"""See `KrakenDepoFetcher` for documentation."""

import datetime
import logging
from decimal import Decimal

import fin_defs
import krakenex

from .data import Depo, DepoFetcher, DepoSingle

logger = logging.getLogger(__name__)


class KrakenDepoFetcher(DepoFetcher):
    """Depository fetcher for [Kraken](https://www.kraken.com), the online crypto currency exchange.

    Requirements for use:
    - Account on [Kraken](https://www.kraken.com).
    - Have performed Know Your Customer (KYC) for your account.
    - Created API key from [Kraken Pro
      settings](https://pro.kraken.com/app/settings/api).
      API key must have the **Query Funds Permission**, and **should not have
      any additional permissions**. Employ principle of least priviledge.
    - Install [`krakenex`](https://pypi.org/project/krakenex/) library.

    Depository structure: A `DepoSingle`. No nesting.
    """

    def __init__(self, kraken_key: str, kraken_secret: str):
        self.assert_param('kraken_key', str, kraken_key)
        self.assert_param('kraken_secret', str, kraken_secret)
        self.client = krakenex.API(
            kraken_key,
            kraken_secret,
        )

    def get_depo(self) -> Depo:
        now = datetime.datetime.now(tz=datetime.UTC)

        result = self.client.query_private('Balance')

        assets: dict[fin_defs.Asset, Decimal] = {}
        for account_raw, balance_str in result['result'].items():
            account = account_raw.removesuffix('.HOLD')
            asset = fin_defs.WELL_KNOWN_SYMBOLS[account]
            balance = Decimal(balance_str)
            if balance != 0:
                assets[asset] = assets.get(asset, Decimal(0)) + balance
            del account, account_raw, balance_str, asset, balance

        return DepoSingle(
            name='Kraken',
            _assets=assets,
            updated_time=now,
        )