'''WizardKit: Log Functions'''
# vim: sts=2 sw=2 ts=2

import logging
import os
import pathlib
import shutil
import time

from . import cfg


# STATIC VARIABLES
LOG = logging.getLogger(__name__)


# Functions
def enable_debug_mode():
  """Configures logging for better debugging."""
  root_logger = logging.getLogger()
  for handler in root_logger.handlers:
    formatter = logging.Formatter(
      datefmt=cfg.log.DEBUG['datefmt'],
      fmt=cfg.log.DEBUG['format'],
      )
    handler.setFormatter(formatter)
  root_logger.setLevel('DEBUG')


def update_log_path(dest_dir, dest_filename=''):
  """Copies current log file to new dir and updates the root logger."""
  dest = pathlib.Path(dest_dir)
  dest = dest.expanduser()
  root_logger = logging.getLogger()
  cur_handler = root_logger.handlers[0]

  # Safety checks
  if len(root_logger.handlers) > 1:
    raise NotImplementedError('update_log_path() only supports a single handler.')
  if not isinstance(cur_handler, logging.FileHandler):
    raise NotImplementedError('update_log_path() only supports FileHandlers.')

  # Set source
  source = pathlib.Path(cur_handler.baseFilename)
  source = source.resolve()

  # Copy original log to new location
  if dest_filename:
    dest = dest.joinpath(dest_filename)
  else:
    dest = dest.joinpath(source.name)
  dest = dest.resolve()
  os.makedirs(dest.parent, exist_ok=True)
  shutil.copy(source, dest)

  # Create new cur_handler (preserving formatter settings)
  new_handler = logging.FileHandler(dest, mode='a')
  new_handler.setFormatter(cur_handler.formatter)

  # Replace current handler
  root_logger.removeHandler(cur_handler)
  root_logger.addHandler(new_handler)


def start(config=None):
  """Configure and start logging using safe defaults."""
  log_dir = '{}/Logs/'.format(os.path.expanduser('~'))
  log_path = '{}/{}_{}.log'.format(
    log_dir,
    cfg.main.KIT_NAME_FULL,
    time.strftime('%Y-%m-%d_%H%M%z'),
    )
  root_logger = logging.getLogger()

  # Safety checks
  if not config:
    config = cfg.log.DEFAULT
  if root_logger.hasHandlers():
    raise UserWarning('Logging already started.')

  # Create log_dir
  os.makedirs(log_dir, exist_ok=True)

  # Config logger
  logging.basicConfig(filename=log_path, **config)

if __name__ == '__main__':
  print("This file is not meant to be called directly.")