/*
 * Copyright 2014 Red Hat, Inc.
 *
 *  All rights reserved. This program and the accompanying materials
 *  are made available under the terms of the Eclipse Public License v1.0
 *  and Apache License v2.0 which accompanies this distribution.
 *
 *  The Eclipse Public License is available at
 *  http://www.eclipse.org/legal/epl-v10.html
 *
 *  The Apache License v2.0 is available at
 *  http://www.opensource.org/licenses/apache2.0.php
 *
 *  You may elect to redistribute this code under either of these licenses.
 */
package io.vertx.ext.auth;

import io.vertx.codegen.annotations.Fluent;
import io.vertx.codegen.annotations.VertxGen;
import io.vertx.ext.auth.impl.HashingStrategyImpl;

import java.util.Map;
import java.util.ServiceLoader;

/**
 * Hashing Strategy manager.
 *
 * This class will load system provided hashing strategies and algorithms.
 *
 * @author <a href="mailto:plopes@redhat.com">Paulo Lopes</a>
 */
@VertxGen
public interface HashingStrategy {

  /**
   * Factory method to load the algorithms from the system
   *
   * @return a Hashing Strategy capable of hashing using the available algorithms
   */
  static HashingStrategy load() {
    final HashingStrategyImpl strategy = new HashingStrategyImpl();
    ServiceLoader<HashingAlgorithm> serviceLoader = ServiceLoader.load(HashingAlgorithm.class);

    for (HashingAlgorithm algorithm : serviceLoader) {
      strategy.add(algorithm);
    }

    return strategy;
  }

  /**
   * Hashes a password.
   *
   * @param id the algorithm id
   * @param params the algorithm specific parameters
   * @param salt the given salt
   * @param password the given password
   * @return the hashed string
   */
  String hash(String id, Map<String, String> params, String salt, String password);

  /**
   * Time constant password check. Regardless of the check, this algorithm executes the same number of
   * checks regardless of the correctly number of characters
   *
   * @param hash the hash to verify
   * @param password the password to test against
   * @return boolean
   */
  boolean verify(String hash, String password);

  /**
   * Get an algorithm interface by its Id
   * @param id the algorithm id
   * @return the algorithm
   */
  HashingAlgorithm get(String id);

  /**
   * Put or replace an algorithm into the list of system loaded algorithms.
   *
   * @param id the algorithm id
   * @param algorithm the implementation
   * @return self
   */
  @Fluent
  HashingStrategy put(String id, HashingAlgorithm algorithm);
}
