class EpicsServerState(ReadonlyAsyncRegisterBase):
    def __init__(self, name, channel, as_string=True):
        RegisterBase.__init__(self, name)
        self.channel=channel
        self.as_string=as_string
        self.val = "Unknown"
        self.cas = None
        self.state_change_listener=None        
        
    def doInitialize(self):   
        super(EpicsServerState, self).doInitialize()
        if self.as_string:
            self.cas = CAS(self.channel, self, 'string')
        else:
            self.cas = CAS(self.channel, self, 'byte')
        if self.state_change_listener is None:
            class StateChangeListener(ContextListener):
                def onContextStateChanged(_self, state, former):  
                    self.set(state)        
            self.state_change_listener = StateChangeListener()   
            get_context().addListener(self.state_change_listener)
                     
    def getSize(self):
        if self.as_string:
            return 1            
        else:
            return 100
                        
    def doClose(self):
        if self.state_change_listener:
            get_context().removeListener(self.state_change_listener)
        if self.cas:
            self.cas.close()
            self.cas = None
        super(EpicsServerState, self).doClose()        

    def set(self, value):
        if self.as_string:
            self.onReadout(str(value)) 
        else:
            self.onReadout(string_to_list(str(value)))
        
    



if "server_state_channel" in globals():
    server_state_channel.close()
server_state_channel = EpicsServerState("server_state_channel", "PSHELL_OP:STATE", False)
server_state_channel.initialize()