using System;
using System.Collections.Generic;
using Avalonia;
using Avalonia.Controls;
using Avalonia.Controls.Presenters;
using Avalonia.Controls.Templates;
using Avalonia.Markup.Xaml.Templates;
using Avalonia.Platform;
using Notes.ViewModels;

namespace Notes;
//    public class ViewLocator : IDataTemplate
//    {
//        Control? ITemplate<object?, Control?>.Build(object? param)
//        {
//            if (param == null) throw new NullReferenceException(nameof(param));
//            var name = param.GetType().FullName!.Replace("ViewModel", "View");
//            var type = Type.GetType(name);
//
//            if (type != null)
//            {
//                return (Control?)Activator.CreateInstance(type);
//            }
//            else
//            {
//                return new TextBlock { Text = "1Not Found: " + name };
//            }
//        }
//
//        public bool Match(object? data)
//        {
//            return data is ViewModelBase;
//        }
//    }


public sealed class ViewSelector : AvaloniaObject, IDataTemplate
{
    private static readonly Dictionary<object, Control?> controls = new Dictionary<object, Control?>();
    public ViewSelector()
    {
        
    }

    /// <summary>
    /// 根据ViewModel 查找view ，这里直接拿到资源文件夹的资源来构建
    /// </summary>
    /// <param name="param"></param>
    /// <returns></returns>
    /// <exception cref="NullReferenceException"></exception>
    public Control? Build(object? param)
    {
        if (param == null) throw new NullReferenceException(nameof(param));
        if (controls.TryGetValue(param, out var control))
        {
            return control;
        }
        var name = param.GetType().FullName!.Replace("ViewModel", "View").Replace("DesignData","");
        var type = Type.GetType(name);

        if (type != null)
        {
            var instance = (Control?)Activator.CreateInstance(type);
            controls[param] = instance;
            return instance;
        }
        else
        {
            return new TextBlock { Text = "2Not Found: " + name };
        }
    }

    public bool Match(object? data)
    {
        return data is ViewModelBase;
    }
}