import argparse
import sys
import requests


def find_email(username: str, token: str | None = None) -> str | None:
    headers = {"Accept": "application/vnd.github+json"}
    if token:
        headers["Authorization"] = f"Bearer {token}"

    url = f"https://api.github.com/users/{username}/events/public"

    try:
        resp = requests.get(url, headers=headers, timeout=10)
    except requests.RequestException as e:
        print(f"Network error: {e}", file=sys.stderr)
        return None

    if resp.status_code == 404:
        print(f"User '{username}' not found.", file=sys.stderr)
        return None
    if resp.status_code == 403:
        print("Rate limited by GitHub API. Try again later or use --token.", file=sys.stderr)
        return None
    if resp.status_code != 200:
        print(f"GitHub API error: {resp.status_code} {resp.text}", file=sys.stderr)
        return None

    events = resp.json()

    for event in events:
        if event.get("type") != "PushEvent":
            continue

        commits = event.get("payload", {}).get("commits", [])
        for commit in commits:
            author = commit.get("author", {})
            email = author.get("email")
            name = author.get("name", "")

            if not email:
                continue
            if "noreply.github.com" in email:
                continue
            print(f"Found: {name} <{email}>  (from a push event)")
            return email

    print(f"No public email found for '{username}'.", file=sys.stderr)
    print(
        "This can happen if the user has enabled 'Keep my email addresses "
        "private', has no recent public push events, or only committed "
        "using a noreply address.",
        file=sys.stderr,
    )
    return None


def main():
    parser = argparse.ArgumentParser(description="Find a GitHub user's public commit email.")
    parser.add_argument("username", help="GitHub username to look up")
    parser.add_argument("--token", help="GitHub personal access token (optional, raises rate limits)")
    args = parser.parse_args()

    email = find_email(args.username, args.token)
    if email:
        print(email)
        sys.exit(0)
    else:
        sys.exit(1)


if __name__ == "__main__":
    main()