using System.Collections.Generic;

namespace TINK.Model.Connector.Filter
{
    /// <summary> Filters to enumerations of string by intersecting.</summary>
    public class IntersectGroupFilter : IGroupFilter
    {
        private IEnumerable<string> Group { get; set; }

        public IntersectGroupFilter(IEnumerable<string> group) => Group = group ?? new List<string>();

        /// <summary> Applies filtering. </summary>
        /// <param name="filter">Enumeration of filter values to filter with or null if no filtering has to be applied.</param>
        /// <returns></returns>
        public IEnumerable<string> DoFilter(IEnumerable<string> filter) => filter != null
            ? Group.IntersectByGoupId(filter)
            : Group;
    }
}