"""
Currency Model.

Model for getting information about currency
"""

from sqlalchemy import Column
from sqlalchemy import Integer
from sqlalchemy import String
from sqlalchemy.exc import SQLAlchemyError

from ows_accounting import response
from ows_accounting.constants import error
from ows_accounting.utils import mysql
from ows_accounting.utils import sentry

_cached_currencies = []


class Currency(mysql.BaseModel):
    """Class for currency model."""

    __tablename__ = "currencies"
    currency_id = Column('id', Integer,  primary_key=True, autoincrement=True)
    code = Column('ISO_4217_code', String(12))
    symbol = Column('symbol_html_entity_code', String(45))
    name = Column('currency_name', String(45))

    def as_dict(self):
        """Return object as dict.

        Returns
            dict: Dictionary representation of the object
        """
        currency_dict = {
            'id': self.currency_id,
            'code': self.code,
            'symbol': self.symbol,
            'name': self.name
        }
        return currency_dict


def _get_cached_currency_by_id(currency_id):
    """Get currency from cached list by id.

    Args:
        currency_id (int): Currency Id.
    Returns:
        Currency: currency model or None
    """
    return next(
        (item for item in _cached_currencies
            if item['id'] == currency_id), None)


def get_currency_by_id(currency_id):
    """Get currency by id.

    Args:
        currency_id (int): Currency Id.
    Returns:
        response.Response: Currency or error
                           in Response object.
    """
    currency = _get_cached_currency_by_id(currency_id)
    if currency:
        return response.Response(currency)
    try:
        with mysql.db_session(False) as session:
            currency = session.query(Currency).filter_by(
                currency_id=currency_id).first()
            if not currency:
                return response.create_not_found_response(
                    error.ERROR_MESSAGE_CURRENCY_NOT_FOUND)
            _cached_currencies.append(currency.as_dict())
            return response.Response(currency.as_dict())
    except SQLAlchemyError as ex:
        if sentry.sentry_client:
            sentry.sentry_client.captureException()
        return response.create_fatal_response(str(ex))