package org.junit.runners;


import java.util.ConcurrentModificationException;

import org.junit.internal.runners.InitializationError;
import org.junit.internal.runners.TestClassRunner;
import org.junit.runner.Description;
import org.junit.runner.notification.RunListener;
import org.junit.runner.notification.RunNotifier;

/**
 * Provides the current test name, available for the <code>@Test</code> method and <code>@Before</code> and <code>@After</code> methods, <strong>just like the default runner should!</strong><br/> (see <code>Test.getName()</code> in JUnit3)
 * @since JUnit 4
 * @author Joshua.Graham@thoughtworks.com
 * @author based on http://tech.groups.yahoo.com/group/junit/message/18728
 * 
 * Another warm, sunny Autumn day in Sydney ends, and I'm making this testable...
 */
public class NameAwareTestClassRunner extends TestClassRunner {
    private final static ThreadLocal<String> testClassName = new ThreadLocal<String>();

    private final static ThreadLocal<String> testMethodName = new ThreadLocal<String>();

    protected static void setName(final String name) {
        testMethodName.set(extractTestMethodName(name));
        testClassName.set(extractTestClassName(name));
    }

    /**
     * Old-style JUnit 3 TestCase.getName() format
     * @return package.class.method()
     */
    public static String getName() {
        return String.format("%s.%s()", getTestClassName(), getTestMethodName());
    }

    /**
     * JUnit 4 test name format
     * @return method(package.class)
     */
    public static String getTestName() {
        return String.format("%s(%s)", getTestMethodName(), getTestClassName());
    }

    public static String getTestMethodName() {
        return testMethodName.get();
    }

    public static String getTestClassName() {
        return testClassName.get();
    }

    public NameAwareTestClassRunner(final Class<?> klass) throws InitializationError {
        super(klass);
    }

    @Override
    public void run(final RunNotifier notifier) {
        notifier.addListener(new NameListener());
        super.run(notifier);
    }

    private static String extractTestMethodName(final String name) {
        if (name != null) {
            int last = name.lastIndexOf('(');
            return last < 0 ? name : name.substring(0, last);
        }
        return null;
    }

    private static String extractTestClassName(final String name) {
        if (name != null) {
            int last = name.lastIndexOf('(');
            return last < 0 ? null : name.substring(last + 1, name.length() - 1);
        }
        return null;
    }

    private static class NameListener extends RunListener {
        @Override
        public void testStarted(final Description description) {
            setName(description.isTest() ? description.getDisplayName() : null); /* record start of tests, not suites */
        }

        @Override
        public void testFinished(final Description description) {
            if (getTestName() != null) {
                if (getTestName().equals(description.getDisplayName())) {
                    setName(null);
                } else {
                    throw new ConcurrentModificationException("Test name mismatch. Was " + description.getDisplayName() + " expected "
                            + getTestName());
                }
            }
        }
    }
}