import sys

from os import environ as env
from datetime import datetime


# Custom logger
class Log():
	def __init__(self, minimum='INFO', datefmt='%Y-%m-%d %H:%M:%S', date=True):
		self.levels = {
			'CRIT': 60,
			'ERROR': 50,
			'WARN': 40,
			'INFO': 30,
			'VERB': 20,
			'DEBUG': 10,
			'MERP': 0
		}

		self.date = date
		self.datefmt = datefmt
		self.minimum = self._lvlCheck(minimum)

		# make sure the minimum logging level is an int
	def _lvlCheck(self, level):
		try:
			value = int(level)

		except ValueError:
			value = self.levels.get(level)

		if value not in self.levels.values():
			raise InvalidLevel(f'Invalid logging level: {level}')

		return value

	def setLevel(self, level):
		self.minimum = self._lvlCheck(level)

	def log(self, level, msg):
		levelNum = self._lvlCheck(level)

		if type(level) == int:
			for k,v in self.levels.items():
				if v == levelNum:
					level = k

		if levelNum < self.minimum:
			return

		output = f'{level}: {msg}\n'

		# Only show date when not running in systemd and date var is True
		if self.date and not env.get('INVOCATION_ID'):
			date = datetime.now().strftime(self.datefmt)
			output = f'{date} {output}'

		stdout = sys.stdout
		stdout.write(output)
		stdout.flush()


	def critical(self, msg):
		self.log('CRIT', msg)

	def error(self, msg):
		self.log('ERROR', msg)

	def warning(self, msg):
		self.log('WARN', msg)

	def info(self, msg):
		self.log('INFO', msg)

	def verbose(self, msg):
		self.log('VERB', msg)

	def debug(self, msg):
		self.log('DEBUG', msg)

	def merp(self, msg):
		self.log('MERP', msg)


class InvalidType(Exception):
	'''Raise when the log level isn't a str or an int'''

class InvalidLevel(Exception):
	'''Raise when an invalid logging level was specified'''