#!/usr/bin/env python3
from pyln.client import Plugin
from collections import namedtuple
from pyln.client import Millisatoshi
from cachetools import cached, TTLCache
from requests.adapters import HTTPAdapter
from requests.packages.urllib3.util.retry import Retry
import requests
import statistics

plugin = Plugin()

Source = namedtuple('Source', ['name', 'urlformat', 'replymembers'])

sources = [
    # e.g. {"GBP": {"volume_btc": "24.36647424", "rates": {"last": "13667.63"}, "avg_1h": "13786.86", "avg_6h": "13723.65", "avg_12h": "13680.23", "avg_24h": "13739.56"}, "USD": {"volume_btc": "27.97517017", "rates": {"last": "18204.21"}, "avg_1h": "19349.46", "avg_6h": "18621.72", "avg_12h": "18642.28", "avg_24h": "18698.94"}
    # ...
    # "GTQ": {"volume_btc": "0.03756101", "rates": {"last": "148505.46"}, "avg_1h": "148505.46", "avg_6h": "162463.69", "avg_12h": "162003.10", "avg_24h": "162003.10"}, "DKK": {"volume_btc": "0.00339923", "rates": {"last": "139737.53"}, "avg_12h": "139737.53", "avg_24h": "139737.53"}, "HTG": {"volume_btc": "0.00024758", "rates": {"last": "2019549.24"}, "avg_6h": "2019549.24", "avg_12h": "2019549.24", "avg_24h": "2019549.24"}, "NAD": {"volume_btc": "0.00722222", "rates": {"last": "360000.11"}, "avg_12h": "360000.11", "avg_24h": "360000.11"}}
    Source('localbitcoins',
           'https://localbitcoins.com/bitcoinaverage/ticker-all-currencies/',
           ['{currency}', "avg_6h"]),
    # e.g. {"high": "18502.56", "last": "17970.41", "timestamp": "1607650787", "bid": "17961.87", "vwap": "18223.42", "volume": "7055.63066541", "low": "17815.92", "ask": "17970.41", "open": "18250.30"}
    Source('bitstamp',
           'https://www.bitstamp.net/api/v2/ticker/btc{currency_lc}/',
           ['last']),
    # e.g. {"bitcoin":{"usd":17885.84}}
    Source('coingecko',
           'https://api.coingecko.com/api/v3/simple/price?ids=bitcoin&vs_currencies={currency_lc}',
           ['bitcoin', '{currency_lc}']),
    # e.g. {"time":{"updated":"Dec 16, 2020 00:58:00 UTC","updatedISO":"2020-12-16T00:58:00+00:00","updateduk":"Dec 16, 2020 at 00:58 GMT"},"disclaimer":"This data was produced from the CoinDesk Bitcoin Price Index (USD). Non-USD currency data converted using hourly conversion rate from openexchangerates.org","bpi":{"USD":{"code":"USD","rate":"19,395.1400","description":"United States Dollar","rate_float":19395.14},"AUD":{"code":"AUD","rate":"25,663.5329","description":"Australian Dollar","rate_float":25663.5329}}}
    Source('coindesk',
           'https://api.coindesk.com/v1/bpi/currentprice/{currency}.json',
           ['bpi', '{currency}', 'rate_float']),
    # e.g. {"data":{"base":"BTC","currency":"USD","amount":"19414.63"}}
    Source('coinbase',
           'https://api.coinbase.com/v2/prices/spot?currency={currency}',
           ['data', 'amount']),
    # e.g. {  "USD" : {"15m" : 6650.3, "last" : 6650.3, "buy" : 6650.3, "sell" : 6650.3, "symbol" : "$"},  "AUD" : {"15m" : 10857.19, "last" : 10857.19, "buy" : 10857.19, "sell" : 10857.19, "symbol" : "$"},...
    Source('blockchain.info',
           'https://blockchain.info/ticker',
           ['{currency}', 'last']),
]


# Stolen from https://www.peterbe.com/plog/best-practice-with-retries-with-requests
def requests_retry_session(
    retries=3,
    backoff_factor=0.3,
    status_forcelist=(500, 502, 504),
    session=None,
):
    session = session or requests.Session()
    retry = Retry(
        total=retries,
        read=retries,
        connect=retries,
        backoff_factor=backoff_factor,
        status_forcelist=status_forcelist,
    )
    adapter = HTTPAdapter(max_retries=retry)
    session.mount('http://', adapter)
    session.mount('https://', adapter)
    return session


def get_currencyrate(plugin, currency, urlformat, replymembers):
    # NOTE: Bitstamp has a DNS/Proxy issues that can return 404
    # Workaround: retry up to 5 times with a delay
    currency_lc = currency.lower()
    url = urlformat.format(currency_lc=currency_lc, currency=currency)
    r = requests_retry_session(retries=5, status_forcelist=[404]).get(url, proxies=plugin.proxies)

    if r.status_code != 200:
        plugin.log(level='info', message='{}: bad response {}'.format(url, r.status_code))
        return None

    json = r.json()
    for m in replymembers:
        expanded = m.format(currency_lc=currency_lc, currency=currency)
        if expanded not in json:
            plugin.log(level='debug', message='{}: {} not in {}'.format(url, expanded, json))
            return None
        json = json[expanded]

    try:
        return Millisatoshi(int(10**11 / float(json)))
    except Exception:
        plugin.log(level='info', message='{}: could not convert {} to msat'.format(url, json))
        return None


def set_proxies(plugin):
    config = plugin.rpc.listconfigs()
    if 'always-use-proxy' in config and config['always-use-proxy']:
        paddr = config['proxy']
        # Default port in 9050
        if ':' not in paddr:
            paddr += ':9050'
        plugin.proxies = {'https': 'socks5h://' + paddr,
                          'http': 'socks5h://' + paddr}
    else:
        plugin.proxies = None


# Don't grab these more than once per hour.
@cached(cache=TTLCache(maxsize=1024, ttl=3600))
def get_rates(plugin, currency):
    rates = {}
    for s in sources:
        r = get_currencyrate(plugin, currency, s.urlformat, s.replymembers)
        if r is not None:
            rates[s.name] = r

    return rates


@plugin.method("currencyrates")
def currencyrates(plugin, currency):
    """Gets currency from given APIs."""

    return get_rates(plugin, currency.upper())


@plugin.method("currencyconvert")
def currencyconvert(plugin, amount, currency):
    """Converts currency using given APIs."""
    rates = get_rates(plugin, currency.upper())
    if len(rates) == 0:
        raise Exception("No values available for currency {}".format(currency.upper()))
    val = statistics.median([m.millisatoshis for m in rates.values()]) * float(amount)
    return {"msat": Millisatoshi(round(val))}


@plugin.init()
def init(options, configuration, plugin):
    set_proxies(plugin)

    sourceopts = options['add-source']
    # Prior to 0.9.3, 'multi' was unsupported.
    if type(sourceopts) is not list:
        sourceopts = [sourceopts]
    if sourceopts != ['']:
        for s in sourceopts:
            parts = s.split(',')
            sources.append(Source(parts[0], parts[1], parts[2:]))

    disableopts = options['disable-source']
    # Prior to 0.9.3, 'multi' was unsupported.
    if type(disableopts) is not list:
        disableopts = [disableopts]
    if disableopts != ['']:
        for s in sources[:]:
            if s.name in disableopts:
                sources.remove(s)


# As a bad example: binance,https://api.binance.com/api/v3/ticker/price?symbol=BTC{currency}T,price
plugin.add_option(name='add-source', default='', description='Add source name,urlformat,resultmembers...')
plugin.add_option(name='disable-source', default='', description='Disable source by name')

# This has an effect only for recent pyln versions (0.9.3+).
plugin.options['add-source']['multi'] = True
plugin.options['disable-source']['multi'] = True

plugin.run()