from kwargsparser import kwargsParser as kwargsParser

class SimpleStateMachine():
    def __init__(self,default_state,**kwargs):
        parser = kwargsParser(kwargs)

        self.log_cb = parser.parse_args("log_cb",None)

        parser.validate_args()
        self.current_state = None
        self.change_state(default_state)

    def log(self,log_string):
        if self.log_cb: self.log_cb(log_string)

    def change_state(self,new_state):
        if new_state != self.current_state:
            if self.current_state != None:
                if self.current_state.on_exit != None:
                    self.current_state.on_exit()
                self.log(f"Changing from state {self.current_state.state_name} to {new_state.state_name}")
            else:
                self.log(f"Initialising with state {new_state.state_name}")
            self.current_state = new_state
            if self.current_state.on_enter != None: 
                self.current_state.on_enter()

class State():
    def __init__(self,state_name,**kwargs):
        self.state_name = state_name
        
        parser = kwargsParser(kwargs)

        self.on_enter = parser.parse_args("on_enter_cb",None)
        self.on_exit = parser.parse_args("on_exit_cb",None)

        parser.validate_args()