/**
 * 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.cxf.systest.jaxrs.tracing.htrace;

import java.net.MalformedURLException;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.Response.Status;

import com.fasterxml.jackson.jaxrs.json.JacksonJsonProvider;

import org.apache.cxf.jaxrs.JAXRSServerFactoryBean;
import org.apache.cxf.jaxrs.client.WebClient;
import org.apache.cxf.jaxrs.lifecycle.SingletonResourceProvider;
import org.apache.cxf.jaxrs.model.AbstractResourceInfo;
import org.apache.cxf.systest.htrace.TestSpanReceiver;
import org.apache.cxf.systest.jaxrs.tracing.BookStore;
import org.apache.cxf.testutil.common.AbstractBusClientServerTestBase;
import org.apache.cxf.testutil.common.AbstractBusTestServerBase;
import org.apache.cxf.tracing.TracerHeaders;
import org.apache.cxf.tracing.htrace.jaxrs.HTraceClientProvider;
import org.apache.cxf.tracing.htrace.jaxrs.HTraceFeature;
import org.apache.htrace.core.AlwaysSampler;
import org.apache.htrace.core.HTraceConfiguration;
import org.apache.htrace.core.SpanId;
import org.apache.htrace.core.StandardOutSpanReceiver;
import org.apache.htrace.core.TraceScope;
import org.apache.htrace.core.Tracer;

import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Ignore;
import org.junit.Test;

import static org.apache.cxf.systest.jaxrs.tracing.htrace.HasSpan.hasSpan;
import static org.apache.cxf.systest.jaxrs.tracing.htrace.IsTimelineContaining.hasItem;
import static org.apache.cxf.systest.jaxrs.tracing.htrace.IsTimelineEmpty.empty;
import static org.hamcrest.CoreMatchers.equalTo;

public class HTraceTracingTest extends AbstractBusClientServerTestBase {
    public static final String PORT = allocatePort(HTraceTracingTest.class);

    private Tracer tracer;
    private HTraceClientProvider htraceClientProvider;

    @Ignore
    public static class Server extends AbstractBusTestServerBase {
        protected void run() {
            final Map<String, String> properties = new HashMap<>();
            properties.put(Tracer.SPAN_RECEIVER_CLASSES_KEY, TestSpanReceiver.class.getName());
            properties.put(Tracer.SAMPLER_CLASSES_KEY, AlwaysSampler.class.getName());

            final JAXRSServerFactoryBean sf = new JAXRSServerFactoryBean();
            sf.setResourceClasses(BookStore.class);
            sf.setResourceProvider(BookStore.class, new SingletonResourceProvider(new BookStore<TraceScope>()));
            sf.setAddress("http://localhost:" + PORT);
            sf.setProvider(new JacksonJsonProvider());
            sf.setFeatures(Arrays.asList(new HTraceFeature(HTraceConfiguration.fromMap(properties), "tracer")));
            sf.create();
        }
    }

    @BeforeClass
    public static void startServers() throws Exception {
        AbstractResourceInfo.clearAllMaps();
        //keep out of process due to stack traces testing failures
        assertTrue("server did not launch correctly", launchServer(Server.class, true));
        createStaticBus();
    }

    @Before
    public void setUp() {
        TestSpanReceiver.clear();

        final Map<String, String> properties = new HashMap<>();
        properties.put(Tracer.SPAN_RECEIVER_CLASSES_KEY, StandardOutSpanReceiver.class.getName());
        properties.put(Tracer.SAMPLER_CLASSES_KEY, AlwaysSampler.class.getName());

        tracer = new Tracer.Builder("tracer")
            .conf(HTraceConfiguration.fromMap(properties))
            .build();

        htraceClientProvider = new HTraceClientProvider(tracer);
    }

    @Test
    public void testThatNewSpanIsCreatedWhenNotProvided() {
        final Response r = createWebClient("/bookstore/books").get();
        assertEquals(Status.OK.getStatusCode(), r.getStatus());

        assertThat(TestSpanReceiver.getAllSpans().size(), equalTo(2));
        assertThat(TestSpanReceiver.getAllSpans().get(0).getDescription(), equalTo("Get Books"));
        assertThat(TestSpanReceiver.getAllSpans().get(1).getDescription(), equalTo("GET bookstore/books"));

        assertFalse(r.getHeaders().containsKey(TracerHeaders.DEFAULT_HEADER_SPAN_ID));
    }

    @Test
    public void testThatNewInnerSpanIsCreated() {
        final SpanId spanId = SpanId.fromRandom();

        final Response r = createWebClient("/bookstore/books")
            .header(TracerHeaders.DEFAULT_HEADER_SPAN_ID, spanId.toString())
            .get();
        assertEquals(Status.OK.getStatusCode(), r.getStatus());

        assertThat(TestSpanReceiver.getAllSpans().size(), equalTo(2));
        assertThat(TestSpanReceiver.getAllSpans().get(0).getDescription(), equalTo("Get Books"));
        assertThat(TestSpanReceiver.getAllSpans().get(1).getDescription(), equalTo("GET bookstore/books"));

        assertThat((String)r.getHeaders().getFirst(TracerHeaders.DEFAULT_HEADER_SPAN_ID), equalTo(spanId.toString()));
    }

    @Test
    public void testThatCurrentSpanIsAnnotatedWithKeyValue() {
        final SpanId spanId = SpanId.fromRandom();

        final Response r = createWebClient("/bookstore/book/1")
            .header(TracerHeaders.DEFAULT_HEADER_SPAN_ID, spanId.toString())
            .get();
        assertEquals(Status.OK.getStatusCode(), r.getStatus());

        assertThat(TestSpanReceiver.getAllSpans().size(), equalTo(1));
        assertThat(TestSpanReceiver.getAllSpans().get(0).getDescription(), equalTo("GET bookstore/book/1"));
        assertThat(TestSpanReceiver.getAllSpans().get(0).getKVAnnotations().size(), equalTo(1));

        assertThat((String)r.getHeaders().getFirst(TracerHeaders.DEFAULT_HEADER_SPAN_ID), equalTo(spanId.toString()));
    }

    @Test
    public void testThatParallelSpanIsAnnotatedWithTimeline() {
        final SpanId spanId = SpanId.fromRandom();

        final Response r = createWebClient("/bookstore/process")
            .header(TracerHeaders.DEFAULT_HEADER_SPAN_ID, spanId.toString())
            .put("");
        assertEquals(Status.OK.getStatusCode(), r.getStatus());

        assertThat(TestSpanReceiver.getAllSpans().size(), equalTo(2));
        assertThat(TestSpanReceiver.getAllSpans(), hasSpan("Processing books", hasItem("Processing started")));
        assertThat(TestSpanReceiver.getAllSpans(), hasSpan("PUT bookstore/process", empty()));

        assertThat((String)r.getHeaders().getFirst(TracerHeaders.DEFAULT_HEADER_SPAN_ID), equalTo(spanId.toString()));
    }

    @Test
    public void testThatNewChildSpanIsCreatedWhenParentIsProvided() {
        final Response r = createWebClient("/bookstore/books", htraceClientProvider).get();
        assertEquals(Status.OK.getStatusCode(), r.getStatus());

        assertThat(TestSpanReceiver.getAllSpans().size(), equalTo(3));
        assertThat(TestSpanReceiver.getAllSpans().get(0).getDescription(), equalTo("Get Books"));
        assertThat(TestSpanReceiver.getAllSpans().get(0).getParents().length, equalTo(1));

        assertTrue(r.getHeaders().containsKey(TracerHeaders.DEFAULT_HEADER_SPAN_ID));
    }

    @Test
    public void testThatNewInnerSpanIsCreatedUsingAsyncInvocation() {
        final SpanId spanId = SpanId.fromRandom();

        final Response r = createWebClient("/bookstore/books/async")
            .header(TracerHeaders.DEFAULT_HEADER_SPAN_ID, spanId.toString())
            .get();
        assertEquals(Status.OK.getStatusCode(), r.getStatus());

        assertThat(TestSpanReceiver.getAllSpans().size(), equalTo(2));
        assertThat(TestSpanReceiver.getAllSpans().get(1).getDescription(), equalTo("GET bookstore/books/async"));
        assertThat(TestSpanReceiver.getAllSpans().get(0).getDescription(), equalTo("Processing books"));

        assertThat((String)r.getHeaders().getFirst(TracerHeaders.DEFAULT_HEADER_SPAN_ID), equalTo(spanId.toString()));
    }

    @Test
    public void testThatOuterSpanIsCreatedUsingAsyncInvocation() {
        final SpanId spanId = SpanId.fromRandom();

        final Response r = createWebClient("/bookstore/books/async/notrace")
            .header(TracerHeaders.DEFAULT_HEADER_SPAN_ID, spanId.toString())
            .get();
        assertEquals(Status.OK.getStatusCode(), r.getStatus());

        assertThat(TestSpanReceiver.getAllSpans().size(), equalTo(1));
        assertThat(TestSpanReceiver.getAllSpans().get(0).getDescription(),
            equalTo("GET bookstore/books/async/notrace"));

        assertThat((String)r.getHeaders().getFirst(TracerHeaders.DEFAULT_HEADER_SPAN_ID), equalTo(spanId.toString()));
    }

    @Test
    public void testThatNewSpanIsCreatedUsingAsyncInvocation() {
        final Response r = createWebClient("/bookstore/books/async").get();
        assertEquals(Status.OK.getStatusCode(), r.getStatus());

        assertThat(TestSpanReceiver.getAllSpans().size(), equalTo(2));
        assertThat(TestSpanReceiver.getAllSpans().get(1).getDescription(), equalTo("GET bookstore/books/async"));
        assertThat(TestSpanReceiver.getAllSpans().get(0).getDescription(), equalTo("Processing books"));
    }

    @Test
    public void testThatNewSpanIsCreatedWhenNotProvidedUsingAsyncClient() throws Exception {
        final WebClient client = createWebClient("/bookstore/books", htraceClientProvider);
        final Future<Response> f = client.async().get();

        final Response r = f.get(1, TimeUnit.SECONDS);
        assertEquals(Status.OK.getStatusCode(), r.getStatus());

        assertThat(TestSpanReceiver.getAllSpans().size(), equalTo(3));
        assertThat(TestSpanReceiver.getAllSpans().get(0).getDescription(), equalTo("Get Books"));
        assertThat(TestSpanReceiver.getAllSpans().get(1).getDescription(), equalTo("GET bookstore/books"));
        assertThat(TestSpanReceiver.getAllSpans().get(2).getDescription(), equalTo("GET " + client.getCurrentURI()));

        assertTrue(r.getHeaders().containsKey(TracerHeaders.DEFAULT_HEADER_SPAN_ID));
    }

    @Test
    public void testThatProvidedSpanIsNotClosedWhenActive() throws MalformedURLException {
        try (TraceScope scope = tracer.newScope("test span")) {
            final Response r = createWebClient("/bookstore/books", htraceClientProvider).get();
            assertEquals(Status.OK.getStatusCode(), r.getStatus());

            assertThat(TestSpanReceiver.getAllSpans().size(), equalTo(2));
            assertThat(TestSpanReceiver.getAllSpans().get(0).getDescription(), equalTo("Get Books"));
            assertThat(TestSpanReceiver.getAllSpans().get(0).getParents().length, equalTo(1));
            assertThat(TestSpanReceiver.getAllSpans().get(1).getDescription(), equalTo("GET bookstore/books"));

            assertTrue(r.getHeaders().containsKey(TracerHeaders.DEFAULT_HEADER_SPAN_ID));
        }

        assertThat(TestSpanReceiver.getAllSpans().size(), equalTo(3));
        assertThat(TestSpanReceiver.getAllSpans().get(2).getDescription(), equalTo("test span"));
    }

    @Test
    public void testThatProvidedSpanIsNotDetachedWhenActiveUsingAsyncClient() throws Exception {
        final WebClient client = createWebClient("/bookstore/books", htraceClientProvider);
        try (TraceScope scope = tracer.newScope("test span")) {
            final Future<Response> f = client.async().get();

            final Response r = f.get(1, TimeUnit.SECONDS);
            assertEquals(Status.OK.getStatusCode(), r.getStatus());
            assertThat(Tracer.getCurrentSpan(), equalTo(scope.getSpan()));

            assertThat(TestSpanReceiver.getAllSpans().size(), equalTo(2));
            assertThat(TestSpanReceiver.getAllSpans().get(0).getDescription(), equalTo("Get Books"));
            assertThat(TestSpanReceiver.getAllSpans().get(1).getDescription(), equalTo("GET bookstore/books"));

            assertTrue(r.getHeaders().containsKey(TracerHeaders.DEFAULT_HEADER_SPAN_ID));
        }

        assertThat(TestSpanReceiver.getAllSpans().get(2).getDescription(), equalTo("test span"));
    }

    @Test
    public void testThatInnerSpanIsCreatedUsingPseudoAsyncInvocation() {
        final SpanId spanId = SpanId.fromRandom();

        final Response r = createWebClient("/bookstore/books/pseudo-async")
            .header(TracerHeaders.DEFAULT_HEADER_SPAN_ID, spanId.toString())
            .get();
        assertEquals(Status.OK.getStatusCode(), r.getStatus());

        assertThat(TestSpanReceiver.getAllSpans().size(), equalTo(2));
        assertThat(TestSpanReceiver.getAllSpans().get(1).getDescription(), equalTo("GET bookstore/books/pseudo-async"));
        assertThat(TestSpanReceiver.getAllSpans().get(0).getDescription(), equalTo("Processing books"));

        assertThat((String)r.getHeaders().getFirst(TracerHeaders.DEFAULT_HEADER_SPAN_ID), equalTo(spanId.toString()));
    }

    @Test
    public void testThatNewSpansAreCreatedWhenNotProvidedUsingMultipleAsyncClients() throws Exception {
        final WebClient client = createWebClient("/bookstore/books", htraceClientProvider);
        
        // The intention is to make a calls one after another, not in parallel, to ensure the
        // thread have trace contexts cleared out.
        final Collection<Response> responses = IntStream
            .range(0, 4)
            .mapToObj(index -> client.async().get())
            .map(this::get)
            .collect(Collectors.toList());

        for (final Response r: responses) {
            assertEquals(Status.OK.getStatusCode(), r.getStatus());
            assertTrue(r.getHeaders().containsKey(TracerHeaders.DEFAULT_HEADER_SPAN_ID));
        }

        assertThat(TestSpanReceiver.getAllSpans().size(), equalTo(12));
        
        IntStream
            .range(0, 4)
            .map(index -> index * 3)
            .forEach(index -> {
                assertThat(TestSpanReceiver.getAllSpans().get(index).getDescription(), 
                    equalTo("Get Books"));
                assertThat(TestSpanReceiver.getAllSpans().get(index + 1).getDescription(), 
                    equalTo("GET bookstore/books"));
                assertThat(TestSpanReceiver.getAllSpans().get(index + 2).getDescription(), 
                    equalTo("GET " + client.getCurrentURI()));
            });
    }
    
    @Test
    public void testThatNewSpansAreCreatedWhenNotProvidedUsingMultipleClients() throws Exception {
        final WebClient client = createWebClient("/bookstore/books", htraceClientProvider);
        
        // The intention is to make a calls one after another, not in parallel, to ensure the
        // thread have trace contexts cleared out.
        final Collection<Response> responses = IntStream
            .range(0, 4)
            .mapToObj(index -> client.get())
            .collect(Collectors.toList());

        for (final Response r: responses) {
            assertEquals(Status.OK.getStatusCode(), r.getStatus());
            assertTrue(r.getHeaders().containsKey(TracerHeaders.DEFAULT_HEADER_SPAN_ID));
        }

        assertThat(TestSpanReceiver.getAllSpans().size(), equalTo(12));
        
        IntStream
            .range(0, 4)
            .map(index -> index * 3)
            .forEach(index -> {
                assertThat(TestSpanReceiver.getAllSpans().get(index).getDescription(), 
                    equalTo("Get Books"));
                assertThat(TestSpanReceiver.getAllSpans().get(index + 1).getDescription(), 
                    equalTo("GET bookstore/books"));
                assertThat(TestSpanReceiver.getAllSpans().get(index + 2).getDescription(), 
                    equalTo("GET " + client.getCurrentURI()));
            });
    }

    private<T> T get(final Future<T> future) {
        try {
            return future.get(1, TimeUnit.HOURS);
        } catch (InterruptedException | TimeoutException | ExecutionException ex) {
            throw new RuntimeException(ex);
        }
    }

    protected WebClient createWebClient(final String url, final Object ... providers) {
        return WebClient
            .create("http://localhost:" + PORT + url, Arrays.asList(providers))
            .accept(MediaType.APPLICATION_JSON);
    }
}
