/*
 * JBoss, Home of Professional Open Source
 * Copyright 2009 Red Hat Inc. and/or its affiliates and other contributors
 * by the @authors tag. See the copyright.txt in the distribution for a
 * full listing of individual contributors.
 *
 * 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.jboss.arquillian.container.test.spi.util;

import org.jboss.arquillian.container.test.spi.TestRunner;

/**
 * TestRunners
 * <p>
 * Helper factory for loading TestRunners in container.
 *
 * @author <a href="mailto:aslak@conduct.no">Aslak Knutsen</a>
 * @version $Revision: $
 */
public final class TestRunners {
    // Hide ctor
    private TestRunners() {
    }

    /**
     * Dynamically loads an instance of a test runner.
     *
     * @return A Initialized TestRunner
     *
     * @throws IllegalStateException
     *     if multiple TestRunners found in classpath.
     */
    public static TestRunner getTestRunner() {
        return getTestRunner(SecurityActions.getThreadContextClassLoader());
    }

    /**
     * Dynamically loads an instance of a test runner.
     *
     * @return A Initialized TestRunner
     *
     * @throws IllegalStateException
     *     if multiple TestRunners found in classpath.
     */
    public static TestRunner getTestRunner(ClassLoader classLoader) {
        ServiceLoader<TestRunner> serviceLoader = ServiceLoader.load(TestRunner.class, classLoader);

        if (serviceLoader.getProviders().size() > 1) {
            throw new IllegalStateException("Multiple TestRunners found, only one allowed. Check your classpath");
        }

        return serviceLoader.iterator().next();
    }
}
