# scraper/logger.py
import logging
from io import StringIO

# In-memory buffer (voor eindresultaat)
LOG_BUFFER = StringIO()

# List van callbacks (SSE-clients)
LISTENERS = []


def add_listener(callback):
    """Registreer een SSE listener callback."""
    LISTENERS.append(callback)


def remove_listener(callback):
    """Verwijder SSE listener (bij disconnect)."""
    if callback in LISTENERS:
        LISTENERS.remove(callback)


def broadcast(line):
    """Stuur logregel naar alle listeners."""
    for cb in LISTENERS[:]:
        try:
            cb(line)
        except Exception:
            LISTENERS.remove(cb)


def setup_logger():
    """Creëer logger die naar console, buffer én SSE broadcast."""
    logger = logging.getLogger("bookscraper")
    logger.setLevel(logging.DEBUG)
    logger.handlers = []

    # formatter
    fmt = logging.Formatter("[%(levelname)s] %(message)s")

    # console handler
    ch = logging.StreamHandler()
    ch.setLevel(logging.DEBUG)
    ch.setFormatter(fmt)

    # buffer handler
    bh = logging.StreamHandler(LOG_BUFFER)
    bh.setLevel(logging.DEBUG)
    bh.setFormatter(fmt)

    # SSE handler
    class SSEHandler(logging.Handler):
        def emit(self, record):
            msg = self.format(record)
            broadcast(msg)

    sh = SSEHandler()
    sh.setLevel(logging.DEBUG)
    sh.setFormatter(fmt)

    logger.addHandler(ch)
    logger.addHandler(bh)
    logger.addHandler(sh)

    return logger


# Globale logger
LOGGER = setup_logger()


def log_debug(msg):
    LOGGER.debug(msg)