import logging
import os
from datetime import datetime


def setup_logging(log_dir=None):
    """Initialize file + console logging. Call once at application startup.

    log_dir: str or Path to log directory. Defaults to <app_dir>/logs/ via
             file_service.get_log_dir(). Falls back to console-only if the
             directory cannot be created.
    """
    if log_dir is None:
        try:
            from services.file_service import get_log_dir
            log_dir = get_log_dir()
        except OSError as exc:
            _setup_console_only()
            logging.getLogger(__name__).warning(
                "Cannot create log directory: %s. Falling back to console only.", exc
            )
            return
    else:
        try:
            os.makedirs(str(log_dir), exist_ok=True)
        except OSError as exc:
            _setup_console_only()
            logging.getLogger(__name__).warning(
                "Cannot create log directory %s: %s. Falling back to console only.", log_dir, exc
            )
            return

    timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
    log_file = os.path.join(str(log_dir), "app_{}.log".format(timestamp))

    formatter = logging.Formatter("%(asctime)s %(name)s %(levelname)s %(message)s")

    root = logging.getLogger()
    root.setLevel(logging.INFO)

    fh = logging.FileHandler(log_file, encoding="utf-8")
    fh.setFormatter(formatter)
    root.addHandler(fh)

    sh = logging.StreamHandler()
    sh.setFormatter(formatter)
    root.addHandler(sh)

    logging.getLogger(__name__).info("Logging initialized. Log file: %s", log_file)


def _setup_console_only():
    logging.basicConfig(
        level=logging.INFO,
        format="%(asctime)s %(name)s %(levelname)s %(message)s",
    )