/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.brooklyn.policy.enricher;

import java.net.URL;
import java.util.concurrent.TimeUnit;

import org.apache.brooklyn.api.entity.Entity;
import org.apache.brooklyn.api.entity.EntitySpec;
import org.apache.brooklyn.api.sensor.AttributeSensor;
import org.apache.brooklyn.core.entity.Entities;
import org.apache.brooklyn.core.entity.EntityAsserts;
import org.apache.brooklyn.core.sensor.Sensors;
import org.apache.brooklyn.core.test.entity.TestApplication;
import org.apache.brooklyn.core.test.entity.TestEntity;
import org.apache.brooklyn.util.collections.MutableMap;
import org.apache.brooklyn.util.core.http.BetterMockWebServer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.testng.annotations.AfterMethod;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.Test;
import org.apache.brooklyn.location.localhost.LocalhostMachineProvisioningLocation;

import com.google.common.collect.ImmutableList;
import com.google.mockwebserver.MockResponse;

public class HttpLatencyDetectorTest {

    private static final Logger log = LoggerFactory.getLogger(HttpLatencyDetectorTest.class);
    public static final AttributeSensor<String> TEST_URL = Sensors.newStringSensor( "test.url");
    
    private BetterMockWebServer server;
    private LocalhostMachineProvisioningLocation loc;
    private TestApplication app;
    private TestEntity entity;
    private URL baseUrl;
    
    @BeforeMethod(alwaysRun=true)
    public void setUp() throws Exception {
        loc = new LocalhostMachineProvisioningLocation();
        app = TestApplication.Factory.newManagedInstanceForTests();
        entity = app.createAndManageChild(EntitySpec.create(TestEntity.class));
        app.start(ImmutableList.of(loc));
        
        server = BetterMockWebServer.newInstanceLocalhost();
        for (int i = 0; i < 100; i++) {
            server.enqueue(new MockResponse().setResponseCode(200).addHeader("content-type: application/json").setBody("{\"foo\":\"myfoo\"}"));
        }
        server.play();
        baseUrl = server.getUrl("/");
    }

    @AfterMethod(alwaysRun=true)
    public void tearDown() throws Exception {
        if (server != null) server.shutdown();
        if (app != null) Entities.destroyAll(app.getManagementContext());
    }
    
    @Test(groups="Integration")
    public void testPollsUrl() throws Exception {
        entity.sensors().set(TestEntity.SERVICE_UP, true);
        
        entity.enrichers().add(HttpLatencyDetector.builder()
                .url(baseUrl)
                .rollup(500, TimeUnit.MILLISECONDS)
                .period(100, TimeUnit.MILLISECONDS)
                .build());
        
        assertLatencyAttributesNonNull(entity);
    }
    
    @Test(groups="Integration")
    public void testWaitsForSensorThenPolls() throws Exception {
        entity.enrichers().add(HttpLatencyDetector.builder()
                .url(TEST_URL)
                .noServiceUp()
                .rollup(500, TimeUnit.MILLISECONDS)
                .period(100, TimeUnit.MILLISECONDS)
                .build());
        
        // nothing until url is set
        EntityAsserts.assertAttributeEqualsContinually(
                MutableMap.of("timeout", 200), 
                entity, HttpLatencyDetector.REQUEST_LATENCY_IN_SECONDS_MOST_RECENT, null);
        
        // gets value after url is set, and gets rolling average
        entity.sensors().set(TEST_URL, baseUrl.toString());
        assertLatencyAttributesNonNull(entity);
    }

    @Test(groups="Integration")
    public void testGetsSensorIfAlredySetThenPolls() throws Exception {
        entity.sensors().set(TEST_URL, baseUrl.toString());
        
        entity.enrichers().add(HttpLatencyDetector.builder()
                .url(TEST_URL)
                .noServiceUp()
                .rollup(500, TimeUnit.MILLISECONDS)
                .period(100, TimeUnit.MILLISECONDS)
                .build());
        
        assertLatencyAttributesNonNull(entity);
    }

    @Test(groups="Integration")
    public void testWaitsForServiceUp() throws Exception {
        entity.sensors().set(TestEntity.SERVICE_UP, false);
        
        entity.enrichers().add(HttpLatencyDetector.builder()
                .url(baseUrl)
                .period(100, TimeUnit.MILLISECONDS)
                .build());
        
        // nothing until url is set
        EntityAsserts.assertAttributeEqualsContinually(
                MutableMap.of("timeout", 200), 
                entity, HttpLatencyDetector.REQUEST_LATENCY_IN_SECONDS_MOST_RECENT, null);
        
        // gets value after url is set, and gets rolling average
        entity.sensors().set(TestEntity.SERVICE_UP, true);
        assertLatencyAttributesNonNull(entity); 
    }
    
    protected void assertLatencyAttributesNonNull(Entity entity) {
        EntityAsserts.assertAttributeEventuallyNonNull(entity, HttpLatencyDetector.REQUEST_LATENCY_IN_SECONDS_MOST_RECENT); 
        EntityAsserts.assertAttributeEventuallyNonNull(entity, HttpLatencyDetector.REQUEST_LATENCY_IN_SECONDS_IN_WINDOW);

        log.info("Latency to "+entity.getAttribute(TEST_URL)+" is "+entity.getAttribute(HttpLatencyDetector.REQUEST_LATENCY_IN_SECONDS_MOST_RECENT));
        log.info("Mean latency to "+entity.getAttribute(TEST_URL)+" is "+entity.getAttribute(HttpLatencyDetector.REQUEST_LATENCY_IN_SECONDS_IN_WINDOW));
    }
}
