/*
 * Copyright 2017 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;

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

/** {@link NullTernary}Test */
@RunWith(JUnit4.class)
public class NullTernaryTest {

  private final CompilationTestHelper testHelper =
      CompilationTestHelper.newInstance(NullTernary.class, getClass());

  @Test
  public void positive() {
    testHelper
        .addSourceLines(
            "Test.java",
            """
            class Test {
              void f(boolean b) {
                // BUG: Diagnostic contains:
                int x = b ? 0 : null;
                // BUG: Diagnostic contains:
                long l = b ? null : 0;
                // BUG: Diagnostic contains:
                g("", b ? null : 0);
                // BUG: Diagnostic contains:
                h("", 1, b ? null : 0);
                // BUG: Diagnostic contains:
                h("", 1, b ? null : 0, 3);
                // BUG: Diagnostic contains:
                int z = 0 + (b ? null : 1);
                // BUG: Diagnostic contains:
                z = (b ? null : 1) + 0;
              }

              void g(String s, int y) {}

              void h(String s, int... y) {}
            }
            """)
        .doTest();
  }

  @Test
  public void negative() {
    testHelper
        .addSourceLines(
            "Test.java",
            """
            class Test {
              void f(boolean b) {
                int x = b ? 0 : 1;
                Integer y = b ? 0 : null;
                g("", b ? 1 : 0);
                h("", 1, b ? 1 : 0);
                h("", 1, b ? 1 : 0, 3);
                int z = 0 + (b ? 0 : 1);
                boolean t = (b ? 0 : null) == Integer.valueOf(0);
              }

              void g(String s, int y) {}

              void h(String s, int... y) {}
            }
            """)
        .doTest();
  }

  @Test
  public void lambdas() {
    testHelper
        .addSourceLines(
            "Test.java",
            """
            class Test {
              interface I {
                int f();
              }

              interface J {
                Integer f();
              }

              interface K<X> {
                X f();
              }

              void f(boolean b) {
                I i =
                    () -> {
                      // BUG: Diagnostic contains:
                      return b ? null : 1;
                    };
                J j =
                    () -> {
                      return b ? null : 1;
                    };
                K<Integer> k =
                    () -> {
                      return b ? null : 1;
                    };
                // BUG: Diagnostic contains:
                i = () -> b ? null : 1;
                j = () -> b ? null : 1;
                k = () -> b ? null : 1;
              }
            }
            """)
        .doTest();
  }

  @Test
  public void conditionalInCondition() {
    testHelper
        .addSourceLines(
            "Test.java",
"""
class Test {
  void conditionalInCondition(Object array, String input) {
    int arrayDimensions =
        ((array != null ? input : null) == null) ? 0 : (array != null ? input : null).length();
  }
}
""")
        .doTest();
  }

  @Test
  public void expressionSwitch_doesNotCrash() {
    testHelper
        .addSourceLines(
            "Test.java",
            """
            class Test {
              static String doStuff(SomeEnum enumVar) {
                return switch (enumVar) {
                  case A -> enumVar.name() != null ? "AAA" : null;
                  default -> null;
                };
              }

              static enum SomeEnum {
                A,
                B
              }
            }
            """)
        .doTest();
  }

  @Test
  public void nullTernaryInSwitch_negative() {
    testHelper
        .addSourceLines(
            "Test.java",
            """
            class Test {
              String f(int n) {
                return switch (n) {
                  case 0 -> "zero";
                  default -> (n % 2 == 0) ? "even" : null;
                };
              }
            }
            """)
        .doTest();
  }

  @Test
  public void nullTernaryInSwitch_positive() {
    testHelper
        .addSourceLines(
            "Test.java",
            """
            class Test {
              int f(int n) {
                return switch (n) {
                  default -> {
                    // BUG: Diagnostic contains:
                    yield (n % 2 == 0) ? 0 : null;
                  }
                };
              }
            }
            """)
        .doTest();
  }
}
