"""Interest tracking data structures."""
import datetime
from dataclasses import dataclass, field
from decimal import Decimal
from typing import Dict
from dataclasses_json import dataclass_json
from tradeexecutor.state.identifier import AssetIdentifier
from tradeexecutor.state.types import BlockNumber
from tradeexecutor.utils.accuracy import ZERO_DECIMAL, QUANTITY_EPSILON
[docs]@dataclass_json
@dataclass(slots=True)
class Interest:
"""Interest data tracking for positions that where the amount changes over time.
- Credit positions (depositing in Aave reservess)
- Longs / shorts
"""
#: How many tokens we deposited to this position at amount.
#:
#: Use this only for calculation verifications,
#: because the amount can be increased/reduced over time
#:
opening_amount: Decimal
#: How many atokens/votkens we had on the previous read.
#:
#: Absolute number of on-chain balance.
#:
#: This is principal + interest.
#:
last_token_amount: Decimal
#: When the denormalised data was last updated.
#:
#: Wall clock time.
#:
last_updated_at: datetime.datetime
#: When the denormalised data was last updated.
#:
#: Event time (block mined timestamp).
#:
last_event_at: datetime.datetime
#: How much interest we have gained
#:
#:
last_accrued_interest: Decimal
#: Block number for the update
#:
#: When was the last time we read aToken balance.
#:
last_updated_block_number: int | None = None
#: How much repayments this loan has received.
#:
#: - If this is collateral, then this is how much interest we have claimed
#:
#: - If this is borrow, then this is how much interest we have paid back
#:
#: TODO: This must be reset when there is change to underlying aToken/vToken amount
# e.g. when partially closing a position.
#:
interest_payments: Decimal = ZERO_DECIMAL
def __repr__(self):
return f"<Interest, current principal + interest {self.last_token_amount}, current tracked interest gains {self.last_accrued_interest}>"
def __post_init__(self):
assert isinstance(self.opening_amount, Decimal)
assert isinstance(self.last_accrued_interest, Decimal)
[docs] def get_principal_and_interest_quantity(self) -> Decimal:
"""Return how many tokens exactly we have on the loan.
Assuming any aToken/vToken will be fully converted to the underlying.
"""
return self.last_token_amount
@staticmethod
def open_new(opening_amount: Decimal, timestamp: datetime.datetime) -> "Interest":
assert opening_amount > 0
return Interest(
opening_amount=opening_amount,
last_updated_at=timestamp,
last_event_at=timestamp,
last_accrued_interest=Decimal(0),
last_token_amount=opening_amount,
)
[docs] def get_remaining_interest(self) -> Decimal:
"""GEt the amount of interest this position has still left.
This is total lifetime interest + repayments / claims.
"""
return self.last_accrued_interest - self.interest_payments
[docs] def claim_interest(self, quantity: Decimal):
"""Update interest claims from profit from accuring interest on collateral/"""
self.interest_payments += quantity
[docs] def repay_interest(self, quantity: Decimal):
"""Update interest payments needed to maintain the borrowed debt."""
self.interest_payments += quantity
[docs] def adjust(self, delta: Decimal, epsilon: Decimal = QUANTITY_EPSILON):
"""Adjust the quantity on this loan.
Used when doing increase/reduce shorts to get a new amount.
With safety checks.
:param delta:
Positive: increase amount, negative decrease amount.
"""
self.last_token_amount += delta
if abs(self.last_token_amount) < epsilon:
self.last_token_amount = ZERO_DECIMAL
assert self.last_token_amount >= 0, f"last_token_amount cannot go negative. Got {self.last_token_amount} on {self}, delta was {delta}, epsilon was {epsilon}"