/*
 * Copyright 2017 Graz University of Technology EAAF-Core Components has been developed in a
 * cooperation between EGIZ, A-SIT Plus, A-SIT, and Graz University of Technology.
 *
 * Licensed under the EUPL, Version 1.2 or - as soon they will be approved by the European
 * Commission - subsequent versions of the EUPL (the "Licence"); You may not use this work except in
 * compliance with the Licence. You may obtain a copy of the Licence at:
 * https://joinup.ec.europa.eu/news/understanding-eupl-v12
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the Licence
 * is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the Licence for the specific language governing permissions and limitations under
 * the Licence.
 *
 * This product combines work with different licenses. See the "NOTICE" text file for details on the
 * various modules and licenses. The "NOTICE" text file is part of the distribution. Any derivative
 * works that you distribute must include a readable copy of the "NOTICE" text file.
*/

package at.gv.egiz.eaaf.core.api.storage;

import java.util.Date;
import java.util.List;

import javax.annotation.Nonnull;
import javax.annotation.Nullable;

import at.gv.egiz.eaaf.core.exceptions.EaafException;
import at.gv.egiz.eaaf.core.exceptions.EaafStorageException;

/**
 * Interface to store arbitrary data.
 *
 * @author tlenz
 *
 */
public interface ITransactionStorage {

  /**
   * Check if transaction storage contains a data object with a specific key.
   *
   * @param key Key, which identifies a data object
   * @return true if key is found, otherwise false
   */
  boolean containsKey(String key);

  /**
   * Store a data object with a key to transaction storage.
   *
   * @param key       Id which identifiers the data object
   * @param value     Data object which should be stored. This data must implement
   *                  the <code>java.io.Serializable</code> interface
   * @param timeoutMs Defines the period of time a data object is kept within the
   *                  storage
   * @throws EaafStorageException In case of store operation failed
   */
  void put(String key, Object value, int timeoutMs) throws EaafException;

  /**
   * Get a data object from transaction storage.
   *
   * @param key key Id which identifiers the data object
   * @return The transaction-data object, or null
   * @throws EaafStorageException In case of load operation failed
   */
  Object get(String key) throws EaafException;

  /**
   * Get a data object from transaction storage.
   *
   * @param key   Id which identifiers the data object
   * @param clazz The class type which is stored with this key
   * @return The transaction-data object from type class, or null
   * @throws EaafStorageException In case of load operation failed
   */
  <T> T get(String key, final Class<T> clazz) throws EaafException;

  /**
   * Get a data object from transaction storage.
   *
   * @param key         Id which identifiers the data object
   * @param clazz       The class type which is stored with this key
   * @param dataTimeOut Data-object timeout in [ms]
   * @return The transaction-data object from type class, or null
   * @throws EaafStorageException In case of load operation failed
   */
  <T> T get(String key, final Class<T> clazz, long dataTimeOut) throws EaafException;

  /**
   * Change the key of a data object and store it under the new key.
   *
   * @param oldKey Old key of the data object
   * @param newKey New key, which should be used to store the data object
   * @param value  Data object which should be stored
   * @throws EaafStorageException In case of store operation failed
   */
  void changeKey(String oldKey, String newKey, Object value) throws EaafException;

  /**
   * Remove a data object from transaction storage.
   *
   * @param key Id which identifiers the data object
   */
  void remove(String key);

  /**
   * Get all entries for Clean-up the transaction storage.
   *
   * @param now         Current time
   * @param dataTimeOut Data-object timeout in [ms]
   * @return List of entry-keys which as a timeout
   */
  List<String> clean(Date now, long dataTimeOut);

  /**
   * Get a raw object from storage by using this key.
   *
   * @param key Storagekey
   * @return Object stored with this key, or null
   * @throws EaafException In case of a storage error
   */
  @Nullable
  Object getRaw(String key) throws EaafException;

  /**
   * Set a raw object to storage.
   *
   * @param key     Storagekey
   * @param element Object to store
   * @throws EaafException In case of a storage error
   */
  void putRaw(@Nonnull String key, @Nonnull Object element) throws EaafException;

}