/*
 * oauth2-oidc-sdk
 *
 * Copyright 2012-2016, Connect2id Ltd and contributors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use
 * this file except in compliance with the License. You may obtain a copy of the
 * License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed
 * under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
 * CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
 */

package com.nimbusds.oauth2.sdk.id;


import java.net.URI;
import java.util.*;

import net.jcip.annotations.Immutable;


/**
 * Audience identifier.
 *
 * <p>Provides helper methods for:
 *
 * <ul>
 *     <li>Converting to / from string arrays and collections
 *     <li>Matching audience values
 * </ul>
 */
@Immutable
public final class Audience extends Identifier {
        
        
        private static final long serialVersionUID = 9149519511538940783L;
        
        
        /**
         * Creates a new audience identifier with the specified value.
         *
         * @param value The audience identifier value. Must not be {@code null}
         *              or empty string.
         */
        public Audience(final String value) {

                super(value);
        }


        /**
         * Creates a new audience identifier with the specified URI value.
         *
         * @param value The URI value. Must not be {@code null}.
         */
        public Audience(final URI value) {

                super(value.toString());
        }


        /**
         * Creates a new audience identifier with the specified value.
         *
         * @param value The value. Must not be {@code null}.
         */
        public Audience(final Identifier value) {

                super(value.getValue());
        }


        /**
         * Returns a singleton list of this audience.
         *
         * @return A singleton list consisting of this audience only.
         */
        public List<Audience> toSingleAudienceList() {

                List<Audience> audienceList = new ArrayList<>(1);
                audienceList.add(this);
                return audienceList;
        }


        @Override
        public boolean equals(final Object object) {
        
                return object instanceof Audience &&
                       this.toString().equals(object.toString());
        }


        /**
         * Returns a string list representation of the specified audience.
         *
         * @param audience The audience. May be {@code null}.
         *
         * @return The string list, {@code null} if the argument was
         *         {@code null}.
         */
        public static List<String> toStringList(final Audience audience) {

                if (audience == null) {
                        return null;
                }
                return Collections.singletonList(audience.getValue());
        }


        /**
         * Returns a string list representation of the specified audience list.
         *
         * @param audienceList The audience list. May be {@code null}.
         *
         * @return The string list, {@code null} if the argument was
         *         {@code null}.
         */
        public static List<String> toStringList(final List<Audience> audienceList) {

                if (audienceList == null) {
                        return null;
                }

                List<String> list = new ArrayList<>(audienceList.size());
                for (Audience aud: audienceList) {
                        list.add(aud.getValue());
                }
                return list;
        }


        /**
         * Creates an audience list from the specified string list
         * representation.
         *
         * @param strings The string list. May be {@code null}.
         *
         * @return The audience list, {@code null} if the argument was
         *         {@code null}.
         */
        public static List<Audience> create(final List<String> strings) {

                if (strings == null) {
                        return null;
                }

                List<Audience> audienceList = new ArrayList<>(strings.size());

                for (String s: strings) {
                        audienceList.add(new Audience(s));
                }
                return audienceList;
        }


        /**
         * Creates an audience list from the specified string array.
         *
         * @param strings The strings. May be {@code null}.
         *
         * @return The audience list, {@code null} if the argument was
         *         {@code null}.
         */
        public static List<Audience> create(final String ... strings) {

                if (strings == null) {
                        return null;
                }

                return create(Arrays.asList(strings));
        }


        /**
         * Returns {@code true} if the specified collections have at at least
         * one matching audience value.
         *
         * @param c1 The first audience collection. May be {@code null}.
         * @param c2 The second audience collection. May be {@code null}.
         *
         * @return {@code true} if the specified collections have at at least
         *         one matching audience value, {@code false} if there are no
         *         matches or either collection is {@code null} or empty.
         */
        public static boolean matchesAny(final Collection<Audience> c1, final Collection<Audience> c2) {

                if (c1 == null || c2 == null) {
                        return false;
                }

                for (Audience aud: c1) {
                        if (c2.contains(aud)) {
                                return true;
                        }
                }

                return false;
        }
}