/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
package org.hibernate.cfg;

import java.io.Serializable;
import java.util.Locale;

import org.hibernate.AssertionFailure;
import org.hibernate.internal.util.StringHelper;

An improved naming strategy that prefers embedded
underscores to mixed case names
Author:
Gavin King
See Also:
the default strategy/**
 * An improved naming strategy that prefers embedded
 * underscores to mixed case names
 * @see DefaultNamingStrategy the default strategy
 * @author Gavin King
 */
public class ImprovedNamingStrategy implements NamingStrategy, Serializable {

	
A convenient singleton instance
/**
	 * A convenient singleton instance
	 */
	public static final NamingStrategy INSTANCE = new ImprovedNamingStrategy();

	
Return the unqualified class name, mixed case converted to
underscores
/**
	 * Return the unqualified class name, mixed case converted to
	 * underscores
	 */
	public String classToTableName(String className) {
		return addUnderscores( StringHelper.unqualify(className) );
	}
	
Return the full property path with underscore seperators, mixed
case converted to underscores
/**
	 * Return the full property path with underscore seperators, mixed
	 * case converted to underscores
	 */
	public String propertyToColumnName(String propertyName) {
		return addUnderscores( StringHelper.unqualify(propertyName) );
	}
	
Convert mixed case to underscores
/**
	 * Convert mixed case to underscores
	 */
	public String tableName(String tableName) {
		return addUnderscores(tableName);
	}
	
Convert mixed case to underscores
/**
	 * Convert mixed case to underscores
	 */
	public String columnName(String columnName) {
		return addUnderscores(columnName);
	}

	protected static String addUnderscores(String name) {
		StringBuilder buf = new StringBuilder( name.replace('.', '_') );
		for (int i=1; i<buf.length()-1; i++) {
			if (
				Character.isLowerCase( buf.charAt(i-1) ) &&
				Character.isUpperCase( buf.charAt(i) ) &&
				Character.isLowerCase( buf.charAt(i+1) )
			) {
				buf.insert(i++, '_');
			}
		}
		return buf.toString().toLowerCase(Locale.ROOT);
	}

	public String collectionTableName(
			String ownerEntity, String ownerEntityTable, String associatedEntity, String associatedEntityTable,
			String propertyName
	) {
		return tableName( ownerEntityTable + '_' + propertyToColumnName(propertyName) );
	}

	
Return the argument
/**
	 * Return the argument
	 */
	public String joinKeyColumnName(String joinedColumn, String joinedTable) {
		return columnName( joinedColumn );
	}

	
Return the property name or propertyTableName
/**
	 * Return the property name or propertyTableName
	 */
	public String foreignKeyColumnName(
			String propertyName, String propertyEntityName, String propertyTableName, String referencedColumnName
	) {
		String header = propertyName != null ? StringHelper.unqualify( propertyName ) : propertyTableName;
		if (header == null) throw new AssertionFailure("NamingStrategy not properly filled");
		return columnName( header ); //+ "_" + referencedColumnName not used for backward compatibility
	}

	
Return the column name or the unqualified property name
/**
	 * Return the column name or the unqualified property name
	 */
	public String logicalColumnName(String columnName, String propertyName) {
		return StringHelper.isNotEmpty( columnName ) ? columnName : StringHelper.unqualify( propertyName );
	}

	
Returns either the table name if explicit or
if there is an associated table, the concatenation of owner entity table and associated table
otherwise the concatenation of owner entity table and the unqualified property name
/**
	 * Returns either the table name if explicit or
	 * if there is an associated table, the concatenation of owner entity table and associated table
	 * otherwise the concatenation of owner entity table and the unqualified property name
	 */
	public String logicalCollectionTableName(String tableName,
			String ownerEntityTable, String associatedEntityTable, String propertyName
	) {
		if ( tableName != null ) {
			return tableName;
		}
		else {
			//use of a stringbuffer to workaround a JDK bug
			return new StringBuffer(ownerEntityTable).append("_")
					.append(
						associatedEntityTable != null ?
						associatedEntityTable :
						StringHelper.unqualify( propertyName )
					).toString();
		}
	}
	
Return the column name if explicit or the concatenation of the property name and the referenced column
/**
	 * Return the column name if explicit or the concatenation of the property name and the referenced column
	 */
	public String logicalCollectionColumnName(String columnName, String propertyName, String referencedColumn) {
		return StringHelper.isNotEmpty( columnName ) ?
				columnName :
				StringHelper.unqualify( propertyName ) + "_" + referencedColumn;
	}
}