/*
    * 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.lang3.concurrent;
  
  import static org.apache.commons.lang3.LangAssertions.assertIllegalArgumentException;
  import static org.easymock.EasyMock.expect;
  import static org.easymock.EasyMock.replay;
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  
  import java.util.function.Function;
  
  import org.apache.commons.lang3.AbstractLangTest;
  import org.easymock.EasyMock;
  import org.junit.jupiter.api.BeforeEach;
  import org.junit.jupiter.api.Test;
  
  class MemoizerFunctionTest extends AbstractLangTest {
  
      private Function<Integer, Integer> function;
  
      @BeforeEach
      public void setUpComputableMock() {
          function = EasyMock.mock(Function.class);
      }
  
      @Test
      void testDefaultBehaviourNotToRecalculateExecutionExceptions() throws Exception {
          final Integer input = 1;
          final Memoizer<Integer, Integer> memoizer = new Memoizer<>(function);
          final IllegalArgumentException interruptedException = new IllegalArgumentException();
          expect(function.apply(input)).andThrow(interruptedException);
          replay(function);
  
          assertThrows(Throwable.class, () -> memoizer.compute(input));
          assertIllegalArgumentException(() -> memoizer.compute(input));
      }
  
      @Test
      void testDoesNotRecalculateWhenSetToFalse() throws Exception {
          final Integer input = 1;
          final Memoizer<Integer, Integer> memoizer = new Memoizer<>(function, false);
          final IllegalArgumentException interruptedException = new IllegalArgumentException();
          expect(function.apply(input)).andThrow(interruptedException);
          replay(function);
  
          assertThrows(Throwable.class, () -> memoizer.compute(input));
          assertIllegalArgumentException(() -> memoizer.compute(input));
      }
  
      @Test
      void testDoesRecalculateWhenSetToTrue() throws Exception {
          final Integer input = 1;
          final Integer answer = 3;
          final Memoizer<Integer, Integer> memoizer = new Memoizer<>(function, true);
          final IllegalArgumentException interruptedException = new IllegalArgumentException();
          expect(function.apply(input)).andThrow(interruptedException).andReturn(answer);
          replay(function);
  
          assertThrows(Throwable.class, () -> memoizer.compute(input));
          assertEquals(answer, memoizer.compute(input));
      }
  
      @Test
      void testOnlyCallComputableOnceIfDoesNotThrowException() throws Exception {
          final Integer input = 1;
          final Memoizer<Integer, Integer> memoizer = new Memoizer<>(function);
          expect(function.apply(input)).andReturn(input);
          replay(function);
  
          assertEquals(input, memoizer.compute(input), "Should call computable first time");
          assertEquals(input, memoizer.compute(input), "Should not call the computable the second time");
      }
  
      @Test
      void testWhenComputableThrowsError() throws Exception {
          final Integer input = 1;
          final Memoizer<Integer, Integer> memoizer = new Memoizer<>(function);
          final Error error = new Error();
          expect(function.apply(input)).andThrow(error);
          replay(function);
  
          assertThrows(Error.class, () -> memoizer.compute(input));
      }
  
     @Test
     void testWhenComputableThrowsRuntimeException() throws Exception {
         final Integer input = 1;
         final Memoizer<Integer, Integer> memoizer = new Memoizer<>(function);
         final RuntimeException runtimeException = new RuntimeException("Some runtime exception");
         expect(function.apply(input)).andThrow(runtimeException);
         replay(function);
 
         assertThrows(RuntimeException.class, () -> memoizer.compute(input));
     }
 }