package com.datadoghq.trace;

import static org.assertj.core.api.Assertions.assertThat;

import com.datadoghq.trace.writer.ListWriter;
import io.opentracing.ActiveSpan.Continuation;
import org.junit.Before;
import org.junit.Test;

public class DDActiveSpanTest {

  private ListWriter listWriter = new ListWriter();
  private DDTracer ddTracer = new DDTracer(listWriter);

  @Before
  public void setUp() {
    listWriter.start();
  }

  @Test
  public void testThreadContextPropagation() {

    DDActiveSpan span1 = ddTracer.buildSpan("op1").startActive();

    assertThat(span1.getOperationName()).isEqualTo("op1");
    assertThat(ddTracer.activeSpan()).isEqualTo(span1);

    DDActiveSpan span2 = ddTracer.buildSpan("op2").startActive();
    assertThat(span2.getOperationName()).isEqualTo("op2");
    assertThat(span2.getParent()).isEqualTo(span1);
    assertThat(span2.context().getParentId()).isEqualTo(span1.getSpanId());
    assertThat(span2.context().getTraceId()).isEqualTo(span1.getTraceId());
    assertThat(ddTracer.activeSpan()).isEqualTo(span2);

    span2.deactivate();
    assertThat(ddTracer.activeSpan()).isEqualTo(span1);

    assertThat(listWriter.getList().size()).isEqualTo(0);
    span1.deactivate();
    assertThat(ddTracer.activeSpan()).isNull();

    assertThat(listWriter.getList().size()).isEqualTo(1);
    assertThat(listWriter.getList().get(0).size()).isEqualTo(2);
    assertThat(listWriter.getList().get(0).get(0)).isEqualTo(span1);
    assertThat(listWriter.getList().get(0).get(1)).isEqualTo(span2);
  }

  @Test
  public void testParentDeactivationFirst() {

    DDActiveSpan span1 = ddTracer.buildSpan("op1").startActive();

    assertThat(span1.getOperationName()).isEqualTo("op1");

    DDActiveSpan span2 = ddTracer.buildSpan("op2").startActive();

    assertThat(ddTracer.activeSpan()).isEqualTo(span2);

    span1.deactivate();

    //If parent span deactivated first => Span 2 remains the active span
    assertThat(ddTracer.activeSpan()).isEqualTo(span2);

    span2.deactivate();

    //If span2 comes to be deactivated
    assertThat(ddTracer.activeSpan()).isNull();

    assertThat(listWriter.getList().size()).isEqualTo(1);
    assertThat(listWriter.getList().get(0).size()).isEqualTo(2);
    assertThat(listWriter.getList().get(0).get(0)).isEqualTo(span1);
    assertThat(listWriter.getList().get(0).get(1)).isEqualTo(span2);
  }

  @Test
  public void testContinuation() throws Exception {
    final DDActiveSpan span1 = ddTracer.buildSpan("op1").startActive();

    final Continuation continuation = span1.capture();

    Thread t =
        new Thread(
            new Runnable() {
              @Override
              public void run() {
                assertThat(ddTracer.activeSpan()).isNull();
                continuation.activate();
                assertThat(ddTracer.activeSpan()).isEqualTo(span1);
                DDActiveSpan span2 = ddTracer.buildSpan("op2").startActive();
                assertThat(ddTracer.activeSpan()).isEqualTo(span2);
                span2.deactivate();
                assertThat(ddTracer.activeSpan()).isEqualTo(span1);
              }
            });

    t.start();
    t.join();

    span1.deactivate();
    assertThat(ddTracer.activeSpan()).isNull();

    assertThat(listWriter.getList().size()).isEqualTo(1);
    assertThat(listWriter.getList().get(0).size()).isEqualTo(2);
    assertThat(listWriter.getList().get(0).get(0)).isEqualTo(span1);
  }

  @Test
  public void testMakeSpanActive() {
    final DDSpan manualSpan = ddTracer.buildSpan("op1").startManual();

    DDActiveSpan span1 = ddTracer.makeActive(manualSpan);

    assertThat(span1.getOperationName()).isEqualTo("op1");
    assertThat(ddTracer.activeSpan()).isEqualTo(span1);
    assertThat(manualSpan.context()).isEqualTo(span1.context());
    assertThat(manualSpan.startTimeNano).isEqualTo(span1.startTimeNano);
    assertThat(manualSpan.startTimeMicro).isEqualTo(span1.startTimeMicro);
  }

  @Test
  public void testCrossContextPropagation() {
    final DDSpan manualSpan = ddTracer.buildSpan("op1").startManual();

    DDActiveSpan activeSpan =
        ddTracer.buildSpan("op2").asChildOf(manualSpan.context()).startActive();

    assertThat(activeSpan.getParentId()).isEqualTo(manualSpan.getSpanId());
    assertThat(activeSpan.getTraceId()).isEqualTo(manualSpan.getTraceId());
  }
}