song.js

define(function (require) {
    'use strict';
    
    var SongType = require('background/enum/songType');
    var Utility = require('common/utility');

    var Song = Backbone.Model.extend({
        defaults: {
            //  ID is a YouTube Video ID.
            id: '',
            //  Title is immutable. PlaylistItem might support editing the title, but applied to the PlaylistItem and not to Song.
            title: '',
            author: '',
            //  Duration in seconds for the length of the given song.
            duration: -1,
            type: SongType.None,
                
            //  These are calculated:
            prettyDuration: '',
            url: '',
            cleanTitle: ''
        },
        
        //  Song is never saved to the server -- it gets flattened into a PlaylistItem
        sync: function() {
            return false;
        },
        
        initialize: function () {
            this._setPrettyDuration(this.get('duration'));
            this._setCleanTitle(this.get('title'));
            this._setUrl(this.get('id'));

            this.on('change:duration', this._onChangeDuration);
            this.on('change:title', this._onChangeTitle);
            this.on('change:id', this._onChangeId);
        },
        
        getSyncAttributes: function () {
            return {
                id: this.get('id'),
                title: this.get('title'),
                author: this.get('author'),
                duration: this.get('duration'),
                type: this.get('type')
            };
        },
        
        copyUrl: function () {
            var url = this.get('url');
            Streamus.channels.clipboard.commands.trigger('copy:text', url);
            
            Streamus.channels.notification.commands.trigger('show:notification', {
                message: chrome.i18n.getMessage('urlCopied')
            });
        },
        
        copyTitleAndUrl: function () {
            var titleAndUrl = this.get('title') + ' - ' + this.get('url');
            Streamus.channels.clipboard.commands.trigger('copy:text', titleAndUrl);
            
            Streamus.channels.notification.commands.trigger('show:notification', {
                message: chrome.i18n.getMessage('urlCopied')
            });
        },
        
        _onChangeId: function (model, id) {
            this._setUrl(id);
        },
        
        _onChangeTitle: function(model, title) {
            this._setCleanTitle(title);
        },
        
        _onChangeDuration: function(model, duration) {
            this._setPrettyDuration(duration);
        },
        
        //  Calculate this value pre-emptively because when rendering I don't want to incur inefficiency
        _setPrettyDuration: function (duration) {
            this.set('prettyDuration', Utility.prettyPrintTime(duration));
        },
        
        //  Useful for comparisons and other searching.
        _setCleanTitle: function (title) {
            this.set('cleanTitle', Utility.cleanTitle(title));
        },
        
        _setUrl: function (id) {
            this.set('url', 'https://youtu.be/' + id);
        }
    });

    return Song;
});