import time

class Contour:
	EXPIRE_TIME = 120 # sensor value considered expired in 2 minutes
	CHANGE_FREQ = 600 # change of state allowed after 10 minutes

	current_value = None
	value_time = 0
	state = None
	state_change_time = 0
	target_value = None

	def __init__(self, config, logger):
		self.sensor_topic = config['sensor']
		self.out_topic = config['control']
		self.target_topic = config['target']
		self.logger = logger

	def update(self, value):
		self.current_value = value
		self.value_time = time.time()

	def get_value(self):
		if (time.time() - self.value_time <= self.EXPIRE_TIME):
			return self.current_value
		return None
	
	def check_state(self, state_value, force = False):
		if self.state == state_value:
			return False
		if (self.state is None) or (time.time() - self.state_change_time > self.CHANGE_FREQ) or force:
			self.state = state_value
			self.state_change_time = time.time()
			self.logger.info("Contour " + self.sensor_topic + " changed state to " + str(self.state))
			return True
		return False
	
	def update_target(self, target_value):
		self.target_value = target_value