from datetime import datetime
import inspect
import requests
import sys
from threading import Thread
import time
import csv
from decimal import Decimal

from .bitcoin import COIN
from .i18n import _
from .util import PrintError, ThreadJob


# See https://en.wikipedia.org/wiki/ISO_4217
CCY_PRECISIONS = {'BHD': 3, 'BIF': 0, 'BYR': 0, 'CLF': 4, 'CLP': 0,
                  'CVE': 0, 'DJF': 0, 'GNF': 0, 'IQD': 3, 'ISK': 0,
                  'JOD': 3, 'JPY': 0, 'KMF': 0, 'KRW': 0, 'KWD': 3,
                  'LYD': 3, 'MGA': 1, 'MRO': 1, 'OMR': 3, 'PYG': 0,
                  'RWF': 0, 'TND': 3, 'UGX': 0, 'UYI': 0, 'VND': 0,
                  'VUV': 0, 'XAF': 0, 'XAU': 4, 'XOF': 0, 'XPF': 0}


class ExchangeBase(PrintError):

    def __init__(self, on_quotes, on_history):
        self.history = {}
        self.quotes = {}
        self.on_quotes = on_quotes
        self.on_history = on_history

    def get_json(self, site, get_string):
        # APIs must have https
        url = ''.join(['https://', site, get_string])
        response = requests.request('GET', url, headers={'User-Agent' : 'Electrum'})
        return response.json()

    def get_csv(self, site, get_string):
        url = ''.join(['https://', site, get_string])
        response = requests.request('GET', url, headers={'User-Agent' : 'Electrum'})
        reader = csv.DictReader(response.content.decode().split('\n'))
        return list(reader)

    def name(self):
        return self.__class__.__name__

    def update_safe(self, ccy):
        try:
            self.print_error("getting fx quotes for", ccy)
            self.quotes = self.get_rates(ccy)
            self.print_error("received fx quotes")
        except BaseException as e:
            self.print_error("failed fx quotes:", e)
        self.on_quotes()

    def update(self, ccy):
        t = Thread(target=self.update_safe, args=(ccy,))
        t.setDaemon(True)
        t.start()

    def get_historical_rates_safe(self, ccy):
        try:
            self.print_error("requesting fx history for", ccy)
            self.history[ccy] = self.historical_rates(ccy)
            self.print_error("received fx history for", ccy)
            self.on_history()
        except BaseException as e:
            self.print_error("failed fx history:", e)

    def get_historical_rates(self, ccy):
        result = self.history.get(ccy)
        if not result and ccy in self.history_ccys():
            t = Thread(target=self.get_historical_rates_safe, args=(ccy,))
            t.setDaemon(True)
            t.start()
        return result

    def history_ccys(self):
        return []

    def historical_rate(self, ccy, d_t):
        return self.history.get(ccy, {}).get(d_t.strftime('%Y-%m-%d'))

    def get_currencies(self):
        rates = self.get_rates('')
        return sorted([str(a) for (a, b) in rates.items() if b is not None and len(a)==3])


class BitcoinAverage(ExchangeBase):

    def get_rates(self, ccy):
        json = self.get_json('apiv2.bitcoinaverage.com', '/indices/global/ticker/short')
        return dict([(r.replace("BTC", ""), Decimal(json[r]['last']))
                     for r in json if r != 'timestamp'])

    def history_ccys(self):
        return ['AUD', 'BRL', 'CAD', 'CHF', 'CNY', 'EUR', 'GBP', 'IDR', 'ILS',
                'MXN', 'NOK', 'NZD', 'PLN', 'RON', 'RUB', 'SEK', 'SGD', 'USD',
                'ZAR']

    def historical_rates(self, ccy):
        history = self.get_csv('apiv2.bitcoinaverage.com',
                               "/indices/global/history/BTC%s?period=alltime&format=csv" % ccy)
        return dict([(h['DateTime'][:10], h['Average'])
                     for h in history])


class Bitcointoyou(ExchangeBase):

    def get_rates(self, ccy):
        json = self.get_json('bitcointoyou.com', "/API/ticker.aspx")
        return {'BRL': Decimal(json['ticker']['last'])}

    def history_ccys(self):
        return ['BRL']


class BitcoinVenezuela(ExchangeBase):

    def get_rates(self, ccy):
        json = self.get_json('api.bitcoinvenezuela.com', '/')
        rates = [(r, json['BTC'][r]) for r in json['BTC']
                 if json['BTC'][r] is not None]  # Giving NULL for LTC
        return dict(rates)

    def history_ccys(self):
        return ['ARS', 'EUR', 'USD', 'VEF']

    def historical_rates(self, ccy):
        return self.get_json('api.bitcoinvenezuela.com',
                             "/historical/index.php?coin=BTC")[ccy +'_BTC']


class Bitmarket(ExchangeBase):

    def get_rates(self, ccy):
        json = self.get_json('www.bitmarket.pl', '/json/BTCPLN/ticker.json')
        return {'PLN': Decimal(json['last'])}


class BitPay(ExchangeBase):

    def get_rates(self, ccy):
        json = self.get_json('bitpay.com', '/api/rates')
        return dict([(r['code'], Decimal(r['rate'])) for r in json])


class Bitso(ExchangeBase):

    def get_rates(self, ccy):
        json = self.get_json('api.bitso.com', '/v2/ticker')
        return {'MXN': Decimal(json['last'])}


class BitStamp(ExchangeBase):

    def get_rates(self, ccy):
        json = self.get_json('www.bitstamp.net', '/api/ticker/')
        return {'USD': Decimal(json['last'])}


class Bitvalor(ExchangeBase):

    def get_rates(self,ccy):
        json = self.get_json('api.bitvalor.com', '/v1/ticker.json')
        return {'BRL': Decimal(json['ticker_1h']['total']['last'])}


class BlockchainInfo(ExchangeBase):

    def get_rates(self, ccy):
        json = self.get_json('blockchain.info', '/ticker')
        return dict([(r, Decimal(json[r]['15m'])) for r in json])


class BTCChina(ExchangeBase):

    def get_rates(self, ccy):
        json = self.get_json('data.btcchina.com', '/data/ticker')
        return {'CNY': Decimal(json['ticker']['last'])}


class BTCParalelo(ExchangeBase):

    def get_rates(self, ccy):
        json = self.get_json('btcparalelo.com', '/api/price')
        return {'VEF': Decimal(json['price'])}


class Coinbase(ExchangeBase):

    def get_rates(self, ccy):
        json = self.get_json('coinbase.com',
                             '/api/v1/currencies/exchange_rates')
        return dict([(r[7:].upper(), Decimal(json[r]))
                     for r in json if r.startswith('btc_to_')])


class CoinDesk(ExchangeBase):

    def get_rates(self, ccy):
        dicts = self.get_json('api.coindesk.com',
                              '/v1/bpi/supported-currencies.json')
        json = self.get_json('api.coindesk.com',
                             '/v1/bpi/currentprice/%s.json' % ccy)
        ccys = [d['currency'] for d in dicts]
        result = dict.fromkeys(ccys)
        result[ccy] = Decimal(json['bpi'][ccy]['rate_float'])
        return result

    def history_starts(self):
        return { 'USD': '2012-11-30' }

    def history_ccys(self):
        return self.history_starts().keys()

    def historical_rates(self, ccy):
        start = self.history_starts()[ccy]
        end = datetime.today().strftime('%Y-%m-%d')
        # Note ?currency and ?index don't work as documented.  Sigh.
        query = ('/v1/bpi/historical/close.json?start=%s&end=%s'
                 % (start, end))
        json = self.get_json('api.coindesk.com', query)
        return json['bpi']


class Coinsecure(ExchangeBase):

    def get_rates(self, ccy):
        json = self.get_json('api.coinsecure.in', '/v0/noauth/newticker')
        return {'INR': Decimal(json['lastprice'] / 100.0 )}


class Foxbit(ExchangeBase):

    def get_rates(self,ccy):
        json = self.get_json('api.bitvalor.com', '/v1/ticker.json')
        return {'BRL': Decimal(json['ticker_1h']['exchanges']['FOX']['last'])}


class itBit(ExchangeBase):

    def get_rates(self, ccy):
        ccys = ['USD', 'EUR', 'SGD']
        json = self.get_json('api.itbit.com', '/v1/markets/XBT%s/ticker' % ccy)
        result = dict.fromkeys(ccys)
        if ccy in ccys:
            result[ccy] = Decimal(json['lastPrice'])
        return result


class Kraken(ExchangeBase):

    def get_rates(self, ccy):
        ccys = ['EUR', 'USD', 'CAD', 'GBP', 'JPY']
        pairs = ['XBT%s' % c for c in ccys]
        json = self.get_json('api.kraken.com',
                             '/0/public/Ticker?pair=%s' % ','.join(pairs))
        return dict((k[-3:], Decimal(float(v['c'][0])))
                     for k, v in json['result'].items())


class LocalBitcoins(ExchangeBase):

    def get_rates(self, ccy):
        json = self.get_json('localbitcoins.com',
                             '/bitcoinaverage/ticker-all-currencies/')
        return dict([(r, Decimal(json[r]['rates']['last'])) for r in json])


class MercadoBitcoin(ExchangeBase):

    def get_rates(self, ccy):
        json = self.get_json('api.bitvalor.com', '/v1/ticker.json')
        return {'BRL': Decimal(json['ticker_1h']['exchanges']['MBT']['last'])}


class NegocieCoins(ExchangeBase):

    def get_rates(self,ccy):
        json = self.get_json('api.bitvalor.com', '/v1/ticker.json')
        return {'BRL': Decimal(json['ticker_1h']['exchanges']['NEG']['last'])}

    def history_ccys(self):
        return ['BRL']


class Unocoin(ExchangeBase):

    def get_rates(self, ccy):
        json = self.get_json('www.unocoin.com', 'trade?buy')
        return {'INR': Decimal(json)}


class WEX(ExchangeBase):

    def get_rates(self, ccy):
        json_eur = self.get_json('wex.nz', '/api/3/ticker/btc_eur')
        json_rub = self.get_json('wex.nz', '/api/3/ticker/btc_rur')
        json_usd = self.get_json('wex.nz', '/api/3/ticker/btc_usd')
        return {'EUR': Decimal(json_eur['btc_eur']['last']),
                'RUB': Decimal(json_rub['btc_rur']['last']),
                'USD': Decimal(json_usd['btc_usd']['last'])}


class Winkdex(ExchangeBase):

    def get_rates(self, ccy):
        json = self.get_json('winkdex.com', '/api/v0/price')
        return {'USD': Decimal(json['price'] / 100.0)}

    def history_ccys(self):
        return ['USD']

    def historical_rates(self, ccy):
        json = self.get_json('winkdex.com',
                             "/api/v0/series?start_time=1342915200")
        history = json['series'][0]['results']
        return dict([(h['timestamp'][:10], h['price'] / 100.0)
                     for h in history])


def dictinvert(d):
    inv = {}
    for k, vlist in d.items():
        for v in vlist:
            keys = inv.setdefault(v, [])
            keys.append(k)
    return inv

def get_exchanges_and_currencies():
    import os, json
    path = os.path.join(os.path.dirname(__file__), 'currencies.json')
    try:
        with open(path, 'r') as f:
            return json.loads(f.read())
    except:
        pass
    d = {}
    is_exchange = lambda obj: (inspect.isclass(obj)
                               and issubclass(obj, ExchangeBase)
                               and obj != ExchangeBase)
    exchanges = dict(inspect.getmembers(sys.modules[__name__], is_exchange))
    for name, klass in exchanges.items():
        exchange = klass(None, None)
        try:
            d[name] = exchange.get_currencies()
        except:
            continue
    with open(path, 'w') as f:
        f.write(json.dumps(d, indent=4, sort_keys=True))
    return d


CURRENCIES = get_exchanges_and_currencies()


def get_exchanges_by_ccy(history=True):
    if not history:
        return dictinvert(CURRENCIES)
    d = {}
    exchanges = CURRENCIES.keys()
    for name in exchanges:
        klass = globals()[name]
        exchange = klass(None, None)
        d[name] = exchange.history_ccys()
    return dictinvert(d)


class FxThread(ThreadJob):

    def __init__(self, config, network):
        self.config = config
        self.network = network
        self.ccy = self.get_currency()
        self.history_used_spot = False
        self.ccy_combo = None
        self.hist_checkbox = None
        self.set_exchange(self.config_exchange())

    def get_currencies(self, h):
        d = get_exchanges_by_ccy(h)
        return sorted(d.keys())

    def get_exchanges_by_ccy(self, ccy, h):
        d = get_exchanges_by_ccy(h)
        return d.get(ccy, [])

    def ccy_amount_str(self, amount, commas):
        prec = CCY_PRECISIONS.get(self.ccy, 2)
        fmt_str = "{:%s.%df}" % ("," if commas else "", max(0, prec))
        return fmt_str.format(round(amount, prec))

    def run(self):
        # This runs from the plugins thread which catches exceptions
        if self.is_enabled():
            if self.timeout ==0 and self.show_history():
                self.exchange.get_historical_rates(self.ccy)
            if self.timeout <= time.time():
                self.timeout = time.time() + 150
                self.exchange.update(self.ccy)

    def is_enabled(self):
        return bool(self.config.get('use_exchange_rate'))

    def set_enabled(self, b):
        return self.config.set_key('use_exchange_rate', bool(b))

    def get_history_config(self):
        return bool(self.config.get('history_rates'))

    def set_history_config(self, b):
        self.config.set_key('history_rates', bool(b))

    def get_fiat_address_config(self):
        return bool(self.config.get('fiat_address'))

    def set_fiat_address_config(self, b):
        self.config.set_key('fiat_address', bool(b))

    def get_currency(self):
        '''Use when dynamic fetching is needed'''
        return self.config.get("currency", "EUR")

    def config_exchange(self):
        return self.config.get('use_exchange', 'BitcoinAverage')

    def show_history(self):
        return self.is_enabled() and self.get_history_config() and self.ccy in self.exchange.history_ccys()

    def set_currency(self, ccy):
        self.ccy = ccy
        self.config.set_key('currency', ccy, True)
        self.timeout = 0 # Because self.ccy changes
        self.on_quotes()

    def set_exchange(self, name):
        class_ = globals().get(name, BitcoinAverage)
        self.print_error("using exchange", name)
        if self.config_exchange() != name:
            self.config.set_key('use_exchange', name, True)
        self.exchange = class_(self.on_quotes, self.on_history)
        # A new exchange means new fx quotes, initially empty.  Force
        # a quote refresh
        self.timeout = 0

    def on_quotes(self):
        self.network.trigger_callback('on_quotes')

    def on_history(self):
        self.network.trigger_callback('on_history')

    def exchange_rate(self):
        '''Returns None, or the exchange rate as a Decimal'''
        rate = self.exchange.quotes.get(self.ccy)
        if rate:
            return Decimal(rate)

    def format_amount_and_units(self, btc_balance):
        rate = self.exchange_rate()
        return '' if rate is None else "%s %s" % (self.value_str(btc_balance, rate), self.ccy)

    def get_fiat_status_text(self, btc_balance, base_unit, decimal_point):
        rate = self.exchange_rate()
        return _("  (No FX rate available)") if rate is None else " 1 %s~%s %s" % (base_unit,
            self.value_str(COIN / (10**(8 - decimal_point)), rate), self.ccy)

    def value_str(self, satoshis, rate):
        if satoshis is None:  # Can happen with incomplete history
            return _("Unknown")
        if rate:
            value = Decimal(satoshis) / COIN * Decimal(rate)
            return "%s" % (self.ccy_amount_str(value, True))
        return _("No data")

    def history_rate(self, d_t):
        rate = self.exchange.historical_rate(self.ccy, d_t)
        # Frequently there is no rate for today, until tomorrow :)
        # Use spot quotes in that case
        if rate is None and (datetime.today().date() - d_t.date()).days <= 2:
            rate = self.exchange.quotes.get(self.ccy)
            self.history_used_spot = True
        return rate

    def historical_value_str(self, satoshis, d_t):
        rate = self.history_rate(d_t)
        return self.value_str(satoshis, rate)
