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;

     }

 }