from panflute import Doc

class Context:
	def __init__(self, doc: Doc=None, parent: 'Context'=None):
		self.parent = parent
		self._commands = {}
		self._flags = {}
		self.doc = doc

	def get_command(self, command: str):
		if command in self._commands:
			return self._commands[command]
		elif self.parent:
			return self.parent.get_command(command)
		else:
			return None

	def set_command(self, command: str, val):
		self._commands[command] = val
	
	def unset_command(self, command: str):
		del self._commands[command]

	def is_flag_set(self, flag: str):
		if flag in self._flags and self._flags[flag]:
			return True
		elif self.parent:
			return self.parent.is_set(flag)
		else:
			return False

	def set_flag(self, flag: str, val: bool):
		self._flags[flag] = val

	def unset_flag(self, flag):
		del self._flags[flag]

	def get_metadata(self, key, simple=True):
		value = self.doc.get_metadata(key, None, simple)
		if value is not None:
			return value
		elif self.parent:
			return self.parent.get_metadata(key)
		else:
			return None