electrum/electrum/gui/qml/qeinvoice.py

import copy
import threading
from enum import IntEnum
from typing import Optional, Dict, Any, Tuple
from urllib.parse import urlparse

from PyQt6.QtCore import pyqtProperty, pyqtSignal, pyqtSlot, QObject, pyqtEnum, QTimer

from electrum.i18n import _
from electrum.logging import get_logger
from electrum.invoices import (
    Invoice, PR_UNPAID, PR_EXPIRED, PR_UNKNOWN, PR_PAID, PR_INFLIGHT, PR_FAILED, PR_ROUTING, PR_UNCONFIRMED,
    PR_BROADCASTING, PR_BROADCAST, LN_EXPIRY_NEVER
)
from electrum.transaction import PartialTxOutput, TxOutput
from electrum.lnutil import format_short_channel_id
from electrum.lnurl import LNURL6Data
from electrum.bitcoin import COIN, address_to_script
from electrum.paymentrequest import PaymentRequest
from electrum.payment_identifier import PaymentIdentifier, PaymentIdentifierState, PaymentIdentifierType
from electrum.network import Network

from .qetypes import QEAmount
from .qewallet import QEWallet
from .util import status_update_timer_interval, QtEventListener, event_listener
from ...util import InvoiceError


class QEInvoice(QObject, QtEventListener):
    @pyqtEnum
    class Type(IntEnum):
        Invalid = -1
        OnchainInvoice = 0
        LightningInvoice = 1
        LNURLPayRequest = 2

    @pyqtEnum
    class Status(IntEnum):
        Unpaid = PR_UNPAID
        Expired = PR_EXPIRED
        Unknown = PR_UNKNOWN
        Paid = PR_PAID
        Inflight = PR_INFLIGHT
        Failed = PR_FAILED
        Routing = PR_ROUTING
        Unconfirmed = PR_UNCONFIRMED

    _logger = get_logger(__name__)

    invoiceChanged = pyqtSignal()
    invoiceSaved = pyqtSignal([str], arguments=['key'])
    amountOverrideChanged = pyqtSignal()
    maxAmountMessage = pyqtSignal([str], arguments=['message'])

    def __init__(self, parent=None):
        super().__init__(parent)

        self._wallet = None  # type: Optional[QEWallet]
        self._isSaved = False
        self._canSave = False
        self._canPay = False
        self._key = None
        self._invoiceType = QEInvoice.Type.Invalid
        self._effectiveInvoice = None  # type: Optional[Invoice]
        self._userinfo = ''
        self._lnprops = {}
        self._amount = QEAmount()
        self._amountOverride = QEAmount()

        self._timer = QTimer(self)
        self._timer.setSingleShot(True)
        self._timer.timeout.connect(self.updateStatusString)

        self._amountOverride.valueChanged.connect(self._on_amountoverride_value_changed)

        self._updating_max = False

        self.register_callbacks()
        self.destroyed.connect(lambda: self.on_destroy())

    def on_destroy(self):
        self.unregister_callbacks()

    @event_listener
    def on_event_payment_succeeded(self, wallet, key):
        if wallet == self._wallet.wallet and key == self.key:
            self.statusChanged.emit()
            self.determine_can_pay()
            self.userinfo = _('Paid!')

    @event_listener
    def on_event_payment_failed(self, wallet, key, reason):
        if wallet == self._wallet.wallet and key == self.key:
            self.statusChanged.emit()
            self.determine_can_pay()
            self.userinfo = _('Payment failed: ') + reason

    @event_listener
    def on_event_invoice_status(self, wallet, key, status):
        if self._wallet and wallet == self._wallet.wallet and key == self.key:
            self.update_userinfo()
            self.determine_can_pay()
            self.statusChanged.emit()

    @event_listener
    def on_event_channel(self, wallet, channel):
        if self._wallet and wallet == self._wallet.wallet:
            self.update_userinfo()
            self.determine_can_pay()

    walletChanged = pyqtSignal()
    @pyqtProperty(QEWallet, notify=walletChanged)
    def wallet(self):
        return self._wallet

    @wallet.setter
    def wallet(self, wallet: QEWallet):
        if self._wallet != wallet:
            self._wallet = wallet
            self.walletChanged.emit()

    @pyqtProperty(int, notify=invoiceChanged)
    def invoiceType(self):
        return self._invoiceType

    # not a qt setter, don't let outside set state
    def setInvoiceType(self, invoiceType: Type):
        self._invoiceType = invoiceType

    @pyqtProperty(str, notify=invoiceChanged)
    def message(self):
        return self._effectiveInvoice.message if self._effectiveInvoice else ''

    @pyqtProperty('quint64', notify=invoiceChanged)
    def time(self):
        return self._effectiveInvoice.time if self._effectiveInvoice else 0

    @pyqtProperty('quint64', notify=invoiceChanged)
    def expiration(self):
        return self._effectiveInvoice.exp if self._effectiveInvoice else 0

    @pyqtProperty(str, notify=invoiceChanged)
    def address(self):
        return self._effectiveInvoice.get_address() if self._effectiveInvoice else ''

    @pyqtProperty(QEAmount, notify=invoiceChanged)
    def amount(self):
        if not self._effectiveInvoice:
            self._amount.clear()
            return self._amount
        self._amount.copyFrom(QEAmount(from_invoice=self._effectiveInvoice))
        return self._amount

    @pyqtProperty(QEAmount, notify=amountOverrideChanged)
    def amountOverride(self):
        return self._amountOverride

    @amountOverride.setter
    def amountOverride(self, new_amount: QEAmount):
        self._logger.debug(f'set new override amount {repr(new_amount)}')
        self._amountOverride.copyFrom(new_amount)
        self.amountOverrideChanged.emit()

    @pyqtSlot()
    def _on_amountoverride_value_changed(self):
        self.update_userinfo()
        self.determine_can_pay()

    statusChanged = pyqtSignal()
    @pyqtProperty(int, notify=statusChanged)
    def status(self):
        if not self._effectiveInvoice:
            return PR_UNKNOWN
        if self.invoiceType == QEInvoice.Type.OnchainInvoice and self._effectiveInvoice.get_amount_sat() == 0:
            # no amount set, not a final invoice, get_invoice_status would be wrong
            return PR_UNPAID
        return self._wallet.wallet.get_invoice_status(self._effectiveInvoice)

    @pyqtProperty(str, notify=statusChanged)
    def statusString(self):
        if not self._effectiveInvoice:
            return ''
        status = self._wallet.wallet.get_invoice_status(self._effectiveInvoice)
        return self._effectiveInvoice.get_status_str(status)

    isSavedChanged = pyqtSignal()
    @pyqtProperty(bool, notify=isSavedChanged)
    def isSaved(self):
        return self._isSaved

    canSaveChanged = pyqtSignal()
    @pyqtProperty(bool, notify=canSaveChanged)
    def canSave(self):
        return self._canSave

    @canSave.setter
    def canSave(self, canSave):
        if self._canSave != canSave:
            self._canSave = canSave
            self.canSaveChanged.emit()

    canPayChanged = pyqtSignal()
    @pyqtProperty(bool, notify=canPayChanged)
    def canPay(self):
        return self._canPay

    @canPay.setter
    def canPay(self, canPay):
        if self._canPay != canPay:
            self._canPay = canPay
            self.canPayChanged.emit()

    keyChanged = pyqtSignal()
    @pyqtProperty(str, notify=keyChanged)
    def key(self):
        return self._key

    @key.setter
    def key(self, key):
        self._key = key
        invoice = copy.copy(self._wallet.wallet.get_invoice(key))  # copy, so any mutations stay out of wallet invoice list
        self._logger.debug(f'invoice from key {key}: {repr(invoice)}')
        self.set_effective_invoice(invoice)
        self.keyChanged.emit()

    userinfoChanged = pyqtSignal()
    @pyqtProperty(str, notify=userinfoChanged)
    def userinfo(self):
        return self._userinfo

    @userinfo.setter
    def userinfo(self, userinfo):
        if self._userinfo != userinfo:
            self._userinfo = userinfo
            self.userinfoChanged.emit()

    @pyqtProperty('QVariantMap', notify=invoiceChanged)
    def lnprops(self):
        return self._lnprops

    def set_lnprops(self):
        self._lnprops = {}
        if not self.invoiceType == QEInvoice.Type.LightningInvoice:
            return

        lnaddr = self._effectiveInvoice._lnaddr
        ln_routing_info = lnaddr.get_routing_info('r')
        self._logger.debug(str(ln_routing_info))

        self._lnprops = {
            'pubkey': lnaddr.pubkey.serialize().hex(),
            'payment_hash': lnaddr.paymenthash.hex(),
            'r': [{
                'node': self.name_for_node_id(x[-1][0]),
                'scid': format_short_channel_id(x[-1][1])
                } for x in ln_routing_info] if ln_routing_info else []
        }

    def name_for_node_id(self, node_id):
        lnworker = self._wallet.wallet.lnworker
        return (lnworker.lnpeermgr.get_node_alias(node_id) if lnworker else None) or node_id.hex()

    def set_effective_invoice(self, invoice: Invoice):
        self._effectiveInvoice = invoice

        if invoice is None:
            self.setInvoiceType(QEInvoice.Type.Invalid)
        else:
            if invoice.is_lightning():
                self.setInvoiceType(QEInvoice.Type.LightningInvoice)
            else:
                self.setInvoiceType(QEInvoice.Type.OnchainInvoice)
            self._isSaved = self._wallet.wallet.get_invoice(invoice.get_id()) is not None

        self.set_lnprops()

        self.update_userinfo()
        self.determine_can_pay()

        self.invoiceChanged.emit()
        self.statusChanged.emit()
        self.isSavedChanged.emit()

        self.set_status_timer()

    def set_status_timer(self):
        if self.status != PR_EXPIRED:
            if self.expiration > 0 and self.expiration != LN_EXPIRY_NEVER:
                interval = status_update_timer_interval(self.time + self.expiration)
                if interval > 0:
                    self._timer.setInterval(interval)  # msec
                    self._timer.start()
        else:
            self.update_userinfo()
            self.determine_can_pay()  # status went to PR_EXPIRED

    @pyqtSlot()
    def updateStatusString(self):
        self.statusChanged.emit()
        self.set_status_timer()

    def update_userinfo(self):
        self.userinfo = ''

        if not self.amountOverride.isEmpty:
            amount = self.amountOverride
        else:
            amount = self.amount

        if self.amount.isEmpty:
            self.userinfo = _('Enter the amount you want to send')

        status = self.status

        if amount.isEmpty and status == PR_UNPAID:  # unspecified amount
            return

        def userinfo_for_invoice_status(_status: int) -> str:
            return {
                PR_EXPIRED: _('This invoice has expired'),
                PR_PAID: _('This invoice was already paid'),
                PR_INFLIGHT: _('Payment in progress...'),
                PR_ROUTING: _('Payment in progress...'),
                PR_BROADCASTING: _('Payment in progress...') + ' (' + _('broadcasting') + ')',
                PR_BROADCAST:  _('Payment in progress...') + ' (' + _('broadcast successfully') + ')',
                PR_UNCONFIRMED: _('Payment in progress...') + ' (' + _('waiting for confirmation') + ')',
                PR_UNKNOWN: _('Invoice has unknown status'),
            }[_status]

        if status in [PR_UNPAID, PR_FAILED]:
            x, self.userinfo = self.check_can_pay_amount(amount)
        else:
            self.userinfo = userinfo_for_invoice_status(status)

    def determine_can_pay(self):
        self.canPay = False
        self.canSave = False

        if self.invoiceType not in [QEInvoice.Type.LightningInvoice, QEInvoice.Type.OnchainInvoice]:
            return

        if not self.amountOverride.isEmpty:
            amount = self.amountOverride
        else:
            amount = self.amount

        self.canSave = not bool(self._wallet.wallet.get_invoice(self._effectiveInvoice.get_id()))

        status = self.status

        if amount.isEmpty and status == PR_UNPAID:  # unspecified amount
            return

        if status in [PR_UNPAID, PR_FAILED]:
            self.canPay, x = self.check_can_pay_amount(amount)

    def check_can_pay_amount(self, amount: QEAmount) -> Tuple[bool, Optional[str]]:
        assert self.status in [PR_UNPAID, PR_FAILED]
        if self.invoiceType == QEInvoice.Type.LightningInvoice:
            if self.get_max_spendable_lightning() * 1000 >= amount.msatsInt:
                lnaddr = self._effectiveInvoice._lnaddr
                if lnaddr.amount and amount.msatsInt < lnaddr.amount * COIN * 1000:
                    return False, _('Cannot pay less than the amount specified in the invoice')
                else:
                    return True, None
            elif self.address and self.get_max_spendable_onchain() > amount.satsInt:
                return True, None
        elif self.invoiceType == QEInvoice.Type.OnchainInvoice:
            if (amount.isMax and self.get_max_spendable_onchain() > 0) or (self.get_max_spendable_onchain() >= amount.satsInt):
                return True, None

        return False, _('Insufficient balance')

    @pyqtSlot()
    def payLightningInvoice(self):
        if not self.canPay:
            raise Exception('can not pay invoice, canPay is false')

        if self.invoiceType != QEInvoice.Type.LightningInvoice:
            raise Exception('payLightningInvoice can only pay lightning invoices')

        amount_msat = None
        if self.amount.isEmpty:
            if self.amountOverride.isEmpty:
                raise Exception('can not pay 0 amount')
            amount_msat = self.amountOverride.msatsInt

        self._wallet.pay_lightning_invoice(self._effectiveInvoice, amount_msat)

    def get_max_spendable_onchain(self):
        return self._wallet.wallet.get_spendable_balance_sat()

    def get_max_spendable_lightning(self):
        return self._wallet.wallet.lnworker.num_sats_can_send() if self._wallet.wallet.lnworker else 0

    @pyqtSlot()
    def updateMaxAmount(self):
        if self._updating_max:
            return

        assert self.invoiceType == QEInvoice.Type.OnchainInvoice

        # only single address invoice supported
        invoice_address = self._effectiveInvoice.get_address()

        self._updating_max = True

        def calc_max(address):
            try:
                outputs = [PartialTxOutput(scriptpubkey=address_to_script(address), value='!')]
                make_tx = lambda fee_policy, *, confirmed_only=False: self._wallet.wallet.make_unsigned_transaction(
                    coins=self._wallet.wallet.get_spendable_coins(None),
                    outputs=outputs,
                    fee_policy=fee_policy,
                    is_sweep=False)
                amount, message = self._wallet.determine_max(mktx=make_tx)
                if amount is None:
                    self._amountOverride.isMax = False
                else:
                    self._amountOverride.satsInt = amount
                if message:
                    self.maxAmountMessage.emit(message)
            finally:
                self._updating_max = False

        threading.Thread(target=calc_max, args=(invoice_address,), daemon=True).start()


class QEInvoiceParser(QEInvoice):
    _logger = get_logger(__name__)

    validationSuccess = pyqtSignal()
    validationWarning = pyqtSignal([str, str], arguments=['code', 'message'])
    validationError = pyqtSignal([str, str], arguments=['code', 'message'])

    invoiceCreateError = pyqtSignal([str, str], arguments=['code', 'message'])

    lnurlRetrieved = pyqtSignal()
    lnurlError = pyqtSignal([str, str], arguments=['code', 'message'])

    busyChanged = pyqtSignal()

    def __init__(self, parent=None):
        super().__init__(parent)

        self._pi = None
        self._lnurlData = None
        self._busy = False

        self.clear()

    @pyqtSlot(object)
    def fromResolvedPaymentIdentifier(self, resolved_pi: PaymentIdentifier) -> None:
        self.clear()
        self.amountOverride = QEAmount()
        if resolved_pi:
            assert not resolved_pi.need_resolve()
            self.validateRecipient(resolved_pi)

    @pyqtProperty('QVariantMap', notify=lnurlRetrieved)
    def lnurlData(self):
        return self._lnurlData

    @pyqtProperty(bool, notify=lnurlRetrieved)
    def isLnurlPay(self):
        return self._lnurlData is not None

    @pyqtProperty(bool, notify=busyChanged)
    def busy(self):
        return self._busy

    @pyqtSlot()
    def clear(self):
        self.setInvoiceType(QEInvoice.Type.Invalid)
        self._lnurlData = None
        self.canSave = False
        self.canPay = False
        self.userinfo = ''
        self.invoiceChanged.emit()

    def setValidOnchainInvoice(self, invoice: Invoice):
        self._logger.debug('setValidOnchainInvoice')
        if invoice.is_lightning():
            raise Exception('unexpected LN invoice')
        self.set_effective_invoice(invoice)

    def setValidLightningInvoice(self, invoice: Invoice):
        self._logger.debug('setValidLightningInvoice')
        if not invoice.is_lightning():
            raise Exception('unexpected Onchain invoice')
        self._key = invoice.get_id()
        self.set_effective_invoice(invoice)

    def setValidLNURLPayRequest(self):
        self._logger.debug('setValidLNURLPayRequest')
        self.setInvoiceType(QEInvoice.Type.LNURLPayRequest)
        self._effectiveInvoice = None
        self.invoiceChanged.emit()

    def create_onchain_invoice(self, outputs, message, payment_request, uri):
        return self._wallet.wallet.create_invoice(
            outputs=outputs,
            message=message,
            pr=payment_request,
            URI=uri
            )

    def _bip70_payment_request_resolved(self, pr: 'PaymentRequest'):
        self._logger.debug('resolved payment request')
        if Network.run_from_another_thread(pr.verify()):
            invoice = Invoice.from_bip70_payreq(pr, height=0)
            if self._wallet.wallet.get_invoice_status(invoice) == PR_PAID:
                self.validationError.emit('unknown', _('Invoice already paid'))
            elif pr.has_expired():
                self.validationError.emit('unknown', _('Payment request has expired'))
            else:
                self.setValidOnchainInvoice(invoice)
                self.validationSuccess.emit()
        else:
            self.validationError.emit('unknown', f'invoice error:\n{pr.error}')

    def validateRecipient(self, pi: PaymentIdentifier):
        if not pi:
            self.setInvoiceType(QEInvoice.Type.Invalid)
            return

        self._pi = pi
        if not self._pi.is_valid() or self._pi.type not in [
            PaymentIdentifierType.SPK, PaymentIdentifierType.BIP21,
            PaymentIdentifierType.BIP70, PaymentIdentifierType.BOLT11,
            PaymentIdentifierType.LNADDR, PaymentIdentifierType.LNURLP,
            PaymentIdentifierType.EMAILLIKE, PaymentIdentifierType.DOMAINLIKE,
            PaymentIdentifierType.OPENALIAS,
        ]:
            self.validationError.emit('unknown', _('Unknown invoice'))
            return

        if self._pi.type == PaymentIdentifierType.SPK:
            txo = TxOutput(scriptpubkey=self._pi.spk, value=0)
            if not txo.address:
                self.validationError.emit('unknown', _('Unknown invoice'))
                return

        self._update_from_payment_identifier()

    def _update_from_payment_identifier(self):
        assert not self._pi.need_resolve(), "Should have been resolved by QEPIResolver"

        if self._pi.type in [
            PaymentIdentifierType.LNURLP,
            PaymentIdentifierType.LNADDR,
        ]:
            self.on_lnurl_pay(self._pi.lnurl_data)
            return

        if self._pi.type == PaymentIdentifierType.BIP70:
            self._bip70_payment_request_resolved(self._pi.bip70_data)
            return

        if self._pi.is_available():
            if self._pi.type in [PaymentIdentifierType.SPK, PaymentIdentifierType.OPENALIAS]:
                outputs = [PartialTxOutput(scriptpubkey=self._pi.spk, value=0)]
                invoice = self.create_onchain_invoice(outputs, None, None, None)
                self._logger.debug(repr(invoice))
                self.setValidOnchainInvoice(invoice)
                self.validationSuccess.emit()
                return
            elif self._pi.type == PaymentIdentifierType.BOLT11:
                lninvoice = self._pi.bolt11
                if not self._wallet.wallet.has_lightning() and not lninvoice.get_address():
                    self.validationError.emit('no_lightning',
                        _('Detected valid Lightning invoice, but Lightning not enabled for wallet and no fallback address found.'))
                    return
                if self._wallet.wallet.lnworker and not self._wallet.wallet.lnworker.channels and not lninvoice.get_address():
                    self.validationWarning.emit('no_channels',
                        _('Detected valid Lightning invoice, but there are no open channels'))
                self.setValidLightningInvoice(lninvoice)
                self.validationSuccess.emit()
            elif self._pi.type == PaymentIdentifierType.BIP21:
                if self._wallet.wallet.has_lightning() and self._wallet.wallet.lnworker.channels and self._pi.bolt11:
                    lninvoice = self._pi.bolt11
                    self.setValidLightningInvoice(lninvoice)
                    self.validationSuccess.emit()
                else:
                    self._validateRecipient_bip21_onchain(self._pi.bip21)

    def _validateRecipient_bip21_onchain(self, bip21: Dict[str, Any]) -> None:
        if 'address' not in bip21:
            self._logger.debug('Neither LN invoice nor address in bip21 uri')
            self.validationError.emit('unknown', _('Unknown invoice'))
            return

        amount = bip21.get('amount', 0)
        outputs = [PartialTxOutput.from_address_and_value(bip21['address'], amount)]
        self._logger.debug(outputs)
        message = bip21.get('message', '')
        invoice = self.create_onchain_invoice(outputs, message, None, bip21)
        self._logger.debug(repr(invoice))
        self.setValidOnchainInvoice(invoice)
        self.validationSuccess.emit()

    def on_lnurl_pay(self, lnurldata: LNURL6Data):
        assert isinstance(lnurldata, LNURL6Data)
        self._logger.debug('on_lnurl')
        self._logger.debug(f'{repr(lnurldata)}')

        self._lnurlData = {
            'domain': urlparse(lnurldata.callback_url).netloc,
            'callback_url': lnurldata.callback_url,
            'min_sendable_sat': lnurldata.min_sendable_sat,
            'max_sendable_sat': lnurldata.max_sendable_sat,
            'metadata_plaintext': lnurldata.metadata_plaintext,
            'comment_allowed': lnurldata.comment_allowed,
        }
        self.setValidLNURLPayRequest()
        self.lnurlRetrieved.emit()

    @pyqtSlot()
    @pyqtSlot(str)
    def lnurlGetInvoice(self, comment=None):
        assert self._lnurlData
        assert self._pi.need_finalize()
        assert self.invoiceType == QEInvoice.Type.LNURLPayRequest
        self._logger.debug(f'{repr(self._lnurlData)}')

        amount = self.amountOverride.satsInt

        if self._lnurlData['comment_allowed'] == 0:
            comment = None

        def on_finished(pi):
            self._busy = False
            self.busyChanged.emit()

            if pi.is_error():
                if pi.state == PaymentIdentifierState.INVALID_AMOUNT:
                    self.lnurlError.emit('amount', pi.get_error())
                else:
                    self.lnurlError.emit('lnurl', pi.get_error())
            else:
                self.on_lnurl_invoice(self.amountOverride.satsInt, pi.bolt11)

        self._busy = True
        self.busyChanged.emit()

        self._pi.finalize(amount_sat=amount, comment=comment, on_finished=on_finished)

    def on_lnurl_invoice(self, orig_amount, invoice):
        self._logger.debug('on_lnurl_invoice')
        self._logger.debug(f'{repr(invoice)}')

        # assure no shenanigans with the bolt11 invoice we get back
        if orig_amount * 1000 != invoice.amount_msat:  # TODO msat precision can cause trouble here
            raise Exception('Unexpected amount in invoice, differs from lnurl-pay specified amount')

        self.amountOverride = QEAmount()
        self.validateRecipient(
            PaymentIdentifier(self._wallet.wallet, invoice.lightning_invoice)
        )

    @pyqtSlot(result=bool)
    def saveInvoice(self) -> bool:
        if not self._effectiveInvoice:
            return False
        if self.isSaved:
            return False

        try:
            if not self._effectiveInvoice.amount_msat and not self.amountOverride.isEmpty:
                if self.invoiceType == QEInvoice.Type.OnchainInvoice and self.amountOverride.isMax:
                    self._effectiveInvoice.set_amount_msat('!')
                else:
                    self._effectiveInvoice.set_amount_msat(self.amountOverride.satsInt * 1000)
        except InvoiceError as e:
            self.invoiceCreateError.emit('validation', str(e))
            return False

        self.canSave = False

        self._wallet.wallet.save_invoice(self._effectiveInvoice)
        self._key = self._effectiveInvoice.get_id()
        self._wallet.invoiceModel.addInvoice(self._key)
        self.invoiceSaved.emit(self._key)

        return True