/*
 * Copyright (c) 2004-2010 The Regents of the University of California.
 * All rights reserved.
 *
 * '$Author: welker $'
 * '$Date: 2010-05-06 05:21:26 +0000 (Thu, 06 May 2010) $' 
 * '$Revision: 24234 $'
 * 
 * Permission is hereby granted, without written agreement and without
 * license or royalty fees, to use, copy, modify, and distribute this
 * software and its documentation for any purpose, provided that the above
 * copyright notice and the following two paragraphs appear in all copies
 * of this software.
 *
 * IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
 * FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
 * THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
 * PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
 * CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
 * ENHANCEMENTS, OR MODIFICATIONS.
 *
 */

package org.kepler.objectmanager.data.db;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * This class represents a join condtion (join two tables without
 * primary/foreign key) in table level
 * 
 * @author Jing Tao
 * 
 */

public class JoinConditionConstraint implements Constraint {
        private int type = Constraint.JOINCONDITIONCONSTRAINT;
        private String name = null;
        private String[] keys = null;
        private String entityReference = null;
        private String[] referencedKeys = null;

        private static Log log;

        static {
                log = LogFactory
                                .getLog("org.kepler.objectmanager.data.db.JoinConditionConstraint");
        }

        /**
         * Default constructor
         */
        public JoinConditionConstraint() {

        }

        /**
         * Method to get type
         * 
         * @return int
         */
        public int getType() {
                return type;
        }

        /**
         * Method to get constraint name
         * 
         * @return String
         */
        public String getName() {
                return name;
        }

        /**
         * Method to get keys
         * 
         * @return String[]
         */
        public String[] getKeys() {
                return keys;
        }

        /**
         * Method to get referenced entity(parent table)
         * 
         * @return String
         */
        public String getEntityReference() {
                return entityReference;
        }

        /**
         * Method to get referenced key in parent table
         * 
         * @return String[]
         */
        public String[] getReferencedKeys() {
                return referencedKeys;
        }

        /**
         * Method to set constraint name
         * 
         * @param constraintName
         *            String
         */
        public void setName(String constraintName) {
                name = constraintName;
        }

        /**
         * Method to set keys
         * 
         * @param constraintKeys
         *            String[]
         */
        public void setKeys(String[] constraintKeys) {
                keys = constraintKeys;
        }

        /**
         * Method to set referenced entity name
         * 
         * @param referencedEntity
         *            String
         */
        public void setEntityReference(String referencedEntity) {
                entityReference = referencedEntity;
        }

        /**
         * Method to set up referenced key in parent table(referencedEntity)
         * 
         * @param keyList
         *            String[]
         */

        public void setReferencedKeys(String[] keyList) {
                referencedKeys = keyList;
        }

        /**
         * Method to print out a part sql command about joincondition. In
         * joinCondition, we need to specify the referenced entity's column name. It
         * is same as foreign key except to specify referenced key name in parent
         * table
         * 
         * @return String
         */
        public String printString() throws UnWellFormedConstraintException {
                String sql = null;
                if (referencedKeys == null || referencedKeys.length == 0) {
                        throw new UnWellFormedConstraintException(
                                        "The refrenced key in parent "
                                                        + "table is empty in join condition constaint");
                }
                // in joincondition the first part is as same as foreign key
                // so we can first create a foreginkey object and print out the sql
                ForeignKey foreignKey = new ForeignKey();
                foreignKey.setName(name);
                foreignKey.setKeys(keys);
                foreignKey.setEntityReference(entityReference);
                String foreignKeySql = foreignKey.printString();

                StringBuffer buffer = new StringBuffer(foreignKeySql);

                // add referencedkey list in parent table
                buffer.append(Constraint.LEFTPARENTH);
                // add keys into parenthesis
                boolean firstKey = true;
                for (int i = 0; i < referencedKeys.length; i++) {
                        String keyName = keys[i];
                        // if any key is null or empty, we will throw a exception
                        if (keyName == null || keyName.trim().equals("")) {
                                throw new UnWellFormedConstraintException(
                                                "refernced key name in "
                                                                + "parent table is empty or null in join condition");
                        }
                        // if this is not the first key, we need add a comma
                        if (!firstKey) {
                                buffer.append(Constraint.COMMA);
                        }
                        buffer.append(keyName);
                        firstKey = false;
                }// for
                buffer.append(Constraint.RIGHTPARENTH);
                buffer.append(Constraint.SPACESTRING);
                sql = buffer.toString();
                log.debug("The foreign key part of sql is " + sql);
                return sql;
        }

}