001/*
002 * Copyright (c) 2011-2017 Nexmo Inc
003 *
004 * Permission is hereby granted, free of charge, to any person obtaining a copy
005 * of this software and associated documentation files (the "Software"), to deal
006 * in the Software without restriction, including without limitation the rights
007 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
008 * copies of the Software, and to permit persons to whom the Software is
009 * furnished to do so, subject to the following conditions:
010 *
011 * The above copyright notice and this permission notice shall be included in
012 * all copies or substantial portions of the Software.
013 *
014 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
015 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
016 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
017 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
018 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
019 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
020 * THE SOFTWARE.
021 */
022package com.nexmo.client.auth;
023
024import java.util.*;
025
026/**
027 * Internal class, managing a collection of {@link AuthMethod}s.
028 * <p>
029 * This holds a collection of AuthMethod instances, in order of preference, and
030 * allow for simple selection of an appropriate AuthMethod for a particular REST endpoint.
031 */
032public class AuthCollection {
033    private SortedSet<AuthMethod> authList;
034
035    /**
036     * Create a new AuthCollection with an empty set of AuthMethods.
037     */
038    public AuthCollection() {
039        this.authList = new TreeSet<>();
040    }
041
042    public AuthCollection(AuthMethod... authMethods) {
043        this();
044        for (AuthMethod method : authMethods) {
045            add(method);
046        }
047    }
048
049    public AuthCollection(SortedSet<AuthMethod> authMethods) {
050        this.authList = authMethods;
051    }
052
053    /**
054     * Add a new {@link AuthMethod} to the set managed by this AuthCollection
055     *
056     * @param auth AuthMethod method to be added to this collection
057     */
058    public void add(AuthMethod auth) {
059        this.authList.add(auth);
060    }
061
062    /**
063     * Obtain an AuthMethod of type T, if one is contained in this collection.
064     *
065     * @param type The type of AuthMethod to be located
066     * @param <T>  The type of AuthMethod which will be returned
067     *
068     * @return An AuthMethod subclass matching type
069     *
070     * @throws NexmoUnacceptableAuthException if no matching AuthMethod is found.
071     */
072    public <T extends AuthMethod> T getAuth(Class<T> type) throws NexmoUnacceptableAuthException {
073        for (AuthMethod availableAuthMethod : this.authList) {
074            if (type.isInstance(availableAuthMethod)) {
075                return (T) availableAuthMethod;
076            }
077        }
078        throw new NexmoUnacceptableAuthException(this.authList, new HashSet<>(Arrays.asList(new Class[]{type})));
079    }
080
081    /**
082     * Obtain an {@link AuthMethod} instance for a set of acceptable AuthMethod classes.
083     *
084     * @param acceptableAuthMethodClasses A Set of AuthMethod classes which are suitable for the target REST endpoint.
085     *
086     * @return the preferred AuthMethod from the provided set of acceptable AuthMethod classes
087     *
088     * @throws NexmoUnacceptableAuthException if no appropriate AuthMethod is held by this AuthCollection
089     */
090    public AuthMethod getAcceptableAuthMethod(Set<Class> acceptableAuthMethodClasses) throws NexmoUnacceptableAuthException {
091        for (AuthMethod availableAuthMethod : this.authList) {
092            if (acceptableAuthMethodClasses.contains(availableAuthMethod.getClass())) {
093                return availableAuthMethod;
094            }
095        }
096        throw new NexmoUnacceptableAuthException(this.authList, acceptableAuthMethodClasses);
097    }
098}