from __future__ import annotations

import hashlib
import hmac
import time
from collections.abc import Mapping
from urllib.parse import urlencode


def utc_timestamp_ms() -> int:
    return int(time.time() * 1000)


def canonical_query(params: Mapping[str, object]) -> str:
    filtered = {
        key: value
        for key, value in params.items()
        if value is not None and value != ""
    }
    ordered = sorted(filtered.items(), key=lambda item: item[0])
    return urlencode(ordered, doseq=True)


def sign_query(secret_key: str, query: str) -> str:
    return hmac.new(
        secret_key.encode("utf-8"),
        query.encode("utf-8"),
        hashlib.sha256,
    ).hexdigest()


def build_signed_params(
    params: Mapping[str, object],
    secret_key: str,
    *,
    timestamp_ms: int | None = None,
    recv_window_ms: int | None = 5_000,
) -> dict[str, object]:
    signed = dict(params)
    signed["timestamp"] = utc_timestamp_ms() if timestamp_ms is None else int(timestamp_ms)
    try:
        parsed_recv_window = int(recv_window_ms) if recv_window_ms is not None else 5_000
    except Exception:
        parsed_recv_window = 5_000
    signed["recvWindow"] = parsed_recv_window if parsed_recv_window > 0 else 5_000
    query = canonical_query(signed)
    signed["signature"] = sign_query(secret_key, query)
    return signed