/*************************************************************************************
 * Copyright (c) 2014-2015 Red Hat, Inc. and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     JBoss by Red Hat - Initial implementation.
 ************************************************************************************/

package org.eclipse.m2e.core.ui.internal.project;

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

import org.eclipse.core.resources.IMarker;
import org.eclipse.core.resources.IMarkerDelta;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.IResourceDelta;
import org.eclipse.core.resources.IResourceDeltaVisitor;
import org.eclipse.core.runtime.CoreException;

import org.eclipse.m2e.core.internal.IMavenConstants;
import org.eclipse.m2e.core.internal.Messages;


/**
 * Detects Out-Of-Date project configuration {@link IMarker}s on projects
 *
 * @author Fred Bricon
 */
public class OutOfDateConfigurationDeltaVisitor implements IResourceDeltaVisitor {

  List<IProject> outOfDateProjects = new ArrayList<>();

  @Override
  public boolean visit(IResourceDelta delta) throws CoreException {
    switch(delta.getKind()) {
      case IResourceDelta.CHANGED:
        int flags = delta.getFlags();
        if((flags & IResourceDelta.MARKERS) != 0) {
          IResource res = delta.getResource();
          if(res == null) {
            return true;
          }
          IProject project = res.getProject();
          if(project == null || !isMavenProject(project) || outOfDateProjects.contains(project)) {
            return false;
          }

          IMarkerDelta[] markers = delta.getMarkerDeltas();
          boolean hasOutOfDateMarker = containsOutOfDateMarkers(markers);
          if(hasOutOfDateMarker) {
            outOfDateProjects.add(project);
          }
          return false;
        }
        return true;
      default:
        break;
    }
    return false; // visit the children
  }

  private boolean containsOutOfDateMarkers(IMarkerDelta[] markers) throws CoreException {
    if(markers != null && markers.length > 0) {
      for(IMarkerDelta markerDelta : markers) {
        IMarker marker = markerDelta.getMarker();
        if(marker.exists()) {
          String message = (String) marker.getAttribute(IMarker.MESSAGE);
          if(Messages.ProjectConfigurationUpdateRequired.equals(message)) {
            return true;
          }
        }
      }
    }
    return false;
  }

  private boolean isMavenProject(IProject project) throws CoreException {
    return project != null && project.isAccessible() && project.hasNature(IMavenConstants.NATURE_ID);
  }

}