/*
 * 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.htrace.impl;

import com.twitter.zipkin.gen.LogEntry;
import com.twitter.zipkin.gen.ResultCode;
import com.twitter.zipkin.gen.Scribe;
import java.io.IOException;
import java.util.List;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import org.apache.commons.codec.binary.Base64;
import org.apache.htrace.core.AlwaysSampler;
import org.apache.htrace.core.HTraceConfiguration;
import org.apache.htrace.core.MilliSpan;
import org.apache.htrace.core.Span;
import org.apache.htrace.core.SpanId;
import org.apache.htrace.core.TraceCreator;
import org.apache.htrace.core.TraceScope;
import org.apache.htrace.core.Tracer;
import org.apache.htrace.core.TracerPool;
import org.apache.thrift.TException;
import org.apache.thrift.protocol.TBinaryProtocol;
import org.apache.thrift.transport.TMemoryBuffer;
import org.junit.Assert;
import org.junit.Test;

public class TestZipkinSpanReceiver {

  private Tracer newTracer(final Scribe.Iface scribe) {
    TracerPool pool = new TracerPool("newTracer");
    pool.addReceiver(new ZipkinSpanReceiver(HTraceConfiguration.EMPTY) {
      @Override Scribe.Iface newScribe() {
        return scribe;
      }
    });
    return new Tracer.Builder().
        name("ZipkinTracer").
        tracerPool(pool).
        conf(HTraceConfiguration.fromKeyValuePairs(
            "sampler.classes", AlwaysSampler.class.getName()
        )).
        build();
  }

  @Test
  public void testSimpleTraces() throws IOException, InterruptedException {
    FakeZipkinScribe scribe = new FakeZipkinScribe();
    Tracer tracer = newTracer(scribe);
    Span rootSpan = new MilliSpan.Builder().
        description("root").
        spanId(new SpanId(100, 100)).
        tracerId("test").
        begin(System.currentTimeMillis()).
        build();
    TraceScope rootScope = tracer.newScope("root");
    TraceScope innerOne = tracer.newScope("innerOne");
    TraceScope innerTwo = tracer.newScope("innerTwo");
    innerTwo.close();
    Assert.assertTrue(scribe.nextMessageAsSpan().getName().contains("innerTwo"));
    innerOne.close();
    Assert.assertTrue(scribe.nextMessageAsSpan().getName().contains("innerOne"));
    rootSpan.addKVAnnotation("foo", "bar");
    rootSpan.addTimelineAnnotation("timeline");
    rootScope.close();
    Assert.assertTrue(scribe.nextMessageAsSpan().getName().contains("root"));
    tracer.close();
  }

  @Test
  public void testConcurrency() throws IOException {
    Scribe.Iface alwaysOk = new Scribe.Iface() {
      @Override
      public ResultCode Log(List<LogEntry> messages) throws TException {
        return ResultCode.OK;
      }
    };
    Tracer tracer = newTracer(alwaysOk);
    TraceCreator traceCreator = new TraceCreator(tracer);
    traceCreator.createThreadedTrace();
  }

  @Test
  public void testResilience() throws IOException {
    Scribe.Iface alwaysTryLater = new Scribe.Iface() {
      @Override
      public ResultCode Log(List<LogEntry> messages) throws TException {
        return ResultCode.TRY_LATER;
      }
    };
    Tracer tracer = newTracer(alwaysTryLater);
    TraceCreator traceCreator = new TraceCreator(tracer);
    traceCreator.createThreadedTrace();
  }

  private static class FakeZipkinScribe implements Scribe.Iface {

    private final BlockingQueue<com.twitter.zipkin.gen.Span> receivedSpans =
        new ArrayBlockingQueue<com.twitter.zipkin.gen.Span>(1);

    com.twitter.zipkin.gen.Span nextMessageAsSpan() throws InterruptedException {
      return receivedSpans.take();
    }

    @Override
    public ResultCode Log(List<LogEntry> messages) throws TException {
      for (LogEntry message : messages) {
        Assert.assertEquals("zipkin", message.category);
        byte[] bytes = Base64.decodeBase64(message.message);

        TMemoryBuffer transport = new TMemoryBuffer(bytes.length);
        transport.write(bytes);
        com.twitter.zipkin.gen.Span zSpan = new com.twitter.zipkin.gen.Span();
        zSpan.read(new TBinaryProtocol(transport));
        receivedSpans.add(zSpan);
      }
      return ResultCode.OK;
    }
  }
}