/**
 * Copyright (c) 2013-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

'use strict';

var {HostComponent, HostText} = require('shared/ReactTypeOfWork');
var invariant = require('fbjs/lib/invariant');

var randomKey = Math.random().toString(36).slice(2);
var internalInstanceKey = '__reactInternalInstance$' + randomKey;
var internalEventHandlersKey = '__reactEventHandlers$' + randomKey;

function precacheFiberNode(hostInst, node) {
  node[internalInstanceKey] = hostInst;
}

/**
 * Given a DOM node, return the closest ReactDOMComponent or
 * ReactDOMTextComponent instance ancestor.
 */
function getClosestInstanceFromNode(node) {
  if (node[internalInstanceKey]) {
    return node[internalInstanceKey];
  }

  // Walk up the tree until we find an ancestor whose instance we have cached.
  var parents = [];
  while (!node[internalInstanceKey]) {
    parents.push(node);
    if (node.parentNode) {
      node = node.parentNode;
    } else {
      // Top of the tree. This node must not be part of a React tree (or is
      // unmounted, potentially).
      return null;
    }
  }

  var closest;
  var inst = node[internalInstanceKey];
  if (inst.tag === HostComponent || inst.tag === HostText) {
    // In Fiber, this will always be the deepest root.
    return inst;
  }
  for (; node && (inst = node[internalInstanceKey]); node = parents.pop()) {
    closest = inst;
  }

  return closest;
}

/**
 * Given a DOM node, return the ReactDOMComponent or ReactDOMTextComponent
 * instance, or null if the node was not rendered by this React.
 */
function getInstanceFromNode(node) {
  var inst = node[internalInstanceKey];
  if (inst) {
    if (inst.tag === HostComponent || inst.tag === HostText) {
      return inst;
    } else {
      return null;
    }
  }
  return null;
}

/**
 * Given a ReactDOMComponent or ReactDOMTextComponent, return the corresponding
 * DOM node.
 */
function getNodeFromInstance(inst) {
  if (inst.tag === HostComponent || inst.tag === HostText) {
    // In Fiber this, is just the state node right now. We assume it will be
    // a host component or host text.
    return inst.stateNode;
  }

  // Without this first invariant, passing a non-DOM-component triggers the next
  // invariant for a missing parent, which is super confusing.
  invariant(false, 'getNodeFromInstance: Invalid argument.');
}

function getFiberCurrentPropsFromNode(node) {
  return node[internalEventHandlersKey] || null;
}

function updateFiberProps(node, props) {
  node[internalEventHandlersKey] = props;
}

var ReactDOMComponentTree = {
  getClosestInstanceFromNode: getClosestInstanceFromNode,
  getInstanceFromNode: getInstanceFromNode,
  getNodeFromInstance: getNodeFromInstance,
  precacheFiberNode: precacheFiberNode,
  getFiberCurrentPropsFromNode,
  updateFiberProps,
};

module.exports = ReactDOMComponentTree;
