import java.util.Optional;
import javax.annotation.Nullable;

interface A {

  @Nullable // Noncompliant [[sc=3;ec=12]] {{Methods with an "Optional" return type should not be "@Nullable".}}
  public Optional<String> getOptionalKo();

}

class ClassA {

  public ClassA() {
  }

  @Nullable // Noncompliant [[sc=3;ec=12]] {{Methods with an "Optional" return type should not be "@Nullable".}}
  public Optional<String> getOptionalKo() {
    return null; // Noncompliant [[sc=12;ec=16]] {{Methods with an "Optional" return type should never return null.}}
  }

  public Optional<String> getOptionalOk() {
    return Optional.of("hello");
  }

  public Object doSomething1() {
    return null;
  }

  public Optional<String> doSomething2() {
    Worker x = new Worker() {
      public String work() {
        return null;
      }
    };
    return Optional.of("hello");
  }

  public int doSomething3(Optional<String> arg) {
    if (arg == null) { // Noncompliant [[sc=9;ec=20]] {{Remove this null-check of an "Optional".}}
      return 0;
    }

    Optional<String> optional = getOptionalOk();
    if (optional == null) { // Noncompliant [[sc=9;ec=25]] {{Remove this null-check of an "Optional".}}
      return 0;
    } else if (null != optional) { // Noncompliant [[sc=16;ec=32]] {{Remove this null-check of an "Optional".}}
      return 0;
    }

    Optional<String> optional2 = getOptionalOk();
    if (optional == optional2) {
      return 0;
    } else if (null == null) {
      return 0;
    }

    Optional<String> optional3 = getOptionalOk();
    return optional3 == null ? 0 : 1; // Noncompliant [[sc=12;ec=29]] {{Remove this null-check of an "Optional".}}
  }

  public Optional<String> doSomething4(List<String> myList) {
    myList.stream().map(s -> {
      if (s.length() > 0) {
        return null;
      }
      return s;
    });
    return Optional.of("hello");
  }

  @Deprecated
  public Optional<String> doSomething5(List<String> myList) {
    return myList.isEmpty() ? Optional.of("hello") : null; // Noncompliant [[sc=54;ec=58]] {{Methods with an "Optional" return type should never return null.}}
  }

  @Nullable // Noncompliant [[sc=3;ec=12]] {{"Optional" variables should not be "@Nullable".}}
  private Optional<String> field;

  public void doSomething6(@Nullable Optional<String> arg) { // Noncompliant [[sc=28;ec=37]] {{"Optional" variables should not be "@Nullable".}}
  }

  public void doSomething7() {
    @Nullable // Noncompliant [[sc=5;ec=14]] {{"Optional" variables should not be "@Nullable".}}
    Optional<String> var;
  }
  
  public Optional<String> doSomething8(boolean b) {
    Object obj = b ? null : new Object();
    return Optional.of("hello");
  }

  interface Worker {
    String work();
  }

}