/*
 * Copyright (c) 2014 The Polymer Project Authors. All rights reserved.
 * This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
 * The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
 * The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
 * Code distributed by Google as part of the polymer project is also
 * subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
 */

(function(scope) {

  /**
   * @class polymer-base
   */

  // imports

  var log = window.WebComponents ? WebComponents.flags.log : {};

  // element api supporting mdv
  var mdv = {

    /**
     * Creates dom cloned from the given template, instantiating bindings
     * with this element as the template model and `PolymerExpressions` as the
     * binding delegate.
     *
     * @method instanceTemplate
     * @param {Template} template source template from which to create dom.
     */
    instanceTemplate: function(template) {
      // ensure template is decorated (lets' things like <tr template ...> work)
      HTMLTemplateElement.decorate(template);
      // ensure a default bindingDelegate
      var syntax = this.syntax || (!template.bindingDelegate &&
          this.element.syntax);
      var dom = template.createInstance(this, syntax);
      var observers = dom.bindings_;
      for (var i = 0; i < observers.length; i++) {
        this.registerObserver(observers[i]);
      }
      return dom;
    },

    // Called by TemplateBinding/NodeBind to setup a binding to the given
    // property. It's overridden here to support property bindings
    // in addition to attribute bindings that are supported by default.
    bind: function(name, observable, oneTime) {
      var property = this.propertyForAttribute(name);
      if (!property) {
        // TODO(sjmiles): this mixin method must use the special form
        // of `super` installed by `mixinMethod` in declaration/prototype.js
        return this.mixinSuper(arguments);
      } else {
        // use n-way Polymer binding
        var observer = this.bindProperty(property, observable, oneTime);
        // NOTE: reflecting binding information is typically required only for
        // tooling. It has a performance cost so it's opt-in in Node.bind.
        if (Platform.enableBindingsReflection && observer) {
          observer.path = observable.path_;
          this._recordBinding(property, observer);
        }
        if (this.reflect[property]) {
          this.reflectPropertyToAttribute(property);
        }
        return observer;
      }
    },

    _recordBinding: function(name, observer) {
      this.bindings_ = this.bindings_ || {};
      this.bindings_[name] = observer;
    },

    // Called by TemplateBinding when all bindings on an element have been 
    // executed. This signals that all element inputs have been gathered
    // and it's safe to ready the element, create shadow-root and start
    // data-observation.
    bindFinished: function() {
      this.makeElementReady();
    },

    // called at detached time to signal that an element's bindings should be
    // cleaned up. This is done asynchronously so that users have the chance
    // to call `cancelUnbindAll` to prevent unbinding.
    asyncUnbindAll: function() {
      if (!this._unbound) {
        log.unbind && console.log('[%s] asyncUnbindAll', this.localName);
        this._unbindAllJob = this.job(this._unbindAllJob, this.unbindAll, 0);
      }
    },
    
    /**
     * This method should rarely be used and only if 
     * <a href="#cancelUnbindAll">`cancelUnbindAll`</a> has been called to 
     * prevent element unbinding. In this case, the element's bindings will 
     * not be automatically cleaned up and it cannot be garbage collected 
     * by the system. If memory pressure is a concern or a 
     * large amount of elements need to be managed in this way, `unbindAll`
     * can be called to deactivate the element's bindings and allow its 
     * memory to be reclaimed.
     *
     * @method unbindAll
     */
    unbindAll: function() {
      if (!this._unbound) {
        this.closeObservers();
        this.closeNamedObservers();
        this._unbound = true;
      }
    },

    /**
     * Call in `detached` to prevent the element from unbinding when it is 
     * detached from the dom. The element is unbound as a cleanup step that 
     * allows its memory to be reclaimed. 
     * If `cancelUnbindAll` is used, consider calling 
     * <a href="#unbindAll">`unbindAll`</a> when the element is no longer
     * needed. This will allow its memory to be reclaimed.
     * 
     * @method cancelUnbindAll
     */
    cancelUnbindAll: function() {
      if (this._unbound) {
        log.unbind && console.warn('[%s] already unbound, cannot cancel unbindAll', this.localName);
        return;
      }
      log.unbind && console.log('[%s] cancelUnbindAll', this.localName);
      if (this._unbindAllJob) {
        this._unbindAllJob = this._unbindAllJob.stop();
      }
    }

  };

  function unbindNodeTree(node) {
    forNodeTree(node, _nodeUnbindAll);
  }

  function _nodeUnbindAll(node) {
    node.unbindAll();
  }

  function forNodeTree(node, callback) {
    if (node) {
      callback(node);
      for (var child = node.firstChild; child; child = child.nextSibling) {
        forNodeTree(child, callback);
      }
    }
  }

  var mustachePattern = /\{\{([^{}]*)}}/;

  // exports

  scope.bindPattern = mustachePattern;
  scope.api.instance.mdv = mdv;

})(Polymer);