// Backbone.BabySitter
// -------------------
// v1.0.0
//
// Copyright (c)2019 Derick Bailey, Muted Solutions, LLC.
// Distributed under MIT license
//
// http://github.com/marionettejs/backbone.babysitter

(function(root, factory) {

  if (typeof define === 'function' && define.amd) {
    define(['backbone', 'underscore'], function(Backbone, _) {
      return factory(Backbone, _);
    });
  } else if (typeof exports !== 'undefined') {
    var Backbone = require('backbone');
    var _ = require('underscore');
    module.exports = factory(Backbone, _);
  } else {
    factory(root.Backbone, root._);
  }

}(this, function(Backbone, _) {
  'use strict';

  var previousChildViewContainer = Backbone.ChildViewContainer;

  // BabySitter.ChildViewContainer
  // -----------------------------
  //
  // Provide a container to store, retrieve and
  // shut down child views.
  
  Backbone.ChildViewContainer = (function (Backbone, _) {
  
    // Container Constructor
    // ---------------------
  
    var Container = function(views){
      this._views = {};
      this._indexByModel = {};
      this._indexByCustom = {};
      this._updateLength();
  
      _.each(views, _.bind(this.add, this));
    };
  
    // Container Methods
    // -----------------
  
    _.extend(Container.prototype, {
  
      // Add a view to this container. Stores the view
      // by `cid` and makes it searchable by the model
      // cid (and model itself). Optionally specify
      // a custom key to store an retrieve the view.
      add: function(view, customIndex){
        return this._add(view, customIndex)
                   ._updateLength();
      },
  
      // Find a view by the model that was attached to
      // it. Uses the model's `cid` to find it.
      findByModel: function(model){
        return this.findByModelCid(model.cid);
      },
  
      // Find a view by the `cid` of the model that was attached to
      // it. Uses the model's `cid` to find the view `cid` and
      // retrieve the view using it.
      findByModelCid: function(modelCid){
        var viewCid = this._indexByModel[modelCid];
        return this.findByCid(viewCid);
      },
  
      // Find a view by a custom indexer.
      findByCustom: function(index){
        var viewCid = this._indexByCustom[index];
        return this.findByCid(viewCid);
      },
  
      // Find by index. This is not guaranteed to be a
      // stable index.
      findByIndex: function(index){
        return _.values(this._views)[index];
      },
  
      // retrieve a view by its `cid` directly
      findByCid: function(cid){
        return this._views[cid];
      },
  
      // Remove a view
      remove: function(view){
        return this._remove(view)
                   ._updateLength();
      },
  
      // Call a method on every view in the container,
      // passing parameters to the call method one at a
      // time, like `function.call`.
      call: function(method){
        this.apply(method, _.toArray(arguments).slice(1));
      },
  
      // Apply a method on every view in the container,
      // passing parameters to the call method one at a
      // time, like `function.apply`.
      apply: function(method, args){
        _.each(this._views, function(view){
          if (_.isFunction(view[method])){
            view[method].apply(view, args || []);
          }
        });
      },
  
      // Update the `.length` attribute on this container
      _updateLength: function(){
        this.length = _.size(this._views);
  
        return this;
      },
      // To be used when avoiding call _updateLength
      // When you are done adding all your new views
      // call _updateLength
      _add: function(view, customIndex){
        var viewCid = view.cid;
  
        // store the view
        this._views[viewCid] = view;
  
        // index it by model
        if (view.model){
          this._indexByModel[view.model.cid] = viewCid;
        }
  
        // index by custom
        if (customIndex){
          this._indexByCustom[customIndex] = viewCid;
        }
  
        return this;
      },
      // To be used when avoiding call _updateLength
      // When you are done adding all your new views
      // call _updateLength
      _remove: function (view){
        var viewCid = view.cid;
  
        // delete model index
        if (view.model){
          delete this._indexByModel[view.model.cid];
        }
  
        // delete custom index
        _.some(this._indexByCustom, _.bind(function(cid, key) {
          if (cid === viewCid) {
            delete this._indexByCustom[key];
            return true;
          }
        }, this));
  
        // remove the view from the container
        delete this._views[viewCid];
  
        return this;
      }
    });
  
    // Borrowing this code from Backbone.Collection:
    // http://backbonejs.org/docs/backbone.html#section-106
    //
    // Mix in methods from Underscore, for iteration, and other
    // collection related features.
    var methods = ['forEach', 'each', 'map', 'find', 'detect', 'filter',
      'select', 'reject', 'every', 'all', 'some', 'any', 'include',
      'contains', 'invoke', 'toArray', 'first', 'initial', 'rest',
      'last', 'without', 'isEmpty', 'pluck', 'reduce'];
  
    _.each(methods, function(method) {
      Container.prototype[method] = function() {
        var views = _.values(this._views);
        var args = [views].concat(_.toArray(arguments));
        return _[method].apply(_, args);
      };
    });
  
    // return the public API
    return Container;
  })(Backbone, _);
  

  Backbone.ChildViewContainer.VERSION = '1.0.0';

  Backbone.ChildViewContainer.noConflict = function () {
    Backbone.ChildViewContainer = previousChildViewContainer;
    return this;
  };

  return Backbone.ChildViewContainer;

}));