'use strict';

var path = require('path'),
	async = require('async'),
	sm = require('sitemap'),
	url = require('url'),
	nconf = require('nconf'),
	categories = require('./categories'),
	topics = require('./topics'),
	sitemap = {
		getStaticUrls: function(callback) {
			callback(null, [{
				url: '',
				changefreq: 'weekly',
				priority: '0.6'
			}, {
				url: '/recent',
				changefreq: 'daily',
				priority: '0.4'
			}, {
				url: '/users',
				changefreq: 'daily',
				priority: '0.4'
			}]);
		},
		getDynamicUrls: function(callback) {
			var returnUrls = [];

			async.parallel([
				function(next) {
					var categoryUrls = [];
					categories.getVisibleCategories(0, function(err, data) {
						if (err) {
							return next(err);
						}

						data.categories.forEach(function(category) {
							categoryUrls.push({
								url: path.join('/category', category.slug),
								changefreq: 'weekly',
								priority: '0.4'
							});
						});

						next(null, categoryUrls);
					});
				},
				function(next) {
					var topicUrls = [];
					topics.getTopicsFromSet(0, 'topics:recent', 0, -1, function(err, data) {
						if (err) {
							return next(err);
						}

						data.topics.forEach(function(topic) {
							topicUrls.push({
								url: path.join('/topic', topic.slug),
								changefreq: 'daily',
								priority: '0.6'
							});
						});

						next(null, topicUrls);
					});
				}
			], function(err, data) {
				if (!err) {
					returnUrls = returnUrls.concat(data[0]).concat(data[1]);
				}

				callback(err, returnUrls);
			});
		},
		render: function(callback) {
			async.parallel([sitemap.getStaticUrls, sitemap.getDynamicUrls], function(err, urls) {
				urls = urls[0].concat(urls[1]);
				var map = sm.createSitemap({
						hostname: nconf.get('url'),
						cacheTime: 60*60,	// Cached for 1 hour
						urls: urls
					}),
					xml = map.toXML(function(xml) {
						callback(xml);
					});
			});
		}
	};

module.exports = sitemap;