/*
 * 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
 * 
 * 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();
   }
}
