var _ = require('lodash');

// Tree manipulation helpers

exports.walk = function(branch, func, parent) {

  if(!branch) return;

  var breakHere = func(branch, parent);

  if(breakHere) return breakHere;

  var items = branch.items;

  if(!items) return;

  for( var i = 0, item = items[i]; (item = items[i]); i++ ) {
    breakHere = exports.walk(item, func, branch);
    if(breakHere) return breakHere;
  }

};

exports.find = function(tree, obj) {

  var result;

  exports.walk(tree, function(item, parent) {
    if( _.isEqual(item, obj) ) {
      result = {item: item, parent: parent};
      return true;
    }
  });

  return result;

};

exports.matches = function(tree, obj) {

  var results = [];

  var matches = _.matches(obj);

  exports.walk(tree, function(item) {
    if( matches(item) ) {
      results.push(item);
    }
  });

  return results;

};