/*
 * 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.ozone.test;

import jakarta.annotation.Nullable;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.lang.management.LockInfo;
import java.lang.management.ManagementFactory;
import java.lang.management.MonitorInfo;
import java.lang.management.ThreadInfo;
import java.lang.management.ThreadMXBean;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
import java.util.Map;
import java.util.concurrent.TimeoutException;
import org.junit.platform.engine.TestExecutionResult;
import org.junit.platform.launcher.TestExecutionListener;
import org.junit.platform.launcher.TestIdentifier;

/**
 * JUnit test execution listener which prints full thread dump to System.err
 * in case a test fails due to timeout.
 */
public class TimedOutTestsListener implements TestExecutionListener {

  private static final String INDENT = "    ";

  @Override
  public void executionFinished(TestIdentifier identifier, TestExecutionResult result) {
    if (result.getStatus() == TestExecutionResult.Status.FAILED) {
      result.getThrowable().ifPresent(t -> {
        if (t instanceof TimeoutException) {
          System.err.println("====> " + identifier.getDisplayName() + " TIMED OUT. PRINTING THREAD DUMP. <====");
          System.err.println();
          System.err.print(buildThreadDiagnosticString());
        }
      });
    }
  }

  public static String buildThreadDiagnosticString() {
    StringWriter sw = new StringWriter();
    PrintWriter output = new PrintWriter(sw);

    DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss,SSS");
    output
        .println(String.format("Timestamp: %s", dateFormat.format(new Date())));
    output.println();
    output.println(buildThreadDump());
    
    String deadlocksInfo = buildDeadlockInfo();
    if (deadlocksInfo != null) {
      output.println("====> DEADLOCKS DETECTED <====");
      output.println();
      output.println(deadlocksInfo);
    }

    return sw.toString();
  }

  private static String buildThreadDump() {
    StringBuilder dump = new StringBuilder();
    Map<Thread, StackTraceElement[]> stackTraces = Thread.getAllStackTraces();
    for (Map.Entry<Thread, StackTraceElement[]> e : stackTraces.entrySet()) {
      Thread thread = e.getKey();
      dump.append(String.format(
          "\"%s\" %s prio=%d tid=%d %s%njava.lang.Thread.State: %s",
          thread.getName(),
          (thread.isDaemon() ? "daemon" : ""),
          thread.getPriority(),
          thread.getId(),
          Thread.State.WAITING.equals(thread.getState()) ? 
              "in Object.wait()" :
              thread.getState().name().toLowerCase(Locale.ENGLISH),
          Thread.State.WAITING.equals(thread.getState()) ?
              "WAITING (on object monitor)" : thread.getState()));
      for (StackTraceElement stackTraceElement : e.getValue()) {
        dump.append("\n        at ")
            .append(stackTraceElement);
      }
      dump.append('\n');
    }
    return dump.toString();
  }

  @Nullable
  private static String buildDeadlockInfo() {
    ThreadMXBean threadBean = ManagementFactory.getThreadMXBean();
    long[] threadIds = threadBean.findMonitorDeadlockedThreads();
    if (threadIds != null && threadIds.length > 0) {
      StringWriter stringWriter = new StringWriter();
      PrintWriter out = new PrintWriter(stringWriter);
      
      ThreadInfo[] infos = threadBean.getThreadInfo(threadIds, true, true);
      for (ThreadInfo ti : infos) {
        printThreadInfo(ti, out);
        printLockInfo(ti.getLockedSynchronizers(), out);
        out.println();
      }
      
      out.close();
      return stringWriter.toString();
    } else {
      return null;
    }
  }
  
  private static void printThreadInfo(ThreadInfo ti, PrintWriter out) {
    // print thread information
    printThread(ti, out);

    // print stack trace with locks
    StackTraceElement[] stacktrace = ti.getStackTrace();
    MonitorInfo[] monitors = ti.getLockedMonitors();
    for (int i = 0; i < stacktrace.length; i++) {
      StackTraceElement ste = stacktrace[i];
      out.println(INDENT + "at " + ste.toString());
      for (MonitorInfo mi : monitors) {
        if (mi.getLockedStackDepth() == i) {
          out.println(INDENT + "  - locked " + mi);
        }
      }
    }
    out.println();
  }

  private static void printThread(ThreadInfo ti, PrintWriter out) {
    out.print("\"" + ti.getThreadName() + "\"" + " Id="
        + ti.getThreadId() + " in " + ti.getThreadState());
    if (ti.getLockName() != null) {
      out.print(" on lock=" + ti.getLockName());
    }
    if (ti.isSuspended()) {
      out.print(" (suspended)");
    }
    if (ti.isInNative()) {
      out.print(" (running in native)");
    }
    out.println();
    if (ti.getLockOwnerName() != null) {
      out.println(INDENT + " owned by " + ti.getLockOwnerName() + " Id="
          + ti.getLockOwnerId());
    }
  }

  private static void printLockInfo(LockInfo[] locks, PrintWriter out) {
    out.println(INDENT + "Locked synchronizers: count = " + locks.length);
    for (LockInfo li : locks) {
      out.println(INDENT + "  - " + li);
    }
    out.println();
  }
  
}
