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

public class Test
{
	public static IEnumerable<T> SelectItems<T>(IEnumerable<T> items, string propName, string value)
	{
		IEnumerable<PropertyInfo> props;
		if (!string.IsNullOrEmpty(propName))
			props = new PropertyInfo[] { typeof(T).GetProperty(propName) };
		else
			props = typeof(T).GetProperties();
		props = props.Where(x => x != null && x.PropertyType == typeof(string));
		Expression lastExpr = null;
		ParameterExpression paramExpr = Expression.Parameter(typeof(T), "x");
		ConstantExpression valueExpr = Expression.Constant(value);
		foreach(var prop in props)
		{
			var propExpr = GetPropertyExpression(prop, paramExpr, valueExpr);
			if (lastExpr == null)
				lastExpr = propExpr;
			else
				lastExpr = Expression.MakeBinary(ExpressionType.Or, lastExpr, propExpr);
		}
		if (lastExpr == null)
			return new T[] {};
		var filterExpr = Expression.Lambda(lastExpr, paramExpr);
		return items.Where<T>((Func<T, bool>) filterExpr.Compile());
	}
	
	private static Expression GetPropertyExpression(PropertyInfo prop, ParameterExpression paramExpr, ConstantExpression valueExpr)
	{
		var memberAcc = Expression.MakeMemberAccess(paramExpr, prop);
		var containsMember = typeof(string).GetMethod("Contains");
		return Expression.Call(memberAcc, containsMember, valueExpr);
	}
	
	class TestClass
	{
		public string SomeProp { get; set; }
		public string SomeOtherProp { get; set; }
	}
	
	public static void Main()
	{
		var data = new TestClass[] {
			new TestClass() { SomeProp = "AAA", SomeOtherProp = "BBB" }, 
			new TestClass() { SomeProp = "BBB", SomeOtherProp = "CCC" }, 
			new TestClass() { SomeProp = "CCC", SomeOtherProp = "AAA" }, 
		};
		var result = SelectItems(data, "", "A");
		foreach(var item in result)
			Console.WriteLine(item.SomeProp);
	}
}