package jp.ac.u_ryukyu.ie.cr.shoshi.jungle;

import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.persistent.ChangeListWriter;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.store.ChangeSet;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.store.TreeEditor;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.store.impl.TreeNode;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.transaction.AtomicReservableReference;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.transaction.DefaultJungleTreeEditor;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.transaction.DefaultTransactionManager;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.transaction.DefaultTreeContext;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.transaction.TreeContext;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.traverser.InterfaceTraverser;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.util.DefaultEither;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.util.Either;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.util.Error;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.util.GetOldTreeError;
import jp.ac.u_ryukyu.ie.cr.tatsuki.jungle.store.index.Index;
import jp.ac.u_ryukyu.ie.cr.tatsuki.jungle.store.index.IndexManager;
import jp.ac.u_ryukyu.ie.cr.tatsuki.jungle.store.index.ParentIndex;

public class DefaultJungleTree implements JungleTree {
  
  private final AtomicReservableReference<TreeContext> repository;
  private final String uuid;
  private final ChangeListWriter writer;
  private final TreeEditor treeEditor;

  public DefaultJungleTree(TreeContext tc, String uuid, ChangeListWriter writer, TreeEditor editor) {
    this.repository = new AtomicReservableReference<TreeContext>(tc);
    this.uuid = uuid;
    this.writer = writer;
    this.treeEditor = editor;
  }

  @Override
  public JungleTreeEditor getTreeEditor() {
    TreeContext tc = repository.get();
    DefaultTransactionManager txManager = new DefaultTransactionManager(writer, tc, repository, uuid);
    TreeNode root = tc.getTreeNode();
    return new DefaultJungleTreeEditor(root, txManager, treeEditor);
  }


  @Override
  public JungleTreeEditor getLocalTreeEditor() {
    return getTreeEditor();
  }

  @Override
  public TreeNode getRootNode() {
    TreeContext tc = repository.get();
    ChangeSet cs = tc.getChangeSet();
    return cs.getRoot();
  }

  @Override
  public InterfaceTraverser getTraverser(boolean useIndex) {
    AtomicReservableReference<TreeContext>.Reservation reservation = repository.getReservation();
    IndexManager indexManager = new IndexManager(reservation);
    Index index = getIndex();
    ParentIndex parentIndex = getParentIndex();
    return new InterfaceTraverser(getRootNode(), index, parentIndex, indexManager,useIndex);
  }

  @Override
  public ParentIndex getParentIndex() {
    TreeContext tc = repository.get();
    ChangeSet cs = tc.getChangeSet();
    return cs.getParentIndex();
  }

  @Override
  public Index getIndex() {
    TreeContext tc = repository.get();
    ChangeSet cs = tc.getChangeSet();
    return cs.getIndex();
  }


  @Override
  public long revision() {
    TreeContext tc = repository.get();
    ChangeSet cs = tc.getChangeSet();
    return cs.revision();
  }

  @Override
  public Either<Error, JungleTree> getOldTree(long revision) {
    TreeContext tc = repository.get();
    ChangeSet cs = tc.getChangeSet();

    for (;cs.revision() != revision;) {
      cs = cs.prev();
      if (cs == null)
        return DefaultEither.newA(GetOldTreeError.OLD_TREE_NOT_FOUND);
    }

    TreeNode root = cs.getRoot();

    TreeContext oldTc = new DefaultTreeContext(root, cs);
    String oldTreeUuid = uuid + revision;
    JungleTree oldTree = new DefaultJungleTree(oldTc, oldTreeUuid, writer, treeEditor);
    return DefaultEither.newB(oldTree);
  }


}