/**
 * Copyright 2013-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.
 *
 */

'use strict';

var _assign = require('object-assign');

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

function _possibleConstructorReturn(self, call) { if (!self) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return call && (typeof call === "object" || typeof call === "function") ? call : self; }

function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function, not " + typeof superClass); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) Object.setPrototypeOf ? Object.setPrototypeOf(subClass, superClass) : subClass.__proto__ = superClass; }

var React = require('./React');
var ReactTransitionChildMapping = require('./ReactTransitionChildMapping');

var emptyFunction = require('fbjs/lib/emptyFunction');

/**
 * A basis for animations. When children are declaratively added or removed,
 * special lifecycle hooks are called.
 * See https://facebook.github.io/react/docs/animation.html#low-level-api-reacttransitiongroup
 */

var ReactTransitionGroup = function (_React$Component) {
  _inherits(ReactTransitionGroup, _React$Component);

  function ReactTransitionGroup() {
    var _temp, _this, _ret;

    _classCallCheck(this, ReactTransitionGroup);

    for (var _len = arguments.length, args = Array(_len), _key = 0; _key < _len; _key++) {
      args[_key] = arguments[_key];
    }

    return _ret = (_temp = (_this = _possibleConstructorReturn(this, _React$Component.call.apply(_React$Component, [this].concat(args))), _this), _this.state = {
      // TODO: can we get useful debug information to show at this point?
      children: ReactTransitionChildMapping.getChildMapping(_this.props.children)
    }, _this.performAppear = function (key) {
      _this.currentlyTransitioningKeys[key] = true;

      var component = _this.refs[key];

      if (component.componentWillAppear) {
        component.componentWillAppear(_this._handleDoneAppearing.bind(_this, key));
      } else {
        _this._handleDoneAppearing(key);
      }
    }, _this._handleDoneAppearing = function (key) {
      var component = _this.refs[key];
      if (component.componentDidAppear) {
        component.componentDidAppear();
      }

      delete _this.currentlyTransitioningKeys[key];

      var currentChildMapping = ReactTransitionChildMapping.getChildMapping(_this.props.children);

      if (!currentChildMapping || !currentChildMapping.hasOwnProperty(key)) {
        // This was removed before it had fully appeared. Remove it.
        _this.performLeave(key);
      }
    }, _this.performEnter = function (key) {
      _this.currentlyTransitioningKeys[key] = true;

      var component = _this.refs[key];

      if (component.componentWillEnter) {
        component.componentWillEnter(_this._handleDoneEntering.bind(_this, key));
      } else {
        _this._handleDoneEntering(key);
      }
    }, _this._handleDoneEntering = function (key) {
      var component = _this.refs[key];
      if (component.componentDidEnter) {
        component.componentDidEnter();
      }

      delete _this.currentlyTransitioningKeys[key];

      var currentChildMapping = ReactTransitionChildMapping.getChildMapping(_this.props.children);

      if (!currentChildMapping || !currentChildMapping.hasOwnProperty(key)) {
        // This was removed before it had fully entered. Remove it.
        _this.performLeave(key);
      }
    }, _this.performLeave = function (key) {
      _this.currentlyTransitioningKeys[key] = true;

      var component = _this.refs[key];
      if (component.componentWillLeave) {
        component.componentWillLeave(_this._handleDoneLeaving.bind(_this, key));
      } else {
        // Note that this is somewhat dangerous b/c it calls setState()
        // again, effectively mutating the component before all the work
        // is done.
        _this._handleDoneLeaving(key);
      }
    }, _this._handleDoneLeaving = function (key) {
      var component = _this.refs[key];

      if (component.componentDidLeave) {
        component.componentDidLeave();
      }

      delete _this.currentlyTransitioningKeys[key];

      var currentChildMapping = ReactTransitionChildMapping.getChildMapping(_this.props.children);

      if (currentChildMapping && currentChildMapping.hasOwnProperty(key)) {
        // This entered again before it fully left. Add it again.
        _this.performEnter(key);
      } else {
        _this.setState(function (state) {
          var newChildren = _assign({}, state.children);
          delete newChildren[key];
          return { children: newChildren };
        });
      }
    }, _temp), _possibleConstructorReturn(_this, _ret);
  }

  ReactTransitionGroup.prototype.componentWillMount = function componentWillMount() {
    this.currentlyTransitioningKeys = {};
    this.keysToEnter = [];
    this.keysToLeave = [];
  };

  ReactTransitionGroup.prototype.componentDidMount = function componentDidMount() {
    var initialChildMapping = this.state.children;
    for (var key in initialChildMapping) {
      if (initialChildMapping[key]) {
        this.performAppear(key);
      }
    }
  };

  ReactTransitionGroup.prototype.componentWillReceiveProps = function componentWillReceiveProps(nextProps) {
    var nextChildMapping = ReactTransitionChildMapping.getChildMapping(nextProps.children);
    var prevChildMapping = this.state.children;

    this.setState({
      children: ReactTransitionChildMapping.mergeChildMappings(prevChildMapping, nextChildMapping)
    });

    var key;

    for (key in nextChildMapping) {
      var hasPrev = prevChildMapping && prevChildMapping.hasOwnProperty(key);
      if (nextChildMapping[key] && !hasPrev && !this.currentlyTransitioningKeys[key]) {
        this.keysToEnter.push(key);
      }
    }

    for (key in prevChildMapping) {
      var hasNext = nextChildMapping && nextChildMapping.hasOwnProperty(key);
      if (prevChildMapping[key] && !hasNext && !this.currentlyTransitioningKeys[key]) {
        this.keysToLeave.push(key);
      }
    }

    // If we want to someday check for reordering, we could do it here.
  };

  ReactTransitionGroup.prototype.componentDidUpdate = function componentDidUpdate() {
    var keysToEnter = this.keysToEnter;
    this.keysToEnter = [];
    keysToEnter.forEach(this.performEnter);

    var keysToLeave = this.keysToLeave;
    this.keysToLeave = [];
    keysToLeave.forEach(this.performLeave);
  };

  ReactTransitionGroup.prototype.render = function render() {
    // TODO: we could get rid of the need for the wrapper node
    // by cloning a single child
    var childrenToRender = [];
    for (var key in this.state.children) {
      var child = this.state.children[key];
      if (child) {
        // You may need to apply reactive updates to a child as it is leaving.
        // The normal React way to do it won't work since the child will have
        // already been removed. In case you need this behavior you can provide
        // a childFactory function to wrap every child, even the ones that are
        // leaving.
        childrenToRender.push(React.cloneElement(this.props.childFactory(child), { ref: key, key: key }));
      }
    }

    // Do not forward ReactTransitionGroup props to primitive DOM nodes
    var props = _assign({}, this.props);
    delete props.transitionLeave;
    delete props.transitionName;
    delete props.transitionAppear;
    delete props.transitionEnter;
    delete props.childFactory;
    delete props.transitionLeaveTimeout;
    delete props.transitionEnterTimeout;
    delete props.transitionAppearTimeout;
    delete props.component;

    return React.createElement(this.props.component, props, childrenToRender);
  };

  return ReactTransitionGroup;
}(React.Component);

ReactTransitionGroup.displayName = 'ReactTransitionGroup';
ReactTransitionGroup.propTypes = {
  component: React.PropTypes.any,
  childFactory: React.PropTypes.func
};
ReactTransitionGroup.defaultProps = {
  component: 'span',
  childFactory: emptyFunction.thatReturnsArgument
};


module.exports = ReactTransitionGroup;