"""Root-logger configuration: a rotating file handler under the same
/data volume as the sqlite DB and legacy config.json, so the admin log
viewer has something to read and log content survives container
restarts -- a redeploy happens on every push to main touching
server/**, which would make an in-memory-only log buffer nearly
useless in practice. Before this, the root logger had no handler at
all, so every module's logger.info() call (user creation, claims,
password resets, ...) was silently dropped rather than merely
un-viewable -- this fixes that too, not just adds a viewer."""

from __future__ import annotations

import logging
import os
from logging.handlers import RotatingFileHandler
from pathlib import Path

LOG_PATH = Path(os.environ.get("LOG_PATH", "/data/server.log"))


def configure_logging() -> None:
    LOG_PATH.parent.mkdir(parents=True, exist_ok=True)
    handler = RotatingFileHandler(LOG_PATH, maxBytes=2_000_000, backupCount=3)
    handler.setFormatter(logging.Formatter("%(asctime)s %(levelname)s %(name)s: %(message)s"))
    root = logging.getLogger()
    root.addHandler(handler)
    root.setLevel(os.environ.get("LOG_LEVEL", "INFO"))


def read_log_tail(lines: int) -> str:
    if not LOG_PATH.exists():
        return ""
    text = LOG_PATH.read_text(errors="replace")
    return "\n".join(text.splitlines()[-lines:])