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

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
		
	#Relative Strength Index (RSI)
	def rsi(self, datapoints):
		totalGain = 0.0001
		totalLoss = 0.0001
		n_deltas = len(datapoints)-1
		
		for x in range(0, n_deltas):
			delta = datapoints[x+1] - datapoints[x]
			if delta > 0:
				totalGain += delta
			else:
				totalLoss -= delta #losses should also be positive
				
		RS = (totalGain / n_deltas) / (totalLoss / n_deltas)		
		return 100 - ( 100 / (1 + RS) )
		
	#get the stability based on the standard deviation
	#the closer to 1, the better. (can be < 0, by the way. sue me.)
	def getCoinStability(self, history):
		histMean = statistics.mean(history)
		if(histMean == 0):
			return 0
		return 1 - (statistics.stdev(history) / histMean)
	
	def getCoinPrice(self, coinId, currencyId="USD", time="now"):
				
		if (time == "now"): #for the most current price, don't use the history API
			url = "https://min-api.cryptocompare.com/data/price?tsyms=" + currencyId + "&fsym=" + coinId
		else:
			url = "https://min-api.cryptocompare.com/data/pricehistorical?tsyms=" + currencyId + "&fsym=" + coinId + "&ts=" + str(time)
		
		response = requests.get(url)
		
		try:
			priceData = json.loads(response.content.decode('utf-8'))
			if (time == "now"):
				return priceData[currencyId]
			else:
				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-1):
			history.append(self.getCoinPrice(coinId, "USD", int(time.time()) - (N_DATAPOINTS-j)*TIME_BETWEEN_DATAPOINTS))
		history.append(self.getCoinPrice(coinId, "USD")) #now
		
		#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
		
		stability = self.getCoinStability(history)
		
		return growPercentage, stability, 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, stability, tempHistory = self.analyseCoin(tempId)

				#For the first few iterations we're picky
				if (growPercentage > 0.1 and stability > 0.5):
					return (tempName + " (" + tempId + ") gaat to the moon!")
				if (growPercentage > 0.06 and stability > 0.25):
					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 and stability > 0.15):
						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)
		Stroopwafel en zijn development team nemen geen verantwoordelijkheid voor 
		eventuele financiele schade en verwoeste levens.
		"""	
		
		#Geen specieke coin? Doe random.
		if(coinId == ""):
			yield from ctx.channel.send( self.getRandomCoinAdvice() )
			return
		
		coinId = coinId.upper()
		
		growPercentage, coinStability, coinHistory = self.analyseCoin(coinId)
		coinRsi = self.rsi(coinHistory) 
		#TODO, get more recent data to feed the RSI
		
		message = ""
		
		if (growPercentage < -0.04):
			if (coinRsi > 70):
				message = "Sell! Sell! Sell! Aan " + coinId + " heb je niks meer."
			elif (coinStability < 0.3):
				message = coinId + " takelt op lange termijn af en is instabiel. Net als je moeder."
			elif (coinRsi < 30):
				message = "Op de lange termijn is " + coinId + " waardeloos, maar wacht nog even met verkopen."
			else:
				message = "Als je " + coinId + " hebt, verkopen die handel. Daar heb je op de lange termijn niks aan."
		elif (growPercentage < 0):
			message = coinId + " gaat geen winnaar worden. "
			if (coinRsi > 70):
				message += "Ditchen."
			elif (coinRsi < 30):
				message += "Maar hou hem nog even vast."
		elif (growPercentage < 0.025):
			if (coinStability > 0.6):
				message = coinId + " lijkt redelijk stabiel. "
				if (coinRsi < 30):
					message += "Bovendien een goed moment om te kopen."
			elif (coinRsi > 70):
				message = "Ik zou " + coinId + " verkopen."
			else:
				message = "Niks bijzonders, die " + coinId
		elif (growPercentage < 0.08):
			if (coinStability > 0.45):
				message = coinId + " is een stabiele groeier. "
				if (coinRsi < 30):
					message += "Nu kopen!"
			elif (coinStability < 0.2):
				message = coinId + " groeit lekker, maar is instabiel."
			else:
				message = coinId + " is aan het groeien... "
			if (coinRsi > 70):
				message += "Hij lijkt overbought, dus je kan nu verkopen."
		else: 
			if (coinRsi < 30 and coinStability > 0.4):
				message = "TO THE MOON! Nu " + coinId + " kopen!!"
			elif (coinStability > 0.7):
				message = coinId + " is op de lange termijn erg sterk en stabiel!"
			elif (coinRsi < 30):
				message = "Ik raad sterk aan om " + coinId + " te kopen."
			elif (coinRsi < 70):
				message = coinId + " groeit wel erg hard. Wellicht overbought?"
			else:
				message = coinId + " gaat toenemen in waarde... "
				if (coinStability < 0.3):
					message += "Denk ik?"
					
		yield from ctx.channel.send(message)