/**
 *
 * Copyright 2003-2007 Jive Software.
 *
 * 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 org.jivesoftware.smackx.offline.packet;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import org.jivesoftware.smack.packet.IQ;
import org.jivesoftware.smack.packet.XmlEnvironment;
import org.jivesoftware.smack.provider.IQProvider;
import org.jivesoftware.smack.xml.XmlPullParser;
import org.jivesoftware.smack.xml.XmlPullParserException;
import org.jivesoftware.smackx.offline.OfflineMessageManager;

/**
 * Represents a request to get some or all the offline messages of a user. This class can also
 * be used for deleting some or all the offline messages of a user.
 *
 * @author Gaston Dombiak
 */
public class OfflineMessageRequest extends IQ {

    public static final String ELEMENT = "offline";
    public static final String NAMESPACE = OfflineMessageManager.NAMESPACE;

    private final List<Item> items = new ArrayList<>();
    private boolean purge = false;
    private boolean fetch = false;

    public OfflineMessageRequest() {
        super(ELEMENT, NAMESPACE);
    }

    /**
     * Returns a List of item children that holds information about offline messages to
     * view or delete.
     *
     * @return a List of item children that holds information about offline messages to
     *         view or delete.
     */
    public List<Item> getItems() {
        synchronized (items) {
            return Collections.unmodifiableList(new ArrayList<>(items));
        }
    }

    /**
     * Adds an item child that holds information about offline messages to view or delete.
     *
     * @param item the item child that holds information about offline messages to view or delete.
     */
    public void addItem(Item item) {
        synchronized (items) {
            items.add(item);
        }
    }

    /**
     * Returns true if all the offline messages of the user should be deleted.
     *
     * @return true if all the offline messages of the user should be deleted.
     */
    public boolean isPurge() {
        return purge;
    }

    /**
     * Sets if all the offline messages of the user should be deleted.
     *
     * @param purge true if all the offline messages of the user should be deleted.
     */
    public void setPurge(boolean purge) {
        this.purge = purge;
    }

    /**
     * Returns true if all the offline messages of the user should be retrieved.
     *
     * @return true if all the offline messages of the user should be retrieved.
     */
    public boolean isFetch() {
        return fetch;
    }

    /**
     * Sets if all the offline messages of the user should be retrieved.
     *
     * @param fetch true if all the offline messages of the user should be retrieved.
     */
    public void setFetch(boolean fetch) {
        this.fetch = fetch;
    }

    @Override
    protected IQChildElementXmlStringBuilder getIQChildElementBuilder(IQChildElementXmlStringBuilder buf) {
        buf.rightAngleBracket();

        synchronized (items) {
            for (Item item : items) {
                buf.append(item.toXML());
            }
        }
        if (purge) {
            buf.append("<purge/>");
        }
        if (fetch) {
            buf.append("<fetch/>");
        }

        return buf;
    }

    /**
     * Item child that holds information about offline messages to view or delete.
     *
     * @author Gaston Dombiak
     */
    public static class Item {
        private String action;
        private String jid;
        private String node;

        /**
         * Creates a new item child.
         *
         * @param node the actor's affiliation to the room
         */
        public Item(String node) {
            this.node = node;
        }

        public String getNode() {
            return node;
        }

        /**
         * Returns "view" or "remove" that indicate if the server should return the specified
         * offline message or delete it.
         *
         * @return "view" or "remove" that indicate if the server should return the specified
         *         offline message or delete it.
         */
        public String getAction() {
            return action;
        }

        /**
         * Sets if the server should return the specified offline message or delete it. Possible
         * values are "view" or "remove".
         *
         * @param action if the server should return the specified offline message or delete it.
         */
        public void setAction(String action) {
            this.action = action;
        }

        public String getJid() {
            return jid;
        }

        public void setJid(String jid) {
            this.jid = jid;
        }

        public String toXML() {
            StringBuilder buf = new StringBuilder();
            buf.append("<item");
            if (getAction() != null) {
                buf.append(" action=\"").append(getAction()).append('"');
            }
            if (getJid() != null) {
                buf.append(" jid=\"").append(getJid()).append('"');
            }
            if (getNode() != null) {
                buf.append(" node=\"").append(getNode()).append('"');
            }
            buf.append("/>");
            return buf.toString();
        }
    }

    public static class Provider extends IQProvider<OfflineMessageRequest> {

        @Override
        public OfflineMessageRequest parse(XmlPullParser parser,
                        int initialDepth, XmlEnvironment xmlEnvironment) throws XmlPullParserException,
                        IOException {
            OfflineMessageRequest request = new OfflineMessageRequest();
            boolean done = false;
            while (!done) {
                XmlPullParser.Event eventType = parser.next();
                if (eventType == XmlPullParser.Event.START_ELEMENT) {
                    if (parser.getName().equals("item")) {
                        request.addItem(parseItem(parser));
                    }
                    else if (parser.getName().equals("purge")) {
                        request.setPurge(true);
                    }
                    else if (parser.getName().equals("fetch")) {
                        request.setFetch(true);
                    }
                } else if (eventType == XmlPullParser.Event.END_ELEMENT) {
                    if (parser.getName().equals("offline")) {
                        done = true;
                    }
                }
            }

            return request;
        }

        private static Item parseItem(XmlPullParser parser)
                        throws XmlPullParserException, IOException {
            boolean done = false;
            Item item = new Item(parser.getAttributeValue("", "node"));
            item.setAction(parser.getAttributeValue("", "action"));
            item.setJid(parser.getAttributeValue("", "jid"));
            while (!done) {
                XmlPullParser.Event eventType = parser.next();
                if (eventType == XmlPullParser.Event.END_ELEMENT) {
                    if (parser.getName().equals("item")) {
                        done = true;
                    }
                }
            }
            return item;
        }
    }
}