/*
 * Ivory: A Hadoop toolkit for web-scale information retrieval
 *
 * 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 ivory.smrf.model.builder;

import ivory.core.ConfigurationException;
import ivory.core.RetrievalEnvironment;
import ivory.smrf.model.Clique;

import java.util.List;

import org.w3c.dom.Node;

import com.google.common.base.Preconditions;
import com.google.common.collect.Lists;

/**
 * A set of cliques.
 *
 * @author Don Metzler
 */
public abstract class CliqueSet {
  protected final List<Clique> cliques = Lists.newArrayList();

  /**
   * Configures this {@code CliqueSet}.
   *
   * @param env retrieval environment
   * @param queryTerms array of query terms
   * @param domNode XML DOM node with configuration information
   * @throws ConfigurationException
   */
  public abstract void configure(RetrievalEnvironment env, String[] queryTerms, Node domNode)
      throws ConfigurationException;

  /**
   * Returns the type of this clique.
   *
   * @return type of this clique
   */
  public abstract Clique.Type getType();

  /**
   * Adds a clique to this set.
   *
   * @param c clique to add
   */
  protected void addClique(Clique c) {
    cliques.add(c);
  }

  /**
   * Adds a list of cliques of this set.
   *
   * @param cliques cliques to add
   */
  protected void addCliques(List<Clique> cliques) {
    this.cliques.addAll(cliques);
  }

  /**
   * Returns the list of cliques in this set.
   *
   * @return list of cliques in this set
   */
  public List<Clique> getCliques() {
    return cliques;
  }

  /**
   * Clears all cliques in this set.
   */
  protected void clearCliques() {
    cliques.clear();
  }

  @SuppressWarnings("unchecked")
  public static CliqueSet create(String type, RetrievalEnvironment env, String[] queryTerms,
      Node domNode) throws ConfigurationException {
    Preconditions.checkNotNull(type);
    Preconditions.checkNotNull(env);
    Preconditions.checkNotNull(queryTerms);
    Preconditions.checkNotNull(domNode);

    try {
      Class<? extends CliqueSet> clz = (Class<? extends CliqueSet>) Class.forName(type);
      CliqueSet f = clz.newInstance();
      f.configure(env, queryTerms, domNode);

      return f;
    } catch (Exception e) {
      throw new ConfigurationException("Unable to instantiate CliqueSet type " + type, e);
    }
  }
}