from ccxt import ExchangeError, NotSupported
import ccxt_wrapper as ccxt
import time
from store import *
from cachetools.func import ttl_cache

class Market:
    debug = False
    ccxt = None
    report = None
    trades = None
    balances = None

    def __init__(self, ccxt_instance, debug=False):
        self.debug = debug
        self.ccxt = ccxt_instance
        self.ccxt._market = self
        self.report = ReportStore(self)
        self.trades = TradeStore(self)
        self.balances = BalanceStore(self)

    @classmethod
    def from_config(cls, config, debug=False):
        config["apiKey"] = config.pop("key")

        ccxt_instance = ccxt.poloniexE(config)

        # For requests logging
        ccxt_instance.session.origin_request = ccxt_instance.session.request
        ccxt_instance.session._parent = ccxt_instance

        def request_wrap(self, *args, **kwargs):
            r = self.origin_request(*args, **kwargs)
            self._parent._market.report.log_http_request(args[0],
                    args[1], kwargs["data"], kwargs["headers"], r)
            return r
        ccxt_instance.session.request = request_wrap.__get__(ccxt_instance.session,
                ccxt_instance.session.__class__)

        return cls(ccxt_instance, debug=debug)

    def move_balances(self):
        needed_in_margin = {} 
        moving_to_margin = {}

        for currency, balance in self.balances.all.items():
            needed_in_margin[currency] = balance.margin_in_position - balance.margin_pending_gain
        for trade in self.trades.pending:
            needed_in_margin.setdefault(trade.base_currency, 0)
            if trade.trade_type == "short":
                needed_in_margin[trade.base_currency] -= trade.delta
        for currency, needed in needed_in_margin.items():
            current_balance = self.balances.all[currency].margin_available
            moving_to_margin[currency] = (needed - current_balance)
            delta = moving_to_margin[currency].value
            if self.debug and delta != 0:
                self.report.log_debug_action("Moving {} from exchange to margin".format(moving_to_margin[currency]))
                continue
            if delta > 0:
                self.ccxt.transfer_balance(currency, delta, "exchange", "margin")
            elif delta < 0:
                self.ccxt.transfer_balance(currency, -delta, "margin", "exchange")
        self.report.log_move_balances(needed_in_margin, moving_to_margin)

        self.balances.fetch_balances()

    @ttl_cache(ttl=3600)
    def fetch_fees(self):
        return self.ccxt.fetch_fees()

    @ttl_cache(maxsize=20, ttl=5)
    def get_tickers(self, refresh=False):
        try:
            return self.ccxt.fetch_tickers()
        except NotSupported:
            return None

    @ttl_cache(maxsize=20, ttl=5)
    def get_ticker(self, c1, c2, refresh=False):
        def invert(ticker):
            return {
                    "inverted": True,
                    "average": (1/ticker["bid"] + 1/ticker["ask"]) / 2,
                    "original": ticker,
                    }
        def augment_ticker(ticker):
            ticker.update({
                "inverted": False,
                "average": (ticker["bid"] + ticker["ask"] ) / 2,
                })
            return ticker

        tickers = self.get_tickers()
        if tickers is None:
            try:
                ticker = augment_ticker(self.ccxt.fetch_ticker("{}/{}".format(c1, c2)))
            except ExchangeError:
                try:
                    ticker = invert(augment_ticker(self.ccxt.fetch_ticker("{}/{}".format(c2, c1))))
                except ExchangeError:
                    ticker = None
        else:
            if "{}/{}".format(c1, c2) in tickers:
                ticker = augment_ticker(tickers["{}/{}".format(c1, c2)])
            elif "{}/{}".format(c2, c1) in tickers:
                ticker = invert(augment_ticker(tickers["{}/{}".format(c2, c1)]))
            else:
                ticker = None
        return ticker

    def follow_orders(self, sleep=None):
        if sleep is None:
            sleep = 7 if self.debug else 30
            if self.debug:
                self.report.log_debug_action("Set follow_orders tick to {}s".format(sleep))
        tick = 0
        self.report.log_stage("follow_orders_begin")
        while len(self.trades.all_orders(state="open")) > 0:
            time.sleep(sleep)
            tick += 1
            open_orders = self.trades.all_orders(state="open")
            self.report.log_stage("follow_orders_tick_{}".format(tick))
            self.report.log_orders(open_orders, tick=tick)
            for order in open_orders:
                if order.get_status() != "open":
                    self.report.log_order(order, tick, finished=True)
                else:
                    order.trade.update_order(order, tick)
        self.report.log_stage("follow_orders_end")

    def prepare_trades(self, base_currency="BTC", liquidity="medium",
            compute_value="average", repartition=None, only=None):

        self.report.log_stage("prepare_trades",
                base_currency=base_currency, liquidity=liquidity,
                compute_value=compute_value, only=only,
                repartition=repartition)

        values_in_base = self.balances.in_currency(base_currency,
                compute_value=compute_value)
        total_base_value = sum(values_in_base.values())
        new_repartition = self.balances.dispatch_assets(total_base_value,
                liquidity=liquidity, repartition=repartition)
        self.trades.compute_trades(values_in_base, new_repartition, only=only)