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 com.nexmo.client.NexmoClientException;
025
026import java.util.*;
027
028/**
029 * Internal class, managing a collection of {@link AuthMethod}s.
030 * <p>
031 * This holds a collection of AuthMethod instances, in order of preference, and
032 * allow for simple selection of an appropriate AuthMethod for a particular REST endpoint.
033 */
034public class AuthCollection {
035    private SortedSet<AuthMethod> authList;
036
037    /**
038     * Create a new AuthCollection with an empty set of AuthMethods.
039     */
040    public AuthCollection() {
041        this.authList = new TreeSet<>();
042    }
043
044    public AuthCollection(AuthMethod... authMethods) {
045        this();
046        for (AuthMethod method : authMethods) {
047            add(method);
048        }
049    }
050
051    /**
052     * Add a new {@link AuthMethod} to the set managed by this AuthCollection
053     *
054     * @param auth AuthMethod method to be added to this collection
055     */
056    public void add(AuthMethod auth) {
057        this.authList.add(auth);
058    }
059
060    /**
061     * Obtain an AuthMethod of type T, if one is contained in this collection.
062     *
063     * @param type The type of AuthMethod to be located
064     * @param <T>  The type of AuthMethod which will be returned
065     * @return An AuthMethod subclass matching type
066     * @throws NexmoUnacceptableAuthException if no matching AuthMethod is found.
067     */
068    public <T extends AuthMethod> T getAuth(Class<T> type) throws NexmoUnacceptableAuthException {
069        for (AuthMethod availableAuthMethod : this.authList) {
070            if (type.isInstance(availableAuthMethod)) {
071                return (T) availableAuthMethod;
072            }
073        }
074        throw new NexmoUnacceptableAuthException(this.authList, new HashSet<Class>(Arrays.asList(new Class[]{type})));
075    }
076
077    /**
078     * Obtain an {@link AuthMethod} instance for a set of acceptable AuthMethod classes.
079     *
080     * @param acceptableAuthMethodClasses A Set of AuthMethod classes which are suitable for the target REST endpoint.
081     * @return the preferred AuthMethod from the provided set of acceptable AuthMethod classes
082     * @throws NexmoUnacceptableAuthException if no appropriate AuthMethod is held by this AuthCollection
083     */
084    public AuthMethod getAcceptableAuthMethod(Set<Class> acceptableAuthMethodClasses) throws NexmoUnacceptableAuthException {
085        for (AuthMethod availableAuthMethod : this.authList) {
086            if (acceptableAuthMethodClasses.contains(availableAuthMethod.getClass())) {
087                return availableAuthMethod;
088            }
089        }
090        throw new NexmoUnacceptableAuthException(this.authList, acceptableAuthMethodClasses);
091    }
092}