/*
 * Copyright 2023 The Error Prone Authors.
 *
 * 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.google.errorprone.bugpatterns.nullness;

import com.google.errorprone.CompilationTestHelper;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

@RunWith(JUnit4.class)
public class MultipleNullnessAnnotationsTest {
  private final CompilationTestHelper testHelper =
      CompilationTestHelper.newInstance(MultipleNullnessAnnotations.class, getClass());

  @Test
  public void positive() {
    testHelper
        .addSourceLines(
            "Test.java",
            """
            import org.checkerframework.checker.nullness.compatqual.NonNullDecl;
            import org.checkerframework.checker.nullness.compatqual.NullableDecl;
            import org.checkerframework.checker.nullness.qual.NonNull;
            import org.checkerframework.checker.nullness.qual.Nullable;
            import java.util.List;

            abstract class Test {
              // BUG: Diagnostic contains:
              @Nullable @NonNull Object x;
              // BUG: Diagnostic contains:
              @NullableDecl static @NonNull Object y;
              // BUG: Diagnostic contains:
              List<@Nullable @NonNull String> z;

              @NullableDecl
              // BUG: Diagnostic contains:
              abstract @NonNull Object f();

              // BUG: Diagnostic contains:
              abstract void f(@NullableDecl Object @NonNull [] x);
            }
            """)
        .doTest();
  }

  @Test
  public void negative() {
    testHelper
        .addSourceLines(
            "Test.java",
            """
            import org.checkerframework.checker.nullness.compatqual.NonNullDecl;
            import org.checkerframework.checker.nullness.compatqual.NullableDecl;
            import org.checkerframework.checker.nullness.qual.NonNull;
            import org.checkerframework.checker.nullness.qual.Nullable;
            import java.util.List;

            abstract class Test {
              @NonNullDecl @NonNull Object x;
              @NullableDecl static @Nullable Object y;
            }
            """)
        .doTest();
  }

  @Test
  public void disambiguation() {
    testHelper
        .addSourceLines(
            "Test.java",
            """
            import org.checkerframework.checker.nullness.qual.Nullable;
            import java.util.List;

            abstract class Test {
              @Nullable Object @Nullable [] x;

              abstract void f(@Nullable Object @Nullable ... x);
            }
            """)
        .doTest();
  }

  @Test
  public void declarationAndType() {
    testHelper
        .addSourceLines(
            "Nullable.java",
            """
            import java.lang.annotation.Target;
            import java.lang.annotation.ElementType;

            @Target({
              ElementType.METHOD,
              ElementType.FIELD,
              ElementType.PARAMETER,
              ElementType.LOCAL_VARIABLE,
              ElementType.TYPE_USE
            })
            public @interface Nullable {}
            """)
        .addSourceLines(
            "Test.java",
            """
            abstract class Test {
              abstract void f(@Nullable Object x);

              abstract @Nullable Object g();

              @Nullable Object f;
            }
            """)
        .doTest();
  }

  @Test
  public void typeParameter() {
    testHelper
        .addSourceLines(
            "T.java",
            """
            import org.checkerframework.checker.nullness.compatqual.NullableDecl;
            import org.checkerframework.checker.nullness.qual.NonNull;

            class T<X> {
              // BUG: Diagnostic contains:
              @NullableDecl @NonNull X f;

              @NullableDecl
              // BUG: Diagnostic contains:
              @NonNull X g() {
                return null;
              }
            }
            """)
        .doTest();
  }

  @Test
  public void arrayTypeAnnotation() {
    testHelper
        .addSourceLines(
            "T.java",
            """
            import javax.annotation.CheckForNull;
            import org.checkerframework.checker.nullness.qual.NonNull;

            class T {
              // BUG: Diagnostic contains:
              @CheckForNull Object @NonNull [] f;
            }
            """)
        .doTest();
  }
}
