SmartThings SmartApp: auto turn off switch after N minutes

switch-auto-off.groovy

/**
 *  Switch Auto Off.
 *
 *  Copyright 2019 Yuxuan Wang
 *
 *  Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 *  in compliance with the License. You may obtain a copy of the License at:
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software distributed under the License is distributed
 *  on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License
 *  for the specific language governing permissions and limitations under the License.
 *
 */
definition(
	name: "Switch Auto Off",
	namespace: "fishy",
	author: "Yuxuan Wang",
	description: "Auto turn off switch after N minutes",
	category: "My Apps",
	iconUrl: "https://s3.amazonaws.com/smartapp-icons/Convenience/Cat-Convenience.png",
	iconX2Url: "https://s3.amazonaws.com/smartapp-icons/Convenience/Cat-Convenience@2x.png",
	iconX3Url: "https://s3.amazonaws.com/smartapp-icons/Convenience/Cat-Convenience@2x.png",
)


preferences {
	section("Switch") {
		input(
			"myswitch",
			"capability.switch",
			title: "Which one?",
		)
	}
	section("Auto turn off after...") {
		input(
			"minutes",
			"number",
			title: "Minutes?",
		)
	}
}


def installed() {
	log.debug "Installed with settings: ${settings}"

	initialize()
}

def updated() {
	log.debug "Updated with settings: ${settings}"

	unsubscribe()
	initialize()
}

def initialize() {
	subscribe(myswitch, "switch", switchHandler)
}

def switchHandler(evt) {
	log.debug "switchHandler: $evt.value: $evt, $settings"
	if (evt.value == "on") {
		def timestamp = now() + 60 * 1000 * minutes
		def data = [
			startTime: now(),
			stopAt: timestamp,
		]
		checkTime(data)
	} else {
		log.debug "switchHandler: stop checking as it's already off"
		unschedule(checkTime)
	}
}

def checkTime(data) {
	def timestamp = now()
	def target = data.targetStatus
	log.debug "checkTime: ${new Date()}, timestamp: $timestamp, stops at ${data.stopAt}"
	if (timestamp >= data.stopAt) {
		log.debug "Turning off"
		myswitch.off()
		unschedule(checkTime)
		return
	}
	def options = [
		overwrite: true,
		data: data,
	]
	runEvery1Minute(checkTime, options)
}