#!/usr/bin/env python
import rospy
import rospkg

from std_msgs.msg import Bool
from safety_user_plugin.msg import RobotInfoMsg
from safety_user_plugin.msg import RestrictionsMsg

from robot_info import RobotInfo
from master_restrictions import Restrictions

from enums.stop_state import StopState as SS

class ROSWrapper:

    def __init__(self):
        self.robots_list_update_callback = None
        self.robot_info_update_callback = None

        self.robot_info_subscribers = {}
        self.master_stop_publisher = None
        self.restrictions_publisher = None

        self.robots_list_timer = None
        self.periodic_timer = None

        self.setup_subscribers_and_publishers()


    def setup_subscribers_and_publishers(self):
        self.master_stop_publisher = rospy.Publisher('/RosAria/master_stop',Bool,queue_size = 1)
        self.restrictions_publisher = rospy.Publisher('/RosAria/restrictions',RestrictionsMsg,queue_size = 1)

        self.periodic_timer = rospy.Timer(rospy.Duration(0.5),self.publish_periodic_update)

    def add_robot_subscriber(self,robot_id):
        if robot_id not in self.robot_info_subscribers:
            topic_name = '/RosAria/PIONIER{0}/robot_info'.format(robot_id)
            new_sub = rospy.Subscriber(topic_name, RobotInfoMsg, self.handle_robot_info_update)
            self.robot_info_subscribers[robot_id] = new_sub
        else:
            raise RuntimeError('Subscriber for PIONIER{0} already in dictionary'.format(robot_id))

    def remove_robot_subscriber(self,robot_id):
        if robot_id in self.robot_info_subscribers:
            self.unsubscribe(self.robot_info_subscribers[robot_id])
            del self.robot_info_subscribers[robot_id]
        else:
            raise RuntimeError('Subscriber for PIONIER{0} not in dictionary. Cannot be removed'.format(robot_id))

    def unsubscribe(self,subscriber):
        if subscriber != None:
            subscriber.unregister()

    def unregister_publisher(self,publisher):
        if publisher != None:
            publisher.unregister()

    def shutdown_timer(self,timer):
        if timer != None:
            timer.shutdown()

    def publish_periodic_update(self,event):
        restrictions = self.get_restrictions()
        restrictions_msg = RestrictionsMsg()
        restrictions_msg.distance.data = restrictions.distance
        restrictions_msg.linear_velocity.data = restrictions.linear_velocity
        restrictions_msg.angular_velocity.data = restrictions.angular_velocity

        stop_state = self.get_master_stop_state()
        stop_msg = Bool()

        if stop_state == SS.RUNNING:
            stop_msg.data = True
        elif stop_state == SS.STOPPED:
            stop_msg.data = False
        else:
            stop_msg.data = False
            raise ValueError('stop_state UNKNOWN when attempting to publish periodic update')

        self.restrictions_publisher.publish(restrictions_msg)
        self.master_stop_publisher.publish(stop_msg)

    def cancel_subscribers_and_publishers(self):
        self.shutdown_timer(self.robots_list_timer)
        self.shutdown_timer(self.periodic_timer)

        self.unregister_publisher(self.master_stop_publisher)
        self.unregister_publisher(self.restrictions_publisher)

        for key, value in self.robot_info_subscribers.iteritems():
            self.unsubscribe(value)

    def unregister_node(self):
        self.cancel_subscribers_and_publishers()
        rospy.signal_shutdown('Closing safety master plugin')

    def setup_get_master_stop_state_function(self,function):
        self.get_master_stop_state = function

    def setup_get_restrictions_function(self,function):
        self.get_restrictions = function

    # ROSWrapper Callbacks
    def get_robots_list(self,event):
        robots_id_list = []

        published_topics_list = rospy.get_published_topics(namespace='/')
        published_topics = []

        for list_ in published_topics_list:
            published_topics.append(list_[0])

        for topic in published_topics:
            if topic.find('RosAria') ==-1 or topic.find('robot_info') == -1:
                pass
            else:
                robot_number = topic.split('/')
                robot_number = robot_number[2]
                robot_number = robot_number[7:]
                if len(robot_number) > 0:
                    robot_number = int(robot_number)
                    robots_id_list.append(robot_number)

        self.robots_list_update_callback(robots_id_list)


    def handle_robot_info_update(self,msg):
        _robot_info = RobotInfo(0)
        _robot_info.update_robot_info(msg)
        self.robot_info_update_callback(_robot_info)


    # MasterPlugin Callbacks
    def set_robots_list_update_callback(self,callback_function):
        self.robots_list_update_callback = callback_function
        self.robots_list_timer = rospy.Timer(rospy.Duration(0.5),self.get_robots_list)

    def set_robot_info_update_callback(self,callback_function):
        self.robot_info_update_callback = callback_function

    def master_started(self):
        msg = Bool()
        msg.data = True
        self.master_stop_publisher.publish(msg)

    def master_stopped(self):
        msg = Bool()
        msg.data = False
        self.master_stop_publisher.publish(msg)

    def restrictions_changed(self,restrictions):
        msg = RestrictionsMsg()

        msg.distance.data = restrictions.distance
        msg.linear_velocity.data = restrictions.linear_velocity
        msg.angular_velocity.data = restrictions.angular_velocity

        self.restrictions_publisher.publish(msg)