from datetime import datetime

from xively import XivelyAPIClient
from xively import Datastream
from xively import Datapoint


class Logger:
	api   = None
	feed  = None
	queue = []
	last  = 0

	# Constructor
	def __init__(self, config):
		self.config = config

	# Methods
	def connect(self):
		self.api   = XivelyAPIClient(self.config.apikey)
		self.feed  = self.api.feeds.get(self.config.feedid)
		self.last  = datetime.utcnow()
		self.queue = []

	def disconnect(self):
		self.api   = None
		self.feed  = None

	def running(self):
		if not self.api or not self.feed:
			return False
		return True

	def append(self, state):
		if not self.feed:
			return
		self.queue.append(state)
		delta = datetime.utcnow() - self.last
		if delta.total_seconds() > self.config.maxrate:
			self.flush()

	# Private methods
	def flush(self):
		def isset(state, key):
			value = getattr(state, key)
			return any([x!=None for x in value])
		def get(items, key):
			points = [ Datapoint(s.time, getattr(s,key)) \
				for s in items if isset(s,key) ]
			stream = Datastream(id=key)
			stream.datapoints = points
			return stream

		if not self.running() or len(self.queue) == 0:
			return

		self.feed.datastreams = [
			get(self.queue, 'acc'),
			get(self.queue, 'mag'),
			get(self.queue, 'touch'),
			get(self.queue, 'light'),
			get(self.queue, 'a2d'),
		]
		self.feed.update()

		self.last  = datetime.utcnow()
		self.queue = []