using System;
using IwbZero.Expr;
using IwbZero.ToolCommon.StringModel;

namespace IwbZero.ExprFunctions.Functions
{
    /// <summary>
    /// 时间差（月）
    /// </summary>
    public class FunDiffM:IIwbFunction
    {
        public string Invoke(ExprObject exprObj)
        {
            int num = 0;
            var child = exprObj.GetChild(0);
            var child2 = exprObj.GetChild(2);
            if (child != null && child2 != null)
            {
                DateTime dateTime = child.Expr.StrToDt();
                DateTime dateTime2 = child2.Expr.StrToDt();
                num = dateTime.Year * 12 + dateTime.Month - dateTime2.Year * 12 - dateTime2.Month;
            }
            return num.ToString();
        }
    }
}