# Eryn Wells <eryn@erynwells.me>

'''
Initializes and sets up logging for the game.
'''

import json
import logging
import logging.config
import os.path
from typing import Iterator, Optional

# These are re-imports so clients of this module don't have to also import logging
# pylint: disable=unused-import
from logging import CRITICAL, DEBUG, ERROR, FATAL, INFO, NOTSET, WARN, WARNING


def _log_name(*components):
    return '.'.join(['erynrl'] + list(components))


ROOT = logging.getLogger(_log_name())
AI = logging.getLogger(_log_name('ai'))
ACTIONS = logging.getLogger(_log_name('actions'))
ACTIONS_TREE = logging.getLogger(_log_name('actions', 'tree'))
ENGINE = logging.getLogger(_log_name('engine'))
EVENTS = logging.getLogger(_log_name('events'))
UI = logging.getLogger(_log_name('ui'))

MAP = logging.getLogger(_log_name('map'))
MAP_BSP = logging.getLogger(_log_name('map', 'bsp'))
MAP_CELL_ATOM = logging.getLogger(_log_name('map', 'cellular'))


def walk_up_directories_of_path(path: str) -> Iterator[str]:
    '''
    Walk up a path, yielding each directory, until the root of the filesystem is
    found.

    ### Parameters
    `path`: `str`
        The starting path

    ### Returns
    Yields each ancestor directory until the root directory of the filesystem is
    reached.
    '''
    while path and path != '/':
        if os.path.isdir(path):
            yield path
        path = os.path.dirname(path)


def find_logging_config() -> Optional[str]:
    '''
    Walk up the filesystem from this script to find a logging_config.json

    ### Returns
    The path to a logging configuration file, or `None` if no such file was found
    '''
    for parent_dir in walk_up_directories_of_path(__file__):
        possible_logging_config_file = os.path.join(parent_dir, 'logging_config.json')
        if os.path.isfile(possible_logging_config_file):
            ROOT.info('Found logging config file %s', possible_logging_config_file)
            break
    else:
        return None

    return possible_logging_config_file


def init(config_file: Optional[str] = None):
    '''
    Set up the logging system by (preferrably) reading a logging configuration file.

    ### Parameters
    `config_file`: Optional[str]
        Path to a file containing a Python logging configuration in JSON
    '''
    logging_config_path = config_file if config_file else find_logging_config()

    if logging_config_path and os.path.isfile(logging_config_path):
        ROOT.info('Found logging configuration at %s', logging_config_path)
        with open(logging_config_path, encoding='utf-8') as logging_config_file:
            logging_config = json.load(logging_config_file)
            logging.config.dictConfig(logging_config)
    else:
        ROOT.info(
            "Couldn't find logging configuration at %s; using default configuration",
            logging_config_path)

        root_logger = logging.getLogger('')
        root_logger.setLevel(logging.DEBUG)

        stderr_handler = logging.StreamHandler()
        stderr_handler.setFormatter(logging.Formatter("%(asctime)s %(name)s: %(message)s"))

        root_logger.addHandler(stderr_handler)