#!/usr/bin/env python
import rospy
import tf
from gazebo_msgs.msg import LinkStates

class tf_service():
	def __init__(self):
		self._nodes = ['baxter::base',
						't1::Table',
						'ia1::Brick',
						'ia2::Brick',
						'ia3::Brick',
						'ib1::Brick',
						'ib2::Brick',
						'ic1::Brick',
						'ic2::Brick',
						'id1::Brick',
						'ie1::Brick']



	def _callback(self, data):
		# Get index
		for object_name in self._nodes:
			object_idx = data.name.index(object_name)
			# Get baxter_base pose and object pose w.r.t. gazebo world
			object_pose = data.pose[object_idx]
			# Broadcast base and object poses w.r.t. the gazebo world into tf tree
			br = tf.TransformBroadcaster()
			br.sendTransform((object_pose.position.x, object_pose.position.y, object_pose.position.z),
				(object_pose.orientation.x, object_pose.orientation.y, object_pose.orientation.z, object_pose.orientation.w),
				rospy.Time.now(), object_name,'gazebo_world')


	def gazebo_link_subscriber(self):
		rospy.init_node('gazebo_link_subscriber')
		rospy.Subscriber("/gazebo/link_states", LinkStates, self._callback)
		# spin() simply keeps python from exiting until this node is stopped
		rospy.spin()

x = tf_service()

x.gazebo_link_subscriber()