/*
 * SonarQube
 * Copyright (C) 2009-2017 SonarSource SA
 * mailto:info AT sonarsource DOT com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
package org.sonar.scanner.scan;

import java.nio.file.Path;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

import javax.annotation.CheckForNull;

import org.sonar.api.batch.bootstrap.ProjectDefinition;
import org.sonar.api.batch.fs.InputModule;
import org.sonar.api.batch.fs.internal.DefaultInputModule;
import org.sonar.api.batch.fs.internal.InputModuleHierarchy;
import org.sonar.api.scan.filesystem.PathResolver;

import com.google.common.base.Preconditions;
import com.google.common.collect.HashMultimap;
import com.google.common.collect.Multimap;

public class DefaultInputModuleHierarchy implements InputModuleHierarchy {
  private final PathResolver pathResolver = new PathResolver();
  private DefaultInputModule root;
  private final Map<DefaultInputModule, DefaultInputModule> parents = new HashMap<>();
  private final Multimap<DefaultInputModule, DefaultInputModule> children = HashMultimap.create();

  public void setRoot(DefaultInputModule root) {
    this.root = root;
  }

  public void index(DefaultInputModule child, DefaultInputModule parent) {
    Preconditions.checkNotNull(child);
    Preconditions.checkNotNull(parent);
    parents.put(child, parent);
    children.put(parent, child);
  }

  @Override
  public DefaultInputModule root() {
    return root;
  }

  @Override
  public Collection<DefaultInputModule> children(InputModule component) {
    return children.get((DefaultInputModule) component);
  }

  @Override
  public DefaultInputModule parent(InputModule component) {
    return parents.get(component);
  }

  @Override
  public boolean isRoot(InputModule module) {
    return root.equals(module);
  }

  @Override
  @CheckForNull
  public String relativePath(InputModule module) {
    DefaultInputModule parent = parent(module);
    if (parent == null) {
      return null;
    }
    DefaultInputModule inputModule = (DefaultInputModule) module;

    ProjectDefinition parentDefinition = parent.definition();
    Path parentBaseDir = parentDefinition.getBaseDir().toPath();
    ProjectDefinition moduleDefinition = inputModule.definition();
    Path moduleBaseDir = moduleDefinition.getBaseDir().toPath();

    return pathResolver.relativePath(parentBaseDir, moduleBaseDir);
  }
}