Predict future balance of an asset account considering outstanding salary income, bills and credit card balances/resets

appdaemon_budget_future.py

import requests
from datetime import datetime
import appdaemon.plugins.hass.hassapi as hass

app_token = "<FIREFLY_PERSONAL_ACCESS_TOKEN>"
firefly_url = "<FIREFLY_URL>"
main_account_name = "Main account"
salary_amount = 4000
salary_date = 28

class UpdateFuture(hass.Hass):
    def initialize(self):
        # Run once per hour
        self.run_every(self.update_future, "now", 60*60)
        
    def update_future(self, kwargs):
        ent = self.get_entity("sensor.firefly3_main_account_future")
        if not ent.exists():
            ent.add(
                state=0.0,
                attributes={
                    "native_value": 0.0,
                    "native_unit_of_measurement": "EUR",
                    "state_class": "measurement",
                    "device_class": "monetary",
                    "current_balance_date": datetime.now(),
                    "future_target_date": datetime.now(),
                })
       (value, balance_date, future_date) = self._calculate_future()
       ent.set_state(
           state=value,
           attributes={
               "native_value": value,
               "current_balance_date": balance_date,
               "future_target_date": future_date,
       })
            
    def _calculate_future(self):
        r = requests.get(
            firefly_url + "/api/v1/accounts?type=asset",
            headers={
                "Authorization": "Bearer " + app_token,
                "Accept": "application/vnd.api+json",
                "Content-Type": "application/json",
        })
        data = r.json()
        for account in data["data"]:
            if not "attributes" in account or "name" not in account["attributes"]:
                continue
            if account["attributes"]["name"] != "Sparkasse giro":
                continue
        return (
            account["attributes"]["current_balance"],
            datetime.fromisoformat(account["attributes"]["current_balance_date"]),
            prediction_date,
        )