'''Mavros for F651
 
  Copyright (C) 2018, CPS2018 Challenge by Team Halmstad. All rights reserved.
 
  BSD license:
  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions
  are met:
  1. Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.
  2. Redistributions in binary form must reproduce the above copyright
     notice, this list of conditions and the following disclaimer in the
     documentation and/or other materials provided with the distribution.
  3. Neither the name of the copyright holder nor the names of
     contributors to this software may be used to endorse or promote
     products derived from this software without specific prior written
     permission.
 
  THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS''
  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
  HOLDER OR THE CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY
  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
  GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 '''

#!/usr/bin/env python

import rospy
from mavros_msgs.msg import State
from nav_msgs.msg import Odometry
from geometry_msgs.msg import PoseStamped, TwistStamped
from mavros_msgs.srv import SetMode, SetModeRequest, SetModeResponse, CommandBool, CommandBoolRequest, CommandBoolResponse, CommandTOL, CommandTOLRequest
import time
from tf.transformations import *
import numpy as np

class mavros_state():
    def __init__(self):
        ### subscriber ###

        # state subscriber
        self._rate_state = rospy.Rate(1)
        self.current_state = State()
        rospy.Subscriber('/mavros/state', State, self.current_state_callback)

        # wait until connection with FCU
        while not rospy.is_shutdown() and not self.current_state.connected:
            rospy.Rate(20)
        print 'FCU connection successful'

    #callback function for state
    def current_state_callback(self, data):
        self.current_state = data


    #setmode for the drone
    #'OFFBOARD'
    def set_mode(self, mode):
        if not self.current_state.connected:
            print "No FCU connection"

        elif self.current_state.mode == mode:
            print "Already in " + mode + " mode"

        else:

            # wait for service
            rospy.wait_for_service("mavros/set_mode")

            # service client
            set_mode = rospy.ServiceProxy("mavros/set_mode", SetMode)

            # set request object
            req = SetModeRequest()
            req.custom_mode = mode

            # zero time
            t0 = rospy.get_time()

            # check response
            while not rospy.is_shutdown() and (self.current_state.mode != req.custom_mode):
                if rospy.get_time() - t0 > 2.0:  # check every 5 seconds

                    try:
                        # request
                        set_mode.call(req)

                    except rospy.ServiceException, e:
                        print "Service did not process request: %s" % str(e)

                    t0 = rospy.get_time()

            print "Mode: " + self.current_state.mode + " established"


    #Arm the vehicle
    def arm(self, do_arming):

        if self.current_state.armed and do_arming:
            print "already armed"

        else:
            # wait for service
            rospy.wait_for_service("mavros/cmd/arming")

            # service client
            set_arm = rospy.ServiceProxy("mavros/cmd/arming", CommandBool)

            # set request object
            req = CommandBoolRequest()
            req.value = do_arming

            # zero time
            t0 = rospy.get_time()

            # check response
            if do_arming:
                while not rospy.is_shutdown() and not self.current_state.armed:
                    if rospy.get_time() - t0 > 2.0:  # check every 5 seconds

                        try:
                            # request
                            set_arm.call(req)

                        except rospy.ServiceException, e:
                            print "Service did not process request: %s" % str(e)

                        t0 = rospy.get_time()

                print "armed: ", self.current_state.armed

            else:
                while not rospy.is_shutdown() and self.current_state.armed:
                    if rospy.get_time() - t0 > 0.5:  # check every 5 seconds

                        try:
                            # request
                            set_arm.call(req)

                        except rospy.ServiceException, e:
                            print "Service did not process request: %s" % str(e)

                        t0 = rospy.get_time()

    def land(self, height):

        if not self.current_state.armed:

            print "not armed yet"

        else:

            # wait for service
            rospy.wait_for_service("mavros/cmd/land")

            # service client
            set_rq = rospy.ServiceProxy("mavros/cmd/land", CommandTOL)

            # set request object
            req = CommandTOLRequest()
            req.yaw = 0.0
            req.latitude = 0.0
            req.longitude = 0.0
            req.altitude = height
            req.min_pitch = 0.0

            # zero time
            t0 = rospy.get_time()

            # check response
            while self.current_state.armed:
                if rospy.get_time() - t0 > 5.0:  # check every 5 seconds

                    try:
                        # request
                        set_rq.call(req)

                    except rospy.ServiceException, e:
                        print "Service did not process request: %s" % str(e)

                    t0 = rospy.get_time()

            print "landed savely"

    def takeoff(self):

        if not self.current_state.armed:

            print "not armed yet"

        else:

            # wait for service
            rospy.wait_for_service("mavros/cmd/takeoff")

            # service client
            set_rq = rospy.ServiceProxy("mavros/cmd/takeoff", CommandTOL)

            # set request object
            req = CommandTOLRequest()
            req.yaw = 0.0
            req.latitude = 0.0
            req.longitude = 0.0
            req.altitude = 4.0
            req.min_pitch = 0.0

            # zero time
            t0 = rospy.get_time()

            # check response
            while self.current_state.armed:
                if rospy.get_time() - t0 > 5.0:  # check every 5 seconds

                    try:
                        # request
                        set_rq.call(req)

                    except rospy.ServiceException, e:
                        print "Service did not process request: %s" % str(e)

                    t0 = rospy.get_time()

            print "landed savely"