// Copyright 2021 Code Intelligence GmbH
//
// Licensed 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 com.code_intelligence.jazzer.api;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.fail;

import java.util.Arrays;
import java.util.Collections;
import org.junit.BeforeClass;
import org.junit.Test;

public class AutofuzzTest {
  public interface UnimplementedInterface {}

  public interface ImplementedInterface {}
  public static class ImplementingClass implements ImplementedInterface {}

  private static boolean implIsNotNull(ImplementedInterface impl) {
    return impl != null;
  }

  private static boolean implIsNotNull(UnimplementedInterface impl) {
    return impl != null;
  }

  private static void checkAllTheArguments(
      String arg1, int arg2, byte arg3, ImplementedInterface arg4) {
    if (!arg1.equals("foobar") || arg2 != 42 || arg3 != 5 || arg4 == null) {
      throw new IllegalArgumentException();
    }
  }

  @Test
  public void testConsume() {
    FuzzedDataProvider data = CannedFuzzedDataProvider.create(
        Arrays.asList((byte) 1 /* do not return null */, 0 /* first class on the classpath */,
            (byte) 1 /* do not return null */, 0 /* first constructor */));
    ImplementedInterface result = Jazzer.consume(data, ImplementedInterface.class);
    assertNotNull(result);
  }

  @Test
  public void testConsumeFailsWithoutException() {
    FuzzedDataProvider data = CannedFuzzedDataProvider.create(Collections.singletonList(
        (byte) 1 /* do not return null without searching for implementing classes */));
    assertNull(Jazzer.consume(data, UnimplementedInterface.class));
  }

  @Test
  public void testAutofuzz() {
    FuzzedDataProvider data = CannedFuzzedDataProvider.create(
        Arrays.asList((byte) 1 /* do not return null */, 0 /* first class on the classpath */,
            (byte) 1 /* do not return null */, 0 /* first constructor */));
    assertEquals(Boolean.TRUE,
        Jazzer.autofuzz(data, (Function1<ImplementedInterface, ?>) AutofuzzTest::implIsNotNull));
  }

  @Test
  public void testAutofuzzFailsWithException() {
    FuzzedDataProvider data = CannedFuzzedDataProvider.create(
        Collections.singletonList((byte) 1 /* do not return null */));
    try {
      Jazzer.autofuzz(data, (Function1<UnimplementedInterface, ?>) AutofuzzTest::implIsNotNull);
    } catch (AutofuzzConstructionException e) {
      // Pass.
      return;
    }
    fail("should have thrown an AutofuzzConstructionException");
  }

  @Test
  public void testAutofuzzConsumer() {
    FuzzedDataProvider data = CannedFuzzedDataProvider.create(
        Arrays.asList((byte) 1 /* do not return null */, 6 /* string length */, "foobar", 42,
            (byte) 5, (byte) 1 /* do not return null */, 0 /* first class on the classpath */,
            (byte) 1 /* do not return null */, 0 /* first constructor */));
    Jazzer.autofuzz(data, AutofuzzTest::checkAllTheArguments);
  }

  @Test
  public void testAutofuzzConsumerThrowsException() {
    FuzzedDataProvider data =
        CannedFuzzedDataProvider.create(Arrays.asList((byte) 1 /* do not return null */,
            6 /* string length */, "foobar", 42, (byte) 5, (byte) 0 /* *do* return null */));
    try {
      Jazzer.autofuzz(data, AutofuzzTest::checkAllTheArguments);
    } catch (IllegalArgumentException e) {
      // Pass.
      return;
    }
    fail("should have thrown an IllegalArgumentException");
  }
}