var RDB = require('./redis.js'),
	async = require('async'),
	winston = require('winston'),
	notifications = require('./notifications')
	Upgrade = {};

Upgrade.upgrade = function() {
	winston.info('Beginning Redis database schema update');

	async.series([
		function(next) {
			RDB.hget('notifications:1', 'score', function(err, score) {
				if (score) {
					async.series([
						function(next) {
							RDB.keys('uid:*:notifications:flag', function(err, keys) {
								if (keys.length > 0) {
									winston.info('[2013/10/03] Removing deprecated Notification Flags');
									async.each(keys, function(key, next) {
										RDB.del(key, next);
									}, next);
								} else {
									winston.info('[2013/10/03] No Notification Flags found. Good.');
									next();
								}
							});
						},
						function(next) {
							winston.info('[2013/10/03] Updating Notifications');
							RDB.keys('uid:*:notifications:*', function(err, keys) {
								async.each(keys, function(key, next) {
									RDB.zrange(key, 0, -1, function(err, nids) {
										async.each(nids, function(nid, next) {
											notifications.get(nid, null, function(notif_data) {
												RDB.zadd(key, notif_data.datetime, nid, next);
											});
										}, next);
									});
								}, next);
							});
						},
						function(next) {
							RDB.keys('notifications:*', function(err, keys) {
								if (keys.length > 0) {
									winston.info('[2013/10/03] Removing Notification Scores');
									async.each(keys, function(key, next) {
										if (key === 'notifications:next_nid') return next();
										RDB.hdel(key, 'score', next);
									}, next);
								} else {
									winston.info('[2013/10/03] No Notification Scores found. Good.');
									next();
								}
							});
						}
					], next);
				} else {
					winston.info('[2013/10/03] Updates to Notifications skipped.');
					next();
				}
			});
		},
		function(next) {
			RDB.exists('notifications', function(err, exists) {
				if (!exists) {
					RDB.keys('notifications:*', function(err, keys) {
						var	multi = RDB.multi();

						keys = keys.filter(function(key) {
							if (key === 'notifications:next_nid') return false;
							else return true;
						}).map(function(key) {
							return key.slice(14);
						});

						winston.info('[2013/10/23] Adding existing notifications to set');
						RDB.sadd('notifications', keys, next);
					});
				} else {
					winston.info('[2013/10/23] Updates to Notifications skipped.');
					next();
				}
			});
		},
		function(next) {
			RDB.hget('config', 'postDelay', function(err, postDelay) {
				if(parseInt(postDelay, 10) > 150) {
					RDB.hset('config', 'postDelay', 10, function(err, success) {
						winston.info('[2013/11/11] Updated postDelay to 10 seconds.');
						next();
					});
				} else {
					winston.info('[2013/11/11] Update to postDelay skipped.');
					next();
				}
			});
		}
		// Add new schema updates here
	], function(err) {
		if (!err) {
			winston.info('Redis schema update complete!');
			process.exit();
		} else {
			winston.error('Errors were encountered while updating the NodeBB schema: ' + err.message);
		}
	});
};

module.exports = Upgrade;