/*
 * Copyright 2000-2014 JetBrains s.r.o.
 *
 * 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.jetbrains.python.psi.types;

import com.intellij.psi.PsiElement;
import com.intellij.util.ArrayUtil;
import com.intellij.util.ProcessingContext;
import com.jetbrains.python.psi.AccessDirection;
import com.jetbrains.python.psi.PyExpression;
import com.jetbrains.python.psi.resolve.PyResolveContext;
import com.jetbrains.python.psi.resolve.RatedResolveResult;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import java.util.List;

/**
 * @author yole
 */
public class PyNoneType implements PyType { // TODO must extend ClassType. It's an honest instance.
  public static final PyNoneType INSTANCE = new PyNoneType();

  protected PyNoneType() {
  }

  @Nullable
  public List<? extends RatedResolveResult> resolveMember(@NotNull final String name,
                                                          @Nullable PyExpression location,
                                                          @NotNull AccessDirection direction,
                                                          @NotNull PyResolveContext resolveContext) {
    return null;
  }

  public Object[] getCompletionVariants(String completionPrefix, PsiElement location, ProcessingContext context) {
    return ArrayUtil.EMPTY_OBJECT_ARRAY;
  }

  public String getName() {
    return "None";
  }

  @Override
  public boolean isBuiltin() {
    return true;
  }

  @Override
  public void assertValid(String message) {
  }
}