#!/usr/bin/env python
import rospy
from std_msgs.msg import String
import rospkg
import subprocess
import os
import signal

class Bagger(object):

    def __init__(self):
        rospy.init_node("bagger", anonymous=True)
        rospy.Subscriber("bag_publisher", String, self.callback)
        self.pub = rospy.Publisher("bag_notifier", String, queue_size=10)
        self.proc = None
        rospack = rospkg.RosPack()
        self.data_path = os.path.join(rospack.get_path("rosbridge_gui_example"), "data")

    def callback(self, msg):
        if msg.data == "STOP" and self.proc is not None:
            os.killpg(self.proc.pid, signal.SIGINT)
            self.pub.publish("STOPPED")
        else:
            msg_data = msg.data.split()
            self.pub.publish(str(len(msg_data)))
            self.pub.publish(str(msg_data))
            if len(msg_data) == 0: # We only got the name of the bag file and not any topics
                bag_file_name = os.path.join(self.data_path, "bag_file")
                self.proc = subprocess.Popen(["rosbag", "record",
                    "--all", "-o", bag_file_name], preexec_fn=os.setsid)
                self.pub.publish("STARTED")
            elif len(msg_data) == 1: # We only got the name of the bag file and not any topics
                bag_file_name = os.path.join(self.data_path, msg_data)
                self.proc = subprocess.Popen(["rosbag", "record",
                    "--all", "-o", bag_file_name], preexec_fn=os.setsid)
                self.pub.publish("STARTED")
            else: #we posibly have a bag file name and a list of topics
                if msg_data[0].startswith("/"): #then we know there is no bag file name
                    msg_data = ["bagfile"] + msg_data
                msg_data[0] = os.path.join(self.data_path, msg_data[0])
                processList = ["rosbag", "record", "-o"] + msg_data
                self.pub.publish(" ".join(processList))
                self.proc = subprocess.Popen( processList, preexec_fn=os.setsid)
                self.pub.publish("STARTED")


if __name__ == '__main__':
    Bagger()
    rospy.spin()