using Zurnal.Data.Repository;
using Zurnal.domain.Models;
using Zurnal.RemaDateBase;

namespace Zurnal.Domain.UseCase
{
    public class UserUseCase
    {
        private readonly UserRepositoryImpl _repositoryUserImpl;
        internal IGroupRepository RepositoryGroupImpl { get; }

        public UserUseCase(UserRepositoryImpl repositoryImpl, GroupRepositoryImpl repositoryGroupImpl)
        {
            _repositoryUserImpl = repositoryImpl;
            RepositoryGroupImpl = repositoryGroupImpl;
        }

        public List<Group> GetAllGroups()
        {
            return RepositoryGroupImpl.GetAllGroup()
            .Select(it => new Group { Id = it.Id, Name = it.Name }).ToList();
        }

        public List<User> GetAllUsers() => _repositoryUserImpl.GetAllUsers()
            .Join(RepositoryGroupImpl.GetAllGroup(),
            user => user.GroupID,
            group => group.Id,
            (user, group) => 
            new User { FIO = user.FIO, 
                Guid = user.Guid, 
                Group = new Group { Id = group.Id, Name = group.Name } }
            ).ToList();

        public bool RemoveUserByGuid(Guid userGuid) 
        {
            return _repositoryUserImpl.RemoveUserByGuid(userGuid);
        }

        public User UpdateUser(User user) 
        {
            UserLocalEnity userLocalEntity = new UserLocalEntity { FIO = user.FIO, GroupID = user.Group.Id, Guid = user.Guid };
            UserLocalEntity? result = _repositoryUserImpl.UpdateUser(userLocalEntity);
            if (result == null) throw new Exception("User update failed.");
            Group? group = GetAllGroups().FirstOrDefault(it => it.Id = result.GroupID);
            if (group == null) throw new Exception("Group not found.");
            return new User { FIO = user.FIO, Guid = user.Guid, Group = group };
        }

        public User FindUserByGuid(Guid userGuid)
        {
            var user = _repositoryUserImpl.GetAllUsersList().FirstOrDefault(u => u.Guid == userGuid);
            if (user == null) throw new Exception("User not found.");
            var group = RepositoryGroupImpl.GetAllGroup().FirstOrDefault(g => g.Id == user.GroupID);
            return new User { FIO = user.FIO, Guid = user.Guid, Group = group };
        }
    }

    internal class UserLocalEntity
{
    public string FIO { get; set; }
    public Guid GroupID { get; set; }
    public Guid Guid { get; set; }
}
}