MireaBackend/Endpoint/Controllers/V1/GroupController.cs

using MediatR;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
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;

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>
        /// <param name="page">The page number for pagination (optional).</param>
        /// <param name="pageSize">The page size for pagination (optional).</param>
        /// <returns>A list of groups.</returns>
        [HttpGet]
        [ProducesResponseType(StatusCodes.Status200OK)]
        [BadRequestResponse]
        public async Task<ActionResult<List<GroupResponse>>> Get([FromQuery] int? page, [FromQuery] int? pageSize)
        {
            var result = await mediator.Send(new GetGroupListQuery()
            {
                Page = page,
                PageSize = pageSize
            });

            return Ok(result.Groups
                .Select(g => new GroupResponse()
                {
                    Id = g.Id,
                    Name = g.Name,
                    FacultyId = g.FacultyId,
                    CourseNumber = GetCourseNumber(g.Name)
                })
            );
        }

        /// <summary>
        /// Retrieves detailed information about a specific group.
        /// </summary>
        /// <param name="id">The ID of the group to retrieve.</param>
        /// <returns>Detailed information about the group.</returns>
        [HttpGet("{id:int}")]
        [ProducesResponseType(StatusCodes.Status200OK)]
        [BadRequestResponse]
        [NotFoundResponse]
        public async Task<ActionResult<GroupDetailsResponse>> GetDetails(int id)
        {
            var result = await mediator.Send(new GetGroupInfoQuery()
            {
                Id = id
            });

            return Ok(new GroupDetailsResponse()
            {
                Id = result.Id,
                Name = result.Name,
                FacultyId = result.FacultyId,
                FacultyName = result.Faculty,
                CourseNumber = GetCourseNumber(result.Name)
            });
        }

        /// <summary>
        /// Retrieves a list of groups by faculty ID.
        /// </summary>
        /// <param name="id">The ID of the faculty.</param>
        /// <returns>A list of groups belonging to the specified faculty.</returns>
        [HttpGet("{id:int}")]
        [ProducesResponseType(StatusCodes.Status200OK)]
        [BadRequestResponse]
        [NotFoundResponse]
        public async Task<ActionResult<List<GroupResponse>>> GetByFaculty(int id)
        {
            var result = await mediator.Send(new GetGroupListQuery());

            return Ok(result.Groups
                .Where(g => g.FacultyId == id)
                .Select(g => new GroupResponse()
                {
                    Id = g.Id,
                    Name = g.Name,
                    CourseNumber = GetCourseNumber(g.Name),
                    FacultyId = g.FacultyId
                }));
        }
    }
}