import math
from enum import Enum, auto
from typing import override

from internal_types.types import OHLC, BidAsk, Instrument, Position
from strategy.strategy import Strategy
from utils.utils import Portfolio


class State(Enum):
  POS_0 = auto()
  POS_1 = auto()


class BuyAndHold(Strategy):

  def __init__(self, init_balance, instr: Instrument):
    self.state = State.POS_0
    self.balance = init_balance
    self.instr = instr
    self.portfolio = Portfolio()
    self.desired_portfolio = Portfolio()

  def __process(self, at_price: float):
    match self.state:
      case State.POS_0:
        quantity = math.floor(self.balance / at_price / self.instr.multiplier)
        self.desired_portfolio.add_position(Position(self.instr, quantity, at_price))
        self.state = State.POS_1
      case State.POS_1:
        pass
      case _:
        raise RuntimeError('invalid state')

  @override
  def unfilled_positions(self, instr: Instrument) -> Position:
    x = self.desired_portfolio.outstanding_shares(instr) - self.portfolio.outstanding_shares(instr)
    return self.desired_portfolio.consolidate_last_x_shares(instr, x)

  @override
  def order_filled(self, new_pos: Position):
    self.portfolio.add_position(new_pos)

  @override
  def process_bid_ask(self, bid_ask: BidAsk):
    if bid_ask.instr != self.instr:
      return
    self.__process(bid_ask.ask)

  @override
  def process_ohlc(self, ohlc: OHLC):
    if ohlc.instr != self.instr:
      return
    self.__process(ohlc.close)

  @override
  def net_liquid_value(self, at_price: float) -> float:
    return self.balance + self.portfolio.total_gains(self.instr, at_price)