/*
 * Copyright 2003-2014 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 jetbrains.mps.workbench;

import com.intellij.openapi.vfs.VirtualFile;
import jetbrains.mps.extapi.persistence.FileSystemBasedDataSource;
import jetbrains.mps.ide.vfs.VirtualFileUtils;
import org.apache.log4j.LogManager;
import org.apache.log4j.Logger;
import org.jetbrains.annotations.Nullable;
import org.jetbrains.mps.openapi.model.SModel;
import jetbrains.mps.vfs.IFile;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.mps.openapi.persistence.DataSource;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

public final class FileSystemModelHelper {
  private static final Logger LOG = LogManager.getLogger(FileSystemModelHelper.class);
  private final SModel myModel;

  public FileSystemModelHelper(@NotNull SModel model) {
    myModel = model;
  }

  @NotNull
  public Collection<IFile> getFiles() {
    List<IFile> result = new ArrayList<IFile>();
    DataSource source = myModel.getSource();
    if ((source instanceof FileSystemBasedDataSource)) {
      FileSystemBasedDataSource fsDataSource = (FileSystemBasedDataSource) source;
      result.addAll(fsDataSource.getAffectedFiles());
    }
    return result;
  }

  @NotNull
  public Collection<VirtualFile> getVirtualFiles() {
    List<VirtualFile> vFiles = new ArrayList<VirtualFile>();

    Collection<IFile> modelPaths = getFiles();
    for (IFile path : modelPaths) {
      VirtualFile virtualFile = VirtualFileUtils.getOrCreateVirtualFile(path);
      if (virtualFile != null) {
        vFiles.add(virtualFile);
      }
    }

    return vFiles;
  }

  @Nullable
  public VirtualFile getVirtualFile() {
    Collection<VirtualFile> files = getVirtualFiles();
    if (files.isEmpty()) {
      return null;
    } else if (files.size() > 1) {
      LOG.warn("Models with multiple files in the data source are not supported; DataSource :" + myModel.getSource());
      return null;
    }

    return files.iterator().next();
  }
}
