ApiDto/Responses/GroupDetailsResponse.cs

@@ -15,6 +15,11 @@ public class GroupDetailsResponse
     /// </summary>
     public required string Name { get; set; }
 
+    /// <summary>
+    /// Gets or sets the course number of the group.
+    /// </summary>
+    public int CourseNumber { get; set; }
+
     /// <summary>
     /// Gets or sets the unique identifier of the faculty to which the group belongs (optional).
     /// </summary>

ApiDto/Responses/GroupResponse.cs

@@ -15,6 +15,11 @@ public class GroupResponse
     /// </summary>
     public required string Name { get; set; }
 
+    /// <summary>
+    /// Gets or sets the course number of the group.
+    /// </summary>
+    public int CourseNumber { get; set; }
+
     /// <summary>
     /// Gets or sets the unique identifier of the faculty to which the group belongs (optional).
     /// </summary>

Endpoint/Controllers/V1/GroupController.cs

@@ -5,6 +5,7 @@ using Mirea.Api.DataAccess.Application.Cqrs.Group.Queries.GetGroupDetails;
 using Mirea.Api.DataAccess.Application.Cqrs.Group.Queries.GetGroupList;
 using Mirea.Api.Dto.Responses;
 using Mirea.Api.Endpoint.Common.Attributes;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
@@ -13,6 +14,19 @@ namespace Mirea.Api.Endpoint.Controllers.V1
 {
     public class GroupController(IMediator mediator) : BaseControllerV1
     {
+        private static int GetCourseNumber(string groupName)
+        {
+            var current = DateTime.Now;
+            if (!int.TryParse(groupName[2..], out var yearOfGroup)
+                && !int.TryParse(groupName.Split('-')[^1][..2], out yearOfGroup))
+                return -1;
+
+            // Convert a two-digit year to a four-digit one
+            yearOfGroup += current.Year / 100 * 100;
+
+            return current.Year - yearOfGroup + (current.Month < 9 ? 0 : 1);
+        }
+
         /// <summary>
         /// Retrieves a list of groups.
         /// </summary>
@@ -35,7 +49,8 @@ namespace Mirea.Api.Endpoint.Controllers.V1
                 {
                     Id = g.Id,
                     Name = g.Name,
-                    FacultyId = g.FacultyId
+                    FacultyId = g.FacultyId,
+                    CourseNumber = GetCourseNumber(g.Name)
                 })
             );
         }
@@ -61,7 +76,8 @@ namespace Mirea.Api.Endpoint.Controllers.V1
                 Id = result.Id,
                 Name = result.Name,
                 FacultyId = result.FacultyId,
-                FacultyName = result.Faculty
+                FacultyName = result.Faculty,
+                CourseNumber = GetCourseNumber(result.Name)
             });
         }
     }