"""signal_alert."""

from __future__ import annotations

import json
import logging
import socket
from os import getenv

logger = logging.getLogger(__name__)


def signal_alert(body: str) -> None:
    """Send a signal alert.

    Args:
        body (str): The body of the alert.
    """
    from_phone = getenv("SIGNAL_ALERT_FROM_PHONE")
    to_phone = getenv("SIGNAL_ALERT_TO_PHONE")
    if not from_phone or not to_phone:
        logger.info("SIGNAL_ALERT_FROM_PHONE or SIGNAL_ALERT_TO_PHONE not set")
        return

    signal_rpc_id = "signal-alert"
    request = {
        "jsonrpc": "2.0",
        "method": "send",
        "params": {
            "account": from_phone,
            "recipient": [to_phone],
            "message": body,
        },
        "id": signal_rpc_id,
    }

    try:
        with socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) as client:
            client.settimeout(4.0)
            client.connect("/run/signal-cli/socket")
            client.sendall(json.dumps(request).encode() + b"\n")

            buffer = b""
            while chunk := client.recv(65536):
                buffer += chunk
                while b"\n" in buffer:
                    line, buffer = buffer.split(b"\n", maxsplit=1)
                    response = json.loads(line)
                    if response.get("id") == signal_rpc_id:
                        if error := response.get("error"):
                            logger.error("Signal RPC returned an error: %s", error)
                        return

            logger.error("Signal RPC socket closed before returning a response")
    except OSError, json.JSONDecodeError:
        logger.exception("Unable to communicate with signal-cli")