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

namespace Common
{

    /// <summary>
    /// 脏字过滤委托实现
    /// </summary>
    /// <typeparam name="T"></typeparam>
    public static class StrFilteFun<T>
    {
        /// <summary>
        /// 脏字过滤委托
        /// </summary>
        public static Func<T, string[], T> FilterCode = StrFilteFun<T>.Generate();

        private static T FilterCodeJump(T t, string[] s) => FilterCode(t, s);

        /// <summary>
        /// 循环处理
        /// </summary>
        /// <param name="collection"></param>
        /// <param name="loopVar"></param>
        /// <param name="loopContent"></param>
        /// <returns></returns>
        public static Expression ForEach(Expression collection, ParameterExpression loopVar, Expression loopContent)
        {
            var elementType = loopVar.Type;
            var enumerableType = typeof(IEnumerable<>).MakeGenericType(elementType);
            var enumeratorType = typeof(IEnumerator<>).MakeGenericType(elementType);

            var enumeratorVar = Expression.Variable(enumeratorType, "enumerator");
            var getEnumeratorCall = Expression.Call(collection, enumerableType.GetMethod("GetEnumerator"));
            var enumeratorAssign = Expression.Assign(enumeratorVar, getEnumeratorCall);

            // The MoveNext method's actually on IEnumerator, not IEnumerator<T>
            var moveNextCall = Expression.Call(enumeratorVar, typeof(IEnumerator).GetMethod("MoveNext"));

            var breakLabel = Expression.Label("LoopBreak");

            var loop = Expression.Block(new[] { enumeratorVar },
                enumeratorAssign,
                Expression.Loop(
                    Expression.IfThenElse(
                        Expression.Equal(moveNextCall, Expression.Constant(true)),
                        Expression.Block(new[] { loopVar },
                            Expression.Assign(loopVar, Expression.Property(enumeratorVar, "Current")),
                            loopContent
                        ),
                        Expression.Break(breakLabel)
                    ),
                breakLabel)
            );

            return loop;
        }

        public static Expression For(ParameterExpression loopVar, Expression initValue, Expression condition, Expression increment, Expression loopContent)
        {
            var initAssign = Expression.Assign(loopVar, initValue);

            var breakLabel = Expression.Label("LoopBreak");

            var loop = Expression.Block(new[] { loopVar },
                initAssign,
                Expression.Loop(
                    Expression.IfThenElse(
                        condition,
                        Expression.Block(
                            loopContent,
                            increment
                        ),
                        Expression.Break(breakLabel)
                    ),
                breakLabel)
            );

            return loop;
        }



        /// <summary>
        ///委托过滤实现
        /// </summary>
        /// <returns></returns>
        public static Func<T, string[], T> Generate()
        {
            var type = typeof(T);
            var instance = Expression.Parameter(type);
            var strArray = Expression.Parameter(typeof(string[]));
            var returnLable = Expression.Label(type);

            if (type == typeof(string))//数类型是string
                return Expression.Lambda<Func<T, string[], T>>(
                    Expression.Block(
                Expression.Call(StrFilteTools._StrFilter, instance, strArray)
                    ), instance, strArray).Compile();
            List<Expression> expressions = new List<Expression>();

            //数据类型是list
            if (type.IsGenericType && type.GetGenericTypeDefinition() == typeof(IList<>) || type.GetInterfaces().ToList().Where(e => e.IsGenericType && e.GetGenericTypeDefinition() == typeof(IList<>)).Any())
            {
                var loopVar = Expression.Parameter(typeof(int));

                var loopContent = Expression.Assign(Expression.MakeIndex(instance, type.GetProperty("Item"), new[] { loopVar }), Expression.Call(typeof(StrFilteFun<>).MakeGenericType(type.GetGenericArguments()[0]).GetMethod(nameof(FilterCodeJump), BindingFlags.NonPublic | BindingFlags.Static), Expression.MakeIndex(instance, type.GetProperty("Item"), new[] { loopVar }), strArray));

                var @for = For(loopVar, Expression.Constant(0), Expression.LessThan(loopVar, Expression.Property(instance, type.GetProperty("Count"))), Expression.PostIncrementAssign(loopVar), loopContent);
                return Expression.Lambda<Func<T, string[], T>>(Expression.Block(
                    @for
                    , (Expression)Expression.Return(returnLable, instance)
                    , (Expression)Expression.Label(returnLable, instance)
               ), instance, strArray).Compile();


            }

            var pros = type.GetProperties();
            var fieds = type.GetFields();


            foreach (var item in pros)
            {
                try
                {
                    ///list 有属性是list<T>的情况
                    ///
                    var member = Expression.Property(instance, item);
                    if (item.PropertyType == typeof(string) || item.PropertyType == typeof(List<string>) || item.PropertyType.IsGenericType && item.PropertyType.GetGenericTypeDefinition() == typeof(IEnumerable<>) || item.PropertyType.GetInterfaces().ToList().Where(e => e.IsGenericType && e.GetGenericTypeDefinition() == typeof(IEnumerable<>)).Any())
                    {
                        var call = Expression.Call(typeof(StrFilteFun<>).MakeGenericType(item.PropertyType).GetMethod(nameof(FilterCodeJump), BindingFlags.NonPublic | BindingFlags.Static), member, strArray);
                        var ifNotNull = Expression.IfThen(Expression.NotEqual(member, Expression.Constant(null, item.PropertyType)), Expression.Assign(member, call));

                        expressions.Add(ifNotNull);
                    }
                }
                catch  { }

            }

            foreach (var item in fieds)//
            {
                try
                {
                    if (item.FieldType == typeof(string))
                    {
                        var member = Expression.Field(instance, item);
                        var ifNotNull = Expression.IfThen(Expression.NotEqual(member, Expression.Constant(null, typeof(string))), Expression.Assign(member, Expression.Call(StrFilteTools._StrFilter, member, strArray)));
                        expressions.Add(ifNotNull);
                    }
                }
                catch { }
            }




            expressions.Add(Expression.Return(returnLable, instance));
            expressions.Add(Expression.Label(returnLable, instance));

            return Expression.Lambda<Func<T, string[], T>>(Expression.Block(expressions.ToArray()), instance, strArray).Compile();

        }
    }

    /// <summary>
    ///脏字过滤
    /// </summary>
    public static class StrFilteTools
    {

        /// <summary>
        /// 脏字数据List
        /// </summary>

        public static MethodInfo _StrFilter = typeof(StrFilteTools).GetMethod(nameof(StrFilter), BindingFlags.Static | BindingFlags.Public);


        /// <summary>
        /// 批量数据过滤
        /// </summary>
        /// <param name="value">要过滤操作的字符串</param>
        /// <param name="Filterlist">过滤脏字列表</param>
        /// <returns></returns>
        public static string StrFilter(string value, string[] Filterlist)
        {

            var v = value;
            foreach (var item in Filterlist)
            {
                if (!item.IsNull())
                {
                    v = v.Replace(item, "*");
                }
            }
            return v;
        }
    }
}