package jetbrains.buildServer.buildTriggers.vcs.mercurial.command;

import jetbrains.buildServer.buildTriggers.vcs.mercurial.HgRepo;
import jetbrains.buildServer.vcs.VcsException;
import org.jetbrains.annotations.NotNull;

import java.util.List;

/**
 * Implementation of merge-base using hg revsets
 * @author dmitry.neverov
 */
public final class MergeBaseWithRevsets extends MergeBaseCommand {

  public MergeBaseWithRevsets(@NotNull HgRepo repo) {
    super(repo);
  }

  public String call() throws VcsException {
    try {
      List<ChangeSet> csets = myRepo.log()
              .withRevsets("ancestor(" + new ChangeSetRevision(myRevision1).getId() + ", " + new ChangeSetRevision(myRevision2).getId() + ")")
              .showCommitsFromAllBranches()
              .dontCalculateParents()
              .call();
      return csets.isEmpty() ? null : csets.get(0).getId();
    } catch (VcsException e) {
      return null;
    }
  }
}