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.Hashtable;

 import java.util.List;

 import java.util.Map;

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

 import org.xml.sax.Attributes;

 /**

  * A class for information about foreign keys of a table.

  * 

  * @author <a href="mailto:fedor.karpelevitch@home.com">Fedor</a>

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

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

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

  */

 public class ForeignKey {

     private String foreignTableName;

     private String name;

     private String onUpdate;

     private String onDelete;

     private Table parentTable;

     private List localColumns = new ArrayList(3);

     private List foreignColumns = new ArrayList(3);

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

     // the uppercase equivalent of the onDelete/onUpdate values in the dtd

     private static final String NONE = "NONE";

     private static final String SETNULL = "SETNULL";

     /**

      * Imports foreign key from an XML specification

      * 

      * @param attrib

      *            the xml attributes

      */

     public void loadFromXML(Attributes attrib) {

         foreignTableName = attrib.getValue("foreignTable");

         name = attrib.getValue("name");

         onUpdate = attrib.getValue("onUpdate");

         onDelete = attrib.getValue("onDelete");

         onUpdate = normalizeFKey(onUpdate);

         onDelete = normalizeFKey(onDelete);

     }

     /**

      * Normalizes the input of onDelete, onUpdate attributes

      * 

      * @param attrib

      *            the attribute to normalize

      * @return nomalized form

      */

     private String normalizeFKey(String attrib) {

         if (attrib == null) {

             attrib = NONE;

         }

         attrib = attrib.toUpperCase();

         if (attrib.equals(SETNULL)) {

             attrib = "SET NULL";

         }

         return attrib;

     }

     /**

      * Returns whether or not the onUpdate attribute is set

      * 

      * @return true if the onUpdate attribute is set

      */

     public boolean hasOnUpdate() {

         return !onUpdate.equals(NONE);

     }

     /**

      * Returns whether or not the onDelete attribute is set

      * 

      * @return true if the onDelete attribute is set

      */

     public boolean hasOnDelete() {

         return !onDelete.equals(NONE);

     }

     /**

      * Returns the onUpdate attribute

      * 

      * @return the onUpdate attribute

      */

     public String getOnUpdate() {

         return onUpdate;

     }

     /**

      * Returns the onDelete attribute

      * 

      * @return the onDelete attribute

      */

     public String getOnDelete() {

         return onDelete;

     }

     /**

      * Sets the onDelete attribute

      * 

      * @param value

      *            the onDelete attribute

      */

     public void setOnDelete(String value) {

         onDelete = normalizeFKey(value);

     }

     /**

      * Sets the onUpdate attribute

      * 

      * @param value

      *            the onUpdate attribute

      */

     public void setOnUpdate(String value) {

         onUpdate = normalizeFKey(value);

     }

     /**

      * Returns the name attribute.

      * 

      * @return the name

      */

     public String getName() {

         return name;

     }

     /**

      * Sets the name attribute.

      * 

      * @param name

      *            the name

      */

     public void setName(String name) {

         this.name = name;

     }

     /**

      * Get the foreignTableName of the FK

      * 

      * @return the name of the foreign table

      */

     public String getForeignTableName() {

         return foreignTableName;

     }

     /**

      * Set the foreignTableName of the FK

      * 

      * @param tableName

      *            the name of the foreign table

      */

     public void setForeignTableName(String tableName) {

         foreignTableName = tableName;

     }

     /**

      * Set the parent Table of the foreign key

      * 

      * @param parent

      *            the table

      */

     public void setTable(Table parent) {

         parentTable = parent;

     }

     /**

      * Get the parent Table of the foreign key

      * 

      * @return the parent table

      */

     public Table getTable() {

         return parentTable;

     }

     /**

      * Returns the name of the table the foreign key is in

      * 

      * @return the name of the table

      */

     public String getTableName() {

         return parentTable.getName();

     }

     /**

      * Adds a new reference entry to the foreign key

      * 

      * @param attrib

      *            the xml attributes

      */

     public void addReference(Attributes attrib) {

         addReference(attrib.getValue("local"), attrib.getValue("foreign"));

     }

     /**

      * Adds a new reference entry to the foreign key

      * 

      * @param local

      *            name of the local column

      * @param foreign

      *            name of the foreign column

      */

     public void addReference(String local, String foreign) {

         localColumns.add(local);

         foreignColumns.add(foreign);

     }

     /**

      * Returns a comma delimited string of local column names

      * 

      * @return the local column names

      */

     public String getLocalColumnNames() {

         return Column.makeList(getLocalColumns());

     }

     /**

      * Returns a comma delimited string of foreign column names

      * 

      * @return the foreign column names

      */

     public String getForeignColumnNames() {

         return Column.makeList(getForeignColumns());

     }

     /**

      * Returns the list of local column names. You should not edit this List.

      * 

      * @return the local columns

      */

     public List getLocalColumns() {

         return localColumns;

     }

     /**

      * Utility method to get local column names to foreign column names mapping for this foreign key.

      * 

      * @return table mapping foreign names to local names

      */

     public Hashtable getLocalForeignMapping() {

         Hashtable h = new Hashtable();

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

             h.put(localColumns.get(i), foreignColumns.get(i));

         }

         return h;

     }

     /**

      * Returns the list of foreign column names. You should not edit this List.

      * 

      * @return the foreign columns

      */

     public List getForeignColumns() {

         return foreignColumns;

     }

     /**

      * Utility method to get foreign column names to local column names mapping for this foreign key.

      * 

      * @return table mapping local names to foreign names

      */

     public Hashtable getForeignLocalMapping() {

         Hashtable h = new Hashtable();

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

             h.put(foreignColumns.get(i), localColumns.get(i));

         }

         return h;

     }

     /**

      * String representation of the foreign key. This is an xml representation.

      * 

      * @return string representation in xml

      */

     public String toString() {

         StringBuffer result = new StringBuffer();

         result.append("    <foreign-key foreignTable=\"").append(getForeignTableName()).append("\" name=\"")

                 .append(getName()).append("\">\n");

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

             result.append("        <reference local=\"").append(localColumns.get(i)).append("\" foreign=\"")

                     .append(foreignColumns.get(i)).append("\"/>\n");

         }

         result.append("    </foreign-key>\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;

     }

 }