"""
ERC-20 monitoring sandbox

An exercise exploring ABIs and chain events
"""
import requests
from typing import Any, Optional, Dict

JENNER_ADDRESS = '0x482702745260ffd69fc19943f70cffe2cacd70e9'


def fetch_abi(
        address: str,
        headers: Optional[Dict[str, Any]] = None,
        params: Optional[Dict[str, Any]] = None
) -> Optional[Dict[str, Any]]:
    # TODO: Ensure it is a well-formed address
    # TODO: Check for errors, such as a "status" key set to 0
    url = f'https://api.etherscan.io/api?module=contract&action=getabi&address={address}'
    try:
        response = requests.get(url, headers=headers, params=params)
        response.raise_for_status()
        return response.json()
    except requests.exceptions.RequestException as err:
        print(f'Error during the request: {err}')
        return None
    except ValueError as err:
        print(f'Error parsing JSON: {err}')


def main():
    jenner_abi = fetch_abi(JENNER_ADDRESS)
    print(jenner_abi)


if __name__ == '__main__':
    main()