# Copyright © 2020 Interplanetary Database Association e.V.,
# Planetmint and IPDB software contributors.
# SPDX-License-Identifier: (Apache-2.0 AND CC-BY-4.0)
# Code is Apache-2.0 and docs are CC-BY-4.0

from transactions.common.exceptions import ConfigurationError
from logging.config import dictConfig as set_logging_config
from planetmint.config import Config, DEFAULT_LOGGING_CONFIG


def _normalize_log_level(level):
    try:
        return level.upper()
    except AttributeError as exc:
        raise ConfigurationError("Log level must be a string!") from exc


def setup_logging():
    """Function to configure log hadlers.

    .. important::

        Configuration, if needed, should be applied before invoking this
        decorator, as starting the subscriber process for logging will
        configure the root logger for the child process based on the
        state of :obj:`planetmint.config` at the moment this decorator
        is invoked.

    """

    logging_configs = DEFAULT_LOGGING_CONFIG
    new_logging_configs = Config().get()["log"]

    if "file" in new_logging_configs:
        filename = new_logging_configs["file"]
        logging_configs["handlers"]["file"]["filename"] = filename

    if "error_file" in new_logging_configs:
        error_filename = new_logging_configs["error_file"]
        logging_configs["handlers"]["errors"]["filename"] = error_filename

    if "level_console" in new_logging_configs:
        level = _normalize_log_level(new_logging_configs["level_console"])
        logging_configs["handlers"]["console"]["level"] = level

    if "level_logfile" in new_logging_configs:
        level = _normalize_log_level(new_logging_configs["level_logfile"])
        logging_configs["handlers"]["file"]["level"] = level

    if "fmt_console" in new_logging_configs:
        fmt = new_logging_configs["fmt_console"]
        logging_configs["formatters"]["console"]["format"] = fmt

    if "fmt_logfile" in new_logging_configs:
        fmt = new_logging_configs["fmt_logfile"]
        logging_configs["formatters"]["file"]["format"] = fmt

    if "datefmt_console" in new_logging_configs:
        fmt = new_logging_configs["datefmt_console"]
        logging_configs["formatters"]["console"]["datefmt"] = fmt

    if "datefmt_logfile" in new_logging_configs:
        fmt = new_logging_configs["datefmt_logfile"]
        logging_configs["formatters"]["file"]["datefmt"] = fmt

    log_levels = new_logging_configs.get("granular_levels", {})

    for logger_name, level in log_levels.items():
        level = _normalize_log_level(level)
        try:
            logging_configs["loggers"][logger_name]["level"] = level
        except KeyError:
            logging_configs["loggers"][logger_name] = {"level": level}

    set_logging_config(logging_configs)