package ca.uhn.fhir.model.api;

/*
 * #%L
 * HAPI FHIR - Core Library
 * %%
 * Copyright (C) 2014 - 2016 University Health Network
 * %%
 * 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.
 * #L%
 */

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;

import org.hl7.fhir.instance.model.api.IBase;

/**
 * A collection of tags present on a single resource. TagList is backed by a {@link LinkedHashSet}, so the order of
 * added tags will be consistent, but duplicates will not be preserved.
 * 
 * <p>
 * <b>Thread safety:</b> This class is not thread safe
 * </p>
 */
public class TagList implements Set<Tag>, Serializable, IBase {

        public static final String ATTR_CATEGORY = "category";
        public static final String ELEMENT_NAME = "TagList";

        public static final String ELEMENT_NAME_LC = ELEMENT_NAME.toLowerCase();
        private static final long serialVersionUID = 1L;
        private transient List<Tag> myOrderedTags;
        private LinkedHashSet<Tag> myTagSet = new LinkedHashSet<Tag>();

        /**
         * Constructor
         */
        public TagList() {
                super();
        }

        /**
         * Copy constructor
         */
        public TagList(TagList theTags) {
                if (theTags != null) {
                        for (Tag next : theTags) {
                                add(next);
                        }
                }
        }

        @Override
        public String toString() {
                StringBuilder b = new StringBuilder();
                b.append("TagList[").append(size()).append(" tag(s)]");
                for (Tag next : this) {
                        b.append("\n * ").append(next.toString());
                }
                return b.toString();
        }

        @Override
        public boolean add(Tag theE) {
                myOrderedTags = null;
                return myTagSet.add(theE);
        }

        @Override
        public boolean addAll(Collection<? extends Tag> theC) {
                myOrderedTags = null;
                return myTagSet.addAll(theC);
        }

        /**
         * @deprecated Tags wil become immutable in a future release of HAPI, so {@link #addTag(String, String, String)}
         *             should be used instead
         */
        @Deprecated
        public Tag addTag() {
                myOrderedTags = null;
                return addTag(null, null, null);
        }

        /**
         * Add a new tag instance
         * 
         * @param theScheme
         *           The tag scheme
         * @param theTerm
         *           The tag term
         * @return Returns the newly created tag instance. Note that the tag is added to the list by this method, so you
         *         generally do not need to interact directly with the added tag.
         */
        public Tag addTag(String theScheme, String theTerm) {
                Tag retVal = new Tag(theScheme, theTerm);
                add(retVal);
                myOrderedTags = null;
                return retVal;
        }

        /**
         * Add a new tag instance
         * 
         * @param theScheme
         *           The tag scheme
         * @param theTerm
         *           The tag term
         * @param theLabel
         *           The tag label
         * @return Returns the newly created tag instance. Note that the tag is added to the list by this method, so you
         *         generally do not need to interact directly with the added tag.
         */
        public Tag addTag(String theScheme, String theTerm, String theLabel) {
                Tag retVal = new Tag(theScheme, theTerm, theLabel);
                add(retVal);
                myOrderedTags = null;
                return retVal;
        }

        @Override
        public void clear() {
                myOrderedTags = null;
                myTagSet.clear();
        }

        @Override
        public boolean contains(Object theO) {
                return myTagSet.contains(theO);
        }

        @Override
        public boolean containsAll(Collection<?> theC) {
                return myTagSet.containsAll(theC);
        }

        @Override
        public boolean equals(Object obj) {
                if (this == obj)
                        return true;
                if (obj == null)
                        return false;
                if (getClass() != obj.getClass())
                        return false;
                TagList other = (TagList) obj;
                if (myTagSet == null) {
                        if (other.myTagSet != null)
                                return false;
                } else if (!myTagSet.equals(other.myTagSet))
                        return false;
                return true;
        }

        /**
         * Returns the tag at a given index - Note that the TagList is backed by a {@link LinkedHashSet}, so the order of
         * added tags will be consistent, but duplicates will not be preserved.
         */
        public Tag get(int theIndex) {
                if (myOrderedTags == null) {
                        myOrderedTags = new ArrayList<Tag>();
                        for (Tag next : myTagSet) {
                                myOrderedTags.add(next);
                        }
                }
                return myOrderedTags.get(theIndex);
        }

        public Tag getTag(String theScheme, String theTerm) {
                for (Tag next : this) {
                        if (theScheme.equals(next.getScheme()) && theTerm.equals(next.getTerm())) {
                                return next;
                        }
                }
                return null;
        }

        public List<Tag> getTagsWithScheme(String theScheme) {
                ArrayList<Tag> retVal = new ArrayList<Tag>();
                for (Tag next : this) {
                        if (theScheme.equals(next.getScheme())) {
                                retVal.add(next);
                        }
                }
                return retVal;
        }

        @Override
        public int hashCode() {
                return myTagSet.hashCode();
        }

        @Override
        public boolean isEmpty() {
                for (Tag next : myTagSet) {
                        if (next.isEmpty() == false) {
                                return false;
                        }
                }
                return true;
        }

        @Override
        public Iterator<Tag> iterator() {
                return myTagSet.iterator();
        }

        @Override
        public boolean remove(Object theO) {
                myOrderedTags = null;
                return myTagSet.remove(theO);
        }

        @Override
        public boolean removeAll(Collection<?> theC) {
                myOrderedTags = null;
                return myTagSet.removeAll(theC);
        }

        @Override
        public boolean retainAll(Collection<?> theC) {
                myOrderedTags = null;
                return myTagSet.retainAll(theC);
        }

        @Override
        public int size() {
                return myTagSet.size();
        }

        @Override
        public Object[] toArray() {
                return myTagSet.toArray();
        }

        @Override
        public <T> T[] toArray(T[] theA) {
                return myTagSet.toArray(theA);
        }

}