using System;

using System.Collections.Generic;

using System.Linq;

using System.Linq.Expressions;

using System.Text;

using System.Threading.Tasks;

namespace LintwayCommon

{

    public static class PredicateBuilder

    {

        public static Expression<Func<T, bool>> True<T>() { return f => true; }

        public static Expression<Func<T, bool>> False<T>() { return f => false; }

        public static Expression<T> Compose<T>(this Expression<T> first, Expression<T> second, Func<Expression, Expression, Expression> merge)

        {

            // build parameter map (from parameters of second to parameters of first)

            var map = first.Parameters.Select((f, i) => new { f, s = second.Parameters[i] }).ToDictionary(p => p.s, p => p.f);

            // replace parameters in the second lambda expression with parameters from the first

            var secondBody = ParameterRebinder.ReplaceParameters(map, second.Body);

            // apply composition of lambda expression bodies to parameters from the first expression

            return Expression.Lambda<T>(merge(first.Body, secondBody), first.Parameters);

        }

        public static Expression<Func<T, bool>> And<T>(this Expression<Func<T, bool>> first, Expression<Func<T, bool>> second)

        {

            return first.Compose(second, Expression.And);

        }

        public static Expression<Func<T, bool>> Or<T>(this Expression<Func<T, bool>> first, Expression<Func<T, bool>> second)

        {

            return first.Compose(second, Expression.Or);

        }

    }

    public class ParameterRebinder : ExpressionVisitor

    {

        private readonly Dictionary<ParameterExpression, ParameterExpression> map;

        public ParameterRebinder(Dictionary<ParameterExpression, ParameterExpression> map)

        {

            this.map = map ?? new Dictionary<ParameterExpression, ParameterExpression>();

        }

        public static Expression ReplaceParameters(Dictionary<ParameterExpression, ParameterExpression> map, Expression exp)

        {

            return new ParameterRebinder(map).Visit(exp);

        }

        protected override Expression VisitParameter(ParameterExpression p)

        {

            ParameterExpression replacement;

            if (map.TryGetValue(p, out replacement))

            {

                p = replacement;

            }

            return base.VisitParameter(p);

        }

    }

}

  public ActionResult GetListDataBySearch(int pageSize, int pageIndex, string saleNO, string handleStatus)

        {

            if (pageIndex < ) { pageIndex = ; }

            if (pageSize < )

            {

                pageSize = ;

            }

            var whereLambda = PredicateBuilder.True<SaleInfo>(); 

            if (!String.IsNullOrWhiteSpace(saleNO))

            {

               whereLambda= whereLambda.And(c => c.SaleNO.Contains(saleNO));

            }

            if (!String.IsNullOrWhiteSpace(handleStatus))

            {

              whereLambda=  whereLambda.And(c => c.handleStatus.Equals(handleStatus));

            }

            int total = ;

            var saleInfoList = _SaleServer.LoadPageEntities(pageIndex, pageSize, out total, whereLambda, false, c => c.SaleNO);

            return Json(new { rows = saleInfoList, total = total, countPage = pageIndex }, JsonRequestBehavior.AllowGet);

        }