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# Lean Algorithmic Trading Engine v2.0. Copyright 2014 QuantConnect Corporation.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
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from AlgorithmImports import *

import itertools

from OptionStrategyFactoryMethodsBaseAlgorithm import *

### <summary>
### This algorithm demonstrate how to use OptionStrategies helper class to batch send orders for common strategies.
### In this case, the algorithm tests the Butterfly Put and Short Butterfly Put strategies.
### </summary>
class LongAndShortButterflyPutStrategiesAlgorithm(OptionStrategyFactoryMethodsBaseAlgorithm):

    def ExpectedOrdersCount(self) -> int:
        return 6

    def TradeStrategy(self, chain: OptionChain, option_symbol: Symbol):
        putContracts = (contract for contract in chain if contract.Right == OptionRight.Put)

        for expiry, group in itertools.groupby(putContracts, lambda x: x.Expiry):
            contracts = list(group)
            if len(contracts) < 3:
                continue

            strikes = sorted([contract.Strike for contract in contracts])
            atmStrike = min(strikes, key=lambda strike: abs(strike - chain.Underlying.Price))
            spread = min(atmStrike - strikes[0], strikes[-1] - atmStrike)
            itmStrike = atmStrike + spread
            otmStrike = atmStrike - spread

            if otmStrike in strikes and itmStrike in strikes:
                # Ready to trade
                self._butterfly_put = OptionStrategies.ButterflyPut(option_symbol, itmStrike, atmStrike, otmStrike, expiry)
                self._short_butterfly_put = OptionStrategies.ShortButterflyPut(option_symbol, itmStrike, atmStrike, otmStrike, expiry)
                self.Buy(self._butterfly_put, 2)
                return

    def AssertStrategyPositionGroup(self, positionGroup: IPositionGroup, option_symbol: Symbol):
        positions = list(positionGroup.Positions)
        if len(positions) != 3:
            raise Exception(f"Expected position group to have 3 positions. Actual: {len(positions)}")

        higherStrike = max(leg.Strike for leg in self._butterfly_put.OptionLegs)
        higherStrikePosition = next((position for position in positions
                                      if position.Symbol.ID.OptionRight == OptionRight.Put and position.Symbol.ID.StrikePrice == higherStrike),
                                     None)

        if higherStrikePosition.Quantity != 2:
            raise Exception(f"Expected higher strike position quantity to be 2. Actual: {higherStrikePosition.Quantity}")

        lowerStrike = min(leg.Strike for leg in self._butterfly_put.OptionLegs)
        lowerStrikePosition = next((position for position in positions
                                    if position.Symbol.ID.OptionRight == OptionRight.Put and position.Symbol.ID.StrikePrice == lowerStrike),
                                   None)

        if lowerStrikePosition.Quantity != 2:
            raise Exception(f"Expected lower strike position quantity to be 2. Actual: {lowerStrikePosition.Quantity}")

        middleStrike = [leg.Strike for leg in self._butterfly_put.OptionLegs if leg.Strike < higherStrike and leg.Strike > lowerStrike][0]
        middleStrikePosition = next((position for position in positions
                                     if position.Symbol.ID.OptionRight == OptionRight.Put and position.Symbol.ID.StrikePrice == middleStrike),
                                    None)

        if middleStrikePosition.Quantity != -4:
            raise Exception(f"Expected middle strike position quantity to be -4. Actual: {middleStrikePosition.Quantity}")

    def LiquidateStrategy(self):
        # We should be able to close the position using the inverse strategy (a short butterfly put)
        self.Buy(self._short_butterfly_put, 2);