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

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
	
	#dermines the expected growth of coin
	def analyseCoin(self, coinId):
		N_DATAPOINTS = 12
		TIME_BETWEEN_DATAPOINTS = 86400 * 7 #one week

		#Get the price history:
		history = []			
		for j in range(0, N_DATAPOINTS):
			history.append(self.getCoinPrice(coinId, "USD", int(time.time()) - (N_DATAPOINTS-j)*TIME_BETWEEN_DATAPOINTS))
		
		#Check the growth. Do some linear regression
		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] ])
			
		if (history[N_DATAPOINTS-1] == 0):
			growPercentageLongTerm = 0 
			growPercentageShortTerm = 0
		else:
			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???
		
	
	#will return some random advice about a semi-random crypto coin	
	def getRandomCoinAdvice(self):
		#get all the coins!
		coinlistUrl = "https://min-api.cryptocompare.com/data/all/coinlist"
		coinlistResponse = requests.get(coinlistUrl)
		
		popularCoins = [
			{"Symbol" : "BTC", "Name" : "BitCoin"},
			{"Symbol" : "ETH", "Name" : "Ethereum"},
			{"Symbol" : "ETC", "Name" : "Ethereum Classic"},
			{"Symbol" : "LTC", "Name" : "LiteCoin"},
			{"Symbol" : "XMR", "Name" : "Monero"},
			{"Symbol" : "XRP", "Name" : "Ripple"},
			{"Symbol" : "DOGE", "Name" : "Dogecoin"},
			{"Symbol" : "NLG", "Name" : "Gulden"}
		]
		
		if (coinlistResponse.ok):
			coinlistData = json.loads(coinlistResponse.content.decode('utf-8'))
			coinlist = []

			for coin in coinlistData["Data"]:
				coinlist.append({
					"Symbol" : coinlistData["Data"][coin]["Symbol"] ,
					"Name" : coinlistData["Data"][coin]["CoinName"]
				})

			#Analyse until you've found something interesting
			for i in range(0, 99):
			
				#pick a random coin
				if (random.randint(0, 4) == 4):
					#kans van 1 op 5 dat we naar een populaire coin kijken
					randIndex = random.randint(0, len(popularCoins)-1)
					tempId	 = popularCoins[randIndex]["Symbol"]
					tempName   = popularCoins[randIndex]["Name"]
				else:
					randIndex = random.randint(0, len(coinlist)-1)
					tempId	 = coinlist[randIndex]["Symbol"]
					tempName   = coinlist[randIndex]["Name"]
				
				#analyse:
				growPercentage, tempHistory = self.analyseCoin(tempId)
				

				#For the first few iterations we're picky
				if (growPercentage > 0.1):
					return (tempName + " (" + tempId + ") gaat to the moon!")
				if (growPercentage > 0.06):
					return ("Ik zou zeker een paar " + tempName + " (" + tempId + ") kopen.")
					
				if (i > 2):
					#Later, negative advices are also acceptable...
					if (growPercentage < -0.2):
						return ("Ik zou zeker " + tempName + " (" + tempId + ") afraden!")
					if (growPercentage > 0.015):
						return ("Ken je " + tempName + " (" + tempId + ") al? Best leuk")
				if(i > 4):
					#After a while, we're happy to give less useful advice
					if (growPercentage > 0.008):
						return (tempName + " (" + tempId + ") kan interessant worden...")
					if (growPercentage < -0.06):
						return ("Als je toevallig " + tempName + " (" + tempId + ") hebt: verkopen.")
				if(i > 5):
					#Anything goes. We're desperate.
					if (tempHistory[ len(tempHistory)-1 ] == 0):
						return (tempId + " is echt niks waard...")
					if (growPercentage > 0.005):
						return (tempName + " (" + tempId + ") is een crypto currency. Wist je dat?")
				
				time.sleep(0.1) #don't overload the API
			
			return "Sorry. De crypto adviezen zijn uitverkocht vandaag."
		else:
			raise Exception("API error")
	
	#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
		Vraag Stroop's mening over een specifieke coin:
		!coinadvice NLG
		Of vraag gewoon advies in het algemeen:
		!coinadvice
		(Over deze laatste optie moet soms even nagedacht worden)
		"""	
		
		#Geen specieke coin? Doe random.
		if(coinId == ""):
			yield from ctx.channel.send( self.getRandomCoinAdvice() )
			return
		
		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!")