"""ASCII 프로토콜 (시간 동기화 cmd30, 시간 읽기 cmd31)"""

import socket
from datetime import datetime

from config import TCP_TIMEOUT, TCP_RECV_BUFFER, PROTOCOL_ENCODING
from utils.time_format import datetime_to_protocol, protocol_to_datetime


def sync_time(ip: str, port: int, dt: datetime | None = None) -> tuple[bool, str]:
    """컨트롤러에 PC 시간 동기화 (명령 30).

    패킷: ![0030YYMMDDdHHMMSS!]
    예시: ![003026020912 30229!]  (2026-02-09 월 23:02:29)
    응답: ![00300!] (성공) / ![0030F!] (실패)

    Returns: (성공여부, 메시지)
    """
    if dt is None:
        dt = datetime.now()

    time_str = datetime_to_protocol(dt)
    cmd = f"![0030{time_str}!]"

    try:
        resp = _tcp_send_recv(ip, port, cmd)
    except Exception as e:
        return False, f"연결 실패: {e}"

    if "![00300!]" in resp:
        return True, "동기화 성공"
    elif "![0030F!]" in resp:
        return False, "동기화 실패 (컨트롤러 응답 F)"
    else:
        return False, f"알 수 없는 응답: {resp}"


def read_time(ip: str, port: int) -> tuple[datetime | None, datetime, datetime, str]:
    """컨트롤러 시간 읽기 (명령 31).

    패킷: ![0031!]
    응답: ![0031YYMMDDdHHMMSS!]  (13자 시간 데이터)

    Returns: (컨트롤러시간 | None, PC시간_before, PC시간_after, 에러메시지)
    """
    cmd = "![0031!]"

    pc_before = datetime.now()
    try:
        resp = _tcp_send_recv(ip, port, cmd)
    except Exception as e:
        pc_after = datetime.now()
        return None, pc_before, pc_after, f"연결 실패: {e}"
    pc_after = datetime.now()

    # 응답 파싱: ![0031YYMMDDdHHMMSS!]
    # "![0031" 뒤에 13자의 시간 데이터
    try:
        start = resp.index("![0031") + 6
        time_data = resp[start:start + 13]
        ctrl_time = protocol_to_datetime(time_data)
        return ctrl_time, pc_before, pc_after, ""
    except (ValueError, IndexError) as e:
        return None, pc_before, pc_after, f"응답 파싱 실패: {resp} ({e})"


def _tcp_send_recv(ip: str, port: int, cmd: str) -> str:
    """TCP 연결하여 명령 전송 후 응답 수신."""
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.settimeout(TCP_TIMEOUT)
    try:
        sock.connect((ip, port))
        sock.sendall(cmd.encode(PROTOCOL_ENCODING))
        resp = sock.recv(TCP_RECV_BUFFER)
        return resp.decode(PROTOCOL_ENCODING, errors="replace")
    finally:
        sock.close()