/*
 * Copyright (C) 2021 The Android Open Source Project
 *
 * 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 androidx.test.internal.runner.listener;

import android.util.Log;
import androidx.annotation.NonNull;
import androidx.tracing.Trace;
import org.junit.runner.Description;
import org.junit.runner.notification.RunListener;

/** A JUnit RunListener that reports {@link android.os.Trace} info for each test case */
public class TraceRunListener extends RunListener {
  private static final String TAG = TraceRunListener.class.getSimpleName();

  /** android.os.Trace.beginSection() has a limit on name length. */
  private static final int MAX_SECTION_NAME_LEN = 127;

  private Thread startedThread = null;

  @Override
  public void testStarted(Description description) throws Exception {
    startedThread = Thread.currentThread();
    String testClassName =
        description.getTestClass() != null ? description.getTestClass().getSimpleName() : "None";
    String methodName = description.getMethodName() != null ? description.getMethodName() : "None";
    Trace.beginSection(sanitizeSpanName(testClassName + "#" + methodName));
  }

  @Override
  public void testFinished(Description description) throws Exception {
    if (Thread.currentThread().equals(startedThread)) {
      Trace.endSection();
    } else {
      // Trace expects the begin/end section calls to be on same thread.
      // Listeners should always be invoked on test/instrumentation thread,
      // but log an error in case this changes.
      Log.e("TraceRunListener", "testFinished called on different thread than testStarted");
    }
    startedThread = null;
  }

  /**
   * android.os.Trace.beginSection() has a hard limit on the name length and throws if the name is
   * too long. We shorten here with a warning if needed.
   */
  @NonNull
  private static String sanitizeSpanName(@NonNull String name) {
    if (name.length() > MAX_SECTION_NAME_LEN) {
      Log.w(TAG, "Span name exceeds limits: " + name);
      name = name.substring(0, MAX_SECTION_NAME_LEN);
    }
    return name;
  }
}