HRCenter/Diligent.WebAPI.Business/Extensions/SelectionProcessExtensions.cs

namespace Diligent.WebAPI.Business.Extensions
{
    public static class SelectionProcessExtensions
    {
        public static List<SelectionLevel> FilterLevels(this List<SelectionLevel> query, SelectionProcessFilterDto filter)
        {
            var filteredLevels = new List<SelectionLevel>();
            // If filters are empty
            if ((filter == null) || (!filter.DateStart.HasValue && !filter.DateEnd.HasValue && filter.Statuses != null && filter.Statuses.Length == 0))
                return query;

            foreach (var level in query)
            {
                List<SelectionProcess> selectionProcesses = level.SelectionProcesses;
                if (filter.DateStart.HasValue)
                {
                    selectionProcesses = level.SelectionProcesses.Where(sp => sp.Date >= filter.DateStart.Value).ToList();
                }

                if (filter.DateEnd.HasValue)
                {
                    selectionProcesses = selectionProcesses.Where(sp => sp.Date <= filter.DateEnd.Value).ToList();
                }

                var filteredLevel = new SelectionLevel { Id = level.Id, Name = level.Name, SelectionProcesses = level.SelectionProcesses};

                if(filter.Statuses != null && filter.Statuses.Length > 0) {
                    filteredLevel.SelectionProcesses = selectionProcesses.Where(f => filter.Statuses.Contains(f.Status)).ToList();
                }

                filteredLevels.Add(filteredLevel);
            }

            return filteredLevels;
        }
    }
}