sqlsugar/Src/Asp.Net/SqlSugar/ExpressionsToSql/Subquery/Items/SubSelectStringJoin.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Text;
namespace SqlSugar 
{
    public class SubSelectStringJoin : ISubOperation
    {
        public bool HasWhere
        {
            get; set;
        }

        public string Name
        {
            get
            {
                return "SelectStringJoin";
            }
        }

        public Expression Expression
        {
            get; set;
        }


        public int Sort
        {
            get
            {
                return 200;
            }
        }

        public ExpressionContext Context
        {
            get; set;
        }

        public string GetValue(Expression expression = null)
        {
            var exp = expression as MethodCallExpression;
            //var entityType = (exp.Arguments[0] as LambdaExpression).Parameters[0].Type;
            //if (this.Context.InitMappingInfo != null)
            //{
            //    this.Context.InitMappingInfo(entityType);
            //    this.Context.RefreshMapping();
            //}
            InitType(exp);
            var result = "";
            if (this.Context.JoinIndex == 0)
                result = SubTools.GetMethodValue(this.Context, exp.Arguments[0], ResolveExpressType.FieldSingle);
            else
                result = SubTools.GetMethodValueSubJoin(this.Context, exp.Arguments[0], ResolveExpressType.FieldMultiple);

            SetShortName(exp, result);

            if (result == null&& ExpressionTool.GetLambdaExpressionBody(exp.Arguments[0]) is ConstantExpression  ) 
            {
                var constant = ExpressionTool.GetLambdaExpressionBody(exp.Arguments[0]) as ConstantExpression;
                if (constant.Value?.ToString()?.Contains(",")==true) 
                {
                    result =  string.Join(",",(constant.Value+"").Split(',').Select(it=>this.Context.GetTranslationTableName(it)));
                }
            }
            result = this.Context.DbMehtods.GetStringJoinSelector(result, ExpressionTool.GetExpressionValue(exp.Arguments[1]) + "");

            return result;
        }
        private void InitType(MethodCallExpression exp)
        {
            foreach (var arg in (exp.Arguments[0] as LambdaExpression).Parameters)
            {
                if (this.Context.InitMappingInfo != null)
                {
                    this.Context.InitMappingInfo(arg.Type);
                    this.Context.RefreshMapping();
                }
            }
        }
        public void SetShortName(MethodCallExpression exp, string result)
        {
            if (exp.Arguments[0] is LambdaExpression )
            {
                var parameters = (exp.Arguments[0] as LambdaExpression).Parameters;
                if (parameters != null && parameters.Count > 0)
                {
                    this.Context.CurrentShortName = this.Context.GetTranslationColumnName(parameters[0].ObjToString());
                }

            }
        }
        public void SetShortNameNext(MethodCallExpression exp, string result)
        {
            if (exp.Arguments.Count > 1 && exp.Arguments[1] is LambdaExpression  )
            {
                var parameters = (exp.Arguments[1] as LambdaExpression).Parameters;
                if (parameters != null && parameters.Count > 0)
                {
                    this.Context.CurrentShortName = this.Context.GetTranslationColumnName(parameters[0].ObjToString());
                }

            }
        }
    }
}