/*
 * Copyright 2017-2020 The OpenTracing Authors
 *
 * 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 io.opentracing.contrib.kafka;


import io.opentracing.Scope;
import io.opentracing.Span;
import io.opentracing.Tracer;
import java.util.Collection;
import java.util.Collections;
import org.apache.kafka.clients.producer.Callback;
import org.apache.kafka.clients.producer.RecordMetadata;

/**
 * Callback executed after the producer has finished sending a message
 */
public class TracingCallback implements Callback {
  private final Callback callback;
  private Collection<SpanDecorator> spanDecorators;
  private final Span span;
  private final Tracer tracer;

  public TracingCallback(Callback callback, Span span, Tracer tracer) {
    this.callback = callback;
    this.span = span;
    this.tracer = tracer;
    this.spanDecorators = Collections.singletonList(SpanDecorator.STANDARD_TAGS);
  }

  TracingCallback(Callback callback, Span span, Tracer tracer,
      Collection<SpanDecorator> spanDecorators) {
    this.callback = callback;
    this.span = span;
    this.tracer = tracer;
    this.spanDecorators = spanDecorators;
  }

  @Override
  public void onCompletion(RecordMetadata metadata, Exception exception) {
    if (exception != null) {
      for (SpanDecorator decorator : spanDecorators) {
        decorator.onError(exception, span);
      }
    }

    try (Scope ignored = tracer.scopeManager().activate(span)) {
      if (callback != null) {
        callback.onCompletion(metadata, exception);
      }
    } finally {
      span.finish();
    }
  }
}