Initial work on adding Aave inspector

mev_inspect/inspectors/aave.py

@@ -0,0 +1,53 @@
+import json
+from typing import Optional
+
+from web3 import Web3
+
+from mev_inspect.config import load_config
+from mev_inspect.schemas.blocks import NestedTrace
+from mev_inspect.schemas.classifications import Classification, Liquidation
+from mev_inspect.utils import check_trace_for_signature
+
+from .base import Inspector
+
+config = load_config()
+
+aave_v2_lending_pool_abi = json.loads(config["ABI"]["AaveLendingPool"])
+aave_v2_lending_pool_address = config["ADDRESSES"]["AaveV2LendingPool"].lower()
+
+
+class AaveInspector(Inspector):
+    def __init__(self, base_inspector):
+        super().__init__()
+        self.w3 = Web3(base_inspector)
+        self.aave_v2_lendingpool_contract = self.w3.eth.contract(
+            address=aave_v2_lending_pool_address, abi=aave_v2_lending_pool_abi
+        )
+
+        # https://docs.aave.com/developers/the-core-protocol/lendingpool#liquidationcall
+        liquidation_call = "liquidationCall(address,address,address,uint256,bool)"
+        self.liquidation_call_signature = self.w3.sha3(text=liquidation_call)[:4]
+        self.mev_functions = []
+
+    def inspect(self, nested_trace: NestedTrace) -> Optional[Classification]:
+        trace = nested_trace.trace
+
+        # fmt: off
+        if (
+            trace.action["to"] == aave_v2_lending_pool_address and
+            check_trace_for_signature(
+                trace,
+                [self.liquidation_call_signature]
+            )
+        ):
+        # fmt: on
+
+            tx = self.w3.eth.get_transaction(trace.transaction_hash)
+            _, decoded_input = self.aave_v2_lendingpool_contract.decode_function_input(tx.input)
+            print(decoded_input)
+
+            # TODO: check if decoded_input is correct, create a Liquidation classification?
+            #       what about reducers?
+            # return Liquidation()
+
+        return None

mev_inspect/schemas/classifications.py

@@ -9,6 +9,10 @@ class Classification(BaseModel):
     pass
 
 
+class Liquidation(Classification):
+    pass
+
+
 class UnknownClassification(Classification):
     trace: Trace
     internal_classifications: List[Classification]