using data.DAO;
using data.Repository;
using domain.Entity;
using domain.Request;
using domain.UseCase;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace domain.Service
{
    public class GroupService : IGroupUseCase
    {
        private readonly IGroupRepository _groupRepository;
        public GroupService(IGroupRepository groupRepository)
        {
            _groupRepository = groupRepository;
        }

        public bool AddGroup(AddGroupRequest addGroupRequest)
            => _groupRepository.CreateGroup(new Group { Name = addGroupRequest.Name });
        

        public void AddGroupWithStudents(AddGroupWithStudentRequest addGroupWithStudentRequest)
        {
            Group group = new Group { Name = addGroupWithStudentRequest.AddGroupRequest.Name };
            List<Student> students = addGroupWithStudentRequest
                .AddStudentRequests
                .Select(it => new Student { FirstName = it.FirstName, LastName = it.LastName, Patronymic = it.Patronymic})
                .ToList();

            _groupRepository.AddGroupWithStudents(group, students);
        }

        public void EditGroup(EditGroupRequest editGroupRequest)
            => _groupRepository.UpdateGroup(editGroupRequest.GroupId, editGroupRequest.GroupName);

        public IEnumerable<GroupEntity> GetGroupsWithStudents()
        {
            return _groupRepository.GetAllGroups().Select(
                group => new GroupEntity
                {
                    Id = group.Id,
                    Name = group.Name,
                    Users = group.Students.Select(
                        user => new UserEntity
                        {
                            Id = user.Id,
                            LastName = user.LastName,
                            FirstName = user.FirstName,
                            Patronymic = user.Patronymic,
                            Group = new GroupEntity
                            {
                                Id = group.Id,
                                Name = group.Name
                            }
                        })
                });
            }

        public bool RemoveGroup(RemoveGroupRequest removeGroupRequest)
            => _groupRepository.DeleteGroup(removeGroupRequest.GroupId);

        public GroupSubjectEntity GetGroupSubject(int id)
        {
            return _groupRepository.GetAllGroups().Select(
                group => new GroupSubjectEntity
                {
                    Id = group.Id,
                    Name = group.Name,
                    Subjects = group.StudentGroupsSubjects.Select(
                        subject => new SubjectEntity
                        {
                            Id = subject.Subject.Id,
                            Name = subject.Subject.Name,
                        })
                }).Single(g => g.Id == id);
        }
    }
}