using System;
using System.ComponentModel;
using System.Xml;
using System.Xml.Serialization;
using NewLife.Reflection;
using XCode.DataAccessLayer.Model;

namespace XCode.DataAccessLayer
{
    /// <summary>字段构架</summary>
    [Serializable]
    [DisplayName("字段模型")]
    [Description("字段模型")]
    [XmlRoot("Column")]
    class XField : SerializableDataMember, IDataColumn, ICloneable
    {
        #region 属性
        private Int32 _ID;
        /// <summary>顺序编号</summary>
        [XmlAttribute]
        [DisplayName("编号")]
        [Description("编号")]
        public Int32 ID { get { return _ID; } set { _ID = value; } }

        private String _Name;
        /// <summary>名称</summary>
        [XmlAttribute]
        [DisplayName("名称")]
        [Description("名称")]
        public String Name { get { return _Name; } set { _Name = value; _Alias = null; } }

        private String _Alias;
        /// <summary>别名</summary>
        [XmlAttribute]
        [DisplayName("别名")]
        [Description("别名")]
        public String Alias
        {
            get
            {
                if (!String.IsNullOrEmpty(_Alias)) return _Alias;

                //!! 先赋值，非常重要。后面GetAlias时会用到其它列的别名，然后可能形成死循环。先赋值之后，下一次来到这里时将直接返回。
                _Alias = Name;
                _Alias = ModelResolver.Current.GetAlias(this);

                return _Alias;
            }
            set { _Alias = value; }
        }

        private Type _DataType;
        /// <summary>数据类型</summary>
        [XmlAttribute]
        [DisplayName("数据类型")]
        [Description("数据类型")]
        public Type DataType { get { return _DataType; } set { _DataType = value; } }

        /// <summary>字段类型</summary>
        [XmlIgnore]
        [DisplayName("字段类型")]
        [Description("字段类型")]
        public String FieldType { get { return DataType == null ? null : DataType.Name; } set { _DataType = TypeX.GetType(value); } }

        private String _RawType;
        /// <summary>原始数据类型</summary>
        [XmlAttribute]
        [DisplayName("原始类型")]
        [Description("原始类型")]
        public String RawType { get { return _RawType; } set { _RawType = value; } }

        private Boolean _Identity;
        /// <summary>标识</summary>
        [XmlAttribute]
        [DisplayName("标识")]
        [Description("标识")]
        public Boolean Identity { get { return _Identity; } set { _Identity = value; } }

        private Boolean _PrimaryKey;
        /// <summary>主键</summary>
        [XmlAttribute]
        [DisplayName("主键")]
        [Description("主键")]
        public Boolean PrimaryKey { get { return _PrimaryKey; } set { _PrimaryKey = value; } }

        private Int32 _Length;
        /// <summary>长度</summary>
        [XmlAttribute]
        [DisplayName("长度")]
        [Description("长度")]
        public Int32 Length { get { return _Length; } set { _Length = value; } }

        private Int32 _NumOfByte;
        /// <summary>字节数</summary>
        [XmlAttribute]
        [DisplayName("字节数")]
        [Description("字节数")]
        public Int32 NumOfByte { get { return _NumOfByte; } set { _NumOfByte = value; } }

        private Int32 _Precision;
        /// <summary>精度</summary>
        [XmlAttribute]
        [DisplayName("精度")]
        [Description("精度")]
        public Int32 Precision { get { return _Precision; } set { _Precision = value; } }

        private Int32 _Scale;
        /// <summary>位数</summary>
        [XmlAttribute]
        [DisplayName("位数")]
        [Description("位数")]
        public Int32 Scale { get { return _Scale; } set { _Scale = value; } }

        private Boolean _Nullable;
        /// <summary>允许空</summary>
        [XmlAttribute]
        [DisplayName("允许空")]
        [Description("允许空")]
        public Boolean Nullable { get { return _Nullable; } set { _Nullable = value; } }

        private Boolean _IsUnicode;
        /// <summary>是否Unicode</summary>
        [XmlAttribute]
        [DisplayName("Unicode")]
        [Description("Unicode")]
        public Boolean IsUnicode { get { return _IsUnicode; } set { _IsUnicode = value; } }

        private String _Default;
        /// <summary>默认值</summary>
        [XmlAttribute]
        [DisplayName("默认值")]
        [Description("默认值")]
        public String Default { get { return _Default; } set { _Default = value; } }

        private String _Description;
        /// <summary>说明</summary>
        [XmlAttribute]
        [DisplayName("说明")]
        [Description("说明")]
        public String Description
        {
            get { return _Description; }
            set
            {
                if (!String.IsNullOrEmpty(value))
                    value = value.Replace("\r\n", "。")
                        .Replace("\r", " ")
                        .Replace("\n", " ");
                _Description = value;
            }
        }
        #endregion

        #region 扩展属性
        [NonSerialized]
        private IDataTable _Table;
        /// <summary>表</summary>
        [XmlIgnore]
        public IDataTable Table { get { return _Table; } set { _Table = value; } }

        /// <summary>显示名。如果有Description则使用Description，否则使用Name</summary>
        [XmlIgnore]
        public String DisplayName { get { return ModelResolver.Current.GetDisplayName(Alias ?? Name, Description); } }
        #endregion

        #region 构造
        //private XField() { }

        //private XField(IDataTable table) { Table = table; }

        ///// <summary>为制定表创建字段</summary>
        ///// <param name="table"></param>
        ///// <returns></returns>
        //internal static XField Create(IDataTable table)
        //{
        //    if (table == null) throw new ArgumentNullException("table");

        //    return new XField(table);
        //}
        #endregion

        #region 方法
        /// <summary>重新计算修正别名。避免与其它字段名或表名相同，避免关键字</summary>
        /// <returns></returns>
        public IDataColumn Fix()
        {
            //_Alias = ModelResolver.Current.GetAlias(this);
            return ModelResolver.Current.Fix(this);
        }

        /// <summary>已重载。</summary>
        /// <returns></returns>
        public override string ToString()
        {
            if (!String.IsNullOrEmpty(Description))
                return String.Format("ID={0} Name={1} FieldType={2} RawType={3} Description={4}", ID, Name, FieldType, RawType, Description);
            else
                return String.Format("ID={0} Name={1} FieldType={2} RawType={3}", ID, Name, FieldType, RawType);
        }
        #endregion

        #region ICloneable 成员
        /// <summary>克隆</summary>
        /// <returns></returns>
        object ICloneable.Clone()
        {
            return Clone(Table);
        }

        /// <summary>克隆</summary>
        /// <param name="table"></param>
        /// <returns></returns>
        public IDataColumn Clone(IDataTable table)
        {
            var field = base.MemberwiseClone() as XField;
            field.Table = table;
            field.Fix();
            return field;
        }
        #endregion
    }
}