"""
Central logging setup for the application.

- Provides a unified logger via get_logger(__name__)
- Writes all logs to a central rotating log file (logs/app.log)
- Writes errors separately to logs/errors.log
- Automatically includes the module name in each log entry
- Supports standard logging levels: DEBUG, INFO, WARNING, ERROR, CRITICAL

Usage:
    from backend.managers.debug_logger import get_logger
    logger = get_logger(__name__)

    logger.info("Service started")
    logger.debug("Debug details")
    logger.error("Something went wrong")

    try:
        ...
    except Exception:
        logger.exception("Unexpected error")

Logging levels (use consistently):
DEBUG:      Detailed technical info for developers (variables, flow, internal state).
INFO:       Normal application events (start/stop, successful operations, key milestones).
WARNING:    Something unexpected happened, but the program continues normally.
ERROR:      A specific operation failed, but the application is still running.
CRITICAL:   A severe failure that may stop the application or make it unusable.
EXCEPTION:  Same as ERROR, but used inside an `except` block and includes stacktrace
            (via logger.exception()).
"""

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

BASE_DIR = Path(__file__).resolve().parent.parent
LOG_DIR = BASE_DIR / "logs"
LOG_DIR.mkdir(exist_ok=True)

class DebugLogger:

    _initialized = False

    @classmethod
    def setup(cls):
        # prevents multiple setup
        if cls._initialized:
            return

        formatter = logging.Formatter(
            "%(asctime)s [%(levelname)s] [%(name)s: Line %(lineno)d] %(message)s"
        )

        # Main log file
        file_handler = RotatingFileHandler(
            LOG_DIR / "app.log",
            maxBytes=5_000_000,
            backupCount=5,
            encoding="utf-8"
        )

        file_handler.setFormatter(formatter)

        # Separate Error-Log
        error_handler = RotatingFileHandler(
            LOG_DIR / "errors.log",
            maxBytes=5_000_000,
            backupCount=3,
            encoding="utf-8"
        )

        error_handler.setLevel(logging.ERROR)
        error_handler.setFormatter(formatter)

        root_logger = logging.getLogger()

        root_logger.setLevel(logging.DEBUG)

        root_logger.addHandler(file_handler)
        root_logger.addHandler(error_handler)
        #root_logger.propagate = False

        cls._initialized = True

    @classmethod
    def get_logger(cls, name: str):
        cls.setup()
        return logging.getLogger(name)


# praktische shortcut function
def get_logger(name: str):
    return DebugLogger.get_logger(name)