stable/freqtrade/fiat_convert.py
Matthias b67257db35 replace pymarketcap with coinmarketcap (#562)
* replace pymarketcap with coinmarketcap

* fix tests to use coinmarketcap instead of pymarketcap

* use arraypos 0

* update setup.py from pymarketcap to coinmarketcap

* Add test to check for unsupported Crypto currency
2018-03-19 18:40:40 +01:00

193 lines
6.6 KiB
Python

"""
Module that define classes to convert Crypto-currency to FIAT
e.g BTC to USD
"""
import logging
import time
from coinmarketcap import Market
logger = logging.getLogger(__name__)
class CryptoFiat():
"""
Object to describe what is the price of Crypto-currency in a FIAT
"""
# Constants
CACHE_DURATION = 6 * 60 * 60 # 6 hours
def __init__(self, crypto_symbol: str, fiat_symbol: str, price: float) -> None:
"""
Create an object that will contains the price for a crypto-currency in fiat
:param crypto_symbol: Crypto-currency you want to convert (e.g BTC)
:param fiat_symbol: FIAT currency you want to convert to (e.g USD)
:param price: Price in FIAT
"""
# Public attributes
self.crypto_symbol = None
self.fiat_symbol = None
self.price = 0.0
# Private attributes
self._expiration = 0
self.crypto_symbol = crypto_symbol.upper()
self.fiat_symbol = fiat_symbol.upper()
self.set_price(price=price)
def set_price(self, price: float) -> None:
"""
Set the price of the Crypto-currency in FIAT and set the expiration time
:param price: Price of the current Crypto currency in the fiat
:return: None
"""
self.price = price
self._expiration = time.time() + self.CACHE_DURATION
def is_expired(self) -> bool:
"""
Return if the current price is still valid or needs to be refreshed
:return: bool, true the price is expired and needs to be refreshed, false the price is
still valid
"""
return self._expiration - time.time() <= 0
class CryptoToFiatConverter(object):
"""
Main class to initiate Crypto to FIAT.
This object contains a list of pair Crypto, FIAT
This object is also a Singleton
"""
__instance = None
_coinmarketcap = None
# Constants
SUPPORTED_FIAT = [
"AUD", "BRL", "CAD", "CHF", "CLP", "CNY", "CZK", "DKK",
"EUR", "GBP", "HKD", "HUF", "IDR", "ILS", "INR", "JPY",
"KRW", "MXN", "MYR", "NOK", "NZD", "PHP", "PKR", "PLN",
"RUB", "SEK", "SGD", "THB", "TRY", "TWD", "ZAR", "USD"
]
CRYPTOMAP = {
'BTC': 'bitcoin',
'ETH': 'ethereum',
'USDT': 'thether'
}
def __new__(cls):
if CryptoToFiatConverter.__instance is None:
CryptoToFiatConverter.__instance = object.__new__(cls)
try:
CryptoToFiatConverter._coinmarketcap = Market()
except BaseException:
CryptoToFiatConverter._coinmarketcap = None
return CryptoToFiatConverter.__instance
def __init__(self) -> None:
self._pairs = []
def convert_amount(self, crypto_amount: float, crypto_symbol: str, fiat_symbol: str) -> float:
"""
Convert an amount of crypto-currency to fiat
:param crypto_amount: amount of crypto-currency to convert
:param crypto_symbol: crypto-currency used
:param fiat_symbol: fiat to convert to
:return: float, value in fiat of the crypto-currency amount
"""
price = self.get_price(crypto_symbol=crypto_symbol, fiat_symbol=fiat_symbol)
return float(crypto_amount) * float(price)
def get_price(self, crypto_symbol: str, fiat_symbol: str) -> float:
"""
Return the price of the Crypto-currency in Fiat
:param crypto_symbol: Crypto-currency you want to convert (e.g BTC)
:param fiat_symbol: FIAT currency you want to convert to (e.g USD)
:return: Price in FIAT
"""
crypto_symbol = crypto_symbol.upper()
fiat_symbol = fiat_symbol.upper()
# Check if the fiat convertion you want is supported
if not self._is_supported_fiat(fiat=fiat_symbol):
raise ValueError('The fiat {} is not supported.'.format(fiat_symbol))
# Get the pair that interest us and return the price in fiat
for pair in self._pairs:
if pair.crypto_symbol == crypto_symbol and pair.fiat_symbol == fiat_symbol:
# If the price is expired we refresh it, avoid to call the API all the time
if pair.is_expired():
pair.set_price(
price=self._find_price(
crypto_symbol=pair.crypto_symbol,
fiat_symbol=pair.fiat_symbol
)
)
# return the last price we have for this pair
return pair.price
# The pair does not exist, so we create it and return the price
return self._add_pair(
crypto_symbol=crypto_symbol,
fiat_symbol=fiat_symbol,
price=self._find_price(
crypto_symbol=crypto_symbol,
fiat_symbol=fiat_symbol
)
)
def _add_pair(self, crypto_symbol: str, fiat_symbol: str, price: float) -> float:
"""
:param crypto_symbol: Crypto-currency you want to convert (e.g BTC)
:param fiat_symbol: FIAT currency you want to convert to (e.g USD)
:return: price in FIAT
"""
self._pairs.append(
CryptoFiat(
crypto_symbol=crypto_symbol,
fiat_symbol=fiat_symbol,
price=price
)
)
return price
def _is_supported_fiat(self, fiat: str) -> bool:
"""
Check if the FIAT your want to convert to is supported
:param fiat: FIAT to check (e.g USD)
:return: bool, True supported, False not supported
"""
fiat = fiat.upper()
return fiat in self.SUPPORTED_FIAT
def _find_price(self, crypto_symbol: str, fiat_symbol: str) -> float:
"""
Call CoinMarketCap API to retrieve the price in the FIAT
:param crypto_symbol: Crypto-currency you want to convert (e.g BTC)
:param fiat_symbol: FIAT currency you want to convert to (e.g USD)
:return: float, price of the crypto-currency in Fiat
"""
# Check if the fiat convertion you want is supported
if not self._is_supported_fiat(fiat=fiat_symbol):
raise ValueError('The fiat {} is not supported.'.format(fiat_symbol))
if crypto_symbol not in self.CRYPTOMAP:
raise ValueError(
'The crypto symbol {} is not supported.'.format(crypto_symbol))
try:
return float(
self._coinmarketcap.ticker(
currency=self.CRYPTOMAP[crypto_symbol],
convert=fiat_symbol
)[0]['price_' + fiat_symbol.lower()]
)
except BaseException:
return 0.0