/*

   Derby - Class org.apache.derby.iapi.sql.dictionary.ConstraintDescriptorList

   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.

 */

package org.apache.derby.iapi.sql.dictionary;


import java.util.ArrayList;
import org.apache.derby.catalog.UUID;

public class ConstraintDescriptorList extends ArrayList<ConstraintDescriptor>
{

	private boolean scanned;

	/**
	 * Mark whether or not the underlying system table has
	 * been scanned.  (If a table does not have any
	 * constraints then the size of its CDL will always
	 * be 0.  We used these get/set methods to determine
	 * when we need to scan the table.
	 *
	 * @param scanned	Whether or not the underlying system table has been scanned.
	 */
	public void setScanned(boolean scanned)
	{
		this.scanned = scanned;
	}

	/**
	 * Return whether or not the underlying system table has been scanned.
	 *
	 * @return		Where or not the underlying system table has been scanned.
	 */
	public boolean getScanned()
	{
		return scanned;
	}

	/**
	 * Get the ConstraintDescriptor with the matching UUID String for the backing index.
	 *
	 * @param indexUUID		The UUID  for the backing index.
	 *
	 * @return The matching ConstraintDescriptor.
	 */
	public ConstraintDescriptor getConstraintDescriptor(UUID indexUUID)
	{
		ConstraintDescriptor retCD = null;
		int size = size();

		for (int index = 0; index < size; index++)
		{
			ConstraintDescriptor cd = elementAt(index);

			if (! (cd instanceof KeyConstraintDescriptor))
			{
				continue;
			}

			KeyConstraintDescriptor keyCD = (KeyConstraintDescriptor) cd;

			if (keyCD.getIndexId().equals(indexUUID))
			{
				retCD = cd;
				break;
			}
		}
		return retCD;
	}

	/**
	 * Get the ConstraintDescriptor with the matching constraint id.
	 *
	 * @param uuid		The constraint id.
	 *
	 * @return The matching ConstraintDescriptor.
	 */
	public ConstraintDescriptor getConstraintDescriptorById(UUID uuid)
	{
		ConstraintDescriptor returnCD = null;
		int size = size();

		for (int index = 0; index < size; index++)
		{
			ConstraintDescriptor cd = elementAt(index);

			if (cd.getUUID().equals(uuid))
			{
				returnCD = cd;
				break;
			}
		}
		return returnCD;
	}

	/**
	  *	Drop the constraint with the given UUID.
	  *
	  * @param uuid		The constraint id.
	  *
	  * @return The matching ConstraintDescriptor.
	  */
	public ConstraintDescriptor dropConstraintDescriptorById(UUID uuid)
	{
		ConstraintDescriptor cd = null;
		int size = size();

		for (int index = 0; index < size; index++)
		{
			cd = elementAt(index);

			if (cd.getUUID().equals(uuid))
			{
				remove( cd );
				break;
			}
		}

		return cd;
	}



	/**
	 * Get the ConstraintDescriptor with the matching constraint name.
	 *
	 * @param sd		The constraint schema descriptor.
	 * @param name		The constraint name.
	 *
	 * @return The matching ConstraintDescriptor.
	 */
	public ConstraintDescriptor getConstraintDescriptorByName(SchemaDescriptor sd,
																String name)
	{
		ConstraintDescriptor retCD = null;
		int size = size();

		for (int index = 0; index < size; index++)
		{
			ConstraintDescriptor cd = elementAt(index);

			if (cd.getConstraintName().equals(name))
			{
				if ((sd == null) ||
					(sd.equals(cd.getSchemaDescriptor())))
				{
					retCD = cd;
					break;
				}
			}
		}
		return retCD;
	}


	/**
	 * Get the ConstraintDescriptor with the matching constraint name.
	 *
	 * @return The matching ConstraintDescriptor.
	 */
	public ReferencedKeyConstraintDescriptor getPrimaryKey()
	{
		int size = size();

		for (int index = 0; index < size; index++)
		{
			ConstraintDescriptor cd = elementAt(index);

			if (cd.getConstraintType() == DataDictionary.PRIMARYKEY_CONSTRAINT)	
			{
				return (ReferencedKeyConstraintDescriptor)cd;
			}
		}
		return (ReferencedKeyConstraintDescriptor)null;
	}

	/**
     * Return a list of constraints where enforced is
	 * as passed in.
	 *
     * @param enforced true or false
	 *
	 * @return a constraint descriptor list built from this.  Always
	 * a new list even if all the elements in this were of the correct
	 * type (i.e. not optimized for the case where every element is
	 * desired).
	 */
    public ConstraintDescriptorList getConstraintDescriptorList(boolean enforced)
	{
		ConstraintDescriptorList cdl = new ConstraintDescriptorList();
		int size = size();

		for (int index = 0; index < size; index++)
		{
			ConstraintDescriptor cd = elementAt(index);

            if (cd.enforced() == enforced)
			{
				cdl.add(cd);
			}
		}
		return cdl;
	}

	/**
	 * Return the nth (0-based) element in the list.
	 *
	 * @param n	Which element to return.
	 *
	 * @return The nth element in the list.
	 */
	public ConstraintDescriptor elementAt(int n)
	{
		return get(n);
	}

	/**
	 * Return a ConstraintDescriptorList containing the ConstraintDescriptors
	 * of the specified type that are in this list.
	 *
	 * @param type	The constraint type.
	 *
	 * @return A ConstraintDescriptorList containing the ConstraintDescriptors
	 * of the specified type that are in this list.
	 */
	public ConstraintDescriptorList getSubList(int type)
	{
		ConstraintDescriptorList cdl = new ConstraintDescriptorList();
		int size = size();

		for (int index = 0; index < size; index++)
		{
            ConstraintDescriptor cd = elementAt(index);

			if (cd.getConstraintType() == type)
			{
				cdl.add(cd);
			}
		}
		return cdl;
	}
}
