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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 Alex Zirbel

 **/

#include <ros/ros.h>

#include "encoders.h"

/**

 * @defgroup encoders Encoders

 * @brief Functions for using the encoders

 *

 * @{

 */

/* Encoder state variables */

/** @todo Fix types: static */

/** @todo Fix integer overflow possibility */

/* The current position of each encoder, measured in encoder ticks */

int encoder_fl_index;

int encoder_fr_index;

int encoder_bl_index;

int encoder_br_index;

/* The current distance each encoder has traveled in ticks from last reset */

int encoder_fl_distance;

int encoder_fr_distance;

int encoder_bl_distance;

int encoder_br_distance;

/**

 * @brief Outputs current encoder data

 *

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

 * encoder values.

 * @param req The request. The units that the response should be in.

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

 */

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

                           encoders::query_encoders::Response &res)

{

    /* Put index, velocity, and distance data in message */

    res.fl_distance = encoder_fl_distance;

    res.fr_distance = encoder_fr_distance;

    res.bl_distance = encoder_bl_distance;

    res.br_distance = encoder_br_distance;

    ROS_DEBUG("Encoder values queried [Unimplemented]");

    return true;

}

/**

 * @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.

 */

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",

                           handle_encoders_query);

    /* Initialize hardware for motors */

    // Hardware init functions here

    ROS_INFO("Ready to set encoders.");

    // Acutally measure encoders and update values here

    ros::spin();

    return 0;

}

/** @} */