python/src/com/jetbrains/python/refactoring/classes/membersManager/SuperClassesManager.java

package com.jetbrains.python.refactoring.classes.membersManager;

import com.google.common.collect.Collections2;
import com.google.common.collect.Lists;
import com.intellij.refactoring.RefactoringBundle;
import com.intellij.util.containers.MultiMap;
import com.jetbrains.NotNullPredicate;
import com.jetbrains.python.PyNames;
import com.jetbrains.python.psi.*;
import com.jetbrains.python.refactoring.classes.PyClassRefactoringUtil;
import com.jetbrains.python.refactoring.classes.ui.PyClassCellRenderer;
import org.jetbrains.annotations.NotNull;

import java.util.*;

/**
 * Plugin that moves superclasses from one class to another
 *
 * @author Ilya.Kazakevich
 */
class SuperClassesManager extends MembersManager<PyClass> {

  private static final NoFakeSuperClasses NO_FAKE_SUPER_CLASSES = new NoFakeSuperClasses();

  SuperClassesManager() {
    super(PyClass.class);
  }


  @NotNull
  @Override
  protected Collection<PyElement> getDependencies(@NotNull final MultiMap<PyClass, PyElement> usedElements) {
    return Lists.<PyElement>newArrayList(usedElements.keySet());
  }

  @NotNull
  protected MultiMap<PyClass, PyElement> getDependencies(@NotNull PyElement member) {
    return MultiMap.emptyInstance();
  }

  @Override
  public boolean hasConflict(@NotNull final PyClass member, @NotNull final PyClass aClass) {
    final List<PyExpression> expressionList = getExpressionsBySuperClass(aClass, Collections.singleton(member));
    return !expressionList.isEmpty();
  }

  @NotNull
  @Override
  protected List<PyElement> getMembersCouldBeMoved(@NotNull final PyClass pyClass) {
    return Lists.<PyElement>newArrayList(Collections2.filter(Arrays.asList(pyClass.getSuperClasses()), NO_FAKE_SUPER_CLASSES));
  }

  @Override
  protected Collection<PyElement> moveMembers(@NotNull final PyClass from,
                                              @NotNull final Collection<PyMemberInfo<PyClass>> members,
                                              @NotNull final PyClass... to) {
    final Collection<PyClass> elements = fetchElements(members);
    for (final PyClass destClass : to) {
      PyClassRefactoringUtil.addSuperclasses(from.getProject(), destClass, elements.toArray(new PyClass[members.size()]));
    }

    final List<PyExpression> expressionsToDelete = getExpressionsBySuperClass(from, elements);
    for (final PyExpression expressionToDelete : expressionsToDelete) {
      expressionToDelete.delete();
    }

    return Collections.emptyList(); //Hack: we know that "superclass expression" can't have reference
  }

  /**
   * Returns superclass expressions that are resolved to one or more classes from collection
   * @param from class to get superclass expressions from
   * @param classes classes to check superclasses against
   * @return collection of expressions that are resolved to one or more class from classes param
   */
  @NotNull
  private static List<PyExpression> getExpressionsBySuperClass(@NotNull final PyClass from, @NotNull final Collection<PyClass> classes) {
    final List<PyExpression> expressionsToDelete = new ArrayList<PyExpression>(classes.size());

    for (final PyExpression expression : from.getSuperClassExpressions()) {
      // Remove all superclass expressions that point to class from memberinfo
      if (!(expression instanceof PyQualifiedExpression)) {
        continue;
      }
      final PyReferenceExpression reference = (PyReferenceExpression)expression;
      for (final PyClass element : classes) {
        if (reference.getReference().isReferenceTo(element)) {
          expressionsToDelete.add(expression);
        }
      }
    }
    return expressionsToDelete;
  }

  @NotNull
  @Override
  public PyMemberInfo<PyClass> apply(@NotNull final PyClass input) {
    final String name = RefactoringBundle.message("member.info.extends.0", PyClassCellRenderer.getClassText(input));
    //TODO: Check for "overrides"
    return new PyMemberInfo<PyClass>(input, false, name, false, this, false);
  }

  private static class NoFakeSuperClasses extends NotNullPredicate<PyClass> {
    @Override
    protected boolean applyNotNull(@NotNull final PyClass input) {
      return !PyNames.FAKE_OLD_BASE.equals(input.getName());
    }
  }
}