pluto/handler/transactions.py

# Twisted/Klein imports
from twisted.logger import Logger

# Other library imports
from json import dumps
from random import choices
from string import ascii_uppercase

# Project imports
from settings import settings
from db import r
from util import convert


class Transactions(object):
    """
    Handler class for incoming Revolut transactions.
    """

    def __init__(self):
        """
        Initialise the Transaction object.
        Set the logger.
        """
        self.log = Logger("transactions")

    def set_agora(self, agora):
        self.agora = agora

    def set_irc(self, irc):
        self.irc = irc

    def transaction(self, data):
        """
        Store details of transaction and post notifications to IRC.
        Matches it up with data stored in Redis to attempt to reconcile with an Agora trade.
        :param data: details of transaction
        :type data: dict
        """
        event = data["event"]
        ts = data["timestamp"]

        inside = data["data"]
        txid = inside["id"]
        txtype = inside["type"]
        state = inside["state"]
        if "reference" in inside:
            reference = inside["reference"]
        else:
            reference = "not_given"

        leg = inside["legs"][0]

        if "counterparty" in leg:
            account_type = leg["counterparty"]["account_type"]
        else:
            account_type = "not_given"

        amount = leg["amount"]
        currency = leg["currency"]
        description = leg["description"]

        to_store = {
            "event": event,
            "ts": ts,
            "txid": txid,
            "txtype": txtype,
            "state": state,
            "reference": reference,
            "account_type": account_type,
            "amount": amount,
            "currency": currency,
            "description": description,
        }

        self.log.info("Transaction processed: {formatted}", formatted=dumps(to_store, indent=2))
        r.hmset(f"tx.{txid}", to_store)
        self.irc.sendmsg(f"AUTO Incoming transaction: {amount}{currency} ({reference}) - {state} - {description}")

        # Partial reference implementation
        # Account for silly people not removing the default string
        # Split the reference into parts
        ref_split = reference.split(" ")
        # Get all existing references
        existing_refs = self.get_refs()
        # Get all parts of the given reference split that match the existing references
        stored_trade_reference = set(existing_refs).intersection(set(ref_split))
        if len(stored_trade_reference) > 1:
            self.log.error("Multiple references valid for TXID {txid}: {reference}", txid=txid, reference=reference)
            self.irc.sendmsg(f"Multiple references valid for TXID {txid}: {reference}")
            return

        stored_trade = False
        looked_up_without_reference = False

        # Amount/currency lookup implementation
        if not stored_trade_reference:
            self.log.info(f"No reference in DB refs for {reference}", reference=reference)
            self.irc.sendmsg(f"No reference in DB refs for {reference}")
            # Try checking just amount and currency, as some people (usually people buying small amounts)
            #  are unable to put in a reference properly.

            self.log.info("Checking against amount and currency for TXID {txid}", txid=txid)
            self.irc.sendmsg(f"Checking against amount and currency for TXID {txid}")
            stored_trade = self.find_trade(txid, currency, amount)
            if not stored_trade:
                self.log.info(
                    "Failed to get reference by amount and currency: {txid} {currency} {amount}",
                    txid=txid,
                    currency=currency,
                    amount=amount,
                )
                self.irc.sendmsg(f"Failed to get reference by amount and currency: {txid} {currency} {amount}")
                return
            if currency == "USD":
                amount_usd = amount
            else:
                rates = self.agora.get_rates_all()
                amount_usd = amount / rates[currency]
            # Amount is reliable here as it is checked by find_trade, so no need for stored_trade["amount"]
            if float(amount_usd) > float(settings.Agora.AcceptableAltLookupUSD):
                self.log.info("Not checking against amount and currency as amount exceeds MAX")
                self.irc.sendmsg(f"Not checking against amount and currency as amount exceeds MAX")
                # Close here if the amount exceeds the allowable limit for no reference
                return
            # Note that we have looked it up without reference so we don't use +- below
            # This might be redundant given the amount checks in find_trade, but better safe than sorry!
            looked_up_without_reference = True
        if not stored_trade:
            stored_trade = self.get_ref(stored_trade_reference.pop())
        if not stored_trade:
            self.log.info("No reference in DB for {reference}", reference=reference)
            self.irc.sendmsg(f"No reference in DB for {reference}")
            return

        amount = float(amount)
        stored_trade["amount"] = float(stored_trade["amount"])

        # Make sure it was sent in the expected currency
        if not stored_trade["currency"] == currency:
            self.log.info(
                "Currency mismatch, Agora: {currency_agora} / Revolut: {currency}",
                currency_agora=stored_trade["currency"],
                currency=currency,
            )
            self.irc.sendmsg(f"Currency mismatch, Agora: {stored_trade['currency']} / Revolut: {currency}")
            return

        # Make sure the expected amount was sent
        if not stored_trade["amount"] == amount:
            if looked_up_without_reference:
                return
            # If the amount does not match exactly, get the min and max values for our given acceptable margins for trades
            min_amount, max_amount = self.agora.get_acceptable_margins(currency, amount)
            self.log.info(
                "Amount does not match exactly, trying with margins: min: {min_amount} / max: {max_amount}",
                min_amount=min_amount,
                max_amount=max_amount,
            )
            self.irc.sendmsg(f"Amount does not match exactly, trying with margins: min: {min_amount} / max: {max_amount}")
            if not min_amount < stored_trade["amount"] < max_amount:
                self.log.info(
                    "Amount mismatch - not in margins: {amount} (min: {min_amount} / max: {max_amount}",
                    amount=stored_trade["amount"],
                    min_amount=min_amount,
                    max_amount=max_amount,
                )
                self.irc.sendmsg(f"Amount mismatch - not in margins: {stored_trade['amount']} (min: {min_amount} / max: {max_amount}")
                return
        # Make sure the account type was Revolut, as these are completed instantly
        if not account_type == "revolut":
            self.log.info("Account type is not Revolut: {account_type}", account_type=account_type)
            self.irc.sendmsg(f"Account type is not Revolut: {account_type}")
            return
        self.log.info("All checks passed, releasing funds for {trade_id} {reference}", trade_id=stored_trade["id"], reference=reference)
        self.irc.sendmsg(f"All checks passed, releasing funds for {stored_trade['id']} / {reference}")
        # rtrn = self.agora.release_funds(stored_trade["id"])
        # self.agora.agora.contact_message_post(stored_trade["id"], "Thanks! Releasing now :)")
        # self.irc.sendmsg(dumps(rtrn))

    def new_trade(self, trade_id, buyer, currency, amount, amount_xmr):
        """
        Called when we have a new trade in Agora.
        Store details in Redis, generate a reference and optionally let the customer know the reference.
        """
        reference = "".join(choices(ascii_uppercase, k=5))
        reference = f"XMR-{reference}"
        existing_ref = r.get(f"trade.{trade_id}.reference")
        if not existing_ref:
            r.set(f"trade.{trade_id}.reference", reference)
            to_store = {
                "id": trade_id,
                "buyer": buyer,
                "currency": currency,
                "amount": amount,
                "amount_xmr": amount_xmr,
                "reference": reference,
            }
            self.log.info("Storing trade information: {info}", info=str(to_store))
            r.hmset(f"trade.{reference}", to_store)
            self.irc.sendmsg(f"Generated reference for {trade_id}: {reference}")
            if settings.Agora.Send == "1":
                self.agora.agora.contact_message_post(trade_id, f"Hi! When sending the payment please use reference code: {reference}")
        if existing_ref:
            return convert(existing_ref)
        else:
            return reference

    def find_tx(self, reference, amount):
        """
        Find transactions that match the given reference and amount.
        :param reference: transaction reference in Revolut
        :param amount: transaction amount
        :type reference: string
        :type amount: int
        :return: transaction details or AMOUNT_INVALID, or False
        :rtype: dict or string or bool
        """
        all_transactions = r.scan(0, match="tx.*")
        for tx_iter in all_transactions[1]:
            tx_obj = r.hgetall(tx_iter)
            if tx_obj[b"reference"] == str.encode(reference):
                if tx_obj[b"amount"] == str.encode(amount):
                    return convert(tx_obj)
                else:
                    return "AMOUNT_INVALID"
        return False

    def find_trade(self, txid, currency, amount):
        """
        Get a trade reference that matches the given currency and amount.
        Only works if there is one result.
        :param txid: Revolut transaction ID
        :param currency: currency
        :param amount: amount
        :type txid: string
        :type currency: string
        :type amount: int
        :return: matching trade object or False
        :rtype: dict or bool
        """
        refs = self.get_refs()
        matching_refs = []
        for ref in refs:
            stored_trade = self.get_ref(ref)
            if stored_trade["currency"] == currency and float(stored_trade["amount"]) == float(amount):
                matching_refs.append(stored_trade)
        if len(matching_refs) != 1:
            self.log.error("Find trade returned multiple results for TXID {txid}: {matching_refs}", txid=txid, matching_refs=matching_refs)
            return False
        return matching_refs[0]

    def get_refs(self):
        """
        Get all reference IDs for trades.
        :return: list of trade IDs
        :rtype: list
        """
        references = []
        ref_keys = r.keys("trade.*.reference")
        for key in ref_keys:
            references.append(r.get(key))
        return convert(references)

    def get_ref_map(self):
        """
        Get all reference IDs for trades.
        :return: dict of references keyed by TXID
        :rtype: dict
        """
        references = {}
        ref_keys = r.keys("trade.*.reference")
        for key in ref_keys:
            tx = convert(key).split(".")[1]
            references[tx] = r.get(key)
        return convert(references)

    def get_ref(self, reference):
        """
        Get a reference ID for a single trade.
        :return: trade ID
        :rtype: string
        """
        ref_data = r.hgetall(f"trade.{reference}")
        ref_data = convert(ref_data)
        if not ref_data:
            return False
        return ref_data

    def del_ref(self, reference):
        """
        Delete a given reference from the Redis database.
        """
        tx = self.ref_to_tx(reference)
        r.delete(f"trade.{reference}")
        r.delete(f"trade.{tx}.reference")

    def cleanup(self, references):
        for tx, reference in self.get_ref_map().items():
            if reference not in references:
                self.log.info("Archiving trade reference: {reference} / TX: {tx}", reference=reference, tx=tx)
                r.rename(f"trade.{tx}.reference", f"archive.trade.{tx}.reference")
                r.rename(f"trade.{reference}", f"archive.trade.{reference}")

    def del_tx(self, txid):
        pass

    def tx_to_ref(self, tx):
        refs = self.get_refs()
        for reference in refs:
            ref_data = convert(r.hgetall(f"trade.{reference}"))
            if not ref_data:
                continue
            if ref_data["id"] == tx:
                return reference

    def ref_to_tx(self, reference):
        ref_data = convert(r.hgetall(f"trade.{reference}"))
        if not ref_data:
            return False
        return ref_data["id"]