[assembly: PreApplicationStartMethod(typeof(PatulouManager), "Initialize")]

namespace IdeaSite.Web.Framework

{

    public class PatulouManager

    {

        private const string PatulousPath = "~/Patulous";

        public static void Initialize()

        {

            var patulouFolder = new DirectoryInfo(MapPath(PatulousPath));

            var patulouFiles = patulouFolder.GetFiles("*.dll", SearchOption.AllDirectories);

            foreach (var patulouFile in patulouFiles.Where(x => !IsAlreadyLoaded(x)))

            {

                var shadowCopiedAssembly = Assembly.Load(AssemblyName.GetAssemblyName(patulouFile.FullName));

                BuildManager.AddReferencedAssembly(shadowCopiedAssembly);

            }

        }

        /// <summary>

        /// 获取物理路径

        /// </summary>

        /// <param name="path"></param>

        /// <returns></returns>

        public static string MapPath(string path)

        {

            if (HostingEnvironment.IsHosted)

            {

                //hosted

                return HostingEnvironment.MapPath(path);

            }

            //not hosted. For example, run in unit tests

            string baseDirectory = AppDomain.CurrentDomain.BaseDirectory;

            path = path.Replace("~/", "").TrimStart('/').Replace('/', '\\');

            return Path.Combine(baseDirectory, path);

        }

        /// <summary>

        /// 是否已加入程序集

        /// </summary>

        /// <param name="fileInfo"></param>

        /// <returns></returns>

        private static bool IsAlreadyLoaded(FileInfo fileInfo)

        {

            try

            {

                string fileNameWithoutExt = Path.GetFileNameWithoutExtension(fileInfo.FullName);

                if (fileNameWithoutExt == null)

                    throw new Exception(string.Format("Cannot get file extension for {0}", fileInfo.Name));

                foreach (var a in AppDomain.CurrentDomain.GetAssemblies())

                {

                    string assemblyName = a.FullName.Split(new[] { ',' }).FirstOrDefault();

                    if (fileNameWithoutExt.Equals(assemblyName, StringComparison.InvariantCultureIgnoreCase))

                        return true;

                }

            }

            catch (Exception exc)

            {

                Debug.WriteLine("Cannot validate whether an assembly is already loaded. " + exc);

            }

            return false;

        }

    }

}