2021-08-05 12:26:19 -04:00

176 lines
4.9 KiB
Python

from typing import Dict, List, Optional
from pydantic import BaseModel
from mev_inspect.schemas.classified_traces import (
ClassifiedTrace,
Classification,
Protocol,
)
from mev_inspect.schemas.strategies import Arbitrage
class Transfer(BaseModel):
from_address: str
to_address: str
amount: int
token_address: str
class Swap(BaseModel):
transaction_hash: str
protocol: Optional[Protocol]
pool_address: str
from_address: str
to_address: str
token_in_address: str
token_in_amount: int
token_out_address: str
token_out_amount: int
def get_arbitrages(traces: List[ClassifiedTrace]) -> List[Arbitrage]:
all_arbitrages = []
traces_by_transaction = _group_traces_by_transaction(traces)
for transaction_traces in traces_by_transaction.values():
all_arbitrages += _get_arbitrages_for_transaction(
transaction_traces,
)
return all_arbitrages
def _group_traces_by_transaction(
traces: List[ClassifiedTrace],
) -> Dict[str, List[ClassifiedTrace]]:
grouped_traces: Dict[str, List[ClassifiedTrace]] = {}
for trace in traces:
hash = trace.transaction_hash
existing_traces = grouped_traces.get(hash, [])
grouped_traces[hash] = existing_traces + [trace]
return grouped_traces
def _get_arbitrages_for_transaction(
traces: List[ClassifiedTrace],
) -> List[Arbitrage]:
swaps = _get_swaps(traces)
print(swaps)
return []
def _get_swaps(traces: List[ClassifiedTrace]) -> List[Swap]:
ordered_traces = list(sorted(traces, key=lambda t: t.trace_address))
swaps: List[Swap] = []
prior_transfers = []
for trace in ordered_traces:
if trace.classification == Classification.transfer:
transfer = _as_transfer(trace)
prior_transfers.append(transfer)
if trace.classification == Classification.swap:
child_traces = _get_child_traces(trace.trace_address, traces)
swap = _build_swap(trace, prior_transfers, child_traces)
if swap is not None:
swaps.append(swap)
return swaps
def _build_swap(
trace: ClassifiedTrace,
prior_transfers: List[Transfer],
child_traces: List[ClassifiedTrace],
) -> Optional[Swap]:
if trace.abi_name == "UniswapV2Pair":
pool_address = trace.to_address
transfers_to_pool = [
transfer
for transfer in prior_transfers
if transfer.to_address == pool_address
]
# expecting a prior transfer to the pool
if len(transfers_to_pool) == 0:
return None
most_recent_transfer_to_pool = transfers_to_pool[-1]
all_pool_internal_transfers = [
_as_transfer(child)
for child in child_traces
if child.classification == Classification.transfer
]
# expecting exactly one transfer inside the pool
if len(all_pool_internal_transfers) != 1:
return None
pool_internal_transfer = all_pool_internal_transfers[0]
return Swap(
transaction_hash=trace.transaction_hash,
pool_address=pool_address,
from_address=most_recent_transfer_to_pool.from_address,
to_address=pool_internal_transfer.to_address,
token_in_address=most_recent_transfer_to_pool.token_address,
token_in_amount=most_recent_transfer_to_pool.amount,
token_out_address=pool_internal_transfer.token_address,
token_out_amount=pool_internal_transfer.amount,
)
return None
def _get_child_traces(
parent_trace_address: List[int],
traces: List[ClassifiedTrace],
) -> List[ClassifiedTrace]:
ordered_traces = sorted(traces, key=lambda t: t.trace_address)
child_traces = []
for trace in ordered_traces:
if _is_child_trace_address(
parent_trace_address,
trace.trace_address,
):
child_traces.append(trace)
return child_traces
def _is_child_trace_address(
parent_trace_address: List[int],
maybe_child_trace_address: List[int],
) -> bool:
parent_trace_length = len(parent_trace_address)
return (len(maybe_child_trace_address) == parent_trace_length + 1) and (
maybe_child_trace_address[:parent_trace_length] == parent_trace_address
)
def _as_transfer(trace: ClassifiedTrace) -> Transfer:
# todo - this should be enforced at the data level
if trace.inputs is None:
raise ValueError("Invalid transfer")
if trace.protocol == Protocol.weth:
return Transfer(
amount=trace.inputs["wad"],
to_address=trace.inputs["dst"],
from_address=trace.from_address,
token_address=trace.to_address,
)
else:
return Transfer(
amount=trace.inputs["amount"],
to_address=trace.inputs["recipient"],
from_address=trace.from_address,
token_address=trace.to_address,
)