MireaBackend/Application/Cqrs/Faculty/Queries/GetFacultyList/GetFacultyListQueryHandler.cs

using MediatR;
using Microsoft.EntityFrameworkCore;
using Mirea.Api.DataAccess.Application.Interfaces.DbContexts.Schedule;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;

namespace Mirea.Api.DataAccess.Application.Cqrs.Faculty.Queries.GetFacultyList;

public class GetFacultyListQueryHandler(IFacultyDbContext dbContext) : IRequestHandler<GetFacultyListQuery, FacultyListVm>
{
    public async Task<FacultyListVm> Handle(GetFacultyListQuery request, CancellationToken cancellationToken)
    {
        var dtos = dbContext.Faculties.OrderBy(f => f.Id).Select(f => new FacultyLookupDto()
        {
            Id = f.Id,
            Name = f.Name,
            CampusId = f.CampusId
        });

        if (request is { PageSize: not null, Page: not null })
            dtos = dtos.Skip(request.Page.Value * request.PageSize.Value).Take(request.PageSize.Value);

        var result = await dtos.ToListAsync(cancellationToken);

        return new FacultyListVm
        {
            Faculties = result
        };
    }
}