from __future__ import annotations

import json
import os
from typing import Any
from urllib.request import Request, urlopen


def fetch_releases(repo: str) -> list[dict[str, Any]]:
    token = os.environ.get("GITHUB_TOKEN")
    headers = {
        "Accept": "application/vnd.github+json",
        "User-Agent": "plugin-helper",
    }
    if token:
        headers["Authorization"] = f"Bearer {token}"
    request = Request(f"https://api.github.com/repos/{repo}/releases", headers=headers)
    with urlopen(request, timeout=20) as response:
        data = json.loads(response.read().decode("utf-8"))
    if not isinstance(data, list):
        raise ValueError(f"unexpected GitHub releases response for {repo}")
    return data