import yaml
from transitions import State

from tfw import FSMBase


class YamlFSM(FSMBase):
    def __init__(self, config_file):
        self.config = self.parse_config(config_file)
        self.states = [State(**state) for state in self.config['states']]
        super(YamlFSM, self).__init__()
        for transition in self.config['transitions']:
            self.machine.add_transition(**transition)

    @staticmethod
    def parse_config(config_file):
        with open(config_file, 'r') as ifile:
            return yaml.load(ifile)