/*
 * Copyright 2017 Google Inc.
 *
 * 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.google.cloud.tools.eclipse.appengine.compat.gpe;

import com.google.cloud.tools.eclipse.appengine.facets.AppEngineStandardFacet;
import com.google.cloud.tools.eclipse.ui.util.ProjectFromSelectionHelper;
import com.google.cloud.tools.eclipse.util.status.StatusUtil;
import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.wst.common.project.facet.core.IFacetedProject;
import org.eclipse.wst.common.project.facet.core.ProjectFacetsManager;

public class GpeConvertCommandHandler extends AbstractHandler {

  @Override
  public Object execute(ExecutionEvent event) throws ExecutionException {
    try {
      IProject project = ProjectFromSelectionHelper.getFirstProject(event);
      if (project == null) {
        throw new NullPointerException(
            "Convert menu should not be enabled for non-project resources");
      }

      IFacetedProject facetedProject = ProjectFacetsManager.create(project,
          true /* convert to faceted project if necessary */, null /* no monitor here */);
      if (AppEngineStandardFacet.hasFacet(facetedProject)) {
        throw new IllegalStateException(
            "Convert menu should not be enabled for App Engine standard projects");
      }

      GpeConvertJob job = new GpeConvertJob(facetedProject);
      job.setUser(true);
      job.schedule();
    } catch (CoreException ex) {
      StatusUtil.setErrorStatus(this, "Failed to convert to a faceted project", ex);
    }
    return null; // Must return null per method Javadoc.
  }

}
