import os

import json

import functools

from typing import Union, List, Tuple

from web3 import Web3

from .types import AddressLike, Address, Contract

from .exceptions import InvalidToken

def _str_to_addr(s: Union[AddressLike, str]) -> Address:

"""Idempotent"""

if isinstance(s, str):

if s.startswith("0x"):

return Address(bytes.fromhex(s[2:]))

else:

raise Exception(f"Couldn't convert string '{s}' to AddressLike")

else:

return s

def _addr_to_str(a: AddressLike) -> str:

if isinstance(a, bytes):

# Address or ChecksumAddress

addr: str = Web3.toChecksumAddress("0x" + bytes(a).hex())

return addr

elif isinstance(a, str) and a.startswith("0x"):

addr = Web3.toChecksumAddress(a)

return addr

raise InvalidToken(a)

def is_same_address(a1: Union[AddressLike, str], a2: Union[AddressLike, str]) -> bool:

return _str_to_addr(a1) == _str_to_addr(a2)

def _validate_address(a: AddressLike) -> None:

assert _addr_to_str(a)

def _load_abi(name: str) -> str:

path = f"{os.path.dirname(os.path.abspath(__file__))}/assets/"

with open(os.path.abspath(path + f"{name}.abi")) as f:

abi: str = json.load(f)

return abi

@functools.lru_cache()

def _load_contract(w3: Web3, abi_name: str, address: AddressLike) -> Contract:

address = Web3.toChecksumAddress(address)

return w3.eth.contract(address=address, abi=_load_abi(abi_name))

def _load_contract_erc20(w3: Web3, address: AddressLike) -> Contract:

return _load_contract(w3, "erc20", address)

def _encode_path(token_in: AddressLike, route: List[Tuple[int, AddressLike]]) -> bytes:

"""

Needed for multi-hop swaps in V3.

https://github.com/Uniswap/uniswap-v3-sdk/blob/1a74d5f0a31040fec4aeb1f83bba01d7c03f4870/src/utils/encodeRouteToPath.ts

"""

raise NotImplementedError