using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApp1
{
    internal class WindowAutoResizer  // 窗口大小自适应类
    {
        private readonly Form _form;
        private float originalWidth;
        private float originalHeight;

        /// <summary>
        /// 初始化窗口自适应调整器
        /// </summary>
        /// <param name="form">要自适应的窗体</param>
        public WindowAutoResizer(Form form)
        {
            _form = form ?? throw new ArgumentNullException(nameof(form));
            Initialize();
        }

        private void Initialize()
        {
            originalWidth = _form.Width;
            originalHeight = _form.Height;

            // 记录初始控件位置和大小
            SetTag(_form);

            // 注册窗口大小改变事件
            _form.Resize += async (sender, e) => await OnFormResizeAsync();
        }

        /// <summary>
        /// 记录控件初始位置和大小信息
        /// 递归所有控件，存储宽、高、位置等到Tag
        /// </summary>
        /// <param name="container">容器控件</param>
        private void SetTag(Control container)
        {
            foreach (Control control in container.Controls) // 遍历容器（cons）所有子控件。
            {
                control.Tag = $"{control.Width}:{control.Height}:{control.Left}:{control.Top}:{control.Font.Size}";
                if (control.Controls.Count > 0)
                {
                    SetTag(control);
                }
            }
        }

        /// <summary>
        /// 窗体大小改变时异步调整控件
        /// </summary>
        private async Task OnFormResizeAsync()
        {
            float widthRatio = _form.Width / originalWidth;
            float heightRatio = _form.Height / originalHeight;

            await Task.Run(() => AdjustControls(widthRatio, heightRatio, _form));
        }

        /// <summary>
        /// 根据比例调整控件大小和位置
        /// </summary>
        /// <param name="widthRatio">宽度比例</param>
        /// <param name="heightRatio">高度比例</param>
        /// <param name="container">容器控件</param>
        private void AdjustControls(float widthRatio, float heightRatio, Control container)
        {
            if (container.InvokeRequired) // 检查是否在UI线程
            {
                container.Invoke(new Action(() => AdjustControls(widthRatio, heightRatio, container)));
                return;
            }

            // 暂停控件的布局逻辑，直到所有更改完成后再一次性重新计算布局
            container.SuspendLayout(); 

            try
            {
                // 拷贝一份，避免实时读取时被修改造成异常
                var controlsCopy = container.Controls.Cast<Control>().ToArray();

                foreach (Control control in controlsCopy)
                {
                    if (control.Tag == null) continue;

                    string[] tagValues = control.Tag.ToString().Split(':');
                    if (tagValues.Length != 5) continue;

                    control.Width = (int)(float.Parse(tagValues[0]) * widthRatio);
                    control.Height = (int)(float.Parse(tagValues[1]) * heightRatio);
                    control.Left = (int)(float.Parse(tagValues[2]) * widthRatio);
                    control.Top = (int)(float.Parse(tagValues[3]) * heightRatio);

                    float newFontSize = float.Parse(tagValues[4]) * heightRatio;
                    if (Math.Abs(control.Font.Size - newFontSize) > float.Epsilon)
                    {
                        control.Font = new Font(control.Font.Name, newFontSize, control.Font.Style);
                    }

                    // 如果当前控件有子控件，递归调整子控件
                    if (control.HasChildren) 
                    {
                        AdjustControls(widthRatio, heightRatio, control);
                    }
                }
            }
            finally
            {
                // 恢复控件的布局逻辑，并强制立即重新计算布局。
                container.ResumeLayout(true); 
            }
        }

        /// <summary>
        /// 重新初始化控件位置和大小信息（当动态添加控件后调用）
        /// </summary>
        public void RefreshTags()
        {
            SetTag(_form);
        }

        private void AddNewControl()
        {
            //var newButton = new Button { Text = "New Button", ... };
            //this.Controls.Add(newButton);
            //resizer.RefreshTags(); // 重新记录所有控件信息
        }


    }
}