/*
 * BookmarkManager.java
 *
 * Version: $Revision: $
 *
 * Date: $Date: $
 *
 * Copyright (c) 2007, Hewlett-Packard Company and Massachusetts
 * Institute of Technology.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * - Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * - Neither the name of the Hewlett-Packard Company nor the name of the
 * Massachusetts Institute of Technology nor the names of their
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 */

package org.dspace.eperson;

import org.apache.log4j.Logger;
import org.dspace.authorize.AuthorizeException;
import org.dspace.authorize.AuthorizeManager;
import org.dspace.content.Item;
import org.dspace.core.ConfigurationManager;
import org.dspace.core.Context;
import org.dspace.core.LogManager;
import org.dspace.storage.rdbms.DatabaseManager;
import org.dspace.storage.rdbms.TableRowIterator;
import org.dspace.storage.rdbms.TableRow;
import org.dspace.eperson.Tag;

import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.TreeMap;
import java.util.StringTokenizer;

/**
 * Class defining methods for bookmarking items in the repository. Based heavily on the work from Subscribe.java
 *
 * @author Desmond Elliott
 * @version $Revision: $
 */
public class BookmarkManager
{
    /** log4j logger */
    private static Logger log = Logger.getLogger(BookmarkManager.class);
    
    private Context currentContext = null;

    /**
     * Bookmark this item
     *
     * @param context
     *            DSpace context
     * @param eperson
     *            EPerson to associate this bookmark with
     * @param item
     *            Item to bookmark
     */
    public static void bookmark(Context context, EPerson eperson,
            Item item, String tag) throws AuthorizeException, SQLException
    {

        if ( (tag == null) || "".equals(tag) ) {
            BookmarkManager.unBookmark(context, eperson, item);
            return;
        }
        StringTokenizer st = new StringTokenizer(tag,";");
        if (!st.hasMoreTokens()) BookmarkManager.unBookmark(context, eperson, item);

        // Check authorisation. Must be administrator, or the eperson.
        EPerson currentUser = context.getCurrentUser();
        if (AuthorizeManager.isAdmin(context)
                || ((eperson != null)
                    && (currentUser != null)
                    && (currentUser.getID() == eperson.getID())))
        {
            String oldTag = getBookmarkTag(context, eperson, item);
            if ((oldTag != null) && !oldTag.equals(tag) )
                {
                    DatabaseManager.updateQuery(context,
                            "DELETE FROM bookmark WHERE eperson_id= ? " +
                            "AND item_id= ? ",
                            eperson.getID(), item.getID());

                    log.info(LogManager.getHeader(context, "unbookmark",
                            "eperson_id=" + eperson.getID() + ",item_id="
                                    + item.getID()));
                }
            if ((oldTag == null) || !oldTag.equals(tag) )
            {
              while(st.hasMoreTokens()){
		String oneTag = st.nextToken().trim();
		if (oneTag.length() > 0) {
                    TableRow row = DatabaseManager.create(context, "bookmark");
                    row.setColumn("eperson_id", eperson.getID());
                    row.setColumn("item_id", item.getID());
                    row.setColumn("tag_value", oneTag);
                    DatabaseManager.update(context, row);
                }
              }
              log.info(LogManager.getHeader(context, "bookmark ",
                        "eperson_id=" + eperson.getID() + ", item_id="
                                + item.getID() + ", tag=" + tag));
            }
        }
        else
        {
            throw new AuthorizeException(
                    "Only admin or e-person themselves can bookmark");
        }
    }

    /**
     * Unbookmark an item
     *
     * @param context
     *            DSpace context
     * @param eperson
     *            EPerson associated with this bookmarked item
     * @param item
     *            Item to unbookmark
     */
    public static void unBookmark(Context context, EPerson eperson,
            Item item) throws AuthorizeException, SQLException
    {
        // Check authorisation. Must be administrator, or the eperson.
        EPerson currentUser = context.getCurrentUser();
        if (AuthorizeManager.isAdmin(context)
                || ((eperson != null)
                    && (currentUser != null)
                    && (currentUser.getID() == eperson.getID())))
        {
            if (item != null)
            {
                if (isBookmarked(context, eperson, item))
                {
                    DatabaseManager.updateQuery(context,
                            "DELETE FROM bookmark WHERE eperson_id= ? " +
                            "AND item_id= ? ",
                            eperson.getID(), item.getID());

                    log.info(LogManager.getHeader(context, "unbookmark",
                            "eperson_id=" + eperson.getID() + ",item_id="
                                    + item.getID()));
                    }
                else
                {
                    log.info(LogManager.getHeader(context, "unbookmark",
                        "not_bookmarked,item_id=" + item.getID()));
                }
            }
            else
            {
                log.debug(LogManager.getHeader(context, "unbookmark","no item"));
            }
        }
        else
        {
            throw new AuthorizeException(
                    "Only admin or e-person themselves can unbookmark");
        }
    }

    /**
     * Bookmark this item with one tag (may be added to existing one)
     *
     * @param context
     *            DSpace context
     * @param eperson
     *            EPerson to associate this bookmark with
     * @param item
     *            Item to bookmark
     */
    public static void bookmarkOne(Context context, EPerson eperson,
            Item item, String oneTag) throws AuthorizeException, SQLException
    {
        // Check authorisation. Must be administrator, or the eperson.
        EPerson currentUser = context.getCurrentUser();
        if (AuthorizeManager.isAdmin(context)
                || ((eperson != null)
                    && (currentUser != null)
                    && (currentUser.getID() == eperson.getID())))
        {
            if (item != null)
            {
              boolean there = false;
              try {
                Object[] parameters = new Object[3];
                parameters[0] = new Integer(eperson.getID());
                parameters[1] = new Integer(item.getID());
                parameters[2] = oneTag;
                TableRowIterator tri = DatabaseManager.query(context,
                     "SELECT tag_value FROM bookmark WHERE eperson_id= ? AND item_id = ? AND tag_value = ? ",
                     parameters );
                there = tri.hasNext();
                tri.close();
              }
              catch (SQLException e) {
                    log.info(LogManager.getHeader(context, "bookmark ",
                        "eperson_id=" + eperson.getID() + ", item_id="
                                + item.getID() + ", added tag=" + oneTag + ", Exception:" + e.toString() ));
              }

              if ( ! there )
              {
                    TableRow row = DatabaseManager.create(context, "bookmark");
                    row.setColumn("eperson_id", eperson.getID());
                    row.setColumn("item_id", item.getID());
                    row.setColumn("tag_value", oneTag);
                    DatabaseManager.update(context, row);
 
                    log.info(LogManager.getHeader(context, "bookmark ",
                        "eperson_id=" + eperson.getID() + ", item_id="
                                + item.getID() + ", added tag=" + oneTag));
              }
            }
            else
            {
                log.debug(LogManager.getHeader(context, "bookmark "+oneTag,"no item"));
            }
        }
        else
        {
            throw new AuthorizeException(
                    "Only admin or e-person themselves can bookmark");
        }
    }

    /**
     * Unbookmark an item
     *
     * @param context
     *            DSpace context
     * @param eperson
     *            EPerson associated with this bookmarked item
     * @param item
     *            Item to unbookmark
     */
    public static void unBookmarkOne(Context context, EPerson eperson,
            Item item, String oneTag) throws AuthorizeException, SQLException
    {
        // Check authorisation. Must be administrator, or the eperson.
        EPerson currentUser = context.getCurrentUser();
        if (AuthorizeManager.isAdmin(context)
                || ((eperson != null)
                    && (currentUser != null)
                    && (currentUser.getID() == eperson.getID())))
        {
            if (item != null)
            {
                    Object[] parameters = new Object[3];
                    parameters[0] = new Integer(eperson.getID());
                    parameters[1] = new Integer(item.getID());
                    parameters[2] = oneTag;
                    DatabaseManager.updateQuery(context,
                            "DELETE FROM bookmark WHERE eperson_id= ? " +
                            "AND item_id= ? AND tag_value= ? ",
                            parameters );

                    log.info(LogManager.getHeader(context, "unbookmark",
                            "eperson_id=" + eperson.getID() + ",item_id="
                                    + item.getID() + ", tag=" + oneTag ));
            }
            else
            {
                log.debug(LogManager.getHeader(context, "unbookmark "+oneTag,"no item"));
            }
        }
        else
        {
            throw new AuthorizeException(
                    "Only admin or e-person themselves can unbookmark");
        }
    }
    /**
     * Find out which items a person has bookmarked
     *
     * @param context
     *            DSpace context
     * @param eperson
     *            EPerson
     * @return array of items e-person has bookmarked
     */
    public static Item[] getBookmarks(Context context, EPerson eperson) throws SQLException
    {
        TableRowIterator tri = DatabaseManager.query(context,
        "SELECT item_id FROM bookmark WHERE eperson_id= ? ",
        eperson.getID());

        List<Item> items = new ArrayList<Item>();

        while (tri.hasNext())
        {
            TableRow row = tri.next();

            items.add(Item.find(context, row.getIntColumn("item_id")));
        }

        tri.close();

        Item[] itemArray = new Item[items.size()];

        return (Item[]) items.toArray(itemArray);
    }

    public static Item[] getBookmarks(Context context, EPerson eperson, String tag) throws SQLException
    {
        if ((tag == null) || "".equals(tag)) return getBookmarks(context,eperson);

        TableRowIterator tri = DatabaseManager.query(context,
        "SELECT item_id FROM bookmark WHERE tag_value= ? AND eperson_id= ?",
        tag, eperson.getID());

        List<Item> items = new ArrayList<Item>();

        while (tri.hasNext())
        {
            TableRow row = tri.next();

            items.add(Item.find(context, row.getIntColumn("item_id")));
        }

        tri.close();

        Item[] itemArray = new Item[items.size()];

        return (Item[]) items.toArray(itemArray);
    }

    public static Item[] getBookmarks(Context context, String tag) throws SQLException
    {
        if ((tag == null) || "".equals(tag)) return null;

        TableRowIterator tri = DatabaseManager.query(context,
        "SELECT item_id FROM bookmark WHERE tag_value= ?",
        tag);

        List<Item> items = new ArrayList<Item>();

        while (tri.hasNext())
        {
            TableRow row = tri.next();

            items.add(Item.find(context, row.getIntColumn("item_id")));
        }

        tri.close();

        Item[] itemArray = new Item[items.size()];

        return (Item[]) items.toArray(itemArray);
    }

    /**
     * Find out what is the tag a person has bookmarked for an item
     *
     * @param context
     *            DSpace context
     * @param eperson
     *            EPerson
     * @return array of items e-person has bookmarked
     */
    public static String getBookmarkTag(Context context, EPerson eperson, Item item)
    {
        String tag = null;
        
        try {
          TableRowIterator tri = DatabaseManager.query(context,
             "SELECT tag_value FROM bookmark WHERE eperson_id= ? AND item_id= ?",
             eperson.getID(),item.getID());
          tag = "";
          while (tri.hasNext())
          {
            TableRow row = tri.next();
            String aTag = row.getStringColumn("tag_value");
            if ("".equals(aTag)) aTag = "SELECTED";
            tag = tag+aTag+"; ";
          }
          tri.close();
          tag = tag.trim();
        }
        catch (SQLException e) {
        }

        return tag;
    }

    /**
     * Find out what is the tag OTHER persons have bookmarked for an item
     *
     * @param context
     *            DSpace context
     * @param eperson
     *            EPerson
     * @return array of items e-person has bookmarked
     */
    public static String getBookmarkOtherTag(Context context, EPerson eperson, Item item)
    {
        String tag = null;
        
        try {
          TableRowIterator tri = null;
          if (eperson == null) tri = DatabaseManager.query(context,
                   "SELECT tag_value FROM bookmark WHERE item_id= ?",
                   item.getID());
          else tri = DatabaseManager.query(context,
                   "SELECT tag_value FROM bookmark WHERE eperson_id != ? AND item_id= ?",
                   eperson.getID(),item.getID());
          tag = "";
          while (tri.hasNext())
          {
            TableRow row = tri.next();
            String aTag = row.getStringColumn("tag_value");
            if ("".equals(aTag)) aTag = "SELECTED";
            tag = tag+aTag+"; ";
          }
          tri.close();
          tag = tag.trim();
        }
        catch (SQLException e) {
        }

        return tag;
    }

    /**
     * Find out what is the tag a person has bookmarked for an item
     *
     * @param context
     *            DSpace context
     * @param eperson
     *            EPerson
     * @return array of items e-person has bookmarked
     */
    public static TreeMap<String,Integer> getBookmarkTags(Context context, EPerson eperson)
    {
        TreeMap<String,Integer> tags = new TreeMap<String,Integer>();
        try {
          TableRowIterator tri = DatabaseManager.query(context,
             "SELECT tag_value, count(eperson_id) AS freq FROM bookmark WHERE eperson_id= ? GROUP BY tag_value",
             eperson.getID() );

          while (tri.hasNext())
          {
            TableRow row = tri.next();
            String aTag = row.getStringColumn("tag_value");
            int freq = row.getIntColumn("freq");
            if (aTag != null) tags.put(aTag,new Integer(freq));
          }
          tri.close();
        }
        catch (SQLException e) {
        }

        return tags;
    }

    public static TreeMap<String,Integer> getBookmarkAllTags(Context context)
    {
        TreeMap<String,Integer> tags = new TreeMap<String,Integer>();
        try {
          TableRowIterator tri = DatabaseManager.query(context,
             "SELECT tag_value, count(eperson_id) AS freq FROM bookmark GROUP BY tag_value" );

          while (tri.hasNext())
          {
            TableRow row = tri.next();
            String aTag = row.getStringColumn("tag_value");
            int freq = row.getIntColumn("freq");
            if (aTag != null) tags.put(aTag,new Integer(freq));
          }
          tri.close();
        }
        catch (SQLException e) {
        }

        return tags;
    }

    /**
     * Has this eperson bookmarked this item?
     *
     * @param context
     *            DSpace context
     * @param eperson
     *            find out if this e-person has bookmarked
     * @param item
     *            find out if this item has been bookmarked
     * @return <code>true</code> if they are bookmarked
     */
    public static boolean isBookmarked(Context context, EPerson eperson,
            Item item) throws SQLException
    {
    	TableRowIterator tri = DatabaseManager.query(context,
                "SELECT * FROM bookmark WHERE eperson_id= ? " +
                "AND item_id= ? ",
                eperson.getID(), item.getID());

    	boolean result = tri.hasNext();
    	tri.close();

    	return result;
    }

    public void setContext(Context context) {
        this.currentContext = context;
    }

    public Context getContext() {
        return this.currentContext;
    }

    public ArrayList<Tag> getAllTags() {
        if (currentContext == null) return null;
        EPerson currentUser = currentContext.getCurrentUser();

        ArrayList<Tag> tags = new ArrayList<Tag>();
        try {
          TableRowIterator tri = DatabaseManager.query(currentContext,
             "SELECT tag_value, sum (case when eperson_id= ? then 1 else 0 end) AS freqUser, count(eperson_id) AS freq FROM bookmark GROUP BY tag_value",
             currentUser == null? 0 : currentUser.getID() );

          while (tri.hasNext())
          {
            TableRow row = tri.next();
            Tag aTag = new Tag ( row.getStringColumn("tag_value"), currentUser, row.getIntColumn("freq"), row.getIntColumn("freqUser") );
            tags.add(aTag);
          }
          tri.close();
        }
        catch (SQLException e) {
        }

        return tags;
    }

    public static String getStatsTags(Context context) {
        if (context == null) return null;
        String tagVu = ConfigurationManager.getProperty("webui.itemlist.tagviewed");
        if (tagVu == null || tagVu.length()==0) tagVu = "v";
        String result = "";

        try {
          TableRowIterator tri = DatabaseManager.query(context,
             "SELECT sum (case when tag_value ILIKE ? then 1 else 0 end) AS viewed, count(*) AS total FROM bookmark",
             tagVu );

          if (tri.hasNext())
          {
            TableRow row = tri.next();
            result = row.getIntColumn("total") + " (" + tagVu +":"+ row.getIntColumn("viewed") + ")";
          }
          tri.close();
        }
        catch (SQLException e) {
        }

        return result;
    }
}