robosats/api/models/onchain_payment.py

from decouple import config
from django.contrib.auth.models import User
from django.core.validators import MaxValueValidator, MinValueValidator
from django.db import models
from django.template.defaultfilters import truncatechars
from django.utils import timezone

from control.models import BalanceLog

MAX_TRADE = config("MAX_TRADE", cast=int, default=1_000_000)
MIN_SWAP_AMOUNT = config("MIN_SWAP_AMOUNT", cast=int, default=1_000_000)


class OnchainPayment(models.Model):
    class Concepts(models.IntegerChoices):
        PAYBUYER = 3, "Payment to buyer"

    class Status(models.IntegerChoices):
        CREAT = 0, "Created"  # User was given platform fees and suggested mining fees
        VALID = 1, "Valid"  # Valid onchain address and fee submitted
        MEMPO = 2, "In mempool"  # Tx is sent to mempool
        CONFI = 3, "Confirmed"  # Tx is confirmed +2 blocks
        CANCE = 4, "Cancelled"  # Cancelled tx
        QUEUE = 5, "Queued"  # Payment is queued to be sent out

    def get_balance():
        balance = BalanceLog.objects.create()
        return balance.time

    # payment use details
    concept = models.PositiveSmallIntegerField(
        choices=Concepts.choices, null=False, default=Concepts.PAYBUYER
    )
    status = models.PositiveSmallIntegerField(
        choices=Status.choices, null=False, default=Status.CREAT
    )

    broadcasted = models.BooleanField(default=False, null=False, blank=False)

    # payment info
    address = models.CharField(
        max_length=100, unique=False, default=None, null=True, blank=True
    )

    txid = models.CharField(
        max_length=64, unique=True, null=True, default=None, blank=True
    )

    num_satoshis = models.PositiveBigIntegerField(
        null=True,
        validators=[
            MinValueValidator(0.5 * MIN_SWAP_AMOUNT),
            MaxValueValidator(1.5 * MAX_TRADE),
        ],
    )
    sent_satoshis = models.PositiveBigIntegerField(
        null=True,
        validators=[
            MinValueValidator(0.5 * MIN_SWAP_AMOUNT),
            MaxValueValidator(1.5 * MAX_TRADE),
        ],
    )
    # fee in sats/vbyte with mSats decimals fee_msat
    suggested_mining_fee_rate = models.DecimalField(
        max_digits=6,
        decimal_places=3,
        default=2.05,
        null=False,
        blank=False,
        validators=[MinValueValidator(1), MaxValueValidator(999)],
    )
    mining_fee_rate = models.DecimalField(
        max_digits=6,
        decimal_places=3,
        default=2.05,
        null=False,
        blank=False,
        validators=[MinValueValidator(1), MaxValueValidator(999)],
    )
    mining_fee_sats = models.PositiveBigIntegerField(default=0, null=False, blank=False)

    # platform onchain/channels balance at creation, swap fee rate as percent of total volume
    balance = models.ForeignKey(
        BalanceLog,
        related_name="balance",
        on_delete=models.SET_NULL,
        null=True,
        default=get_balance,
    )

    swap_fee_rate = models.DecimalField(
        max_digits=4,
        decimal_places=2,
        default=config("MIN_SWAP_FEE", cast=float, default=0.01) * 100,
        null=False,
        blank=False,
    )

    created_at = models.DateTimeField(default=timezone.now)

    # involved parties
    receiver = models.ForeignKey(
        User,
        related_name="tx_receiver",
        on_delete=models.SET_NULL,
        null=True,
        default=None,
    )

    def __str__(self):
        return f"TX-{str(self.id)}: {self.Concepts(self.concept).label} - {self.Status(self.status).label}"

    class Meta:
        verbose_name = "Onchain payment"
        verbose_name_plural = "Onchain payments"

    @property
    def hash(self):
        # Display txid as 'hash' truncated
        return truncatechars(self.txid, 10)