MireaBackend/Application/Cqrs/Schedule/Queries/GetScheduleList/GetScheduleListQueryHandler.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.Schedule.Queries.GetScheduleList;

public class GetScheduleListQueryHandler(ILessonDbContext dbContext) : IRequestHandler<GetScheduleListQuery, ScheduleListVm>
{
    public async Task<ScheduleListVm> Handle(GetScheduleListQuery request, CancellationToken cancellationToken)
    {
        var query = dbContext.Lessons.Include(l => l.LessonAssociations)
            .ThenInclude(la => la.LectureHall)
            .ThenInclude(lh => lh!.Campus)
            .Include(l => l.LessonAssociations)
            .ThenInclude(la => la.Professor)
            .Include(l => l.Group)
            .Include(l => l.TypeOfOccupation)
            .Include(l => l.Discipline)
            .AsQueryable();

        if (request.IsEven != null)
            query = query.Where(l => l.IsEven == request.IsEven);

        if (request.GroupIds != null && request.GroupIds.Length != 0)
            query = query.Where(l => request.GroupIds.Contains(l.GroupId));

        if (request.DisciplineIds != null && request.DisciplineIds.Length != 0)
            query = query.Where(l => request.DisciplineIds.Contains(l.DisciplineId));

        if (request.LectureHallIds != null && request.LectureHallIds.Length != 0)
            query = query.Where(l => l.LessonAssociations!.Any(la =>
                la.LectureHallId != null && request.LectureHallIds.Contains(la.LectureHallId.Value)));

        if (request.ProfessorIds != null && request.ProfessorIds.Length != 0)
            query = query.Where(l =>
                l.LessonAssociations!.Any(la =>
                    la.ProfessorId != null && request.ProfessorIds.Contains(la.ProfessorId.Value)));

        var data = await query.ToArrayAsync(cancellationToken);

        var result = data.Select(l => new ScheduleLookupDto()
        {
            DayOfWeek = l.DayOfWeek,
            PairNumber = l.PairNumber,
            IsEven = l.IsEven,
            TypeOfOccupation = l.TypeOfOccupation!.ShortName,

            Discipline = l.Discipline!.Name,
            DisciplineId = l.DisciplineId,

            Group = l.Group!.Name,
            GroupId = l.GroupId,

            LectureHalls = l.LessonAssociations!
                .Where(la => !string.IsNullOrEmpty(la.LectureHall?.Name))
                .Select(la => la.LectureHall?.Name),
            LectureHallsId = l.LessonAssociations!
                .Where(la => la.LectureHallId != null)
                .Select(la => la.LectureHallId),

            Campus = l.LessonAssociations!
                .Where(la => !string.IsNullOrEmpty(la.LectureHall?.Campus?.CodeName))
                .Select(la => la.LectureHall?.Campus?.CodeName),
            CampusId = l.LessonAssociations!
                .Where(la => la.LectureHall?.Campus != null)
                .Select(la => la.LectureHall?.CampusId),


            Professors = l.LessonAssociations!
                .Where(la => !string.IsNullOrEmpty(la.Professor?.Name))
                .Select(la => la.Professor?.Name),
            ProfessorsId = l.LessonAssociations!
                .Where(la => la.ProfessorId != null)
                .Select(la => la.ProfessorId),

            LinkToMeet = l.LessonAssociations!.Select(la => la.LinkToMeet)
        }).ToList();

        return new ScheduleListVm
        {
            Schedules = result
        };
    }
}