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/**

 * Copyright (c) 2011 Colony Project

 * 

 * Permission is hereby granted, free of charge, to any person

 * obtaining a copy of this software and associated documentation

 * files (the "Software"), to deal in the Software without

 * restriction, including without limitation the rights to use,

 * copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the

 * Software is furnished to do so, subject to the following

 * conditions:

 * 

 * The above copyright notice and this permission notice shall be

 * included in all copies or substantial portions of the Software.

 * 

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES

 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT

 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,

 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR

 * OTHER DEALINGS IN THE SOFTWARE.

 **/

/**

 * @file encoders.cpp

 * @brief Encoders

 *

 * Implementation of functions for encoder use.

 *

 * @author Colony Project, CMU Robotics Club

 * @author Benjamin Wasserman

 **/

#include "ros/ros.h"

#include "encoders.h"

//#include "libscout/src/constants.h"

#include <cstdlib>

/**

 * @defgroup encoders Encoders

 * @brief Functions for using the encoders

 *

 **/

/* Encoder state variables */

/** \todo Fix types: static */

int encoder_fl; /**< The current state of the front left encoder. */

int encoder_fr; /**< The current state of the front right encoder. */

int encoder_bl; /**< The current state of the back left encoder. */

int encoder_br; /**< The current state of the back right encoder. */

/*!

 * \brief Encoders driver. This is a ROS node that controls encoders.

 *

 * This is the main function for the encoders node. It is run when the node

 * starts and initializes the encoders. It then publishes to the

 * encoder_state topic and advertises the query_encoders service.

 * 

 * \param argc The number of command line arguments (should be 1)

 * \param argv The array of command line arguments

 **/

int main(int argc, char **argv){

  /* Initialize in ROS the encoders driver node */

  ros::init(argc, argv, "encoders_driver");

  /* Advertise that this serves the query_encoders service */

  ros::NodeHandle n;

  ros::ServiceServer service = n.advertiseService("query_encoders", encoders_query);

  /* Subscribe to the encoder_state topic */

  ros::Subscriber sub0 = n.subscribe("encoder_state", 4, encoder_state);

  /* Initialize hardware for motors */

  // Hardware init functions here

  ROS_INFO("Ready to set encoders.");

  ros::spin();

  return 0;

}

/*!

 * \brief Gets encoder state

 *

 * Sets the encoder state based on subscription to the encoder_state topic.

 *

 * \param msg The message from the encoder_state topic, containing encoder

 * configuration settings.

 */

void encoder_state(const encoders::encoder_state::ConstPtr& msg){ 

  encoder_fl = msg->fl_encoder;

  encoder_fr = msg->fr_encoder;

  encoder_bl = msg->bl_encoder;

  encoder_br = msg->br_encoder;

}

/*!

 * \brief Outputs current encoder data

 *

 * Serves the service query_encoders by responding to service requests with the

 * encoder values.

 * \param req The request. Should be empty.

 * \param res The response. The fields will be filled with values.

 */

bool encoders_query(encoders::query_encoders::Request &req,

    encoders::query_encoders::Response &res){

  res.fl_encoder = encoder_fl;

  res.fr_encoder = encoder_fr;

  res.bl_encoder = encoder_bl;

  res.br_encoder = encoder_br;

  ROS_DEBUG("Encoder values queried");

  return true;

}