package fr.tiogars.chat.domains.task.services;
   
   import java.util.List;
   import fr.tiogars.chat.domains.task.entities.TaskEntity;
   import fr.tiogars.chat.domains.tag.repositories.TagRepository;
   import fr.tiogars.chat.domains.nomenclature.repositories.NomenclatureRepository;
   import org.springframework.http.HttpStatus;
   import org.springframework.stereotype.Component;
   import org.springframework.web.server.ResponseStatusException;
  
  @Component
  public class TaskReferences {
      private final TagRepository tags;
      private final NomenclatureRepository nomenclatures;
  
      public TaskReferences(TagRepository tags, NomenclatureRepository nomenclatures) {
          this.tags = tags;
          this.nomenclatures = nomenclatures;
      }
  
      public void apply(TaskEntity entity, List<Long> tagIds, Long nomenclatureId) {
          // Lock in a consistent order with taxonomy mutations to prevent reference/deletion races.
          nomenclatures.lockForest();
          var category = nomenclatureId == null ? null : nomenclatures.findById(nomenclatureId)
                  .orElseThrow(() -> invalid("Nomenclature does not exist."));
          var selectedTags = tagIds.stream().distinct().sorted()
                  .map(id -> tags.lockById(id).orElseThrow(() -> invalid("Tag does not exist: " + id))).toList();
          entity.references(selectedTags, category);
      }
  
      private static ResponseStatusException invalid(String message) {
          return new ResponseStatusException(HttpStatus.BAD_REQUEST, message);
      }
  }