package org.apache.torque.engine.database.model;

 /*

  * Licensed to the Apache Software Foundation (ASF) under one

  * or more contributor license agreements.  See the NOTICE file

  * distributed with this work for additional information

  * regarding copyright ownership.  The ASF licenses this file

  * to you 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.

  */

 import java.util.ArrayList;

 import java.util.Collections;

 import java.util.Iterator;

 import java.util.List;

 import java.util.Map;

 import org.apache.commons.collections.map.ListOrderedMap;

 import org.apache.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 import org.apache.torque.engine.EngineException;

 import org.xml.sax.Attributes;

 /**

  * Information about indices of a table.

  *

  * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>

  * @author <a href="mailto:dlr@finemaltcoding.com>Daniel Rall</a>

  * @author <a href="mailto:monroe@dukece.com>Greg Monroe</a>

  * @version $Id: Index.java,v 1.1 2007-10-21 07:57:27 abyrne Exp $

  */

 public class Index

 {

     /** Logging class from commons.logging */

     private static Log log = LogFactory.getLog(Index.class);

     /** name of the index */

     private String indexName;

     /** table */

     private Table parentTable;

     /** columns */

     private List indexColumns;

     /** The XML Options specified for this index */

     private Map options;

     /**

      * Creates a new instance with default characteristics (no name or

      * parent table, small column list size allocation, non-unique).

      */

     public Index()

     {

         indexColumns = new ArrayList(3);

         options = Collections.synchronizedMap(new ListOrderedMap());

     }

     /**

      * Creates a new instance for the list of columns composing an

      * index.  Otherwise performs as {@link #Index()}.

      *

      * @param table The table this index is associated with.

      * @param indexColumns The list of {@link

      * org.apache.torque.engine.database.model.Column} objects which

      * make up this index.  Cannot be empty.

      * @exception EngineException Error generating name.

      * @see #Index()

      */

     protected Index(Table table, List indexColumns)

         throws EngineException

     {

         this();

         setTable(table);

         if (!indexColumns.isEmpty())

         {

             this.indexColumns = indexColumns;

             if (log.isDebugEnabled())

             {

                 log.debug("Created Index named " + getName()

                         + " with " + indexColumns.size() + " columns");

             }

         }

         else

         {

             throw new EngineException("Cannot create a new Index using an "

                     + "empty list Column object");

         }

     }

     /**

      * Imports index from an XML specification

      *

      * @param attrib the xml attributes

      */

     public void loadFromXML(Attributes attrib)

     {

         indexName = attrib.getValue("name");

     }

     /**

      * Returns the uniqueness of this index.

      *

      * @return the uniqueness of this index

      */

     public boolean isUnique()

     {

         return false;

     }

     /**

      * Gets the name of this index.

      *

      * @return the name of this index

      */

     public String getName()

     {

         return indexName;

     }

     /**

      * Set the name of this index.

      *

      * @param name the name of this index

      */

     public void setName(String name)

     {

         this.indexName = name;

     }

     /**

      * Set the parent Table of the index

      *

      * @param parent the table

      */

     public void setTable(Table parent)

     {

         parentTable = parent;

     }

     /**

      * Get the parent Table of the index

      *

      * @return the table

      */

     public Table getTable()

     {

         return parentTable;

     }

     /**

      * Returns the Name of the table the index is in

      *

      * @return the name of the table

      */

     public String getTableName()

     {

         return parentTable.getName();

     }

     /**

      * Adds a new column to an index.

      *

      * @param attrib xml attributes for the column

      */

     public void addColumn(Attributes attrib)

     {

         indexColumns.add(attrib.getValue("name"));

     }

     /**

      * Return a comma delimited string of the columns which compose this index.

      *

      * @return a list of column names

      */

     public String getColumnList()

     {

         return Column.makeList(getColumns());

     }

     /**

      * Return the list of local columns. You should not edit this list.

      *

      * @return a list of columns

      */

     public List getColumns()

     {

         return indexColumns;

     }

     /**

      * Returns the list of names of the columns referenced by this

      * index.  Slightly over-allocates the list's buffer (just in case

      * more elements are going to be added, such as when a name is

      * being generated).  Feel free to modify this list.

      *

      * @return a list of column names

      */

     protected List getColumnNames()

     {

         List names = new ArrayList(indexColumns.size() + 2);

         Iterator i = getColumns().iterator();

         while (i.hasNext())

         {

             Column c = (Column) i.next();

             names.add(c.getName());

         }

         return names;

     }

     /**

      * String representation of the index. This is an xml representation.

      *

      * @return a xml representation

      */

     public String toString()

     {

         StringBuffer result = new StringBuffer();

         result.append(" <index name=\"")

               .append(getName())

               .append("\"");

         result.append(">\n");

         for (int i = 0; i < indexColumns.size(); i++)

         {

             result.append("  <index-column name=\"")

                 .append(indexColumns.get(i))

                 .append("\"/>\n");

         }

         result.append(" </index>\n");

         return result.toString();

     }

     /**

      * Add an XML Specified option key/value pair to this element's option set.

      *

      * @param key the key of the option.

      * @param value the value of the option.

      */

     public void addOption(String key, String value)

     {

         options.put(key, value);

     }

     /**

      * Get the value that was associated with this key in an XML option

      * element.

      *

      * @param key the key of the option.

      * @return The value for the key or a null.

      */

     public String getOption(String key)

     {

         return (String) options.get(key);

     }

     /**

      * Gets the full ordered hashtable array of items specified by XML option

      * statements under this element.<p>

      *

      * Note, this is not thread save but since it's only used for

      * generation which is single threaded, there should be minimum

      * danger using this in Velocity.

      *

      * @return An Map of all options. Will not be null but may be empty.

      */

     public Map getOptions()

     {

         return options;

     }

 }