MireaBackend/Application/Cqrs/Discipline/Queries/GetDisciplineList/GetDisciplineListQueryHandler.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.Discipline.Queries.GetDisciplineList;

public class GetDisciplineListQueryHandler(IDisciplineDbContext dbContext) : IRequestHandler<GetDisciplineListQuery, DisciplineListVm>
{
    public async Task<DisciplineListVm> Handle(GetDisciplineListQuery request, CancellationToken cancellationToken)
    {
        var dtos = dbContext.Disciplines.OrderBy(d => d.Id).Select(d => new DisciplineLookupDto()
        {
            Id = d.Id,
            Name = d.Name,
        });

        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 DisciplineListVm
        {
            Disciplines = result
        };
    }
}