using JSMachine.WMS.Infrastructure.LambdaHelp;
using System;
using System.Linq;
using System.Linq.Expressions;
using System.Reflection;

namespace JSMachine.WMS.Infrastructure.FullTextSearch
{
    /// <summary>
    /// 全文检索表达式目录树辅助类
    /// </summary>
    public static class FulleTextSearchHelper<T> where T : class, new()
    {
        private static PropertyInfo[] Properties = typeof(T).GetProperties();

        /// <summary>
        /// 构建全文检索表达式目录树(精确匹配)
        /// </summary>
        public static Expression<Func<T, bool>> BuildFullTextSearchEqualExpression(object keyWords)
        {
            if (keyWords == null || string.IsNullOrEmpty(keyWords.ToString()))
            {
                return ExpressionTreeHelper<T>.True();
            }


            Expression<Func<T, bool>> initTree = ExpressionTreeHelper<T>.False();

            foreach (PropertyInfo propertyInfo in Properties)
            {
                FullTextSearchIgnoreAttribute ignoreAttrbute = propertyInfo
                    .GetCustomAttributes()
                    .FirstOrDefault(attribute => attribute is FullTextSearchIgnoreAttribute)
                    as FullTextSearchIgnoreAttribute;

                if (ignoreAttrbute == null)
                {
                    Expression<Func<T, bool>> express = ExpressionTreeHelper<T>.CreateEqual(propertyInfo.Name, keyWords);
                    initTree = initTree.Or(express);
                }
            }

            return initTree;
        }

        /// <summary>
        /// 构建全文检索表达式目录树(模糊匹配)
        /// </summary>
        public static Expression<Func<T, bool>> BuildFullTextSearchLikeExpression(object keyWords)
        {
            if (keyWords == null || string.IsNullOrEmpty(keyWords.ToString()))
            {
                return ExpressionTreeHelper<T>.True();
            }

            Expression<Func<T, bool>> initTree = ExpressionTreeHelper<T>.False();

            foreach (PropertyInfo propertyInfo in Properties)
            {
                FullTextSearchIgnoreAttribute ignoreAttrbute = propertyInfo
                    .GetCustomAttributes()
                    .FirstOrDefault(attribute => attribute is FullTextSearchIgnoreAttribute)
                    as FullTextSearchIgnoreAttribute;

                if (ignoreAttrbute == null)
                {
                    //值类型
                    Type[] valueTypes = new Type[5] ;

                    //如果是可空类型
                    if (propertyInfo.PropertyType.IsGenericType && propertyInfo.PropertyType.GetGenericTypeDefinition().Equals(typeof(Nullable<>)))
                    {
                        valueTypes = new Type[5] { typeof(int?), typeof(byte?), typeof(double?), typeof(float?), typeof(DateTime?) };
                        Expression<Func<T, bool>> express = ExpressionTreeHelper<T>.CreateEqual(propertyInfo.Name, keyWords);
                        initTree = initTree.Or(express);
                    }
                    //值类型只能精准匹配
                    else if (valueTypes.Contains(propertyInfo.PropertyType))
                    {
                        valueTypes = new Type[5] { typeof(int), typeof(byte), typeof(double), typeof(float), typeof(DateTime) };
                        Expression<Func<T, bool>> express = ExpressionTreeHelper<T>.CreateEqual(propertyInfo.Name, keyWords);
                        initTree = initTree.Or(express);
                    }
                    else if(propertyInfo.PropertyType==typeof(string))
                    {
                        Expression<Func<T, bool>> express = ExpressionTreeHelper<T>.GetContains(propertyInfo.Name, keyWords);
                        initTree = initTree.Or(express);
                    }
                }
            }

            return initTree;
        }
    }
}