Add event realted filters

BusinessLayer/Utils/Filters/EventCommentFilter.cs

+using DAL.Models;
+using System.Linq.Expressions;
+
+namespace BusinessLayer.Utils.Filters
+{
+    public class EventCommentFilter
+    {
+        public Guid? PosterId { get; set; }
+        public Guid? EventId { get; set; }
+        public Guid? ParentCommentId { get; set; }
+
+        public Expression<Func<EventComment, bool>> ComposeFilterFunction(Guid[]? ids)
+        {
+            return c => (ids == null || ids.Contains(c.Id))
+                     && (PosterId == null || c.PosterId == PosterId)
+                     && (EventId == null || c.EventId == EventId)
+                     && (ParentCommentId == null || c.ParentCommentId == ParentCommentId)
+                     && c.DeletedAt == null;
+        }
+    }
+}

BusinessLayer/Utils/Filters/EventFilter.cs

+using DAL.Models;
+using System.Linq.Expressions;
+
+namespace BusinessLayer.Utils.Filters
+{
+    public class EventFilter
+    {
+        public Guid? RestaurantId { get; set; }
+        public DateTime? DateFrom { get; set; }
+        public DateTime? DateTo { get; set; }
+
+        public Expression<Func<Event, bool>> ComposeFilterFunction()
+        {
+            return e => (RestaurantId == null || e.RestaurantId == RestaurantId)
+                     && (DateFrom == null || e.Date >= DateFrom)
+                     && (DateTo == null || e.Date <= DateTo)
+                     && e.DeletedAt == null;
+        }
+    }
+}

BusinessLayer/Utils/Filters/EventParticipantFilter.cs

+using DAL.Enums;
+using DAL.Models;
+using System.Linq.Expressions;
+
+namespace BusinessLayer.Utils.Filters
+{
+    public class EventParticipantFilter
+    {
+        public Guid? UserId { get; set; }
+        public Guid? EventId { get; set; }
+        public ParticipantType? Attendance { get; set; }
+
+        public Expression<Func<EventParticipant, bool>> ComposeFilterFunction()
+        {
+            return p => (UserId == null || p.UserId == UserId)
+                     && (EventId == null || p.EventId == EventId)
+                     && (Attendance == null || p.Attendance == Attendance)
+                     && p.DeletedAt == null;
+        }
+    }
+}