/*
    * 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
    *
    *      https://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.commons.dbcp2;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  
  import java.sql.Connection;
  import java.sql.PreparedStatement;
  import java.sql.ResultSet;
  import java.time.Duration;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.List;
  import java.util.Random;
  
  import org.junit.jupiter.api.BeforeEach;
  import org.junit.jupiter.api.Test;
  
  /**
   * Test if the pooling if no idle objects are used
   */
  public class TestParallelCreationWithNoIdle {
  
      final class TestThread extends Thread {
          final Random random = new Random();
          final int iter;
          final int delay;
          final int delayAfter;
  
          public TestThread(final int iter, final int delay, final int delayAfter) {
              this.iter = iter;
              this.delay = delay;
              this.delayAfter = delayAfter;
          }
  
          @Override
          public void run() {
              // System.out.println("Thread started " + Thread.currentThread().toString());
              for (int i = 0; i < iter; i++) {
                  sleepMax(delay);
                  try (Connection conn = ds.getConnection(); PreparedStatement stmt = conn.prepareStatement("select 'literal', SYSDATE from dual")) {
                      // System.out.println("Got Connection " + Thread.currentThread().toString());
                      final ResultSet rset = stmt.executeQuery();
                      rset.next();
                      sleepMax(delayAfter);
                      rset.close();
                  } catch (final Exception e) {
                      e.printStackTrace();
                      throw new RuntimeException(e);
                  }
              }
              // System.out.println("Thread done " + Thread.currentThread().toString());
          }
  
          private void sleepMax(final int timeMax) {
              if (timeMax == 0) {
                  return;
              }
              try {
                  Thread.sleep(random.nextInt(timeMax));
              } catch (final Exception e) {
                  // ignored
              }
          }
      }
  
      private static final String CATALOG = "test catalog";
  
      protected BasicDataSource ds;
  
      @BeforeEach
      public void setUp() throws Exception {
          ds = new BasicDataSource();
          ds.setDriverClassName("org.apache.commons.dbcp2.TesterConnectionDelayDriver");
          ds.setUrl("jdbc:apache:commons:testerConnectionDelayDriver:50");
          ds.setMaxTotal(10);
  
          // this one is actually very important.
          // see DBCP-513
          ds.setMaxIdle(0);
  
          // wait a minute. Usually the test runs in ~ 1 second
          // but often it's getting stuck ^^
          // you have one second to get a thread dump ;)
         ds.setMaxWait(Duration.ofMinutes(1));
 
         ds.setDefaultAutoCommit(Boolean.TRUE);
         ds.setDefaultReadOnly(Boolean.FALSE);
         ds.setDefaultTransactionIsolation(Connection.TRANSACTION_READ_COMMITTED);
         ds.setDefaultCatalog(CATALOG);
         ds.setUsername("userName");
         ds.setPassword("password");
         ds.setValidationQuery("SELECT DUMMY FROM DUAL");
         ds.setConnectionInitSqls(Arrays.asList("SELECT 1", "SELECT 2"));
         ds.setDriverClassLoader(new TesterClassLoader());
         ds.setJmxName("org.apache.commons.dbcp2:name=test");
     }
 
     /**
      * Fire up 100 Threads but only have 10 maxActive and forcedBlock. See
      *
      * @throws Exception
      */
     @Test
     void testMassiveConcurrentInitBorrow() throws Exception {
         final int numThreads = 200;
         ds.setDriverClassName("org.apache.commons.dbcp2.TesterConnectionDelayDriver");
         ds.setUrl("jdbc:apache:commons:testerConnectionDelayDriver:20");
         ds.setInitialSize(8);
         final List<Throwable> errors = Collections.synchronizedList(new ArrayList<>());
 
         final Thread[] threads = new Thread[numThreads];
         for (int i = 0; i < numThreads; i++) {
             threads[i] = new TestThread(2, 0, 50);
             threads[i].setUncaughtExceptionHandler((t, e) -> errors.add(e));
         }
 
         for (int i = 0; i < numThreads; i++) {
             threads[i].start();
 
             if (i % 4 == 0) {
                 Thread.sleep(20);
             }
         }
 
         for (int i = 0; i < numThreads; i++) {
             threads[i].join();
         }
 
         assertEquals(0, errors.size());
         ds.close();
     }
 
 }