using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Ant.ORM
{
    public abstract class BaseModel
    {
        protected string ObjectToString(object obj)
        {
            return DBNull.Value.Equals(obj) ? string.Empty : obj.ToString();
        }

        protected decimal ObjectToDecimal(object obj)
        {
            return DBNull.Value.Equals(obj) ? 0 : Convert.ToDecimal(obj);
        }


        protected Int64 ObjectToInt64(object obj)
        {
            return DBNull.Value.Equals(obj) ? 0 : Convert.ToInt64(obj);
        }


        protected UInt64 ObjectToUInt64(object obj)
        {
            return DBNull.Value.Equals(obj) ? 0 : Convert.ToUInt64(obj);
        }


        protected Int32 ObjectToInt32(object obj)
        {
            return DBNull.Value.Equals(obj) ? 0 : Convert.ToInt32(obj);
        }


        protected UInt32 ObjectToUInt32(object obj)
        {
            return DBNull.Value.Equals(obj) ? 0 : Convert.ToUInt32(obj);
        }

        protected Int16 ObjectToInt16(object obj)
        {
            return DBNull.Value.Equals(obj) ? (Int16)0 : Convert.ToInt16(obj);
        }


        protected UInt16 ObjectToUInt16(object obj)
        {
            return DBNull.Value.Equals(obj) ? (UInt16)0 : Convert.ToUInt16(obj);
        }


        protected sbyte ObjectToSByte(object obj)
        {
            return DBNull.Value.Equals(obj) ? (sbyte)0 : Convert.ToSByte(obj);
        }


        protected bool ObjectToBoolean(object obj)
        {
            return DBNull.Value.Equals(obj) ? false : Convert.ToBoolean(obj);
        }


        protected DateTime ObjectToDateTime(object obj)
        {
            return DBNull.Value.Equals(obj) ? DateTime.MinValue : Convert.ToDateTime(obj);
        }

        protected Guid ObjectToGuid(object obj)
        {
            return Guid.Empty.Equals(obj) ? Guid.Empty : new Guid(Convert.ToString(obj));
        }

        protected byte[] ObjectToBytes(object obj)
        {
            return DBNull.Value.Equals(obj) ? null : (byte[])obj;
        }

        #region 返回DataType DbNll
        public object SqlNull(object obj)
        {
            if (obj == null)
            {
                return obj;
            }
            string tp = string.Empty;
            tp = obj.GetType().ToString();
            switch (tp)
            {
                case "System.Guid":
                    if (obj.ToString() == Guid.Empty.ToString())
                    {
                        return DBNull.Value;
                    }
                    break;
                case "System.DateTime":
                    if (obj.ToString() == new DateTime().ToString())
                    {
                        return DBNull.Value;
                    }
                    break;
                case "System.Int32":
                    if (obj.ToString() == "0")
                    {
                        return DBNull.Value;
                    }
                    else if (obj.ToString() == "-1")
                    {
                        return 0;
                    }
                    break;
                case "System.Decimal":
                    if (obj.ToString() == "0.00")
                    {
                        return DBNull.Value;
                    }
                    break;
            }
            return obj;
        }
        #endregion
    }
}