#!/usr/bin/env python
# -*- coding: utf-8 -*-
from __future__ import (
    absolute_import,
    division,
    print_function,
)

import time
import logging
import agentx
from agentx.dataset import DataSet
from agentx.network import Network


class NullHandler(logging.Handler):
    def emit(self, record):
        pass


class Agent(object):
    def __init__(self, server_address="/var/agentx/master", period=30.0):
        self.logger = logging.getLogger("agentx.agent")
        self.logger.addHandler(NullHandler())

        self._servingset = DataSet()
        self._workingset = DataSet()
        self._lastupdate = 0
        self._update_period = period  # Seconds

        self._net = Network(server_address=server_address)

        self._oid_list = []

    def _update(self):
        ds = self.update()
        if not ds:
            return False

        self._net.update(ds._data)
        self._lastupdate = time.time()
        return True

    def run(self):
        self.logger.info("Calling setup")
        if not self.setup():
            self.logger.error("Setup failed - exiting")
            return

        self.logger.info("Initial update")
        self._update()

        while True:
            if not self._net.is_connected():
                self.logger.info("Opening AgentX connection")
                self._net.start(self._oid_list)

            if time.time() - self._lastupdate > self._update_period:
                if not self._update():
                    self.logger.warning(
                        "Update failed, last successful update was %s"
                        % self._lastupdate
                    )
                    time.sleep(1)

            try:
                self._net.run()
            except Exception as e:
                self.logger.error("An exception occurred: %s" % e)
                self.logger.error("Reconnecting")
                self._net.disconnect()
                time.sleep(0.1)

    def stop(self):
        self.logger.debug("Stopping")
        self._net.disconnect()
        pass

    def setup(self):
        # Override this
        pass

    def update(self):
        # Override this
        pass

    def register(self, oid_list):
        if not isinstance(oid_list, list):
            oid_list = [oid_list]

        for oid in oid_list:
            if not oid in self._oid_list:
                self.logger.debug("Adding %s to list" % oid)
                self._oid_list.append(oid)