package org.slf4j.jul;
   
   import static org.junit.Assert.assertEquals;
   
   import java.util.function.Supplier;
   import java.util.logging.Handler;
   import java.util.logging.Level;
   import java.util.logging.LogRecord;
   
  import org.junit.After;
  import org.junit.Assert;
  import org.junit.Before;
  import org.junit.Test;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  public class FluentApiInvocationTest {
  
      ListHandler listHandler = new ListHandler();
      java.util.logging.Logger root = java.util.logging.Logger.getLogger("");
      Level oldLevel;
      Logger logger = LoggerFactory.getLogger(this.getClass());
  
      @Before
      public void setUp() throws Exception {
          oldLevel = root.getLevel();
          root.setLevel(Level.FINE);
          // removeAllHandlers(root);
          root.addHandler(listHandler);
      }
  
      @After
      public void tearDown() throws Exception {
          root.setLevel(oldLevel);
          removeListHandlers(root);
      }
  
      void removeListHandlers(java.util.logging.Logger logger) {
          Handler[] handlers = logger.getHandlers();
          for (Handler h : handlers) {
              if (h instanceof ListHandler)
                  logger.removeHandler(h);
          }
      }
  
      @Test
      public void singleMessage() {
          String msg = "Hello world.";
          logger.atDebug().log(msg);
          assertLogMessage(msg, 0);
      }
  
      @Test
      public void messageWithArguments() {
          String msg = "Hello {}.";
          logger.atDebug().addArgument("world").log(msg);
          assertLogMessage("Hello world.", 0);
      }
  
      @Test
      public void messageWithTwoArguments() {
          int old = 15;
          int t = 16;
  
          {
              String msg = "Temperature set to {}. Old temperature was {}.";
              logger.atDebug().addArgument(t).addArgument(old).log(msg);
              assertLogMessage("Temperature set to 16. Old temperature was 15.", 0);
          }
  
          {
              String msg = "Temperature set to {}. Old temperature was {}.";
              logger.atDebug().log(msg, t, old);
              assertLogMessage("Temperature set to 16. Old temperature was 15.", 0);
          }
  
          {
              String msg = "Temperature set to {}. Old temperature was {}.";
              logger.atDebug().addArgument(t).log(msg, old);
              assertLogMessage("Temperature set to 16. Old temperature was 15.", 0);
          }
  
          {
              String msg = "Temperature set to {}. Old temperature was {}.";
              logger.atDebug().addArgument(() -> t16()).log(msg, old);
              assertLogMessage("Temperature set to 16. Old temperature was 15.", 0);
          }
      }
  
      @Test
      public void supplierArguments() {
          Supplier<String> stringSupplier = () -> "world";
          logger.atInfo().addArgument(stringSupplier).log("hello {}");
          assertLogMessage("hello world", 0);
      }
  
      public int t16() {
          return 16;
      }
 
     @Test
     public void messageWithThrowable() {
         String msg = "Hello world.";
         Throwable t = new IllegalStateException();
         logger.atDebug().setCause(t).log(msg);
         assertLogMessage("Hello world.", 0);
         assertThrowable(t, 0);
     }
 
     @Test
     public void messageWithArgumentsAndThrowable() {
         String msg = "Hello {}.";
         Throwable t = new IllegalStateException();
 
         logger.atDebug().setCause(t).addArgument("world").log(msg);
         assertLogMessage("Hello world.", 0);
         assertThrowable(t, 0);
     }
 
     @Test
     public void messageWithKeyValuePair() {
         String msg = "Hello world.";
         logger.atDebug().addKeyValue("k", "v").log(msg);
         assertLogMessage("k=v Hello world.", 0);
 
         int oldT = 15;
         int newT = 16;
         logger.atDebug().addKeyValue("oldT", oldT).addKeyValue("newT", newT).log("Temperature changed.");
         assertLogMessage("oldT=15 newT=16 Temperature changed.", 1);
 
     }
 
     private void assertLogMessage(String expected, int index) {
         LogRecord logRecord = listHandler.recordList.get(index);
         Assert.assertNotNull(logRecord);
         assertEquals(expected, logRecord.getMessage());
     }
 
     private void assertThrowable(Throwable expected, int index) {
         LogRecord logRecord = listHandler.recordList.get(index);
         Assert.assertNotNull(logRecord);
         assertEquals(expected, logRecord.getThrown());
     }
 }