using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Xml.XPath;
using ToolsModule.ManagmentExtension;

namespace ToolsModule.ManagmentDependency
{
    /// <summary>
    /// Загрузчик данных
    /// </summary>
    public static partial class ServiceProviderLoader
	{
		private static readonly string _pathToImplementationExt = "..\\..\\..\\..\\ImplementationExtensions\\";

		/// <summary>
		/// Загрузка всех классов-реализаций IImplementationExtension
		/// </summary>
		/// <returns></returns>
		public static List<IDependencyRegistration> GetImplementationExtensions()
		{
			var list = new List<IDependencyRegistration>();
			if(Directory.Exists(_pathToImplementationExt))
			{
				var files = Directory.GetFiles(_pathToImplementationExt, "*.dll", SearchOption.AllDirectories);
				var loadedFiles = new List<string>();
				foreach(var file in files.Distinct())
				{
					if(loadedFiles.Contains(file.GetFileName()))
					{
						continue;
					}
					var asm = Assembly.LoadFrom(file);
					foreach (var t in asm.GetExportedTypes())
					{
						if (t.IsClass && typeof(IDependencyRegistration).IsAssignableFrom(t))
						{
							list.Add((IDependencyRegistration)Activator.CreateInstance(t));
						}
					}
					loadedFiles.Add(file.GetFileName());
				}
			}
			return list;
		}

		/// <summary>
		/// Получение имени файла
		/// </summary>
		/// <param name="fileName"></param>
		/// <returns></returns>
		private static string GetFile(string fileName) => Path.Combine(Path.GetDirectoryName(Assembly.GetEntryAssembly().Location), fileName);
	}
}