Source code for babao.inputs.krakenInputBase

"""
This module define the base class and methods for kraken inputs
"""

import time
from abc import abstractmethod

import krakenex

import babao.config as conf
import babao.utils.log as log
from babao.inputs.inputBase import ABCInput

API = None
API_DELAY = 3


def _initAPI():
    """Start the connexion with the api, eventually load the secret key"""
    global API
    API = krakenex.API()
    try:
        API.load_key(conf.API_KEY_FILE)
    except FileNotFoundError as e:
        log.warning(
            "Couldn't load kraken api key file '"
            + conf.API_KEY_FILE + "': " + repr(e)
        )


class ABCKrakenInput(ABCInput):
    """Base class for any kraken input"""

    def __init__(self):
        ABCInput.__init__(self)
        self._tick = None
        if API is None:
            _initAPI()

    def _doRequest(self, method, req=None):
        """General function for kraken api requests"""
        if req is None:
            req = {}
        if method == "Trades":
            query = API.query_public
        else:
            query = API.query_private
        self._sleep()
        try:
            res = query(method, req, timeout=42)
            if res.get("error"):
                raise ValueError(res["error"][0])
        except (OSError, ValueError) as e:
            log.warning("Error while querying Kraken API!", e)
            return None
        return res["result"]

    def _sleep(self):
        """Handle waiting between each requests, so the api doesn't kick us"""
        if self._tick is not None:
            delta = time.time() - self._tick
            log.debug(
                "Request took " + str(round(delta, 3)) + "s ("
                + self.__class__.__name__ + ")"
            )
        else:
            delta = 0
        delta = API_DELAY - delta
        if delta > 0:
            time.sleep(delta)
        self._tick = time.time()

    @abstractmethod
    def fetch(self):
        pass