Settings = require 'settings-sharelatex'
logger = require('logger-sharelatex')
mongojs = require('mongojs')
db = mongojs(Settings.mongo?.url, ['notifications'])
ObjectId = require("mongojs").ObjectId
metrics = require('metrics-sharelatex')

module.exports = Notifications =

	getUserNotifications: (user_id, callback = (err, notifications)->)->
		query =
			user_id: ObjectId(user_id)
			templateKey: {"$exists":true}
		db.notifications.find query, (err, notifications)->
			callback err, notifications


	_checkExistingNotifcationAndOverride : (user_id, notification, callback)->
		self = @
		query =
			user_id: ObjectId(user_id)
			key: notification.key
		db.notifications.count query, (err, number)->
			if number > 0 and !notification.forceCreate
				logger.log number:number, user_id:user_id, key:notification.key, "alredy has notification key for user"
				return callback(number)
			else if number > 0 and notification.forceCreate
				self.deleteNotificationByKeyOnly notification.key, callback
			else
				callback()

	addNotification: (user_id, notification, callback)->
		@_checkExistingNotifcationAndOverride user_id, notification, (err)->
			if err?
				callback err
			else
				doc =
					user_id: ObjectId(user_id)
					key: notification.key
					messageOpts: notification.messageOpts
					templateKey: notification.templateKey
				# TTL index on the optional `expires` field, which should arrive as an iso date-string, corresponding to
				# a datetime in the future when the document should be automatically removed.
				# in Mongo, TTL indexes only work on date fields, and ignore the document when that field is missing
				# see `README.md` for instruction on creating TTL index
				if notification.expires?
					try
						doc.expires =  new Date(notification.expires)
						_testValue = doc.expires.toISOString()
					catch err
						logger.error {user_id, expires: notification.expires}, "error converting `expires` field to Date"
						return callback(err)
				db.notifications.insert(doc, callback)

	removeNotificationId: (user_id, notification_id, callback)->
		searchOps =
			user_id:ObjectId(user_id)
			_id:ObjectId(notification_id)
		updateOperation =
			"$unset": {templateKey:true, messageOpts: true}
		db.notifications.update searchOps, updateOperation, callback

	removeNotificationKey: (user_id, notification_key, callback)->
		searchOps =
			user_id:ObjectId(user_id)
			key: notification_key
		updateOperation =
			"$unset": {templateKey:true}
		db.notifications.update searchOps, updateOperation, callback

	removeNotificationByKeyOnly: (notification_key, callback)->
		searchOps =
			key: notification_key
		updateOperation =
			"$unset": {templateKey:true}
		db.notifications.update searchOps, updateOperation, callback

	# hard delete of doc, rather than removing the templateKey
	deleteNotificationByKeyOnly: (notification_key, callback)->
		searchOps =
			key: notification_key
		db.notifications.remove searchOps, {justOne: true}, callback


[
	'getUserNotifications',
	'addNotification'
].map (method) ->
	metrics.timeAsyncMethod(Notifications, method, 'mongo.Notifications', logger)