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#include "Odometry.h"

using namespace std;

/** Set up the odometry node and prepare communcations over ROS */

Odometry::Odometry(string scoutname, Sensors* sensors):Behavior(scoutname, 

                                                "odometry", sensors)

{

  name = scoutname;

  scout_pos = new pos;

  motor_fl_ticks = motor_fr_ticks = motor_bl_ticks = motor_br_ticks = 0;

}

/** Query encoders and estimate position based on encoder reading */

void Odometry::get_position()

{

  float left_dist, right_dist, total_dist, theta;

  encoder_readings scout_enc = encoders->query();

  motor_fl_dist = scout_enc.fl_ticks - motor_fl_ticks;

  motor_fr_dist = scout_enc.fr_ticks - motor_fr_ticks;

  motor_bl_dist = scout_enc.bl_ticks - motor_bl_ticks;

  motor_br_dist = scout_enc.br_ticks - motor_br_ticks;

  // Get Left and Right distance

  left_dist = DIST_PER_TICK*(((float)(motor_fl_dist))/2.0 +

                             ((float)(motor_bl_dist))/2.0);

  right_dist = DIST_PER_TICK*(((float)(motor_fr_dist))/2.0 + 

                              ((float)(motor_br_dist))/2.0);

  total_dist = (left_dist)/2.0 + (right_dist)/2.0;

  theta = scout_pos->theta + atan2(right_dist - left_dist, WHEEL_BASE);

  //Use negative theta because we measure theta from 0 on the

  //right to 180 on the left counter-clock-wise, but this is

  //negative theta in the coordinate frame.

  //Also, subtract the delta from y because positive y is down.

  scout_pos->x += total_dist*cos(-theta);

  scout_pos->y -= total_dist*sin(-theta);

  scout_pos->theta = fmod(theta, 2*M_PI);

  //Save state for next time in.

  motor_fl_ticks = scout_enc.fl_ticks;

  motor_fr_ticks = scout_enc.fr_ticks;

  motor_bl_ticks = scout_enc.bl_ticks;

  motor_br_ticks = scout_enc.br_ticks;

 return;

}

void Odometry::run()

{

  scout_position = node.advertise< ::messages::ScoutPosition>(name+"/position", 1000); 

  while(ok())

  {

    get_position();

    position.name = name;

    position.x = scout_pos->x;

    position.y = scout_pos->y;

    position.theta = scout_pos->theta;

    scout_position.publish(position);

  }

}