import json
import os
import logging

logger = logging.getLogger(__name__)

CHANNEL_PREFIX = "audit_task:"
STATE_PREFIX = "audit_task_state:"
STATE_TTL = 7200  # 2 horas


def _get_client():
    import redis
    return redis.Redis(
        host=os.getenv("REDIS_HOST", "localhost"),
        port=int(os.getenv("REDIS_PORT", 6379)),
        db=int(os.getenv("REDIS_DB", 0)),
        decode_responses=True,
        socket_connect_timeout=2,
        socket_timeout=2,
    )


def publish_task_event(task_id: str, status: str, message: str = "", resultado: dict = None, progress: int = None):
    """
    Publica un evento de progreso de tarea en Redis Pub/Sub.
    El microservicio SSE usa el mismo canal para streamear al frontend.
    """
    payload: dict = {"task_id": task_id, "status": status, "message": message}
    if resultado is not None:
        payload["resultado"] = resultado
    if progress is not None:
        payload["progress"] = progress

    try:
        client = _get_client()
        serialized = json.dumps(payload)
        client.publish(f"{CHANNEL_PREFIX}{task_id}", serialized)
        client.setex(f"{STATE_PREFIX}{task_id}", STATE_TTL, serialized)
        client.close()
    except Exception as exc:
        logger.error(f"[redis_events] Error publicando evento para tarea {task_id}: {exc}")