using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Reflection;
using System.Web;

namespace BatchService.Framework.Utility
{
    /// <summary>
    /// ³ÌÐò¼¯·´É丨ÖúÀà 
    /// </summary>
    public static class AssemblyHelper
    {
        /// <summary>
        /// µÃµ½Èë¿Ú³ÌÐò¼¯£¬¼æÈÝWebºÍWinform 
        /// </summary>
        /// <returns></returns>
        public static Assembly GetEntryAssembly()
        {
            var entryAssembly = Assembly.GetEntryAssembly();
            if (entryAssembly != null)
                return entryAssembly;

            if (System.Web.HttpContext.Current == null ||
                System.Web.HttpContext.Current.ApplicationInstance == null)
                return Assembly.GetExecutingAssembly();

            var type = System.Web.HttpContext.Current.ApplicationInstance.GetType();
            while (type != null && type.Namespace == "ASP")
            {
                type = type.BaseType;
            }

            return type == null ? null : type.Assembly;
        }

        public static string GetPropertyValue<T>(T t, string propertyName)
        {
            string ret = "";
            var types = typeof(T);
            var memberResult = types.GetProperties().FirstOrDefault(p => p.Name.ToLower() == propertyName.ToLower());
            var value = memberResult.GetValue(t, null);
            if (value != null)
            {
                ret = value.ToString();
            }
            else
            {
                ret = "";
            }
            return ret;
        }

        public static IList<Stream> GetResourceStream(Assembly assembly, System.Linq.Expressions.Expression<Func<string, bool>> predicate)
        {
            List<Stream> result = new List<Stream>();

            foreach (string resource in assembly.GetManifestResourceNames())
            {
                if (predicate.Compile().Invoke(resource))
                {
                    result.Add(assembly.GetManifestResourceStream(resource));
                }
            }

            StreamReader sr = new StreamReader(result[0]);
            string r = sr.ReadToEnd();
            result[0].Position = 0;

            return result;
        }

        /// <summary>
        /// ɨÃè³ÌÐò¼¯ÕÒµ½¼Ì³ÐÁËij»ùÀàµÄËùÓÐ×ÓÀà
        /// </summary>
        /// <param name="inheritType">»ùÀà</param>
        /// <param name="searchpattern">ÎļþÃû¹ýÂË</param>
        /// <returns></returns>
        public static List<Type> FindTypeByInheritType(Type inheritType, string searchpattern = "*.dll")
        {
            var result = new List<Type>();
            Type attr = inheritType;

            string domain = GetBaseDirectory();
            string[] dllFiles = Directory.GetFiles(domain, searchpattern, SearchOption.TopDirectoryOnly);

            foreach (string dllFileName in dllFiles)
            {
                foreach (Type type in Assembly.LoadFrom(dllFileName).GetLoadableTypes())
                {
                    if (type.BaseType == inheritType)
                    {
                        result.Add(type);
                    }
                }
            }

            return result;
        }

        /// <summary>
        /// ɨÃè³ÌÐò¼¯ÕÒµ½´øÓÐij¸öAttributeµÄËùÓÐPropertyInfo
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="searchpattern">ÎļþÃû¹ýÂË</param>
        /// <returns></returns>
        public static Dictionary<PropertyInfo, T> FindAllPropertyByAttribute<T>(string searchpattern = "*.dll") where T : Attribute
        {
            var result = new Dictionary<PropertyInfo, T>();
            var attr = typeof(T);

            string domain = GetBaseDirectory();
            string[] dllFiles = Directory.GetFiles(domain, searchpattern, SearchOption.TopDirectoryOnly);

            foreach (string dllFileName in dllFiles)
            {
                foreach (Type type in Assembly.LoadFrom(dllFileName).GetLoadableTypes())
                {
                    foreach (var property in type.GetProperties())
                    {
                        var attrs = property.GetCustomAttributes(attr, true);

                        if (attrs.Length == 0)
                            continue;

                        result.Add(property, (T)attrs.First());
                    }
                }
            }


            return result;
        }

        /// <summary>
        /// ɨÃè³ÌÐò¼¯ÕÒµ½ÀàÐÍÉÏ´øÓÐij¸öAttributeµÄËùÓÐÀàÐÍ
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="searchpattern">ÎļþÃû¹ýÂË</param>
        /// <returns></returns>
        public static Dictionary<string, List<T>> FindAllTypeByAttribute<T>(string searchpattern = "*.dll") where T : Attribute
        {
            var result = new Dictionary<string, List<T>>();
            Type attr = typeof(T);

            string domain = GetBaseDirectory();
            string[] dllFiles = Directory.GetFiles(domain, searchpattern, SearchOption.TopDirectoryOnly);

            foreach (string dllFileName in dllFiles)
            {
                foreach (Type type in Assembly.LoadFrom(dllFileName).GetLoadableTypes())
                {
                    var typeName = type.AssemblyQualifiedName;

                    var attrs = type.GetCustomAttributes(attr, true);
                    if (attrs.Length == 0)
                        continue;

                    result.Add(typeName, new List<T>());

                    foreach (T a in attrs)
                        result[typeName].Add(a);

                }
            }

            return result;
        }

        /// <summary>
        /// ɨÃè³ÌÐò¼¯ÕÒµ½ÊµÏÖÁËij¸ö½Ó¿ÚµÄµÚÒ»¸öʵÀý
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="searchpattern">ÎļþÃû¹ýÂË</param>
        /// <returns></returns>
        public static T FindTypeByInterface<T>(string i_servicename, string searchpattern = "BatchService.Custom*.dll") where T : class
        {
            //var interfaceType = typeof(T);
            string domain = GetBaseDirectory();
            //domain = Path.Combine(domain, "Plugin");
            string[] dllFiles = Directory.GetFiles(domain, searchpattern, SearchOption.TopDirectoryOnly);

            foreach (string dllFileName in dllFiles)
            {
                foreach (Type type in Assembly.LoadFrom(dllFileName).GetLoadableTypes())
                {
                    if (i_servicename == type.FullName)
                    {
                        LogHelper.Info("´´½¨ÊµÀý:" + type.FullName);
                        var instance = Activator.CreateInstance(type) as T;
                        return instance;
                    }
                }
            }

            return null;
        }

        public static IEnumerable<Type> GetLoadableTypes(this Assembly assembly)
        {
            if (assembly == null) throw new ArgumentNullException("assembly");
            try
            {
                return assembly.GetTypes();
            }
            catch (ReflectionTypeLoadException e)
            {
                return e.Types.Where(t => t != null);
            }
        }

        /// <summary>
        /// µÃµ½µ±Ç°Ó¦ÓóÌÐòµÄ¸ùĿ¼
        /// </summary>
        /// <returns></returns>
        public static string GetBaseDirectory()
        {
            var baseDirectory = AppDomain.CurrentDomain.SetupInformation.PrivateBinPath;

            if (AppDomain.CurrentDomain.SetupInformation.PrivateBinPath == null)
                baseDirectory = AppDomain.CurrentDomain.BaseDirectory;

            return baseDirectory;
        }

        public static string GetBaseDirectory_Autoswitch()
        {
            var ret = "";
            DirectoryInfo dirInfo = new DirectoryInfo(GetBaseDirectory());
            if (IsWebApp())
            {
                ret = dirInfo.Parent.FullName;
            }
            else
            {
                ret = dirInfo.FullName;
            }
            return ret;
        }

        /// <summary>  
        /// ÅжÏÊÇ·ñÊÇweb³ÌÐò  
        /// </summary>  
        /// <returns>true£ºÊÇ£¬false£ºwinform</returns>  
        public static bool IsWebApp()
        {
            bool flag = false;
            if (HttpContext.Current != null)
            {
                flag = true;
            }
            //·ñÔòÊÇwinform³ÌÐò  
            return flag;
        }

    }
}