package org.checkerframework.common.reflection;

import com.sun.source.tree.Tree;
import java.util.List;
import javax.lang.model.element.AnnotationMirror;
import org.checkerframework.common.basetype.BaseTypeChecker;
import org.checkerframework.common.basetype.BaseTypeValidator;
import org.checkerframework.common.basetype.BaseTypeVisitor;
import org.checkerframework.common.reflection.qual.ClassBound;
import org.checkerframework.common.reflection.qual.ClassVal;
import org.checkerframework.framework.type.AnnotatedTypeFactory;
import org.checkerframework.framework.type.AnnotatedTypeMirror.AnnotatedDeclaredType;
import org.plumelib.reflection.Signatures;

/** A visitor to verify validity of {@code @}{@link ClassVal} annotations. */
public class ClassValVisitor extends BaseTypeVisitor<ClassValAnnotatedTypeFactory> {
  /**
   * Create a new ClassValVisitor.
   *
   * @param checker the associated type-checker
   */
  public ClassValVisitor(BaseTypeChecker checker) {
    super(checker);
  }

  @Override
  protected ClassValAnnotatedTypeFactory createTypeFactory() {
    return new ClassValAnnotatedTypeFactory(checker);
  }

  @Override
  protected BaseTypeValidator createTypeValidator() {
    return new ClassNameValidator(checker, this, atypeFactory);
  }
}

class ClassNameValidator extends BaseTypeValidator {

  public ClassNameValidator(
      BaseTypeChecker checker, BaseTypeVisitor<?> visitor, AnnotatedTypeFactory atypeFactory) {
    super(checker, visitor, atypeFactory);
  }

  /**
   * This implementation reports an "illegal.classname" error if the type contains a @ClassVal
   * annotation with a string that is not a valid class name.
   */
  @Override
  public Void visitDeclared(AnnotatedDeclaredType type, Tree tree) {
    AnnotationMirror classVal = type.getAnnotation(ClassVal.class);
    classVal = classVal == null ? type.getAnnotation(ClassBound.class) : classVal;
    if (classVal != null) {
      List<String> classNames =
          ((ClassValAnnotatedTypeFactory) atypeFactory).getClassNamesFromAnnotation(classVal);
      for (String className : classNames) {
        if (!Signatures.isFqBinaryName(className)) {
          checker.reportError(tree, "illegal.classname", className, type);
        }
      }
    }
    return super.visitDeclared(type, tree);
  }
}