'use strict';

/**

* Copyright (c) 2014 Raynos.

* Copyright (c) 2015 Marcel Klehr

*

* Permission is hereby granted, free of charge, to any person obtaining a copy

* of this software and associated documentation files (the "Software"), to deal

* in the Software without restriction, including without limitation the rights

* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

* copies of the Software, and to permit persons to whom the Software is

* furnished to do so, subject to the following conditions:

*

* The above copyright notice and this permission notice shall be included in

* all copies or substantial portions of the Software.

*

* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

* THE SOFTWARE.

*/

/* This is a reference implementation of how to recursively

observ a Backbone.Model.

A proper implementation is going to need a bunch of

performance optimizations

*/

module.exports = toObserv;

// given some model returns an observable of the model state

function toObserv(model) {

// return an object

var observ = function observ(listener) {

// observ() with no args must return state

if (!listener) {

return serialize(model);

}

// observ(listener) should notify the listener on

// every change

listen(model, function serializeModel() {

listener(serialize(model));

});

};

;['get', 'set', 'fetch', 'save', 'destroy', 'toJSON', 'isValid'].forEach(function(method) {

observ[method] = model[method].bind(model)

})

observ.backboneModel = model

return observ

}

// convert a Backbone model to JSON

function serialize(model) {

var data = model.toJSON();

Object.keys(data).forEach(function serializeRecur(key) {

var value = data[key];

// if any value can be serialized toJSON() then do it

if (value && value.toJSON) {

data[key] = data[key].toJSON();

}

});

return data;

}

// listen to a Backbone model

function listen(model, listener) {

model.on('change', listener);

model.values().forEach(function listenRecur(value) {

var isCollection = value && value._byId;

if (!isCollection) {

return;

}

// for each collection listen to it

// console.log('listenCollection')

listenCollection(value, listener);

});

}

// listen to a Backbone collection

function listenCollection(collection, listener) {

collection.forEach(function listenModel(model) {

listen(model, listener);

});

collection.on('add', function onAdd(model) {

listen(model, listener);

listener();

});

}