# Example consuming OpenADR price signals using HTTP GET
# Copyright 2020, Olivine, Inc.  
import requests
import xml.etree.ElementTree as ET
import isodate

# namespaces
oadr = 'http://openadr.org/oadr-2.0b/2012/07'
ei = 'http://docs.oasis-open.org/ns/energyinterop/201110'
xcal = 'urn:ietf:params:xml:ns:icalendar-2.0'

# request payload
r = requests.get('https://api.olivineinc.com/i/oe/pricing/signal/paced/etou-dyn')
if r.status_code != 200:
    print (f'exiting with HTTP status {{{r.status_code}}}.')
    exit()

# parse
event = ET.fromstring(r.text)

# output event
vtnComment = event.find(f'{{{ei}}}eventDescriptor/{{{ei}}}vtnComment').text
metaData = dict(item.split(':', 1) for item in vtnComment.split(';'))
[print(f'{key}: {value}') for key, value in metaData.items()]
# get start time
activePeriod = event.find(f'{{{ei}}}eiActivePeriod')
isoTime = activePeriod.find(f'{{{xcal}}}properties/{{{xcal}}}dtstart/{{{xcal}}}date-time').text
startTime = isodate.parse_datetime(isoTime)
# process signals
for signal in event.iter(f'{{{ei}}}eiEventSignal'):
    for interval in signal.iter(f'{{{ei}}}interval'):
        isoDuration = interval.find(f'{{{xcal}}}duration')[0].text
        price = float(interval.find(f'{{{ei}}}signalPayload/{{{ei}}}payloadFloat')[0].text)
        duration = isodate.parse_duration(isoDuration)
        endTime = startTime + duration
        print (f'{startTime:%Y-%M-%d %H:%m} to {endTime:%Y-%M-%d %H:%m}: {price:.5f}')
        startTime = endTime