/*************************************************************************
 * 
 * Hxj.Data
 * 
 * 2010-2-10
 * 
 * steven hu   
 *  
 * Support: http://www.cnblogs.com/huxj
 *   
 * 
 * Change History:
 * 
 * 
**************************************************************************/

using System;
using System.Collections.Generic;
using System.Data;
using Dos.ORM;

namespace Dos.ORM
{
    /// <summary>
    /// 实体属性修改记录 （字段修改记录）
    /// </summary>
    [Serializable]
    public class ModifyField
    {
        private Field field;
        private object oldValue;
        private object newValue;

        /// <summary>
        /// 字段
        /// </summary>
        public Field Field { get { return field; } }

        /// <summary>
        /// 原始值
        /// </summary>
        public object OldValue { get { return oldValue; } set { oldValue = value; } }

        /// <summary>
        /// 新值
        /// </summary>
        public object NewValue { get { return newValue; } set { newValue = value; } }


        /// <summary>
        /// 构造函数
        /// </summary>
        /// <param name="field">字段</param>
        /// <param name="oldValue">旧值</param>
        /// <param name="newValue">新值</param>
        public ModifyField(Field field, object oldValue, object newValue)
        {
            this.field = field;
            this.oldValue = oldValue;
            this.newValue = newValue;
        }



    }

    /// <summary>
    /// 实体信息
    /// </summary>
    [Serializable]
    public abstract class Entity
    {

        /// <summary>
        /// 表名
        /// </summary>
        private string tableName;

        /// <summary>
        /// 是否
        /// </summary>
        private bool isAttached;

        /// <summary>
        /// 修改的字段集合
        /// </summary>
        private List<ModifyField> modifyFields = new List<ModifyField>();

        #region 构造函数

        /// <summary>
        /// 构造函数
        /// </summary>
        public Entity() { }

        /// <summary>
        /// 构造函数
        /// </summary>
        /// <param name="tableName">表名</param>
        public Entity(string tableName)
        {
            this.tableName = tableName;
            this.isAttached = false;
        }


        #endregion

        /// <summary>
        /// 将实体置为修改状态
        /// </summary>
        public void Attach()
        {
            this.isAttached = true;
        }


        /// <summary>
        /// 将实体置为插入状态
        /// </summary>
        public void DeAttach()
        {
            this.isAttached = false;
        }






        /// <summary>
        /// 记录 字段修改  
        /// </summary>
        /// <param name="field"></param>
        /// <param name="oldValue"></param>
        /// <param name="newValue"></param>
        public void OnPropertyValueChange(Field field, object oldValue, object newValue)
        {
            if (isAttached)
            {
                if (null == oldValue && null == newValue)
                    return;

                if (null != oldValue && null != newValue && newValue.Equals(oldValue))
                {
                    return;
                    #region HXJ HACK

                    Type t = newValue.GetType();
                    if (t == typeof(int))
                    {
                        if ((int)newValue != 0)
                            return;
                    }
                    else if (t == typeof(decimal))
                    {
                        if (default(decimal) != (decimal)newValue)
                            return;
                    }
                    else if (t == typeof(long))
                    {
                        if (default(long) != (long)newValue)
                            return;
                    }
                    else if (t == typeof(bool))
                    {
                        if (default(bool) != (bool)newValue)
                            return;
                    }
                    else if (t == typeof(Single))
                    {
                        if (default(Single) != (Single)newValue)
                            return;
                    }                   
                    else
                    {
                        return;
                    }

                    #endregion
                }

                lock (modifyFields)
                {
                    bool ishave = false;

                    foreach (ModifyField mf in modifyFields)
                    {
                        if (mf.Field.PropertyName.ToLower().Equals(field.PropertyName.ToLower()))
                        {
                            mf.NewValue = newValue;
                            ishave = true;
                            break;
                        }
                    }

                    if (!ishave)
                    {
                        ModifyField modifyField = new ModifyField(field, oldValue, newValue);
                        modifyFields.Add(modifyField);
                    }
                }

            }

        }


        /// <summary>
        /// 清除修改记录
        /// </summary>
        public void ClearModifyFields()
        {
            modifyFields.Clear();
        }


        /// <summary>
        /// Sets the property values.
        /// </summary>
        /// <param name="reader">The reader.</param>
        public virtual void SetPropertyValues(IDataReader reader) { }

        /// <summary>
        /// Sets the property values.
        /// </summary>
        /// <param name="row">The row.</param>
        public virtual void SetPropertyValues(DataRow row) { }

        /// <summary>
        /// GetFields
        /// </summary>
        /// <returns></returns>
        public virtual Field[] GetFields() { return null; }

        /// <summary>
        /// GetValues
        /// </summary>
        /// <returns></returns>
        public virtual object[] GetValues() { return null; }

        /// <summary>
        /// GetPrimaryKeyFields
        /// </summary>
        /// <returns></returns>
        public virtual Field[] GetPrimaryKeyFields() { return null; }


        /// <summary>
        /// 标识列
        /// </summary>
        public virtual Field GetIdentityField()
        {
            return null;
        }

        /// <summary>
        /// 标识列的名称（例如如Oracle中Sequence名称）
        /// </summary>
        /// <returns></returns>
        public virtual string GetSequence()
        {
            return null;
        }

        /// <summary>
        /// 返回修改记录
        /// </summary>
        public List<ModifyField> GetModifyFields()
        {
            return modifyFields;
        }


        /// <summary>
        /// 是否只读
        /// </summary>
        public virtual bool IsReadOnly()
        {
            return false;
        }

        /// <summary>
        /// 获取表名
        /// </summary>
        public string GetTableName()
        {
            return tableName;
        }

    }
}