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

module.exports = function(oldProfile, action) {

  var newProfile = oldProfile || { items: [] };

  switch(action.type) {

    case actions.common.LOAD_PROFILE_SUCCESS:
      newProfile = _.cloneDeep(action.profile);
      break;

    case actions.edit.MOVE_PROFILE_ITEM:
      newProfile = moveProfileItem(oldProfile, action.movedItem, action.targetItem);
      break;

    case actions.edit.REMOVE_PROFILE_ITEM:
      newProfile = removeProfileItem(oldProfile, action.removedItem);
      break;

    case actions.edit.ADD_PROFILE_ITEM:
      newProfile = addProfileItem(oldProfile, action.newItem, action.targetItem);
      break;

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

  }

  return newProfile;

};

function updateProfileItem(profile, targetItem, key, value) {
  var tree = new Tree(profile);
  var result = tree.find(targetItem);
  var itemPath = result.path;
  tree.update(itemPath.concat(key), {$set: value});
  return tree.getState();
}

function removeProfileItem(profile, removedItem) {
  var tree = new Tree(profile);
  var result = tree.find(removedItem);
  tree.del(result.path);
  return tree.getState();
}

function moveProfileItem(profile, movedItem, targetItem) {

  var tree = new Tree(profile);

  var movedResult = tree.find(movedItem);
  var targetResult = tree.find(targetItem);

  // Remove item from current location
  tree.del(movedResult.path);

  var targetPath = targetResult ? targetResult.path : [];
  var targetItemsPath = targetPath.concat('items');

  // Create "items" collection if not defined on target item
  if( !('items' in targetItem) ) {
    tree.update(targetItemsPath, {
      "$set": []
    });
  }

  // Add moved item to target
  tree.update(targetItemsPath, {
    "$push": [movedItem]
  });

  return tree.getState();

}

function addProfileItem(profile, newItem, targetItem) {

  var tree = new Tree(profile);

  var targetResult = tree.find(targetItem);
  var targetPath = targetResult ? targetResult.path : [];
  var targetItemsPath = targetPath.concat('items');

  // Create "items" collection if not defined on target item
  if( !('items' in targetItem) ) {
    tree.update(targetItemsPath, {
      "$set": []
    });
  }

  // Add moved item to target
  tree.update(targetItemsPath, {
    "$push": [newItem]
  });

  return tree.getState();

}