get_fm_data.py

from datetime import datetime, timedelta
import json
import pytz
import re
import requests
import time
from typing import AsyncGenerator, List, Optional

import appdaemon.plugins.hass.hassapi as hass
import isodate


class FlexMeasuresDataImporter(hass.Hass):
    fm_token: str
    first_try_time_price_data: str
    second_try_time_price_data: str

    first_try_time_emissions_data: str
    second_try_time_emissions_data: str

    def initialize(self):
        """Daily get epex prices purely for display in the UI.

        Try to get EPEX price data from the FM server on a daily basis.
        Normally the prices are avaialable around 14:35.
        When this fails retry at 18:30. These times are related to the
        attempts in the server for retrieving EPEX proce data.

        The retrieved data is written to the HA input_text.epex_prices,
        HA handles this to render the price data in the UI (chart).
        """

        self.log(f"get_fm_data, start setup")

        # Price data should normally be available just after 13:00 when data can be
        # retrieved from its original source (ENTSO-E) but sometimes there is a delay of several hours.
        self.first_try_time_price_data = "14:32:00"
        self.second_try_time_price_data = "18:32:00"
        self.run_daily(self.daily_kickoff_price_data, self.first_try_time_price_data)
        # At init also run this as (re-) start is not always around self.first_try_time
        self.daily_kickoff_price_data()

        self.first_try_time_emissions_data = "15:16:17"
        self.second_try_time_emissions_data = "19:18:17"
        self.run_daily(self.daily_kickoff_emissions_data, self.first_try_time_emissions_data)
        # At init also run this as (re-) start is not always around self.first_try_time
        self.daily_kickoff_emissions_data()

        self.log(f"Done setting up get_fm_data: check daily at {self.first_try_time_price_data} for new data with FM.")

    # ToDo: Make generic function in utils? See v2g_liberty.py for equivalent.
    def notify_user(self, message: str):
        """ Utility function to notify the user
        """
        self.notify(message, title="V2G Liberty")

    def daily_kickoff_price_data(self, *args):
        """ This sets off the daily routine to check for new prices."""
        self.get_epex_prices()

    def daily_kickoff_emissions_data(self, *args):
        """ This sets off the daily routine to check for new emission data."""
        self.get_co2_emissions()

    def log_failed_response(self, res, endpoint: str):
        """Log failed response for a given endpoint."""
        try:
            self.log(f"{endpoint} failed ({res.status_code}) with JSON response {res.json()}")
        except json.decoder.JSONDecodeError:
            self.log(f"{endpoint} failed ({res.status_code}) with response {res}")

    def get_epex_prices(self, *args, **kwargs):
        """ Communicate with FM server and check the results.

        Request prices from the server
        Make prices available in HA by setting them in input_text.epex_prices
        Notify user if there will be negative prices for next day
        """

        self.authenticate_with_fm()
        now = self.get_now()
        # Getting prices since start of yesterday so that user can look back a little further than just current window.
        startEPEX = str((now + timedelta(days=-1)).date())

        url = self.args["fm_data_api"] + self.args["fm_data_api_epex"]
        url_params = {
            "event_starts_after": startEPEX + "T00:00:00.000Z",
        }
        res = requests.get(
            url,
            params=url_params,
            headers={"Authorization": self.fm_token},
        )

        # Authorisation error, retry authoristion.
        if res.status_code == 401:
            self.log_failed_response(res, "Get FM EPEX data")
            self.try_solve_authentication_error(res, url, self.get_epex_prices, *args, **kwargs)
            return

        if res.status_code != 200:
            self.log_failed_response(res, "Get FM EPEX data")

            # Only retry once at second_try_time.
            if self.now_is_between(self.first_try_time_price_data, self.second_try_time_price_data):
                self.log(f"Retry at {self.second_try_time_price_data}.")
                self.run_at(self.get_epex_prices, self.second_try_time_price_data)
            else:
                self.log(f"Retry tomorrow.")
                self.notify_user("Getting EPEX price data failed, retry tomorrow.")
            return

        prices = res.json()

        # From FM format (€/MWh) to user desired format (€ct/kWh) 
        # = * 100/1000 = 1/10. Also include VAT
        VAT = float(self.args["VAT"])
        conversion = 1 / 10 * VAT
        # For NL electricity is a markup for transport and sustainability
        markup = float(self.args["markup_per_kWh"])
        epex_price_points = []
        has_negative_prices = False
        for price in prices:
            data_point = {}
            data_point['time'] = datetime.fromtimestamp(price['event_start'] / 1000).isoformat()
            data_point['price'] = round((price['event_value'] * conversion) + markup, 2)
            if data_point['price'] < 0:
                has_negative_prices = True
            epex_price_points.append(data_point)

        # To make sure HA considers this as new info a datetime is added
        new_state = "EPEX prices collected at " + now.isoformat()
        result = {}
        result['records'] = epex_price_points
        self.set_state("input_text.epex_prices", state=new_state, attributes=result)

        # FM returns all the prices it has, sometimes it has not retrieved new
        # prices yet, than it communicates the prices it does have.
        date_latest_price = datetime.fromtimestamp(prices[-1].get('event_start') / 1000).isoformat()
        date_tomorrow = (now + timedelta(days=1)).isoformat()
        if date_latest_price < date_tomorrow:
            self.log(
                f"FM EPEX prices seem not renewed yet, latest price at: {date_latest_price}, Retry at {self.second_try_time_price_data}.")
            self.run_at(self.get_epex_prices, self.second_try_time_price_data)
        else:
            if has_negative_prices:
                self.notify_user(
                    "Negative electricity prices for tomorrow. Consider to check times in the app to optimising electricity usage.")
            self.log(f"FM EPEX prices successfully retrieved. Latest price at: {date_latest_price}.")

    def get_co2_emissions(self, *args, **kwargs):
        """ Communicate with FM server and check the results.

        Request hourly CO2 emissions due to electricity production in NL from the server
        Make values available in HA by setting them in input_text.co2_emissions
        """

        self.log("FMdata: get_co2_emissions called")

        self.authenticate_with_fm()
        now = self.get_now()
        # Getting emissions since start of yesterday so that user can look back a little furter than just current window.
        start_co2: str = str((now + timedelta(days=-1)).date())

        url = self.args["fm_data_api"] + self.args["fm_data_api_co2"]
        url_params = {
            "event_starts_after": start_co2 + "T00:00:00.000Z",
        }
        res = requests.get(
            url,
            params=url_params,
            headers={"Authorization": self.fm_token},
        )

        # Authorisation error, retry authorisation.
        if res.status_code == 401:
            self.log_failed_response(res, "get CO2 emissions")
            self.try_solve_authentication_error(res, url, self.get_co2_emissions, *args, **kwargs)
            return

        if res.status_code != 200:
            self.log_failed_response(res, "Get FM CO2 emissions data")

            # Only retry once at second_try_time.
            if self.now_is_between(self.first_try_time_emissions_data, self.second_try_time_emissions_data):
                self.log(f"Retry at {self.second_try_time_emissions_data}.")
                self.run_at(self.get_co2_emissions, self.second_try_time_emissions_data)
            return

        emissions = res.json()

        emission_points = []
        for emission in emissions:
            emission_value = emission['event_value']
            if emission_value == "null" or emission_value is None:
                continue
            emission_value = int(round(float(emission_value)/10, 0))
            data_point = {'time': datetime.fromtimestamp(emission['event_start'] / 1000).isoformat(),
                          'emission': emission_value}
            emission_points.append(data_point)

        # To make sure HA considers this as new info a datetime is added
        new_state = "Emissions collected at " + now.isoformat()
        result = {'records': emission_points}
        self.set_state("input_text.co2_emissions", state=new_state, attributes=result)

        # FM returns all the prices it has, sometimes it has not retrieved new
        # prices yet, than it communicates the prices it does have.
        date_latest_emission = datetime.fromtimestamp(emissions[-1].get('event_start') / 1000).isoformat()
        date_tomorrow = (now + timedelta(days=1)).isoformat()
        if date_latest_emission < date_tomorrow:
            self.log(f"FM CO2 emissions seem not renewed yet. {date_latest_emission}, retry at {self.second_try_time_emissions_data}.")
            self.run_at(self.get_co2_emissions, self.second_try_time_emissions_data)
        else:
            self.log(f"FM CO2 successfully retrieved. Latest price at: {date_latest_emission}.")

    def authenticate_with_fm(self):
        """Authenticate with the FlexMeasures server and store the returned auth token.
        Hint: the lifetime of the token is limited, so also call this method whenever the server returns a 401 status code.
        """
        self.log("Authenticating with FlexMeasures")
        res = requests.post(
            self.args["fm_data_api"] + "requestAuthToken",
            json=dict(
                email=self.args["fm_data_user_email"],
                password=self.args["fm_data_user_password"],
            ),
        )
        if not res.status_code == 200:
            self.log_failed_response(res, "requestAuthToken")
        self.fm_token = res.json()["auth_token"]

    def try_solve_authentication_error(self, res, url, fnc, *fnc_args, **fnc_kwargs):
        if fnc_kwargs.get("retry_auth_once", True) and res.status_code == 401:
            self.log(f"Call to  {url} failed on authorization (possibly the token expired); "
                     f"attempting to reauthenticate once")
            self.authenticate_with_fm()
            fnc_kwargs["retry_auth_once"] = False
            fnc(*fnc_args, **fnc_kwargs)