport("user32.dll")]
        private static extern IntPtr SetWindowLong(IntPtr hwnd, int nIndex, int dwNewLong);

        /// <summary>
        /// 改变一个子窗口，弹出式窗口或顶层窗口的尺寸
        /// </summary>
        /// <param name="hWnd"></param>
        /// <param name="hWndInsertAfter"></param>
        /// <param name="X"></param>
        /// <param name="Y"></param>
        /// <param name="cx"></param>
        /// <param name="cy"></param>
        /// <param name="uFlags"></param>
        /// <returns></returns>
        [DllImport("user32.dll")]
        private static extern bool SetWindowPos(IntPtr hWnd, int hWndInsertAfter, int X, int Y, int cx, int cy, uint uFlags);

        /// <summary>
        /// 释放当前线程窗口的鼠标捕获
        /// </summary>
        /// <returns></returns>
        [DllImport("user32.dll")]
        private static extern bool ReleaseCapture();

        /// <summary>
        /// 将指定的消息发送到一个或多个窗口
        /// </summary>
        /// <param name="hwnd">指定要接收消息的窗口的句柄</param>
        /// <param name="wMsg">指定被发送的消息</param>
        /// <param name="wParam">指定附加的消息特定信息</param>
        /// <param name="IParam">指定附加的消息特定信息</param>
        /// <returns></returns>
        [DllImport("user32.dll")]
        private static extern bool SendMessage(IntPtr hwnd, int wMsg, int wParam, int IParam);
        #endregion

        #region 常量

        /// <summary>
        /// 显示窗口
        /// </summary>
        public const int SWP_SHOWWINDOW = 0x0040;

        /// <summary>
        /// 边框样式
        /// </summary>
        public const int GWL_STYLE = -16;

        /// <summary>
        /// 创建一个单边框的窗口
        /// </summary>
        public const int WS_BORDER = 1;

        /// <summary>
        /// 该窗口是一个弹出窗口
        /// </summary>
        public const int WS_POPUP = 0x800000;

        /// <summary>
        /// 激活窗口并将其最小化
        /// </summary>
        public const int SW_SHOWMINIMIZED = 2;

        /// <summary>
        /// 激活窗口并将其最大化
        /// </summary>
        public const int SW_SHOWMAXIMIZED = 3;

        /// <summary>
        /// 当光标在一个窗口的非客户区同时按下鼠标左键时提交此消息 
        /// </summary>
        private const int WM_NCLBUTTONDOWN = 0xA1;

        /// <summary>
        /// 当窗口被销毁时发送
        /// </summary>
        private const int WM_DESTROY = 0x02;

        /// <summary>
        /// 当用户在光标位于窗口的工作区时释放鼠标左键时发布
        /// </summary>
        private const int WM_LBUTTONUP = 0x0202;
        #endregion

        #region 公开
        /// <summary>
        /// 获取当前窗口句柄
        /// </summary>
        /// <param name="_productName">产品名称</param>
        public static void GetCurrentWindowHandle(string _productName)
        {
            IntPtr hWnd = FindWindow("UnityWndClass", _productName);

            if (hWnd != null)
            {
                ProcessHandle = hWnd;
            }
            else
            {
                ProcessHandle = GetForegroundWindow();
            }
        }

        private static string msg = "";

        /// <summary>
        /// 最小化窗口
        /// </summary>
        public static void SetMinWindows()
        {
            ShowWindow(ProcessHandle, SW_SHOWMINIMIZED);
        }

        /// <summary>
        /// 设置无边框窗口
        /// </summary>
        /// <param name="_rect"></param>
        public static void SetNoBorderWindow(Rect _rect)
        {
            //修改指定句柄窗口的样式、框体大小
            SetWindowLong(ProcessHandle, GWL_STYLE, WS_POPUP);

            //设置位置
            SetWindowPos(
                ProcessHandle,
                0,
                (int)_rect.x,
                (int)_rect.y,
                (int)_rect.width,
                (int)_rect.height,
                SWP_SHOWWINDOW);
        }

        /// <summary>
        /// 拖动窗口
        /// </summary>
        public static void DragWindow()
        {
            ReleaseCapture();

            SendMessage(ProcessHandle, WM_NCLBUTTONDOWN, WM_DESTROY, 0);
            SendMessage(ProcessHandle, WM_LBUTTONUP, 0, 0);
        }
        
        #endregion
    }
}