// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Components.WebView.WebView2;
 
namespace Microsoft.AspNetCore.Components.WebView.WindowsForms
{
	/// <summary>
	/// Describes a root component that can be added to a <see cref="BlazorWebView"/>.
	/// </summary>
	public class RootComponent
	{
		/// <summary>
		/// Constructs an instance of <see cref="RootComponent"/>.
		/// </summary>
		/// <param name="selector">The CSS selector string that specifies where in the document the component should be placed. This must be unique among the root components within the <see cref="BlazorWebView"/>.</param>
		/// <param name="componentType">The type of the root component. This type must implement <see cref="IComponent"/>.</param>
		/// <param name="parameters">An optional dictionary of parameters to pass to the root component.</param>
		public RootComponent(string selector, Type componentType, IDictionary<string, object?>? parameters)
		{
			if (string.IsNullOrWhiteSpace(selector))
			{
				throw new ArgumentException($"'{nameof(selector)}' cannot be null or whitespace.", nameof(selector));
			}
 
			Selector = selector;
			ComponentType = componentType ?? throw new ArgumentNullException(nameof(componentType));
			Parameters = parameters;
		}
 
		/// <summary>
		/// Gets the CSS selector string that specifies where in the document the component should be placed.
		/// This must be unique among the root components within the <see cref="BlazorWebView"/>.
		/// </summary>
		public string Selector { get; }
 
		/// <summary>
		/// Gets the type of the root component. This type must implement <see cref="IComponent"/>.
		/// </summary>
		public Type ComponentType { get; }
 
		/// <summary>
		/// Gets an optional dictionary of parameters to pass to the root component.
		/// </summary>
		public IDictionary<string, object?>? Parameters { get; }
 
		internal Task AddToWebViewManagerAsync(WebViewManager webViewManager)
		{
			var parameterView = Parameters == null ? ParameterView.Empty : ParameterView.FromDictionary(Parameters);
			return webViewManager.AddRootComponentAsync(ComponentType, Selector, parameterView);
		}
 
		internal Task RemoveFromWebViewManagerAsync(WebView2WebViewManager webviewManager)
		{
			return webviewManager.RemoveRootComponentAsync(Selector);
		}
	}
}