using System;
using System.ComponentModel;
using System.Drawing;
using System.IO;
using System.Reflection;
using System.Resources;
using System.Text;

namespace Eas.Client
{
	/// <summary>
	/// 反射操作辅助类，如获取或设置字段、属性的值等反射信息。
	/// </summary>
	public sealed class Reflection
	{
		private Reflection()
		{
		}

		#region 属性字段设置

		/// <summary>
		/// 绑定标识
		/// </summary>
		public static BindingFlags bf = BindingFlags.DeclaredOnly | BindingFlags.Public |
								BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Static;

		/// <summary>
		/// 执行方法
		/// </summary>
		/// <param name="obj">对象实例</param>
		/// <param name="methodName">方法名称</param>
		/// <param name="args">参数</param>
		/// <returns></returns>
		public static object InvokeMethod(object obj, string methodName, object[] args)
		{
			object objReturn = null;
			Type type = obj.GetType();
			objReturn = type.InvokeMember(methodName, bf | BindingFlags.InvokeMethod, null, obj, args);
			return objReturn;
		}

		/// <summary>
		/// 设置对象实例的字段值
		/// </summary>
		/// <param name="obj">对象实例</param>
		/// <param name="name">字段名称</param>
		/// <param name="value">字段值</param>
		public static void SetField(object obj, string name, object value)
		{
			FieldInfo fi = obj.GetType().GetField(name, bf);
			fi.SetValue(obj, value);
		}

		/// <summary>
		/// 获取对象实例的字段值
		/// </summary>
		/// <param name="obj">对象实例</param>
		/// <param name="name">字段名称</param>
		/// <returns></returns>
		public static object GetField(object obj, string name)
		{
			FieldInfo fi = obj.GetType().GetField(name, bf);
			return fi.GetValue(obj);
		}

		/// <summary>
		/// 获取对象实例的字段集合
		/// </summary>
		/// <param name="obj">对象实例</param>
		/// <returns></returns>
		public static FieldInfo[] GetFields(object obj)
		{
			FieldInfo[] fieldInfos = obj.GetType().GetFields(bf);
			return fieldInfos;
		}

		/// <summary>
		/// 设置对象实例的属性值
		/// </summary>
		/// <param name="obj">对象实例</param>
		/// <param name="name">属性名称</param>
		/// <param name="value">属性值</param>
		public static void SetProperty(object obj, string name, object value)
		{
			PropertyInfo fieldInfo = obj.GetType().GetProperty(name, bf);
			value = Convert.ChangeType(value, fieldInfo.PropertyType);
			fieldInfo.SetValue(obj, value, null);
		}

		/// <summary>
		/// 获取对象实例的属性值
		/// </summary>
		/// <param name="obj">对象实例</param>
		/// <param name="name">属性名称</param>
		/// <returns></returns>
		public static object GetProperty(object obj, string name)
		{
			PropertyInfo fieldInfo = obj.GetType().GetProperty(name, bf);
			return fieldInfo.GetValue(obj, null);
		}

		/// <summary>
		/// 获取对象实例的属性列表
		/// </summary>
		/// <param name="obj">对象实例</param>
		/// <returns></returns>
		public static PropertyInfo[] GetProperties(object obj)
		{
			PropertyInfo[] propertyInfos = obj.GetType().GetProperties(bf);
			return propertyInfos;
		}

		/// <summary>
		/// 把对象的属性和值，输出一个键值的字符串，如A=1&B=test
		/// </summary>
		/// <param name="obj">实体对象</param>
		/// <param name="includeEmptyProperties">是否包含空白属性的键值</param>
		/// <returns></returns>
		public static string ToNameValuePairs(object obj, bool includeEmptyProperties = true)
		{
			string result = "";

			foreach (PropertyInfo p in obj.GetType().GetProperties())
			{
				var objVal = p.GetValue(obj, null);
				var value = objVal != null ? objVal.ToString() : null;

				if (string.IsNullOrEmpty(value))
				{
					if (includeEmptyProperties)
					{
						if (!string.IsNullOrEmpty(result))
						{
							result += "&";
						}

						result += string.Format("{0}={1}", p.Name, value);
					}
				}
				else
				{
					if (!string.IsNullOrEmpty(result))
					{
						result += "&";
					}

					result += string.Format("{0}={1}", p.Name, value);
				}
			}

			return result;
		}

		#endregion 属性字段设置

		#region 获取Description

		/// <summary>
		/// 获取枚举字段的Description属性值
		/// </summary>
		/// <param name="value">The value.</param>
		/// <returns>return description or value.ToString()</returns>
		public static string GetDescription(Enum value)
		{
			return GetDescription(value, null);
		}

		/// <summary>
		/// Get The Enum Field Description using Description Attribute and
		/// objects to format the Description.
		/// </summary>
		/// <param name="value">Enum For Which description is required.</param>
		/// <param name="args">An Object array containing zero or more objects to format.</param>
		/// <returns>return null if DescriptionAttribute is not found or return type description</returns>
		public static string GetDescription(Enum value, params object[] args)
		{
			if (value == null)
			{
				throw new ArgumentNullException("value");
			}

			string text1;

			FieldInfo fi = value.GetType().GetField(value.ToString());

			DescriptionAttribute[] attributes =
				(DescriptionAttribute[])fi.GetCustomAttributes(typeof(DescriptionAttribute), false);

			text1 = (attributes.Length > 0) ? attributes[0].Description : value.ToString();

			if ((args != null) && (args.Length > 0))
			{
				return string.Format(null, text1, args);
			}
			return text1;
		}

		/// <summary>
		///	获取字段的Description属性值
		/// </summary>
		/// <param name="member">Specified Member for which Info is Required</param>
		/// <returns>return null if DescriptionAttribute is not found or return type description</returns>
		public static string GetDescription(MemberInfo member)
		{
			return GetDescription(member, null);
		}

		/// <summary>
		/// Get The Type Description using Description Attribute and
		/// objects to format the Description.
		/// </summary>
		/// <param name="member"> Specified Member for which Info is Required</param>
		/// <param name="args">An Object array containing zero or more objects to format.</param>
		/// <returns>return <see cref="String.Empty"/> if DescriptionAttribute is
		/// not found or return type description</returns>
		public static string GetDescription(MemberInfo member, params object[] args)
		{
			string text1;

			if (member == null)
			{
				throw new ArgumentNullException("member");
			}

			if (member.IsDefined(typeof(DescriptionAttribute), false))
			{
				DescriptionAttribute[] attributes =
					(DescriptionAttribute[])member.GetCustomAttributes(typeof(DescriptionAttribute), false);
				text1 = attributes[0].Description;
			}
			else
			{
				return String.Empty;
			}

			if ((args != null) && (args.Length > 0))
			{
				return String.Format(null, text1, args);
			}
			return text1;
		}

		#endregion 获取Description

		#region 获取Attribute信息

		/// <summary>
		/// 获取指定对象实例的attributes内容
		/// </summary>
		/// <param name="attributeType">The attribute Type for which the custom attributes are to be returned.</param>
		/// <param name="assembly">the assembly in which the specified attribute is defined</param>
		/// <returns>Attribute as Object or null if not found.</returns>
		public static object GetAttribute(Type attributeType, Assembly assembly)
		{
			if (attributeType == null)
			{
				throw new ArgumentNullException("attributeType");
			}

			if (assembly == null)
			{
				throw new ArgumentNullException("assembly");
			}

			if (assembly.IsDefined(attributeType, false))
			{
				object[] attributes = assembly.GetCustomAttributes(attributeType, false);

				return attributes[0];
			}

			return null;
		}

		/// <summary>
		/// 获取指定对象实例的attributes内容
		/// </summary>
		/// <param name="attributeType">The attribute Type for which the custom attributes are to be returned.</param>
		/// <param name="type">the type on which the specified attribute is defined</param>
		/// <returns>Attribute as Object or null if not found.</returns>
		public static object GetAttribute(Type attributeType, MemberInfo type)
		{
			return GetAttribute(attributeType, type, false);
		}

		/// <summary>
		/// Gets the specified object attributes for type as specified by type with option to serach parent
		/// </summary>
		/// <param name="attributeType">The attribute Type for which the custom attributes are to be returned.</param>
		/// <param name="type">the type on which the specified attribute is defined</param>
		/// <param name="searchParent">if set to <see langword="true"/> [search parent].</param>
		/// <returns>
		/// Attribute as Object or null if not found.
		/// </returns>
		public static object GetAttribute(Type attributeType, MemberInfo type, bool searchParent)
		{
			if (attributeType == null)
			{
				return null;
			}

			if (type == null)
			{
				return null;
			}

			if (!(attributeType.IsSubclassOf(typeof(Attribute))))
			{
				return null;
			}

			if (type.IsDefined(attributeType, searchParent))
			{
				object[] attributes = type.GetCustomAttributes(attributeType, searchParent);

				if (attributes.Length > 0)
				{
					return attributes[0];
				}
			}

			return null;
		}

		/// <summary>
		/// Gets the collection of all specified object attributes for type as specified by type
		/// </summary>
		/// <param name="attributeType">The attribute Type for which the custom attributes are to be returned.</param>
		/// <param name="type">the type on which the specified attribute is defined</param>
		/// <returns>Attribute as Object or null if not found.</returns>
		public static object[] GetAttributes(Type attributeType, MemberInfo type)
		{
			return GetAttributes(attributeType, type, false);
		}

		/// <summary>
		/// Gets the collection of all specified object attributes for type as specified by type with option to serach parent
		/// </summary>
		/// <param name="attributeType">The attribute Type for which the custom attributes are to be returned.</param>
		/// <param name="type">the type on which the specified attribute is defined</param>
		/// <param name="searchParent">The attribute Type for which the custom attribute is to be returned.</param>
		/// <returns>
		/// Attribute as Object or null if not found.
		/// </returns>
		public static object[] GetAttributes(Type attributeType, MemberInfo type, bool searchParent)
		{
			if (type == null)
			{
				return null;
			}

			if (attributeType == null)
			{
				return null;
			}

			if (!(attributeType.IsSubclassOf(typeof(Attribute))))
			{
				return null;
			}

			if (type.IsDefined(attributeType, false))
			{
				return type.GetCustomAttributes(attributeType, searchParent);
			}

			return null;
		}

		#endregion 获取Attribute信息

		#region 资源获取

		/// <summary>
		/// 根据资源名称获取图片资源流
		/// </summary>
		/// <param name="ResourceName"></param>
		/// <returns></returns>
		public static Stream GetImageResource(string ResourceName)
		{
			Assembly asm = Assembly.GetExecutingAssembly();
			return asm.GetManifestResourceStream(ResourceName);
		}

		/// <summary>
		/// 获取程序集资源的位图资源
		/// </summary>
		/// <param name="assemblyType">程序集中的某一对象类型</param>
		/// <param name="resourceHolder">资源的根名称。例如，名为“MyResource.en-US.resources”的资源文件的根名称为“MyResource”。</param>
		/// <param name="imageName">资源项名称</param>
		public static Bitmap LoadBitmap(Type assemblyType, string resourceHolder, string imageName)
		{
			Assembly thisAssembly = Assembly.GetAssembly(assemblyType);
			ResourceManager rm = new ResourceManager(resourceHolder, thisAssembly);
			return (Bitmap)rm.GetObject(imageName);
		}

		/// <summary>
		///  获取程序集资源的文本资源
		/// </summary>
		/// <param name="assemblyType">程序集中的某一对象类型</param>
		/// <param name="resName">资源项名称</param>
		/// <param name="resourceHolder">资源的根名称。例如，名为“MyResource.en-US.resources”的资源文件的根名称为“MyResource”。</param>
		public static string GetStringRes(Type assemblyType, string resName, string resourceHolder)
		{
			Assembly thisAssembly = Assembly.GetAssembly(assemblyType);
			ResourceManager rm = new ResourceManager(resourceHolder, thisAssembly);
			return rm.GetString(resName);
		}

		/// <summary>
		/// 获取程序集嵌入资源的文本形式
		/// </summary>
		/// <param name="assemblyType">程序集中的某一对象类型</param>
		/// <param name="charset">字符集编码</param>
		/// <param name="ResName">嵌入资源相对路径</param>
		/// <returns>如没找到该资源则返回空字符</returns>
		public static string GetManifestString(Type assemblyType, string charset, string ResName)
		{
			Assembly asm = Assembly.GetAssembly(assemblyType);
			Stream st = asm.GetManifestResourceStream(string.Concat(assemblyType.Namespace,
				".", ResName.Replace("/", ".")));
			if (st == null) { return ""; }
			int iLen = (int)st.Length;
			byte[] bytes = new byte[iLen];
			st.Read(bytes, 0, iLen);
			return (bytes != null) ? Encoding.GetEncoding(charset).GetString(bytes) : "";
		}

		#endregion 资源获取

		#region 创建对应实例

		/// <summary>
		/// 创建对应实例
		/// </summary>
		/// <param name="type">类型</param>
		/// <returns>对应实例</returns>
		public static object CreateInstance(string type)
		{
			Type tmp = null;
			Assembly[] assemblies = AppDomain.CurrentDomain.GetAssemblies();
			for (int i = 0; i < assemblies.Length; i++)
			{
				tmp = assemblies[i].GetType(type);
				if (tmp != null)
				{
					return assemblies[i].CreateInstance(type);
				}
			}
			return null;
			//return Assembly.GetExecutingAssembly().CreateInstance(type);
		}

		/// <summary>
		/// 创建对应实例
		/// </summary>
		/// <param name="type">类型</param>
		/// <returns>对应实例</returns>
		public static object CreateInstance(Type type)
		{
			return CreateInstance(type.FullName);
		}

		#endregion 创建对应实例
	}
}