var _ = require('lodash');
var actions = require('../actions');
var tree = require('../../util/tree');

module.exports = function(oldProfile, action) {

  switch(action.type) {

    case actions.common.LOAD_PROFILE_SUCCESS:
      var newProfile = _.cloneDeep(action.profile);
      tree.walk(newProfile, ensureItemKey);
      return newProfile;

    case actions.edit.MOVE_PROFILE_ITEM:
      return moveProfileItem(oldProfile, action.movedItem, action.targetItem);

    case actions.edit.REMOVE_PROFILE_ITEM:
      return removeProfileItem(oldProfile, action.removedItem);

    case actions.edit.ADD_PROFILE_ITEM:
      return addProfileItem(oldProfile, action.newItem, action.targetItem);

    case actions.edit.UPDATE_PROFILE_ITEM:
      return updateProfileItem(oldProfile, action.item, action.key, action.value);

    case actions.edit.SELECT_PROFILE_ITEM:
      return selectProfileItem(oldProfile, action.item);

    default:
      return oldProfile || null;

  }

};

function selectProfileItem(oldProfile, item) {
  var newProfile = _.cloneDeep(oldProfile);
  tree.walk(newProfile, function(currentItem) {
    delete currentItem.selected;
    if( _.isEqual(currentItem, item) ) {
      currentItem.selected = true;
    }
  });
  return newProfile;
}

function updateProfileItem(oldProfile, targetItem, key, value) {
  var newProfile = _.cloneDeep(oldProfile);
  var item = tree.find(newProfile, targetItem).item;
  item[key] = value;
  return newProfile;
}

function removeProfileItem(oldProfile, removedItem) {

  var newProfile = _.cloneDeep(oldProfile);
  var parent = tree.find(newProfile, removedItem).parent;

  parent.items = _.reject(parent.items, function(item) {
    return _.isEqual(item, removedItem);
  });

  return newProfile;

}

function moveProfileItem(oldProfile, movedItem, targetItem) {

  var newProfile = _.cloneDeep(oldProfile);
  var previousParent = tree.find(newProfile, movedItem).parent;
  var newParent = tree.find(newProfile, targetItem).item;

  previousParent.items = _.reject(previousParent.items, function(item) {
    return _.isEqual(item, movedItem);
  });

  newParent.items = newParent.items || [];
  newParent.items.push(_.cloneDeep(movedItem));

  return newProfile;

}

function addProfileItem(oldProfile, newItem, targetItem) {

  var newProfile = _.cloneDeep(oldProfile);
  var newParent = tree.find(newProfile, targetItem).item;

  newParent.items = newParent.items || [];

  newItem = _.cloneDeep(newItem);
  ensureItemKey(newItem);

  newParent.items.push(newItem);

  return newProfile;
}

var _inc = 0;
function ensureItemKey(item) {
  if( item && !('_key' in item) ) {
    item._key = 'item_'+Date.now()+'_'+_inc++;
  }
}