/*******************************************************************************
 * Copyright (c) 2006, 2011 Oracle. All rights reserved.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0, which accompanies this distribution
 * and is available at http://www.eclipse.org/legal/epl-v10.html.
 * 
 * Contributors:
 *     Oracle - initial API and implementation
 ******************************************************************************/
package org.eclipse.jpt.jpa.db.internal;

import java.util.List;

import org.eclipse.jpt.common.utility.internal.ArrayTools;
import org.eclipse.jpt.common.utility.internal.CollectionTools;
import org.eclipse.jpt.common.utility.internal.iterables.ArrayIterable;
import org.eclipse.jpt.common.utility.internal.iterables.TransformationIterable;
import org.eclipse.jpt.jpa.db.DatabaseObject;
import org.eclipse.jpt.jpa.db.Schema;
import org.eclipse.jpt.jpa.db.SchemaContainer;

/**
 * Coalesce behavior for a schema container (i.e. database or catalog).
 */
abstract class DTPSchemaContainerWrapper<P extends DTPDatabaseObject>
	extends DTPDatabaseObjectWrapper<P>
	implements SchemaContainer
{
	/** lazy-initialized */
	private DTPSchemaWrapper[] schemata;


	// ********** constructor **********

	DTPSchemaContainerWrapper(P parent) {
		super(parent);
	}


	// ********** DTPDatabaseObjectWrapper implementation **********

	@Override
	synchronized void catalogObjectChanged() {
		super.catalogObjectChanged();
	}


	// ********** abstract methods **********

	/**
	 * Return the schema container's DTP schemas.
	 */
	abstract List<org.eclipse.datatools.modelbase.sql.schema.Schema> getDTPSchemas();

	/**
	 * Return the schema for the specified DTP schema.
	 */
	abstract DTPSchemaWrapper getSchema(org.eclipse.datatools.modelbase.sql.schema.Schema dtpSchema);

	/**
	 * Pre-condition: The schema container (database or catalog) contains
	 * the specified schema.
	 */
	DTPSchemaWrapper getSchema_(org.eclipse.datatools.modelbase.sql.schema.Schema dtpSchema) {
		for (DTPSchemaWrapper schema : this.getSchemaArray()) {
			if (schema.wraps(dtpSchema)) {
				return schema;
			}
		}
		throw new IllegalArgumentException("invalid DTP schema: " + dtpSchema);  //$NON-NLS-1$
	}

	/**
	 * Return the table for the specified DTP table.
	 * This is only called from a schema (to its container).
	 */
	abstract DTPTableWrapper getTable(org.eclipse.datatools.modelbase.sql.tables.Table dtpTable);

	/**
	 * Pre-condition: The schema container contains the specified table.
	 */
	DTPTableWrapper getTable_(org.eclipse.datatools.modelbase.sql.tables.Table dtpTable) {
		return this.getSchema_(dtpTable.getSchema()).getTable_(dtpTable);
	}

	/**
	 * Return the column for the specified DTP column.
	 * This is only called from a schema (to its container).
	 */
	abstract DTPColumnWrapper getColumn(org.eclipse.datatools.modelbase.sql.tables.Column dtpColumn);

	/**
	 * Pre-condition: The schema container contains the specified column.
	 */
	DTPColumnWrapper getColumn_(org.eclipse.datatools.modelbase.sql.tables.Column dtpColumn) {
		return this.getTable_(dtpColumn.getTable()).getColumn_(dtpColumn);
	}


	// ********** schemata **********

	public Iterable<Schema> getSchemata() {
		return new ArrayIterable<Schema>(this.getSchemaArray());
	}

	Iterable<DTPSchemaWrapper> getSchemaWrappers() {
		return new ArrayIterable<DTPSchemaWrapper>(this.getSchemaArray());
	}

	synchronized DTPSchemaWrapper[] getSchemaArray() {
		if (this.schemata == null) {
			this.schemata = this.buildSchemaArray();
		}
		return this.schemata;
	}

	private DTPSchemaWrapper[] buildSchemaArray() {
		List<org.eclipse.datatools.modelbase.sql.schema.Schema> dtpSchemata = this.getDTPSchemas();
		DTPSchemaWrapper[] result = new DTPSchemaWrapper[dtpSchemata.size()];
		for (int i = result.length; i-- > 0; ) {
			result[i] = new DTPSchemaWrapper(this, dtpSchemata.get(i));
		}
		return ArrayTools.sort(result, DEFAULT_COMPARATOR);
	}

	public int getSchemataSize() {
		return this.getSchemaArray().length;
	}

	public Iterable<String> getSortedSchemaNames() {
		// the schemata are already sorted
		return new TransformationIterable<DatabaseObject, String>(this.getSchemaWrappers(), NAME_TRANSFORMER);
	}

	public DTPSchemaWrapper getSchemaNamed(String name) {
		return this.selectDatabaseObjectNamed(this.getSchemaWrappers(), name);
	}

	public Iterable<String> getSortedSchemaIdentifiers() {
		// the schemata are already sorted
		return new TransformationIterable<DatabaseObject, String>(this.getSchemaWrappers(), IDENTIFIER_TRANSFORMER);
	}

	public Schema getSchemaForIdentifier(String identifier) {
		return this.getDTPDriverAdapter().selectSchemaForIdentifier(this.getSchemata(), identifier);
	}

	public DTPSchemaWrapper getDefaultSchema() {
		return this.getSchemaForNames(this.getDTPDriverAdapter().getDefaultSchemaNames());
	}

	/**
	 * Return the first schema found.
	 */
	DTPSchemaWrapper getSchemaForNames(Iterable<String> names) {
		for (String name : names) {
			DTPSchemaWrapper schema = this.getSchemaNamed(name);
			if (schema != null) {
				return schema;
			}
		}
		return null;
	}

	/**
	 * If we find a default schema, return its identifier;
	 * otherwise, return the last name on the list of default names.
	 * (Some containers have multiple possible default names.)
	 */
	public synchronized String getDefaultSchemaIdentifier() {
		Iterable<String> names = this.getDTPDriverAdapter().getDefaultSchemaNames();
		DTPSchemaWrapper schema = this.getSchemaForNames(names);
		// assume 'names' is non-empty (!)
		return (schema != null) ?
				schema.getIdentifier() :
				this.convertNameToIdentifier(CollectionTools.last(names));
	}


	// ********** listening **********

	@Override
	synchronized void startListening() {
		if (this.schemata != null) {
			this.startSchemata();
		}
		super.startListening();
	}

	private void startSchemata() {
		for (DTPSchemaWrapper schema : this.schemata) {
			schema.startListening();
		}
	}

	@Override
	synchronized void stopListening() {
		if (this.schemata != null) {
			this.stopSchemata();
		}
		super.stopListening();
	}

	private void stopSchemata() {
		for (DTPSchemaWrapper schema : this.schemata) {
			schema.stopListening();
		}
	}


	// ********** clear **********

	@Override
	synchronized void clear() {
		if (this.schemata != null) {
			this.clearSchemata();
		}
	}

	private void clearSchemata() {
		this.stopSchemata();
		for (DTPSchemaWrapper schema : this.schemata) {
			schema.clear();
		}
		this.schemata = null;
	}
}