/*
 * Copyright (C) 2007-2012 Argeo GmbH
 *
 * 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.argeo.slc.runtime.test;

import org.argeo.slc.UnsupportedException;
import org.argeo.slc.test.TestData;
import org.argeo.slc.test.TestDataProvider;

/** Utilities for dealing with test datas. */
public class TestDataUtils {
	/** Extracts the test data from the given provider. */
	public static <T extends TestData> T getFromProvider(Object obj,
			Class<T> clss, String key) {
		if (obj instanceof TestDataProvider) {
			TestDataProvider testDataProvider = (TestDataProvider) obj;
			return testDataProvider.getTestData(clss, key);
		} else {
			throw new UnsupportedException("test data provider", obj);
		}
	}

	/**
	 * Extracts the test data from the given provider using <code>null</code>
	 * as key.
	 */
	public static <T extends TestData> T getFromProvider(Object obj,
			Class<T> clss) {
		return getFromProvider(obj, clss, null);
	}

	/**
	 * Returns it self after making the proper checks. Used for test data being
	 * their own data providers.
	 */
	@SuppressWarnings("unchecked")
	public static <T extends TestData> T getItSelf(Class<T> clss,
			TestData testDataObject) {
		if (clss.isAssignableFrom(testDataObject.getClass())) {
			return (T) testDataObject;
		} else {
			throw new UnsupportedException("test data", testDataObject);
		}

	}

	/** Makes sure this is an utility class. */
	private TestDataUtils() {

	}
}