#
# XCoin API-call related functions
#
# @author	btckorea
# @date	2017-04-12
#
# Compatible with python3 version.

import sys
import time
import math
import base64
import hmac, hashlib
import urllib.parse
import pycurl
import json


class XCoinAPI:
	api_url = "https://api.bithumb.com"
	api_key = ""
	api_secret = ""

	def __init__(self, api_key, api_secret):
		self.api_key = api_key
		self.api_secret = api_secret
		self.contents = bytearray()

	def body_callback(self, buf):
		self.contents.extend(buf)

	def microtime(self, get_as_float=False):
		if get_as_float:
			return time.time()
		else:
			return '%f %d' % math.modf(time.time())

	def usec_time(self):
		mt = self.microtime(False)
		mt_array = mt.split(" ")[:2]
		return mt_array[1] + mt_array[0][2:5]

	def xcoinApiCall(self, endpoint, rgParams):
		# 1. Api-Sign and Api-Nonce information generation.
		# 2. Request related information from the Bithumb API server.
		#
		# - nonce: it is an arbitrary number that may only be used once.
		# - api_sign: API signature information created in various combinations values.

		endpoint_item_array = {
			"endpoint": endpoint
		}

		self.contents = bytearray()
		uri_array = dict(endpoint_item_array, **rgParams) # Concatenate the two arrays.
		str_data = urllib.parse.urlencode(uri_array)

		nonce = self.usec_time()

		data = endpoint + chr(0) + str_data + chr(0) + nonce
		utf8_data = data.encode('utf-8')

		key = self.api_secret
		utf8_key = key.encode('utf-8')

		h = hmac.new(bytes(utf8_key), utf8_data, hashlib.sha512)
		hex_output = h.hexdigest()
		utf8_hex_output = hex_output.encode('utf-8')

		api_sign = base64.b64encode(utf8_hex_output)
		utf8_api_sign = api_sign.decode('utf-8')

		curl_handle = pycurl.Curl()
		curl_handle.setopt(pycurl.POST, 1)
		curl_handle.setopt(pycurl.POSTFIELDS, str_data)

		url = self.api_url + endpoint
		curl_handle.setopt(curl_handle.URL, url)
		curl_handle.setopt(curl_handle.HTTPHEADER, ['Api-Key: ' + self.api_key, 'Api-Sign: ' + utf8_api_sign, 'Api-Nonce: ' + nonce])
		curl_handle.setopt(curl_handle.WRITEFUNCTION, self.body_callback)
		curl_handle.perform()

		# response_code = curl_handle.getinfo(pycurl.RESPONSE_CODE); # Get http response status code.

		curl_handle.close()

		try:
			result = json.loads(self.contents.decode('utf-8'))
		except:
			result = None

		return result