from PyQt4.QtGui import *
from PyQt4.QtCore import *

from datetime import datetime
import inspect
import requests
import sys
from threading import Thread
import time
import traceback
from decimal import Decimal
from functools import partial

from electrum.bitcoin import COIN
from electrum.plugins import BasePlugin, hook
from electrum.i18n import _
from electrum.util import PrintError, ThreadJob, timestamp_to_datetime
from electrum.util import format_satoshis
from electrum_gui.qt.util import *
from electrum_gui.qt.amountedit import AmountEdit

# 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, 'XAG': 2, 'XAU': 4, 'XOF': 0,
                  'XPF': 0}

class ExchangeBase(PrintError):
    def __init__(self, sig):
        self.history = {}
        self.quotes = {}
        self.sig = sig

    def protocol(self):
        return "https"

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

    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")
            self.sig.emit(SIGNAL('fx_quotes'))
        except Exception, e:
            self.print_error("failed fx quotes:", e)

    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.sig.emit(SIGNAL("fx_history"))
        except Exception, 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'))


class BitcoinAverage(ExchangeBase):
    def update(self, ccy):
        json = self.get_json('api.bitcoinaverage.com', '/ticker/global/all')
        return dict([(r, Decimal(json[r]['last']))
                     for r in json if r != 'timestamp'])

class BitcoinVenezuela(ExchangeBase):
    def get_rates(self, ccy):
        json = self.get_json('api.bitcoinvenezuela.com', '/')
        return dict([(r, Decimal(json['BTC'][r]))
                     for r in json['BTC']])

    def protocol(self):
        return "http"

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

    def protocol(self):
        return "http"

class Bitcurex(ExchangeBase):
    def get_rates(self, ccy):
        json = self.get_json('pln.bitcurex.com', '/data/ticker.json')
        pln_price = json['last']
        return {'PLN': Decimal(pln_price)}

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 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])

    def name(self):
        return "Blockchain"

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

class CaVirtEx(ExchangeBase):
    def get_rates(self, ccy):
        json = self.get_json('www.cavirtex.com', '/api/CAD/ticker.json')
        return {'CAD': Decimal(json['last'])}

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 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 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 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])


class Plugin(BasePlugin, ThreadJob):

    def __init__(self, parent, config, name):
        BasePlugin.__init__(self, parent, config, name)
        # Signal object first
        self.sig = QObject()
        self.sig.connect(self.sig, SIGNAL('fx_quotes'), self.on_fx_quotes)
        self.sig.connect(self.sig, SIGNAL('fx_history'), self.on_fx_history)
        self.ccy = self.config_ccy()
        self.history_used_spot = False
        self.ccy_combo = None
        self.hist_checkbox = None
        self.windows = dict()

        is_exchange = lambda obj: (inspect.isclass(obj)
                                   and issubclass(obj, ExchangeBase)
                                   and obj != ExchangeBase)
        self.exchanges = dict(inspect.getmembers(sys.modules[__name__],
                                                 is_exchange))
        self.set_exchange(self.config_exchange())

    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 thread_jobs(self):
        return [self]

    def run(self):
        # This runs from the network thread which catches exceptions
        if self.windows and self.timeout <= time.time():
            self.timeout = time.time() + 150
            self.exchange.update(self.ccy)

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

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

    def config_history(self):
        return self.config.get('history_rates', 'unchecked') != 'unchecked'

    def show_history(self):
        return self.config_history() and self.exchange.history_ccys()

    def set_exchange(self, name):
        class_ = self.exchanges.get(name) or self.exchanges.values()[0]
        name = class_.__name__
        self.print_error("using exchange", name)
        if self.config_exchange() != name:
            self.config.set_key('use_exchange', name, True)
        self.exchange = class_(self.sig)
        # A new exchange means new fx quotes, initially empty.  Force
        # a quote refresh
        self.timeout = 0
        self.get_historical_rates()
        self.on_fx_quotes()

    def update_status_bars(self):
        '''Update status bar fiat balance in all windows'''
        for window in self.windows:
            window.update_status()

    def on_new_window(self, window):
        # Additional send and receive edit boxes
        send_e = AmountEdit(self.config_ccy)
        window.send_grid.addWidget(send_e, 4, 3, Qt.AlignHCenter)
        window.amount_e.frozen.connect(
            lambda: send_e.setFrozen(window.amount_e.isReadOnly()))
        receive_e = AmountEdit(self.config_ccy)
        window.receive_grid.addWidget(receive_e, 2, 3, Qt.AlignHCenter)

        self.windows[window] = {'edits': (send_e, receive_e),
                                'last_edited': {}}
        self.connect_fields(window, window.amount_e, send_e, window.fee_e)
        self.connect_fields(window, window.receive_amount_e, receive_e, None)
        window.history_list.refresh_headers()
        window.update_status()

    def connect_fields(self, window, btc_e, fiat_e, fee_e):
        last_edited = self.windows[window]['last_edited']

        def edit_changed(edit):
            edit.setStyleSheet(BLACK_FG)
            last_edited[(fiat_e, btc_e)] = edit
            amount = edit.get_amount()
            rate = self.exchange_rate()
            if rate is None or amount is None:
                if edit is fiat_e:
                    btc_e.setText("")
                    if fee_e:
                        fee_e.setText("")
                else:
                    fiat_e.setText("")
            else:
                if edit is fiat_e:
                    btc_e.setAmount(int(amount / Decimal(rate) * COIN))
                    if fee_e: window.update_fee()
                    btc_e.setStyleSheet(BLUE_FG)
                else:
                    fiat_e.setText(self.ccy_amount_str(
                        amount * Decimal(rate) / COIN, False))
                    fiat_e.setStyleSheet(BLUE_FG)

        fiat_e.textEdited.connect(partial(edit_changed, fiat_e))
        btc_e.textEdited.connect(partial(edit_changed, btc_e))
        last_edited[(fiat_e, btc_e)] = btc_e

    @hook
    def do_clear(self, window):
        self.windows[window]['edits'][0].setText('')

    def on_close_window(self, window):
        self.windows.pop(window)

    def close(self):
        # Get rid of hooks before updating status bars.
        BasePlugin.close(self)
        self.update_status_bars()
        self.refresh_headers()
        for window, data in self.windows.items():
            for edit in data['edits']:
                edit.hide()
            window.update_status()

    def refresh_headers(self):
        for window in self.windows:
            window.history_list.refresh_headers()

    def on_fx_history(self):
        '''Called when historical fx quotes are updated'''
        for window in self.windows:
            window.update_history_tab()

    def on_fx_quotes(self):
        '''Called when fresh spot fx quotes come in'''
        self.update_status_bars()
        self.populate_ccy_combo()
        # Refresh edits with the new rate
        for window, data in self.windows.items():
            for edit in data['last_edited'].values():
                edit.textEdited.emit(edit.text())
        # History tab needs updating if it used spot
        if self.history_used_spot:
            self.on_fx_history()

    def on_ccy_combo_change(self):
        '''Called when the chosen currency changes'''
        ccy = str(self.ccy_combo.currentText())
        if ccy and ccy != self.ccy:
            self.ccy = ccy
            self.config.set_key('currency', ccy, True)
            self.update_status_bars()
            self.get_historical_rates() # Because self.ccy changes
            self.hist_checkbox_update()

    def hist_checkbox_update(self):
        if self.hist_checkbox:
            self.hist_checkbox.setEnabled(self.ccy in self.exchange.history_ccys())
            self.hist_checkbox.setChecked(self.config_history())

    def populate_ccy_combo(self):
        # There should be at most one instance of the settings dialog
        combo = self.ccy_combo
        # NOTE: bool(combo) is False if it is empty.  Nuts.
        if combo is not None:
            combo.blockSignals(True)
            combo.clear()
            combo.addItems(sorted(self.exchange.quotes.keys()))
            combo.blockSignals(False)
            combo.setCurrentIndex(combo.findText(self.ccy))

    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)

    @hook
    def get_fiat_status_text(self, btc_balance, result):
        # return status as:   (1.23 USD)    1 BTC~123.45 USD
        rate = self.exchange_rate()
        if rate is None:
            text = _("  (No FX rate available)")
        else:
            text =  "  (%s %s)    1 BTC~%s %s" % (self.value_str(btc_balance, rate), self.ccy,
                                                  self.value_str(COIN, rate), self.ccy)
        result['text'] = text

    def get_historical_rates(self):
        if self.show_history():
            self.exchange.get_historical_rates(self.ccy)

    def requires_settings(self):
        return True

    def value_str(self, satoshis, rate):
        if rate:
            value = Decimal(satoshis) / COIN * Decimal(rate)
            return "%s" % (self.ccy_amount_str(value, True))
        return _("No data")

    def historical_value_str(self, satoshis, 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 self.value_str(satoshis, rate)

    @hook
    def history_tab_headers(self, headers):
        if self.show_history():
            headers.extend(['%s '%self.ccy + _('Amount'), '%s '%self.ccy + _('Balance')])

    @hook
    def history_tab_update_begin(self):
        self.history_used_spot = False

    @hook
    def history_tab_update(self, tx, entry):
        if not self.show_history():
            return
        tx_hash, conf, value, timestamp, balance = tx
        date = timestamp_to_datetime(timestamp)
        if not date:
            date = timestamp_to_datetime(0)
        for amount in [value, balance]:
            text = self.historical_value_str(amount, date)
            entry.append(text)

    def settings_widget(self, window):
        return EnterButton(_('Settings'), self.settings_dialog)

    def settings_dialog(self):
        d = QDialog()
        d.setWindowTitle("Settings")
        layout = QGridLayout(d)
        layout.addWidget(QLabel(_('Exchange rate API: ')), 0, 0)
        layout.addWidget(QLabel(_('Currency: ')), 1, 0)
        layout.addWidget(QLabel(_('History Rates: ')), 2, 0)

        # Currency list
        self.ccy_combo = QComboBox()
        self.ccy_combo.currentIndexChanged.connect(self.on_ccy_combo_change)
        self.populate_ccy_combo()

        def on_change_ex(idx):
            exchange = str(combo_ex.currentText())
            if exchange != self.exchange.name():
                self.set_exchange(exchange)
                self.hist_checkbox_update()

        def on_change_hist(checked):
            if checked:
                self.config.set_key('history_rates', 'checked')
                self.get_historical_rates()
            else:
                self.config.set_key('history_rates', 'unchecked')
            self.refresh_headers()

        def ok_clicked():
            self.timeout = 0
            self.ccy_combo = None
            d.accept()

        combo_ex = QComboBox()
        combo_ex.addItems(sorted(self.exchanges.keys()))
        combo_ex.setCurrentIndex(combo_ex.findText(self.config_exchange()))
        combo_ex.currentIndexChanged.connect(on_change_ex)

        self.hist_checkbox = QCheckBox()
        self.hist_checkbox.stateChanged.connect(on_change_hist)
        self.hist_checkbox_update()

        ok_button = QPushButton(_("OK"))
        ok_button.clicked.connect(lambda: ok_clicked())

        layout.addWidget(self.ccy_combo,1,1)
        layout.addWidget(combo_ex,0,1)
        layout.addWidget(self.hist_checkbox,2,1)
        layout.addWidget(ok_button,3,1)

        return d.exec_()