package mockit;
   
   import static org.junit.jupiter.api.Assertions.assertArrayEquals;
   import static org.junit.jupiter.api.Assertions.assertEquals;
   import static org.junit.jupiter.api.Assertions.assertFalse;
   import static org.junit.jupiter.api.Assertions.assertNotNull;
   import static org.junit.jupiter.api.Assertions.assertSame;
   import static org.junit.jupiter.api.Assertions.assertTrue;
   import static org.junit.jupiter.api.Assertions.fail;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.nio.ByteBuffer;
  import java.util.Arrays;
  import java.util.Date;
  import java.util.LinkedList;
  import java.util.Queue;
  
  import org.junit.jupiter.api.Disabled;
  import org.junit.jupiter.api.Test;
  import org.junit.runner.RunWith;
  import org.junit.runners.BlockJUnit4ClassRunner;
  
  /**
   * The Class InstanceSpecificMockingTest.
   */
  final class InstanceSpecificMockingTest {
  
      /**
       * The Class Collaborator.
       */
      static class Collaborator {
  
          /** The value. */
          protected final int value;
  
          /**
           * Instantiates a new collaborator.
           */
          Collaborator() {
              value = -1;
          }
  
          /**
           * Instantiates a new collaborator.
           *
           * @param value
           *            the value
           */
          Collaborator(int value) {
              this.value = value;
          }
  
          /**
           * Gets the value.
           *
           * @return the value
           */
          int getValue() {
              return value;
          }
  
          /**
           * Simple operation.
           *
           * @param a
           *            the a
           * @param b
           *            the b
           * @param c
           *            the c
           *
           * @return true, if successful
           */
          @SuppressWarnings("unused")
          final boolean simpleOperation(int a, String b, Date c) {
              return true;
          }
  
          /**
           * Do something.
           *
           * @param b
           *            the b
           * @param s
           *            the s
           */
          @SuppressWarnings("unused")
          static void doSomething(boolean b, String s) {
              throw new IllegalStateException();
          }
      }
  
      /** The previous instance. */
      final Collaborator previousInstance = new Collaborator();
  
      /** The mock. */
      @Injectable
      Collaborator mock;
 
     /**
      * Exercise injected instance during replay only.
      */
     @Test
     void exerciseInjectedInstanceDuringReplayOnly() {
         assertThatPreviouslyCreatedInstanceIsNotMocked();
 
         assertEquals(0, mock.value);
         assertEquals(0, mock.getValue());
         assertFalse(mock.simpleOperation(1, "test", null));
 
         assertThatNewlyCreatedInstanceIsNotMocked();
     }
 
     /**
      * Assert that previously created instance is not mocked.
      */
     void assertThatPreviouslyCreatedInstanceIsNotMocked() {
         assertEquals(-1, previousInstance.value);
         assertEquals(-1, previousInstance.getValue());
         assertTrue(previousInstance.simpleOperation(1, "test", null));
     }
 
     /**
      * Assert that newly created instance is not mocked.
      */
     void assertThatNewlyCreatedInstanceIsNotMocked() {
         Collaborator newInstance = new Collaborator();
         assertEquals(-1, newInstance.value);
         assertEquals(-1, newInstance.getValue());
         assertTrue(newInstance.simpleOperation(1, "test", null));
     }
 
     /**
      * Mock specific instance.
      */
     @Test
     void mockSpecificInstance() {
         new Expectations() {
             {
                 mock.simpleOperation(1, "", null);
                 result = false;
                 mock.getValue();
                 result = 123;
                 times = 1;
             }
         };
 
         assertFalse(mock.simpleOperation(1, "", null));
         assertEquals(123, mock.getValue());
         assertThatPreviouslyCreatedInstanceIsNotMocked();
         assertThatNewlyCreatedInstanceIsNotMocked();
 
         try {
             Collaborator.doSomething(false, null);
             fail();
         } catch (IllegalStateException ignore) {
         }
     }
 
     /**
      * Use A second mock instance of the same type.
      *
      * @param mock2
      *            the mock 2
      */
     @Test
     void useASecondMockInstanceOfTheSameType(@Injectable final Collaborator mock2) {
         assertThatPreviouslyCreatedInstanceIsNotMocked();
 
         new Expectations() {
             {
                 mock2.getValue();
                 result = 2;
                 mock.getValue();
                 returns(1, 3);
             }
         };
 
         assertEquals(1, mock.getValue());
         assertEquals(2, mock2.getValue());
         assertEquals(3, mock.getValue());
         assertEquals(2, mock2.getValue());
         assertEquals(3, mock.getValue());
 
         assertThatPreviouslyCreatedInstanceIsNotMocked();
         assertThatNewlyCreatedInstanceIsNotMocked();
     }
 
     // Injectable mocks of unusual types ///////////////////////////////////////////////////////////////////////////////
 
     /**
      * Allow injectable mock of interface type.
      *
      * @param runnable
      *            the runnable
      */
     @Test
     void allowInjectableMockOfInterfaceType(@Injectable final Runnable runnable) {
         runnable.run();
         runnable.run();
 
         new Verifications() {
             {
                 runnable.run();
                 minTimes = 1;
                 maxTimes = 2;
             }
         };
     }
 
     /**
      * Allow injectable mock of annotation type.
      *
      * @param runWith
      *            the run with
      */
     @Test
     void allowInjectableMockOfAnnotationType(@Injectable final RunWith runWith) {
         new Expectations() {
             {
                 runWith.value();
                 result = BlockJUnit4ClassRunner.class;
             }
         };
 
         assertSame(BlockJUnit4ClassRunner.class, runWith.value());
     }
 
     // Mocking java.nio.ByteBuffer /////////////////////////////////////////////////////////////////////////////////////
 
     /**
      * Mock byte buffer as injectable.
      *
      * @param buf
      *            the buf
      */
     // TODO JWL 2/18/2024 Test not allowed on jdk21
     @Disabled
     @Test
     void mockByteBufferAsInjectable(@Injectable final ByteBuffer buf) {
         ByteBuffer realBuf = ByteBuffer.allocateDirect(10);
         assertNotNull(realBuf);
         assertEquals(10, realBuf.capacity());
 
         new Expectations() {
             {
                 buf.isDirect();
                 result = true;
 
                 // Calling "getBytes()" here indirectly creates a new ByteBuffer, requiring use of @Injectable.
                 buf.put("Test".getBytes());
                 times = 1;
             }
         };
 
         assertTrue(buf.isDirect());
         buf.put("Test".getBytes());
     }
 
     /**
      * Mock byte buffer regularly.
      *
      * @param mockBuffer
      *            the mock buffer
      */
     // TODO JWL 10/30/2022 Test is very flaky, ignore it
     @Disabled
     @Test
     void mockByteBufferRegularly(@Mocked ByteBuffer mockBuffer) {
         ByteBuffer buffer = ByteBuffer.allocateDirect(10);
         // noinspection MisorderedAssertEqualsArguments
         assertSame(mockBuffer, buffer);
 
         new Verifications() {
             {
                 ByteBuffer.allocateDirect(anyInt);
             }
         };
     }
 
     /**
      * Mock byte buffer as cascading.
      *
      * @param unused
      *            the unused
      */
     // TODO JWL 10/30/2022 Test is very flaky, ignore it
     @Disabled
     @Test
     void mockByteBufferAsCascading(@Mocked ByteBuffer unused) {
         ByteBuffer cascadedBuf = ByteBuffer.allocateDirect(10);
         assertNotNull(cascadedBuf);
         assertEquals(0, cascadedBuf.capacity());
     }
 
     /**
      * A factory for creating Buffer objects.
      */
     static class BufferFactory {
         /**
          * Creates a new Buffer object.
          *
          * @return the byte buffer
          */
         ByteBuffer createBuffer() {
             return null;
         }
     }
 
     /**
      * Mock byte buffer as cascaded mock.
      *
      * @param cascadingMock
      *            the cascading mock
      */
     // TODO JWL 2/18/2024 Test not allowed on jdk21
     @Disabled
     @Test
     void mockByteBufferAsCascadedMock(@Mocked BufferFactory cascadingMock) {
         ByteBuffer realBuf1 = ByteBuffer.allocateDirect(10);
         assertEquals(10, realBuf1.capacity());
 
         ByteBuffer cascadedBuf = cascadingMock.createBuffer();
         assertEquals(0, cascadedBuf.capacity());
 
         ByteBuffer realBuf2 = ByteBuffer.allocateDirect(20);
         assertEquals(20, realBuf2.capacity());
     }
 
     // Mocking java.io.InputStream /////////////////////////////////////////////////////////////////////////////////////
 
     /**
      * The Class ConcatenatingInputStream.
      */
     public static final class ConcatenatingInputStream extends InputStream {
 
         /** The sequential inputs. */
         private final Queue<InputStream> sequentialInputs;
 
         /** The current input. */
         private InputStream currentInput;
 
         /**
          * Instantiates a new concatenating input stream.
          *
          * @param sequentialInputs
          *            the sequential inputs
          */
         public ConcatenatingInputStream(InputStream... sequentialInputs) {
             this.sequentialInputs = new LinkedList<>(Arrays.asList(sequentialInputs));
             currentInput = this.sequentialInputs.poll();
         }
 
         @Override
         public int read() throws IOException {
             if (currentInput == null) {
                 return -1;
             }
 
             int nextByte = currentInput.read();
 
             if (nextByte >= 0) {
                 return nextByte;
             }
 
             currentInput = sequentialInputs.poll();
             // noinspection TailRecursion
             return read();
         }
     }
 
     /**
      * Concatenate input streams.
      *
      * @param input1
      *            the input 1
      * @param input2
      *            the input 2
      *
      * @throws Exception
      *             the exception
      */
     @Test
     void concatenateInputStreams(@Injectable final InputStream input1, @Injectable final InputStream input2)
             throws Exception {
         new Expectations() {
             {
                 input1.read();
                 returns(1, 2, -1);
                 input2.read();
                 returns(3, -1);
             }
         };
 
         InputStream concatenatedInput = new ConcatenatingInputStream(input1, input2);
         byte[] buf = new byte[3];
         concatenatedInput.read(buf);
         concatenatedInput.close();
 
         byte[] expectedBytes = { 1, 2, 3 };
         assertArrayEquals(expectedBytes, buf);
     }
 }