/**
 * Copyright © 2013 Antonin Stefanutti ([email protected])
 *
 * 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.eclipse.microprofile.metrics.tck.metrics;

import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.instanceOf;
import static org.hamcrest.Matchers.is;
import static org.hamcrest.Matchers.notNullValue;
import static org.junit.Assert.assertThat;
import static org.junit.Assert.fail;

import java.util.concurrent.atomic.AtomicLong;

import javax.inject.Inject;

import org.eclipse.microprofile.metrics.Meter;
import org.eclipse.microprofile.metrics.MetricID;
import org.eclipse.microprofile.metrics.MetricRegistry;
import org.jboss.arquillian.container.test.api.Deployment;
import org.jboss.arquillian.junit.Arquillian;
import org.jboss.arquillian.junit.InSequence;
import org.jboss.shrinkwrap.api.Archive;
import org.jboss.shrinkwrap.api.ShrinkWrap;
import org.jboss.shrinkwrap.api.asset.EmptyAsset;
import org.jboss.shrinkwrap.api.spec.WebArchive;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;

@RunWith(Arquillian.class)
public class MeteredMethodBeanTest {

    private final static String METER_NAME = MetricRegistry.name(MeteredMethodBean1.class, "meteredMethod");
    private static MetricID meterMID;

    private final static AtomicLong METER_COUNT = new AtomicLong();

    @Deployment
    static Archive<?> createTestArchive() {
        return ShrinkWrap.create(WebArchive.class)
            // Test bean
            .addClass(MeteredMethodBean1.class)
            // Bean archive deployment descriptor
            .addAsWebInfResource(EmptyAsset.INSTANCE, "beans.xml");
    }

    @Inject
    private MetricRegistry registry;

    @Inject
    private MeteredMethodBean1 bean;

    @Before
    public void instantiateTest() {
        /*
         * The MetricID relies on the MicroProfile Config API.
         * Running a managed arquillian container will result
         * with the MetricID being created in a client process
         * that does not contain the MPConfig impl.
         * 
         * This will cause client instantiated MetricIDs to 
         * throw an exception. (i.e the global MetricIDs)
         */
        meterMID = new MetricID(METER_NAME);
    }
    
    @Test
    @InSequence(1)
    public void meteredMethodNotCalledYet() {
        Meter meter = registry.getMeter(meterMID);
        assertThat("Meter is not registered correctly", meter, notNullValue());

        // Make sure that the meter hasn't been marked yet
        assertThat("Meter count is incorrect", meter.getCount(), is(equalTo(METER_COUNT.get())));
    }

    @Test
    @InSequence(2)
    public void callMeteredMethodOnce() {
        Meter meter = registry.getMeter(meterMID);
        assertThat("Meter is not registered correctly", meter, notNullValue());

        // Call the metered method and assert it's been marked
        bean.meteredMethod();

        // Make sure that the meter has been marked
        assertThat("Timer count is incorrect", meter.getCount(), is(equalTo(METER_COUNT.incrementAndGet())));
    }

    @Test
    @InSequence(3)
    public void removeMeterFromRegistry() {
        Meter meter = registry.getMeter(meterMID);
        assertThat("Meter is not registered correctly", meter, notNullValue());

        // Remove the meter from metrics registry
        registry.remove(meterMID);

        try {
            // Call the metered method and assert an exception is thrown
            bean.meteredMethod();
        }
        catch (RuntimeException cause) {
            assertThat(cause, is(instanceOf(IllegalStateException.class)));
            // Make sure that the meter hasn't been marked
            assertThat("Meter count is incorrect", meter.getCount(), is(equalTo(METER_COUNT.get())));
            return;
        }

        fail("No exception has been re-thrown!");
    }
}