package jp.ac.u_ryukyu.ie.cr.tatsuki.jungle.store.index;

import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.store.impl.TreeNode;
import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.store.impl.TreeNodeAttributes;
import fj.Ord;
import fj.data.List;
import fj.data.Option;
import fj.data.TreeMap;

public class DefaultIndexEditor implements IndexEditor {

  TreeMap<String, TreeMap<String, List<TreeNode>>> indexTreeMap;

  public DefaultIndexEditor(TreeMap<String, TreeMap<String, List<TreeNode>>> indexTreeMap) {
    this.indexTreeMap = indexTreeMap;
  }

  @Override
  public IndexEditor delete(TreeNode node) {
    TreeNodeAttributes attribute = node.getAttributes();
    List<String> keys = attribute.getKeys();
    TreeMap<String, TreeMap<String, List<TreeNode>>> newIndexTreeMap = indexTreeMap;
    for (String key : keys) {
      Option<TreeMap<String, List<TreeNode>>> indexOp = indexTreeMap.get(key);
      if (indexOp.isSome()) {
        TreeMap<String, List<TreeNode>> index = indexOp.some();
        String value = attribute.getString(key);
        Option<List<TreeNode>> nodeListOp = index.get(value);
        if (nodeListOp.isSome()) {
          List<TreeNode> nodeList = nodeListOp.some();
          List<TreeNode> newNodeList = List.nil();
          for (TreeNode indexingNode : nodeList) {
            if (indexingNode != node)
              newNodeList = newNodeList.cons(indexingNode);
          }
          TreeMap<String, List<TreeNode>> newIndex;
          newIndex = index.set(value, newNodeList);
          newIndexTreeMap = newIndexTreeMap.set(key, newIndex);
        }

      }
    }

    return new DefaultIndexEditor(newIndexTreeMap);
  }

  @Override
  public IndexEditor add(TreeNode node) {
    TreeNodeAttributes attribute = node.getAttributes();
    List<String> keys = attribute.getKeys();
    TreeMap<String, TreeMap<String, List<TreeNode>>> newIndexTreeMap = indexTreeMap;
    for (String key : keys) {
      Option<TreeMap<String, List<TreeNode>>> indexOp = indexTreeMap.get(key);
      if (indexOp.isSome()) {
        TreeMap<String, List<TreeNode>> index = indexOp.some();
        String value = attribute.getString(key);
        Option<List<TreeNode>> nodeListOp = index.get(value);
        if (nodeListOp.isSome()) {
          List<TreeNode> nodeList = nodeListOp.some();
          List<TreeNode> newNodeList = nodeList.cons(node);
          TreeMap<String, List<TreeNode>> newIndex = index.set(value, newNodeList);
          newIndexTreeMap = newIndexTreeMap.set(key, newIndex);
        } else { // test
          List<TreeNode> nodeList = List.nil();
          value = attribute.getString(key);
          List<TreeNode> newNodeList = nodeList.cons(node);
          TreeMap<String, List<TreeNode>> newIndex = index.set(value, newNodeList);
          newIndexTreeMap = newIndexTreeMap.set(key, newIndex);
        }

      } else { // test
        TreeMap<String, List<TreeNode>> index = TreeMap.empty(Ord.stringOrd);
        List<TreeNode> nodeList = List.nil();
        String value = attribute.getString(key);
        List<TreeNode> newNodeList = nodeList.cons(node);
        TreeMap<String, List<TreeNode>> newIndex = index.set(value, newNodeList);
        newIndexTreeMap = newIndexTreeMap.set(key, newIndex);
      }
    }

    return new DefaultIndexEditor(newIndexTreeMap);
  }

  @Override
  public TreeMap<String, TreeMap<String, List<TreeNode>>> getIndex() {
    return indexTreeMap;
  }

  @Override
  public IndexEditor edit(TreeNode node) {
    return this;
  }

}