/*
 * Copyright 2000-2012 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.intellij.openapi.vfs;

import com.intellij.openapi.extensions.ExtensionPointName;
import com.intellij.openapi.extensions.Extensions;
import com.intellij.openapi.project.Project;
import org.jetbrains.annotations.NotNull;

import java.util.Collection;

/**
 * @author Dmitry Avdeev
 */
public abstract class WritingAccessProvider {

  public static final ExtensionPointName<WritingAccessProvider> EP_NAME = ExtensionPointName.create("com.intellij.writingAccessProvider");

  /**
   * @param files files to be checked
   * @return set of files that cannot be accessed
   */
  @NotNull
  public abstract Collection<VirtualFile> requestWriting(VirtualFile... files);

  public abstract boolean isPotentiallyWritable(@NotNull VirtualFile file);

  public static WritingAccessProvider[] getProvidersForProject(Project project) {
    return project == null || project.isDefault() ? new WritingAccessProvider[0] : Extensions.getExtensions(EP_NAME, project);
  }

  public static boolean isPotentiallyWritable(VirtualFile file, Project project) {
    WritingAccessProvider[] providers = getProvidersForProject(project);
    for (WritingAccessProvider provider : providers) {
      if (!provider.isPotentiallyWritable(file)) {
        return false;
      }
    }
    return true;
  }
}