using System;
using System.Collections.Generic;
using System.Windows;
using System.Windows.Controls;

namespace Plugins.Vm.Views
{
    /// <summary>
    /// VM 主页多画面显示控件（镜像 UCDispVpp 的角色）：按 RowColNumber 铺设画面框网格。
    /// 单例，供 VisionMasterEngine 与 VM 图像显示插件访问。
    /// </summary>
    public partial class UCDispVm : UserControl
    {
        private static readonly Lazy<UCDispVm> _instance = new Lazy<UCDispVm>(() => new UCDispVm());
        public static UCDispVm Instance => _instance.Value;

        /// <summary>当前画面框集合（下标 = 画面序号-1）。</summary>
        public List<VmWindow> vmWindow { get; } = new List<VmWindow>();

        public UCDispVm()
        {
            InitializeComponent();
        }

        private int[] _rowCol = new[] { 0, 1 };
        /// <summary>{画面总数, 排列方式}：arrange 1=水平最优行列，2=垂直最优行列；总数0=清空。</summary>
        public int[] RowColNumber
        {
            get => _rowCol;
            set
            {
                _rowCol = value ?? new[] { 0, 1 };
                RebuildFrames();
            }
        }

        private void RebuildFrames()
        {
            if (!Dispatcher.CheckAccess()) { Dispatcher.Invoke(new Action(RebuildFrames)); return; }

            RootGrid.Children.Clear();
            RootGrid.RowDefinitions.Clear();
            RootGrid.ColumnDefinitions.Clear();
            vmWindow.Clear();

            int count = _rowCol.Length > 0 ? _rowCol[0] : 0;
            int arrange = _rowCol.Length > 1 ? _rowCol[1] : 1;
            if (count <= 0) return;

            int cols = (int)Math.Ceiling(Math.Sqrt(count));
            if (cols < 1) cols = 1;
            if (arrange == 2)
            {
                int rows = (int)Math.Ceiling(Math.Sqrt(count));
                if (rows < 1) rows = 1;
                cols = (int)Math.Ceiling((double)count / rows);
                if (cols < 1) cols = 1;
            }
            int rowCount = (count + cols - 1) / cols;

            for (int c = 0; c < cols; c++) RootGrid.ColumnDefinitions.Add(new ColumnDefinition());
            for (int r = 0; r < rowCount; r++) RootGrid.RowDefinitions.Add(new RowDefinition());

            for (int i = 0; i < count; i++)
            {
                var w = new VmWindow();
                Grid.SetRow(w, i / cols);
                Grid.SetColumn(w, i % cols);
                RootGrid.Children.Add(w);
                vmWindow.Add(w);
            }
        }
    }
}