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/**
  \brief Nodelet that uses las3D_PointCloud class to generate PointCloud from 2D scan data and external shaft position.
 * This nodelet subscribes sensor_msgs::LaserScan, sensor_msgs::JointState, 
 * and projects the scan in to pointcloud, using the transform published by the pkg laser_rotate3D. 
 * The PointCloud is accumulated on the desired /ac_frame (see laser3D_pointcloud.lauch).
 \file main.cpp
 \author Diogo Matos
 \date June 2013
 **/

#include <laser3D_pointcloud/laser3D_pointcloud.h>


//GLOBAL VARIABLES
las3D_PointCloud *g_las3D;
int phis_count=0;
int firstscan=1;
ros::Time firstscan_stamp;
ros::Time phi1_stamp;
ros::Time phi2_stamp;
sensor_msgs::JointStatePtr first_state1(new sensor_msgs::JointState);
sensor_msgs::JointStatePtr first_state2(new sensor_msgs::JointState);

/**
 * \brief Callback from the JointState subscribed topic
 * \param[in] const sensor_msgs::JointState::ConstPtr&
 */

void state_cb (const sensor_msgs::JointState::ConstPtr& state_in)
{
	//only access corret joint state
	std::string joint_name = "/connect_laser_roof_rotating";
	if (joint_name.compare(state_in->name[0]) != 0)
		return;
	
	if (firstscan)
	{
		*first_state1=*first_state2;
		*first_state2=*state_in;
		
		phi1_stamp=phi2_stamp;
		phi2_stamp = state_in->header.stamp;
	
		phis_count++;
	}
			
	sensor_msgs::JointStatePtr new_state(new sensor_msgs::JointState);	
	*new_state=*state_in;
	
	if (!firstscan)//store the state joints in to vector
		g_las3D->joints.push_back(new_state); 	

}

/**
 * \brief Callback from the LaserScan subscribed topic
 * \param[in] const sensor_msgs::LaserScan::ConstPtr&
 */

void scan_cb(const sensor_msgs::LaserScan::ConstPtr& scan_in)
{	
	
	if (g_las3D->accumulation_mode==2 || g_las3D->accumulation_mode==3)
	{
		sensor_msgs::LaserScanPtr new_scan(new sensor_msgs::LaserScan);
		*new_scan=*scan_in;
		int error=0;
		sensor_msgs::PointCloud2 pcmsg_in;
		
		//transform the laser scan using the scan time stamps
		error=g_las3D->las3D_transformLaserScanToPointCloud(ros::names::remap("/ac_frame"), *new_scan,pcmsg_in,*g_las3D->p_listener); 
	
		if (error)
			return;
		
		pcl::PointCloud<pcl::PointXYZ> pc_in;
		pcl::fromROSMsg(pcmsg_in,pc_in);
		
		//accumulate the laser scans
		g_las3D->accumulate_cloud(&pc_in);
		
		g_las3D->laser_count++;
		g_las3D->laserscan_arrived=true;	
		
	}	
	else if (g_las3D->accumulation_mode==1)
	{
		if (phis_count<2)
			return;
		
		if (firstscan)
		{
			firstscan_stamp = scan_in->header.stamp;
			
			if ( (firstscan_stamp>phi1_stamp && firstscan_stamp<phi2_stamp) && (phi1_stamp.toSec()>0))
			{
				firstscan=0;
				g_las3D->joints.push_back(first_state1); 
				g_las3D->joints.push_back(first_state2);
			}
			else
				return;
		}
		
		int error=0;
		
		sensor_msgs::LaserScanPtr new_scan(new sensor_msgs::LaserScan);
		*new_scan=*scan_in;
		
		g_las3D->scans.push_back(new_scan); //store the scans to a vector
		
		if(g_las3D->joints.size()<2) //not enough phis to process a scan
			return;
		
		while(g_las3D->joints.size()>=2 && g_las3D->scans.size()>0)
		{			
			int need_state=0;
			sensor_msgs::LaserScanPtr working_scan(new sensor_msgs::LaserScan);
			*working_scan=*g_las3D->scans[0]; //get the oldest scan	
			g_las3D->scans.erase(g_las3D->scans.begin()); 
			
			//state start
			sensor_msgs::JointStatePtr state_start(new sensor_msgs::JointState);	
			*state_start=*g_las3D->joints[0];						
			
			g_las3D->joints.erase(g_las3D->joints.begin());
			
			//state end
			sensor_msgs::JointStatePtr state_end(new sensor_msgs::JointState);	
			*state_end=*g_las3D->joints[0];		
			
			//if phi start is lost, get new scan
			while (working_scan->header.stamp<state_start->header.stamp)
			{			
				if (g_las3D->scans.size()>0)
					*working_scan=*g_las3D->scans[0]; 
				else	
				{
					need_state=1;
					break;
				}
				
				g_las3D->scans.erase(g_las3D->scans.begin()); 
							
			}
			//if scan is lost and has no relation with the latest phi, get the phi with relation with the scan
			while (working_scan->header.stamp>state_end->header.stamp)
			{
				g_las3D->joints.erase(g_las3D->joints.begin());
				
				if (g_las3D->joints.size()>0)
					*state_end=*g_las3D->joints[0];
				else	
				{
					need_state=1;
					break;
				}
			}
		
			if (need_state)
				return;
						
			sensor_msgs::PointCloud2 pcmsg_in;
			
			//transform the laser scan in to a point cloud using the external shaft information
			if (g_las3D->accumulation_mode==1) 
				error=g_las3D->las3D_transformLaserScanToPointCloud(ros::names::remap("/ac_frame"), *working_scan,pcmsg_in,*state_start,*state_end,*g_las3D->p_listener);
		
			if (error)
				return;
			
			pcl::PointCloud<pcl::PointXYZ> pc_in;
			pcl::fromROSMsg(pcmsg_in,pc_in);
			
			g_las3D->accumulate_cloud(&pc_in);

			g_las3D->laser_count++;
			g_las3D->laserscan_arrived=true;
			
// 			erase some old data
			if (g_las3D->laser_count>g_las3D->max_scans_accumulated)
				g_las3D->pc_accumulated.erase(g_las3D->pc_accumulated.begin(),g_las3D->pc_accumulated.begin()+g_las3D->cloud_size);
		}
	}
	
}


int main(int argc, char **argv)
{
	ros::init(argc, argv, "laser3D_pointcloud");
	ros::NodeHandle n("~");
	tf::TransformListener listener(n,ros::Duration(100));
	//Declaration of class
	las3D_PointCloud las3D;
	g_las3D=&las3D;
	
	g_las3D->p_listener=&listener;

	double output_freq;
	n.param("output_frequency", output_freq, 200.0);
	n.param("accumulation_mode", g_las3D->accumulation_mode, 1);
	n.param("max_scans_accumulated", g_las3D->max_scans_accumulated, 450);
	n.param("pointcloud_stamp", g_las3D->pointcloud_stamp,1);
	
	//Test the remapping of /ac_frame
	if (ros::names::remap("/ac_frame")=="/ac_frame")
	{
		ROS_ERROR("/ac_frame was not remapped. Aborting program.");	
		ros::shutdown();
	}

	//declare the subsriber
	ros::Subscriber sub_phiversion = n.subscribe ("/laserscan0", 100, scan_cb);
	ros::Subscriber sub_state = n.subscribe ("/joint_state", 100, state_cb);
	
	//declare the publisher
	ros::Publisher pub = n.advertise<sensor_msgs::PointCloud2>("/pc_out", 1);

	ros::Rate loop_rate(output_freq);

	while (n.ok())
	{
		ros::spinOnce();

		if (g_las3D->laserscan_arrived)
		{
			g_las3D->laserscan_arrived=false;			
			sensor_msgs::PointCloud2 pcmsg_out;
			pcl::toROSMsg(g_las3D->pc_accumulated, pcmsg_out);
			// set the time stamp of output pointcloud
			if (g_las3D->pointcloud_stamp)
				pcmsg_out.header.stamp = ros::Time::now();
			else
				pcmsg_out.header.stamp = g_las3D->pc_accumulated.header.stamp;
#if _USE_DEBUG_
			ROS_INFO("Publishing pc_accumulated with %d points", (int)g_las3D->pc_accumulated.size());
#endif
			//publish the pointcloud
			pub.publish(pcmsg_out);

		}
		
		loop_rate.sleep();	
	}
	
}