#!/usr/bin/env python3
"""
Currency conversions. BTC is handled separately from country currencies.
Other crypto coins to be added someday.
"""
import requests

import config
from module import commands, example

CUR_URI = "https://v3.exchangerate-api.com/bulk/{API_KEY}/{CUR_FROM}"
BTC_URI = "https://api.coindesk.com/v1/bpi/currentprice/{CUR_TO}.json"

@commands('cur', 'currency', 'exchange')
@example('.cur 20 EUR to USD')
def exchange(bot, trigger):
	"""
	Show the exchange rate between two currencies.
	
	Supported currencies: https://www.exchangerate-api.com/supported-currencies
	"""
	amount = trigger.group(3)
	cur_from = trigger.group(4)
	cur_to = trigger.group(5)
	if cur_to == "to":
		cur_to = trigger.group(6)

	if not all((amount, cur_to, cur_from)):
		return bot.reply("I didn't understand that. Try: .cur 20 EUR to USD")
	try:
		amount = float(amount)
	except ValueError:
		return bot.reply("Invalid amount. Must be number.")
	cur_to = cur_to.upper()
	cur_from = cur_from.upper()

	api_key = config.exchangerate_api_key
	url = CUR_URI.format(**{"API_KEY": api_key, "CUR_FROM": cur_from})
	res = requests.get(url, verify=True)
	res.raise_for_status()
	data = res.json()

	if data["result"] == "error":
		return bot.msg("Error: " + data["error"])
	rate = data["rates"].get(cur_to)
	if not rate:
		return bot.msg("Invalid output currency. Must be ISO 4217 compliant.")

	new_amount = round(rate*amount, 2)
	msg = f"\x0310{amount} {cur_from}\x03 = \x0312{new_amount} {cur_to}"
	bot.msg(msg)


@commands('btc', 'bitcoin')
@example('.btc EUR')
def bitcoin(bot, trigger):
	"""
	Show the current bitcoin value in USD. Optional parameter allows non-USD
	conversion.
	"""
	cur_to = trigger.group(3)
	if not cur_to:
		cur_to = "USD"
	cur_to = cur_to.upper()

	url = BTC_URI.format(**{"CUR_TO": cur_to})
	res = requests.get(url, verify=True)

	if res.text.startswith("Sorry"):
		return bot.reply("Invalid currency type. Must be ISO 4217 compliant.")
	data = res.json()

	rate = data["bpi"][cur_to]["rate_float"]
	msg = f"\x03101 BTC\x03 = \x0312{rate} {cur_to}"
	bot.msg(msg)