package de.dlr.shepard.data.file.services;
   
   import de.dlr.shepard.auth.permission.services.PermissionsService;
   import de.dlr.shepard.auth.users.entities.User;
   import de.dlr.shepard.auth.users.services.UserService;
   import de.dlr.shepard.common.exceptions.InvalidAuthException;
   import de.dlr.shepard.common.exceptions.InvalidPathException;
   import de.dlr.shepard.common.mongoDB.NamedInputStream;
   import de.dlr.shepard.common.util.DateHelper;
  import de.dlr.shepard.common.util.PermissionType;
  import de.dlr.shepard.common.util.QueryParamHelper;
  import de.dlr.shepard.data.AbstractContainerService;
  import de.dlr.shepard.data.file.daos.FileContainerDAO;
  import de.dlr.shepard.data.file.entities.FileContainer;
  import de.dlr.shepard.data.file.entities.ShepardFile;
  import de.dlr.shepard.data.file.io.FileContainerIO;
  import io.quarkus.logging.Log;
  import jakarta.enterprise.context.RequestScoped;
  import jakarta.inject.Inject;
  import jakarta.ws.rs.InternalServerErrorException;
  import java.io.InputStream;
  import java.text.SimpleDateFormat;
  import java.util.List;
  import java.util.stream.Collectors;
  
  @RequestScoped
  public class FileContainerService extends AbstractContainerService<FileContainer, FileContainerIO> {
  
    @Inject
    FileContainerDAO fileContainerDAO;
  
    @Inject
    UserService userService;
  
    @Inject
    DateHelper dateHelper;
  
    @Inject
    FileService fileService;
  
    @Inject
    PermissionsService permissionsService;
  
    /**
     * Creates a FileContainer and stores it in Neo4J
     *
     * @param fileContainerIO to be stored
     * @param username        of the related user
     * @return the created FileContainer
     */
    @Override
    public FileContainer createContainer(FileContainerIO fileContainerIO) {
      User user = userService.getCurrentUser();
      FileContainer toCreate = new FileContainer();
      toCreate.setCreatedAt(dateHelper.getDate());
      toCreate.setCreatedBy(user);
      toCreate.setMongoId(fileService.createFileContainer());
      toCreate.setName(fileContainerIO.getName());
  
      var created = fileContainerDAO.createOrUpdate(toCreate);
      permissionsService.createPermissions(created, user, PermissionType.Private);
      return created;
    }
  
    /**
     * Gets the FileContainer
     *
     * @param id identifies the searched FileContainer
     * @return the FileContainer with matching id or null
     * @throws InvalidPathException if the file container cannot be found
     * @throws InvalidAuthException if user has no read permission on container
     */
    @Override
    public FileContainer getContainer(long id) {
      FileContainer fileContainer = fileContainerDAO.findByNeo4jId(id);
  
      if (fileContainer == null || fileContainer.isDeleted()) {
        String errorMsg = String.format("ID ERROR - File Container with id %s is null or deleted", id);
        Log.errorf(errorMsg);
        throw new InvalidPathException(errorMsg);
      }
      assertIsAllowedToReadContainer(id);
      fileContainer.setCollectionList(fileContainer.getCollectionList().stream().filter(d -> !d.isDeleted()).toList());
      return fileContainer;
    }
  
    /**
     * Searches the database for all FileContainers
     *
     * @param params   QueryParamsHelper
     * @param username the name of the user
     * @return a list of FileContainers
     */
    @Override
    public List<FileContainer> getAllContainers(QueryParamHelper params) {
      User user = userService.getCurrentUser();
      List<FileContainer> containers = fileContainerDAO.findAllFileContainers(params, user.getUsername());
  
      // this mapping is done because 'findAllFileContainers' does not return all relations of a container
     // therefore the returned list of collection ids is ALWAYS empty, even though the container might be set as the default container by a collection
     // this can lead to confusion
     // by nullifying the collection id list, it is not included in the API response
     containers = containers.stream().map(this::nullifyEmptyCollectionIdList).collect(Collectors.toList());
     return containers;
   }
 
   private FileContainer nullifyEmptyCollectionIdList(FileContainer fileContainer) {
     if (fileContainer.getCollectionList().isEmpty()) {
       fileContainer.setCollectionList(null);
     }
     return fileContainer;
   }
 
   /**
    * Deletes a FileContainer in Neo4j
    *
    * @param fileContainerId identifies the FileContainer
    * @param username        the deleting user
    * @throws InvalidPathException if the file container cannot be found
    * @throws InvalidAuthException if user has no write permission on container
    */
   @Override
   public void deleteContainer(long fileContainerId) {
     User user = userService.getCurrentUser();
     FileContainer fileContainer = getContainer(fileContainerId);
     assertIsAllowedToDeleteContainer(fileContainerId);
 
     String mongoId = fileContainer.getMongoId();
     fileContainer.setDeleted(true);
     fileContainer.setUpdatedAt(dateHelper.getDate());
     fileContainer.setUpdatedBy(user);
     fileContainerDAO.createOrUpdate(fileContainer);
     fileService.deleteFileContainer(mongoId);
   }
 
   /**
    * Get file payload
    *
    * @param fileContainerId The container to get the payload from
    * @param oid             The specific file
    * @return a NamedInputStream
    * @throws InvalidPathException if the file container cannot be found
    * @throws InvalidAuthException if user has no read permission on container
    */
   public NamedInputStream getFile(long fileContainerId, String oid) {
     FileContainer container = getContainer(fileContainerId);
 
     return fileService.getPayload(container.getMongoId(), oid);
   }
 
   /**
    * Create a new file
    *
    * @param fileContainerId identifies the file container
    * @param fileName        the name of the new file
    * @param inputStream     the file itself
    * @return The newly created file
    * @throws InternalServerErrorException if file creation fails
    * @throws InvalidPathException if the file container cannot be found
    * @throws InvalidAuthException if user has no read or write permission on container
    */
   public ShepardFile createFile(long fileContainerId, String fileName, InputStream inputStream) {
     FileContainer fileContainer = getContainer(fileContainerId);
     assertIsAllowedToEditContainer(fileContainerId);
 
     if (fileName == null || fileName.isBlank()) {
       var sdf = new SimpleDateFormat("yyyyMMdd-HHmmss");
       var dateStr = sdf.format(dateHelper.getDate());
       fileName = "shepard-file-" + dateStr;
     }
 
     ShepardFile result = fileService.createFile(fileContainer.getMongoId(), fileName, inputStream);
 
     fileContainer.addFile(result);
     fileContainerDAO.createOrUpdate(fileContainer);
     return result;
   }
 
   /**
    * Delete one file
    *
    * @param fileContainerId The container to get the payload from
    * @param oid             The specific file
    
    */
   public void deleteFile(long fileContainerId, String oid) {
     FileContainer container = getContainer(fileContainerId);
     assertIsAllowedToEditContainer(fileContainerId);
 
     fileService.deleteFile(container.getMongoId(), oid);
 
     List<ShepardFile> newFiles = container.getFiles().stream().filter(f -> !f.getOid().equals(oid)).toList();
     container.setFiles(newFiles);
     fileContainerDAO.createOrUpdate(container);
   }
 }