# # ⚠ Warning
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
# LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
# NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#
# [🥭 Mango Markets](https://mango.markets/) support is available at:
#   [Docs](https://docs.mango.markets/)
#   [Discord](https://discord.gg/67jySBhxrg)
#   [Twitter](https://twitter.com/mangomarkets)
#   [Github](https://github.com/blockworks-foundation)
#   [Email](mailto:hello@blockworks.foundation)


import logging
import mango
import time
import traceback
import typing

from datetime import timedelta
from decimal import Decimal
from pathlib import Path


# # 🥭 SimpleMarketMaker class
#
# This is a simple demonstration of market making. It is intended to show how to do some things market
# makers require. It is not intended to be an actual, useful market maker.
#
# This market maker performs the following steps:
#
# 1. Cancel any orders
# 2. Update current state
#   2a. Fetch current prices
#   2b. Fetch current inventory
# 3. Figure out what orders to place
# 4. Place those orders
# 5. Sleep for a defined period
# 6. Repeat from Step 1
#
# There are many features missing that you'd expect in a more realistic market maker. Here are just a few:
# * There is very little error handling
# * There is no retrying of failed actions
# * There is no introspection on whether orders are filled
# * There is no inventory management, nor any attempt to balance number of filled buys with number of
#   filled sells.
# * Token prices and quantities are rounded to the token mint's decimals, not the market's tick size and
#   lot size
# * The strategy of placing orders at a fixed spread around the mid price without taking any other factors
#   into account is likely to be costly
# * Place and Cancel instructions aren't batched into single transactions
#
class SimpleMarketMaker:
    def __init__(
        self,
        context: mango.Context,
        wallet: mango.Wallet,
        market: mango.SerumMarket,
        market_operations: mango.MarketOperations,
        oracle: mango.Oracle,
        spread_ratio: Decimal,
        position_size_ratio: Decimal,
        existing_order_tolerance: Decimal,
        pause: timedelta,
    ) -> None:
        self._logger: logging.Logger = logging.getLogger(self.__class__.__name__)
        self.context: mango.Context = context
        self.wallet: mango.Wallet = wallet
        self.market: mango.SerumMarket = market
        self.market_operations: mango.MarketOperations = market_operations
        self.oracle: mango.Oracle = oracle
        self.spread_ratio: Decimal = spread_ratio
        self.position_size_ratio: Decimal = position_size_ratio
        self.existing_order_tolerance: Decimal = existing_order_tolerance
        self.pause: timedelta = pause
        self.stop_requested = False
        self.health_filename = "/var/tmp/mango_healthcheck_simple_market_maker"

    def start(self) -> None:
        # On startup there should be no existing orders. If we didn't exit cleanly last time though,
        # there may still be some hanging around. Cancel any existing orders so we start fresh.
        self.cleanup()

        while not self.stop_requested:
            self._logger.info("Starting fresh iteration.")

            try:
                # Update current state
                price = self.oracle.fetch_price(self.context)
                self._logger.info(f"Price is: {price}")
                inventory = self.fetch_inventory()

                # Calculate what we want the orders to be.
                bid, ask = self.calculate_order_prices(price)
                buy_quantity, sell_quantity = self.calculate_order_quantities(
                    price, inventory
                )

                current_orders = self.market_operations.load_my_orders(cutoff=None)
                buy_orders = [
                    order for order in current_orders if order.side == mango.Side.BUY
                ]
                if self.orders_require_action(buy_orders, bid, buy_quantity):
                    self._logger.info("Cancelling BUY orders.")
                    for order in buy_orders:
                        self.market_operations.cancel_order(order)
                    buy_order: mango.Order = mango.Order.from_values(
                        mango.Side.BUY, bid, buy_quantity, mango.OrderType.POST_ONLY
                    )
                    self.market_operations.place_order(buy_order)

                sell_orders = [
                    order for order in current_orders if order.side == mango.Side.SELL
                ]
                if self.orders_require_action(sell_orders, ask, sell_quantity):
                    self._logger.info("Cancelling SELL orders.")
                    for order in sell_orders:
                        self.market_operations.cancel_order(order)
                    sell_order: mango.Order = mango.Order.from_values(
                        mango.Side.SELL, ask, sell_quantity, mango.OrderType.POST_ONLY
                    )
                    self.market_operations.place_order(sell_order)

                self.update_health_on_successful_iteration()
            except Exception as exception:
                self._logger.warning(
                    f"Pausing and continuing after problem running market-making iteration: {exception} - {traceback.format_exc()}"
                )

            # Wait and hope for fills.
            self._logger.info(f"Pausing for {self.pause} seconds.")
            time.sleep(self.pause.seconds)

        self._logger.info("Stopped.")

        self.cleanup()

    def stop(self) -> None:
        self._logger.info("Stop requested.")
        self.stop_requested = True
        Path(self.health_filename).unlink(missing_ok=True)

    def cleanup(self) -> None:
        self._logger.info("Cleaning up.")
        orders = self.market_operations.load_my_orders(cutoff=None)
        for order in orders:
            self.market_operations.cancel_order(order)

    def fetch_inventory(
        self,
    ) -> typing.Sequence[typing.Optional[mango.InstrumentValue]]:
        if self.market.inventory_source == mango.InventorySource.SPL_TOKENS:
            base_account = mango.TokenAccount.fetch_largest_for_owner_and_token(
                self.context, self.wallet.address, self.market.base
            )
            if base_account is None:
                raise Exception(
                    f"Could not find token account owned by {self.wallet.address} for base token {self.market.base}."
                )
            quote_account = mango.TokenAccount.fetch_largest_for_owner_and_token(
                self.context, self.wallet.address, self.market.quote
            )
            if quote_account is None:
                raise Exception(
                    f"Could not find token account owned by {self.wallet.address} for quote token {self.market.quote}."
                )
            return [base_account.value, quote_account.value]
        else:
            group = mango.Group.load(self.context)
            accounts = mango.Account.load_all_for_owner(
                self.context, self.wallet.address, group
            )
            if len(accounts) == 0:
                raise Exception("No Mango account found.")

            account = accounts[0]
            return account.net_values_by_index

    def calculate_order_prices(
        self, price: mango.Price
    ) -> typing.Tuple[Decimal, Decimal]:
        bid = price.mid_price - (price.mid_price * self.spread_ratio)
        ask = price.mid_price + (price.mid_price * self.spread_ratio)

        return (bid, ask)

    def calculate_order_quantities(
        self,
        price: mango.Price,
        inventory: typing.Sequence[typing.Optional[mango.InstrumentValue]],
    ) -> typing.Tuple[Decimal, Decimal]:
        base_tokens: typing.Optional[
            mango.InstrumentValue
        ] = mango.InstrumentValue.find_by_token(inventory, self.market.base)
        if base_tokens is None:
            raise Exception(
                f"Could not find market-maker base token {self.market.base.symbol} in inventory."
            )

        quote_tokens: typing.Optional[
            mango.InstrumentValue
        ] = mango.InstrumentValue.find_by_token(inventory, self.market.quote)
        if quote_tokens is None:
            raise Exception(
                f"Could not find market-maker quote token {self.market.quote.symbol} in inventory."
            )

        buy_quantity = base_tokens.value * self.position_size_ratio
        sell_quantity = (
            quote_tokens.value / price.mid_price
        ) * self.position_size_ratio
        return (buy_quantity, sell_quantity)

    def orders_require_action(
        self, orders: typing.Sequence[mango.Order], price: Decimal, quantity: Decimal
    ) -> bool:
        def within_tolerance(
            target_value: Decimal, order_value: Decimal, tolerance: Decimal
        ) -> bool:
            tolerated = order_value * tolerance
            return bool(
                (order_value < (target_value + tolerated))
                and (order_value > (target_value - tolerated))
            )

        now = mango.utc_now()
        return len(orders) == 0 or not all(
            [
                (
                    not order.is_expired_at(now)
                    and within_tolerance(
                        price, order.price, self.existing_order_tolerance
                    )
                    and within_tolerance(
                        quantity, order.quantity, self.existing_order_tolerance
                    )
                )
                for order in orders
            ]
        )

    def update_health_on_successful_iteration(self) -> None:
        try:
            Path(self.health_filename).touch(mode=0o666, exist_ok=True)
        except Exception as exception:
            self._logger.warning(
                f"Touching file '{self.health_filename}' raised exception: {exception}"
            )

    def __str__(self) -> str:
        return f"""« SimpleMarketMaker for market '{self.market.fully_qualified_symbol}' »"""

    def __repr__(self) -> str:
        return f"{self}"
