import asyncio
import discord
from discord.ext import commands
from urllib import request
import json, requests
import time

class Cryptocoin(object):
	"""Voor al uw crypto currency advies."""
	
	def __init__(self, bot):
		self.bot = bot
		self.voice_states = {}
	def __check(self, ctx): #Todo: Is dit het geld-verdienen kanaal?
		return True
		
		
	#borrowed from: http://jmduke.com/posts/basic-linear-regressions-in-python/
	def basic_linear_regression(self, x, y):
		# Basic computations to save a little time.
		length = len(x)
		sum_x = sum(x)
		sum_y = sum(y)

		# Sx^2, and Sxy respectively.
		sum_x_squared = sum(map(lambda a: a * a, x))
		sum_of_products = sum([x[i] * y[i] for i in range(length)])

		# Magic formulae!
		a = (sum_of_products - (sum_x * sum_y) / length) / (sum_x_squared - ((sum_x ** 2) / length))
		b = (sum_y - a * sum_x) / length
		return a, b
	
	def getCoinPrice(self, coinId, currencyId="USD", time="now"):
		url = "https://min-api.cryptocompare.com/data/pricehistorical?tsyms=" + currencyId + "&fsym=" + coinId
				
		if (time != "now"):
			url += "&ts=" + str(time)
		
		response = requests.get(url)
		
		try:
			priceData = json.loads(response.content.decode('utf-8'))
			return priceData[coinId][currencyId]
		except:
			return -1
			
	def analyseCoin(self, coinId):
		N_DATAPOINTS = 12
		TIME_BETWEEN_DATAPOINTS = 86400 * 7 #one week

		history = []			
		for j in range(0, N_DATAPOINTS):
			history.append(self.getCoinPrice(coinId, "USD", int(time.time()) - (N_DATAPOINTS-j)*TIME_BETWEEN_DATAPOINTS))
		
		#print(history)
		
		growFactorLongTerm, dummy =  self.basic_linear_regression(range(0, N_DATAPOINTS), history)
		growFactorShortTerm, dummy = self.basic_linear_regression(range(0, 3), 
			[ history[N_DATAPOINTS-3], history[N_DATAPOINTS-2], history[N_DATAPOINTS-1] ])
			
		#print("long:   ", growFactorLongTerm)
		#print("short:  ", growFactorShortTerm)
		
		#print(growFactor)

		if (history[N_DATAPOINTS-1] != 0):
			growPercentageLongTerm  = growFactorLongTerm  / history[N_DATAPOINTS-1]
			growPercentageShortTerm = growFactorShortTerm / history[N_DATAPOINTS-1]
		
		growPercentage = growPercentageLongTerm*0.3 + growPercentageShortTerm*0.7 #weighted average
		return growPercentage, history
        
        #TODO:
        # - iets met stabiliteit?
        # - https://en.wikipedia.org/wiki/Head_and_shoulders_(chart_pattern)
        # - neural networks???
	
	#user functions below
	
	@commands.command(pass_context=True)
	@asyncio.coroutine
	def coinprice(self, ctx, coinId: str, currencyId: str="USD"):
		"""Geeft de huidige prijs van de desbetreffende crypto currency
		Bijv: 
		!coinprice BTC
		Of voor de echte (Erik) Hollanders:
		!coinprice NLG EUR
		"""
		allowedCurrencies = ["USD", "EUR", "JPY", "GBP", "CNY", "CAD", "BTC"]
		
		coinId = coinId.upper()
		currencyId = currencyId.upper()
		
		if (currencyId not in allowedCurrencies):
			yield from ctx.channel.send("Valuta " + currencyId + " ken ik niet. :disappointed: ")
			return
		
		price = self.getCoinPrice(coinId, currencyId)
		
		if (price == -1):
			yield from ctx.channel.send("Die cryptocoin ken ik niet... :frowning2: ")
			return
		
		yield from ctx.channel.send(coinId + " is nu " + str(price) + " " + currencyId + " waard.")
		
	@commands.command(pass_context=True)
	@asyncio.coroutine
	def coinadvice(self, ctx, coinId: str=""):
		"""Voor al uw adviezen in monopolygeld
		"""	
		
		if(coinId == ""):
			return #TODO
		
		coinId = coinId.upper()
		
		growPercentage, dummy = self.analyseCoin(coinId)
		
		if (growPercentage < -0.1):
			yield from ctx.channel.send("Sell! Sell! Sell! " + coinId + " gaat erg slecht.")
		elif (growPercentage < -0.03):
			yield from ctx.channel.send("Als je " + coinId + " hebt, verkopen die handel.")
		elif (growPercentage < 0):
			yield from ctx.channel.send("Het gaat niet zo goed met " + coinId + ".")
		elif (growPercentage < 0.015):
			yield from ctx.channel.send(coinId + " lijkt redelijk stabiel.")
		elif (growPercentage < 0.035):
			yield from ctx.channel.send("Tijd om " + coinId + " te kopen.")
		elif (growPercentage < 0.06):
			yield from ctx.channel.send(coinId + " groeit snel")
		elif (growPercentage < 0.1):
			yield from ctx.channel.send("Het gaat heel goed met " + coinId + "!")
		else:
			yield from ctx.channel.send("To the moon! " + coinId + " is niet meer te stoppen!")