util.py

import json
from typing import Set
from urllib import error, request

import discord


async def get_user_ids(r: discord.Reaction) -> Set[int]:
    """
    Extracts user ids from a discord reaction.

    This only exists because testing anything involving discord reactions
    is a pain, and we want to mock it out.
    """
    pids = set()
    async for u in r.users():
        pids.add(u.id)
    return pids


def make_request(base_url,
                 additional_url,
                 params={},
                 data=None,
                 raise_exception_on_http_error=False,
                 method=None):
    """
    Fetches resource at URL, converts JSON response to object.

    The URL is just base_url + additional_url.
    If data is set, it should be a dictionary, which will be encoded as JSON.
    This will make the request a POST request instead of GET.
    """

    url = base_url + additional_url
    first_item = True
    for param, value in params.items():
        if first_item:
            url += f'?{param}={value}'
            first_item = False
            continue

        url += f'&{param}={value}'

    headers = {}
    if data is not None:
        data = json.dumps(data).encode()
        headers['Content-Type'] = 'application/json'
    try:
        r = request.Request(url, data, headers, method=method)
        response = request.urlopen(r)
    except error.HTTPError as e:
        # Usually we want to return any data on an HTTP error,
        # but sometimes we may wish to still treat it as an exception.
        if raise_exception_on_http_error:
            raise e
        response = e

    # Convert raw response to usable JSON object
    response_as_string = response.read().decode('utf-8')
    return json.loads(response_as_string)