from urllib.parse import unquote


def parse_s3_uri(s3_uri: str) -> tuple[str, str]:
    if s3_uri.startswith("s3://"):
        parts = s3_uri[len("s3://") :].split("/", 1)
        if len(parts) < 2 or not parts[0] or not parts[1]:
            raise ValueError("S3 URI must include both a bucket and a key")
        return parts[0], parts[1]

    if "?" not in s3_uri:
        raise ValueError(f"Not an s3:// URI and has no query string: {s3_uri!r}")
    base, query = s3_uri.split("?", 1)

    if "/s3/object/" not in base:
        raise ValueError(f"Console URL has no '/s3/object/' segment: {s3_uri!r}")
    bucket = base.split("/s3/object/", 1)[1]

    params: dict[str, str] = {}
    for item in query.split("&"):
        if "=" in item:
            name, value = item.split("=", 1)
            params[name] = value
    key = unquote(params.get("prefix", ""))
    return bucket, key