/*
 * Copyright Red Hat, Inc. and/or its affiliates
 * and other contributors as indicated by the @author tags and
 * the COPYRIGHT.txt file distributed with this work.
 *
 * Licensed 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.teiid.core.types.basic;

import java.sql.Date;
import java.util.regex.Pattern;

import org.teiid.core.CorePlugin;
import org.teiid.core.types.Transform;
import org.teiid.core.types.TransformationException;


public class StringToDateTransform extends Transform {
	
	private static boolean validate = true;
	private static Pattern pattern = Pattern.compile("\\d{4}-\\d{2}-\\d{2}"); //$NON-NLS-1$
	
	static {
		try {
			Date.valueOf("2000-14-01"); //$NON-NLS-1$
		} catch (Exception e) {
			validate = false;
		}
	}

	/**
	 * This method transforms a value of the source type into a value
	 * of the target type.
	 * @param value Incoming value of source type
	 * @return Outgoing value of target type
	 * @throws TransformationException if value is an incorrect input type or
	 * the transformation fails
	 */
	public Object transformDirect(Object value) throws TransformationException {
		value = ((String) value).trim();
		Date result = null;
		try {
			result = Date.valueOf( (String) value );
		} catch(Exception e) {
		      if (!validate && pattern.matcher((String)value).matches()) {
			      throw new TransformationException(CorePlugin.Event.TEIID10060, CorePlugin.Util.gs(CorePlugin.Event.TEIID10060, value, getTargetType().getSimpleName()));
	          }
			  throw new TransformationException(CorePlugin.Event.TEIID10061, e, CorePlugin.Util.gs(CorePlugin.Event.TEIID10061, value));
		}
		if (!result.toString().equals(value)) {
			  throw new TransformationException(CorePlugin.Event.TEIID10060, CorePlugin.Util.gs(CorePlugin.Event.TEIID10060, value, getTargetType().getSimpleName()));
		}
		return result;
	}

	/**
	 * Type of the incoming value.
	 * @return Source type
	 */
	public Class<?> getSourceType() {
		return String.class;
	}

	/**
	 * Type of the outgoing value.
	 * @return Target type
	 */
	public Class<?> getTargetType() {
		return Date.class;
	}
	
	@Override
	public boolean isExplicit() {
		return true;
	}

}
