import logging
from datetime import datetime

import pytz

from core.data_store import DATA_STORE


class SIGRefDataProvider:
    """Generic SIG reference data provider class. Subclasses of this query the individual URLs or files for data."""

    def __init__(self, sig_name, provider_config):
        """Constructor"""

        self.sig_name = sig_name
        self.enabled = provider_config["enabled"]
        self.last_update_time = datetime.min.replace(tzinfo=pytz.UTC)
        self.last_spot_time = datetime.min.replace(tzinfo=pytz.UTC)
        self.status = "Not Started" if self.enabled else "Disabled"
        self.reference_count = 0

        # Create an empty dict to store data if one doesn't already exist
        if not sig_name in DATA_STORE.sigrefs:
            DATA_STORE.sigrefs[sig_name] = {}


    def start(self):
        """Start the provider. This should return immediately after spawning threads to access the remote resources"""

        raise NotImplementedError("Subclasses must implement this method")


    def stop(self):
        """Stop any threads and prepare for application shutdown"""

        raise NotImplementedError("Subclasses must implement this method")

    def _replace_data(self, new_data):
        """Replace all data for the named sig with the new data. new_data should be a map of reference ID to SIGRef
        objects."""

        DATA_STORE.sigrefs[self.sig_name] = new_data
        self.reference_count = len(new_data)
        logging.info(f"Loaded %d references for %s into the data store.", self.reference_count, self.sig_name)