btce.py

#!/usr/bin/python
import sys
import httplib
import urllib
import json
import hashlib
import hmac

import config

def nonce_generator():
	try:
		fd = open("nonce_state", "r")
		nonce = int(fd.read())
		fd.close()
	except IOError:
		nonce = 1
		pass
		
	while (True):
		nonce = nonce+1
		fd = open("nonce_state", "w")
		fd.write(str(nonce))
		fd.close()
		yield nonce

nonce = nonce_generator()

class BTCEError(Exception):
	def __init__(self, msg):
		self.msg = msg
	def __str__(self):
		return repr(self.msg)

def api_request(method, misc_params = {}):
	params = {
		"method": method,
		"nonce": nonce.next()
	}
	params.update(misc_params)
	params = urllib.urlencode(params)

	H = hmac.new(config.BTC_api_secret, digestmod=hashlib.sha512)
	H.update(params)
	sign = H.hexdigest()
	
	headers = {
		"Content-type": "application/x-www-form-urlencoded",
		"Key":config.BTC_api_key,
		"Sign":sign
	}
	
	conn = httplib.HTTPSConnection("btc-e.com")
	try:
		conn.request("POST", "/tapi", params, headers)
	except httplib.HTTPException:
		raise BTCEError("HTTP error: " + response.reason)
	
	try:
		reply = json.load(conn.getresponse())
		if reply['success'] == 1:
			return reply['return']
		else:
			raise BTCEError("API returned error: " + reply['error'])

		print "API returned error: " + reply['error']
		print response.status, response.reason
	except BTCEError:
		raise
	except:
		raise BTCEError("Unexpected error: " + str(sys.exc_info()[0]))

def pubapi_request(pair, type):
	url = "https://btc-e.com/api/2/" + pair + "/" + type
	try:
		f = urllib.urlopen(url)
		return json.load(f)
	except IOError:
		print f.code()

# TODO: support btc_eur, ltc_btc, ltc_usd, nmc_btc, eur_usd
correct_pairs = [['btc', 'usd'], ['btc', 'rur'], ['usd','rur']]

def ticker(pair):
	return pubapi_request(pair, "ticker")['ticker']

def trades(pair):
	return pubapi_request(pair, "trades")

def depth(pair):
	return pubapi_request(pair, "depth")

def getinfo():
	return api_request('getInfo')

def order_list(filter = {}):
	return api_request('OrderList', filter)

def trans_history(filter = {}):
	return api_request('TransHistory', filter)

def trade_history(filter = {}):
	return api_request('TradeHistory', filter)

def prepare_deal(from_currency, to_currency, rate, amount):
	pair = [from_currency, to_currency]
	for p in correct_pairs:
		if pair == p:
			type = 'sell'
		elif pair == [p[1], p[0]]:
			type = 'buy'
			pair = p
			amount = float(amount) / float(rate)
	pair = '_'.join(pair)
	if not type:
		raise BTCEError("Unsupported currency pair: " + pair[0] + "_" + pair[1])
	return {'pair': pair, 'type':type, 'rate': rate, 'amount': amount}

def trade(deal):
#	print pair, type, amount, rate
	if deal.has_key('pair') and deal.has_key('type') and deal.has_key('rate') and deal.has_key('amount'):
		return api_request('Trade', deal)
	else:
		raise BTCEError("Wrong deal specified: ", str(deal))

def cancel_order(id):
	return api_request('CancelOrder', {'order_id': id})