using System;
using System.Reflection;
using System.Xml.Serialization;
using NewLife.Reflection;

namespace NewLife.Serialization
{
    /// <summary>反射成员信息</summary>
    class ReflectMemberInfo : IObjectMemberInfo
    {
        #region 属性
        private MemberInfo _Member;
        /// <summary>成员</summary>
        public MemberInfo Member
        {
            get { return _Member; }
            private set { _Member = value; }
        }

        private MemberInfoX _Mix;
        /// <summary>快速反射</summary>
        private MemberInfoX Mix { get { return _Mix ?? (_Mix = Member); } }
        #endregion

        #region 构造
        /// <summary>实例化</summary>
        /// <param name="member"></param>
        public ReflectMemberInfo(MemberInfo member)
        {
            Member = member;
        }
        #endregion

        #region IObjectMemberInfo 成员
        /// <summary>名称</summary>
        public string Name { get { return GetName(); } }

        /// <summary>类型</summary>
        public Type Type { get { return Mix.Type; } }

        /// <summary>对目标对象取值赋值</summary>
        /// <param name="target"></param>
        /// <returns></returns>
        public object this[object target] { get { return Mix.GetValue(target); } set { Mix.SetValue(target, value); } }

        /// <summary>是否可读</summary>
        public bool CanRead
        {
            get
            {
                if (Member.MemberType == MemberTypes.Field) return true;
                if (Member.MemberType == MemberTypes.Property) return (Member as PropertyInfo).CanRead;
                return false;
            }
        }

        /// <summary>是否可写</summary>
        public bool CanWrite
        {
            get
            {
                if (Member.MemberType == MemberTypes.Field) return true;
                if (Member.MemberType == MemberTypes.Property) return (Member as PropertyInfo).CanWrite;
                return false;
            }
        }
        #endregion

        #region 方法
        String GetName()
        {
            String name = null;
            if (String.IsNullOrEmpty(name)) name = GetCustomAttributeValue<XmlAttributeAttribute>(Member, "AttributeName");
            //if (String.IsNullOrEmpty(name)) name = GetCustomAttributeValue<XmlArrayItemAttribute>(Member, "ElementName");
            if (String.IsNullOrEmpty(name)) name = GetCustomAttributeValue<XmlArrayAttribute>(Member, "ElementName");
            if (String.IsNullOrEmpty(name)) name = GetCustomAttributeValue<XmlElementAttribute>(Member, "ElementName");
            if (String.IsNullOrEmpty(name)) name = GetCustomAttributeValue<XmlAnyElementAttribute>(Member, "Name");
            if (String.IsNullOrEmpty(name)) name = GetCustomAttributeValue<XmlRootAttribute>(Mix.Type, "ElementName");

            if (String.IsNullOrEmpty(name)) name = Member.Name;
            return name;
        }

        static String GetCustomAttributeValue<TAttribute>(MemberInfo member, String name)
        {
            TAttribute att = AttributeX.GetCustomAttribute<TAttribute>(member, true);
            if (att == null) return null;

            PropertyInfoX pix = PropertyInfoX.Create(typeof(TAttribute), name);
            if (pix == null) return null;

            return (String)pix.GetValue(att);
        }
        #endregion

        #region 已重载
        /// <summary>已重载。</summary>
        /// <returns></returns>
        public override string ToString() { return Name; }
        #endregion
    }
}