"""Snapshot exchange_rates task."""

from abacus_common_data.currency import Currency
import pandas

from lib.constants import DIRECTORY_MODULE_CALCULATE_TOTALS
from lib.constants import FILE_NAME_EXCHANGE_RATES_PARQUET
from lib.utils import aws
from lib.utils import ows
from tasks.accounting_run_calculate import helpers


def snapshot_exchange_rates(dag_run: dict, **kwargs) -> None:
    """Task to snapshot exchange_rates as a parquet file and save them on S3.

    Args:
        dag_run (dict): config of the DAG this task belongs to
        kwargs (dict): any other optional arguments
    """
    event = helpers.get_event_from_params(dag_run, **kwargs)
    accounting_period, accounting_run = helpers.get_event_records(event.target_id)

    snapshot_directory = helpers.build_snapshot_prefix_from_accounting_run(
        accounting_period,
        accounting_run,
        DIRECTORY_MODULE_CALCULATE_TOTALS
    )

    exchange_rates_location = aws.location(
        snapshot_directory,
        FILE_NAME_EXCHANGE_RATES_PARQUET
    )

    exchange_rates = _get_exchange_rates(accounting_period.get('statement_period_id'))

    exchange_rates_df = pandas.DataFrame(exchange_rates)
    exchange_rates_df.to_parquet(
        exchange_rates_location.url,
        index=False
    )


def _get_exchange_rates(statement_period_id: int) -> list:
    """Request exchange_rates from ows-royalties.

    Args:
        statement_period_id (int): ID of the parent statement_period

    Returns:
        a list of formatted exchange_rates
    """
    exchange_rates = []
    response = ows.get_exchange_rates_by_statement_period(statement_period_id)

    for exchange_rate in response:
        from_currency_id = Currency(exchange_rate.get('from_currency_code')).number
        to_currency_id = Currency(exchange_rate.get('to_currency_code')).number
        exchange_rates.append({
            'exchangeRateId': exchange_rate.get('exchange_rate_id'),
            'exchangeFromCurrencyId': from_currency_id,
            'exchangeToCurrencyId': to_currency_id,
            'exchangeRate': exchange_rate.get('rate')
        })

    return exchange_rates