/**
 * Copyright (c) 2015-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 *
 * @providesModule ReactTestMount
 * @flow
 */
'use strict';

var React = require('React');
var ReactReconciler = require('ReactReconciler');
var ReactUpdates = require('ReactUpdates');

var emptyObject = require('emptyObject');
var getHostComponentFromComposite = require('getHostComponentFromComposite');
var instantiateReactComponent = require('instantiateReactComponent');
var invariant = require('invariant');

export type TestRendererOptions = {
  createNodeMock: (element: ReactElement<any>) => any,
};

var defaultTestOptions = {
  createNodeMock: function() {
    return null;
  },
};

/**
 * Temporary (?) hack so that we can store all top-level pending updates on
 * composites instead of having to worry about different types of components
 * here.
 */
var TopLevelWrapper = function() {};
TopLevelWrapper.prototype.isReactComponent = {};
if (__DEV__) {
  TopLevelWrapper.displayName = 'TopLevelWrapper';
}
TopLevelWrapper.prototype.render = function() {
  return this.props.child;
};
TopLevelWrapper.isReactTopLevelWrapper = true;

/**
 * Mounts this component and inserts it into the DOM.
 *
 * @param {ReactComponent} componentInstance The instance to mount.
 * @param {ReactReconcileTransaction} transaction
 * @param {Object} hostParent
 * @param {Object} hostContainerInfo
 */
function mountComponentIntoNode(
    componentInstance,
    transaction,
    hostParent,
    hostContainerInfo
  ) {
  var image = ReactReconciler.mountComponent(
    componentInstance,
    transaction,
    null,
    hostContainerInfo,
    emptyObject
  );
  componentInstance._renderedComponent._topLevelWrapper = componentInstance;
  return image;
}

/**
 * Batched mount.
 *
 * @param {ReactComponent} componentInstance The instance to mount.
 * @param {number} rootID ID of the root node.
 * @param {number} containerTag container element to mount into.
 */
function batchedMountComponentIntoNode(
    componentInstance,
    options,
  ) {
  var transaction = ReactUpdates.ReactReconcileTransaction.getPooled(true);
  var image = transaction.perform(
    mountComponentIntoNode,
    null,
    componentInstance,
    transaction,
    null,
    options
  );
  ReactUpdates.ReactReconcileTransaction.release(transaction);
  return image;
}

var ReactTestInstance = function(component) {
  this._component = component;
};
ReactTestInstance.prototype.getInstance = function() {
  return this._component._renderedComponent.getPublicInstance();
};
ReactTestInstance.prototype.update = function(nextElement) {
  invariant(
    this._component,
    "ReactTestRenderer: .update() can't be called after unmount."
  );
  var nextWrappedElement = React.createElement(
    TopLevelWrapper,
    { child: nextElement }
  );
  var component = this._component;
  ReactUpdates.batchedUpdates(function() {
    var transaction = ReactUpdates.ReactReconcileTransaction.getPooled(true);
    transaction.perform(function() {
      ReactReconciler.receiveComponent(
        component,
        nextWrappedElement,
        transaction,
        emptyObject
      );
    });
    ReactUpdates.ReactReconcileTransaction.release(transaction);
  });
};
ReactTestInstance.prototype.unmount = function(nextElement) {
  var component = this._component;
  ReactUpdates.batchedUpdates(function() {
    var transaction = ReactUpdates.ReactReconcileTransaction.getPooled(true);
    transaction.perform(function() {
      ReactReconciler.unmountComponent(
        component,
        false, /* safely */
        false /* skipLifecycle */
      );
    });
    ReactUpdates.ReactReconcileTransaction.release(transaction);
  });
  this._component = null;
};
ReactTestInstance.prototype.toJSON = function() {
  var inst = getHostComponentFromComposite(this._component);
  if (inst === null) {
    return null;
  }
  return inst.toJSON();
};

/**
 * As soon as `ReactMount` is refactored to not rely on the DOM, we can share
 * code between the two. For now, we'll hard code the ID logic.
 */
var ReactTestMount = {

  render: function(
    nextElement: ReactElement<any>,
    options?: TestRendererOptions,
  ): ReactTestInstance {
    var nextWrappedElement = React.createElement(
      TopLevelWrapper,
      {child: nextElement},
    );

    var instance = instantiateReactComponent(nextWrappedElement, false);

    // The initial render is synchronous but any updates that happen during
    // rendering, in componentWillMount or componentDidMount, will be batched
    // according to the current batching strategy.
    ReactUpdates.batchedUpdates(
      batchedMountComponentIntoNode,
      instance,
      Object.assign({}, defaultTestOptions, options),
    );
    return new ReactTestInstance(instance);
  },

};

module.exports = ReactTestMount;