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/**
 * @file geofence.cpp
 * Provides functions for handling the geofence
 *
 * @author Jean Cyr <jean.m.cyr@gmail.com>
 * @author Thomas Gubler <thomasgubler@gmail.com>
 */
#include "geofence.h"

#include <uORB/topics/home_position.h>
#include <uORB/topics/vehicle_global_position.h>
#include <string.h>
#include <dataman/dataman.h>
#include <systemlib/err.h>
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include <nuttx/config.h>
#include <unistd.h>
#include <mavlink/mavlink_log.h>
#include <geo/geo.h>
#include <drivers/drv_hrt.h>

#define GEOFENCE_OFF 0
#define GEOFENCE_FILE_ONLY 1
#define GEOFENCE_MAX_DISTANCES_ONLY 2
#define GEOFENCE_FILE_AND_MAX_DISTANCES 3

#define GEOFENCE_RANGE_WARNING_LIMIT 3000000


/* Oddly, ERROR is not defined for C++ */
#ifdef ERROR
# undef ERROR
#endif
static const int ERROR = -1;

Geofence::Geofence() :
	SuperBlock(NULL, "GF"),
	_fence_pub(-1),
	_home_pos{},
	_home_pos_set(false),
	_last_horizontal_range_warning(0),
	_last_vertical_range_warning(0),
	_altitude_min(0),
	_altitude_max(0),
	_verticesCount(0),
	_param_geofence_mode(this, "MODE"),
	_param_altitude_mode(this, "ALTMODE"),
	_param_source(this, "SOURCE"),
	_param_counter_threshold(this, "COUNT"),
	_param_max_hor_distance(this, "MAX_HOR_DIST"),
	_param_max_ver_distance(this, "MAX_VER_DIST"),
	_outside_counter(0),
	_mavlinkFd(-1)
{
	/* Load initial params */
	updateParams();
}

Geofence::~Geofence()
{

}


bool Geofence::inside(const struct vehicle_global_position_s &global_position)
{
	return inside(global_position.lat, global_position.lon, global_position.alt);
}

bool Geofence::inside(const struct vehicle_global_position_s &global_position, float baro_altitude_amsl)
{
	return inside(global_position.lat, global_position.lon, baro_altitude_amsl);
}


bool Geofence::inside(const struct vehicle_global_position_s &global_position,
		      const struct vehicle_gps_position_s &gps_position, float baro_altitude_amsl,
		      const struct home_position_s home_pos, bool home_position_set)
{
	updateParams();

	_home_pos = home_pos;
	_home_pos_set = home_position_set;

	if (getAltitudeMode() == Geofence::GF_ALT_MODE_WGS84) {
		if (getSource() == Geofence::GF_SOURCE_GLOBALPOS) {
			return inside(global_position);

		} else {
			return inside((double)gps_position.lat * 1.0e-7, (double)gps_position.lon * 1.0e-7,
				      (double)gps_position.alt * 1.0e-3);
		}

	} else {
		if (getSource() == Geofence::GF_SOURCE_GLOBALPOS) {
			return inside(global_position, baro_altitude_amsl);

		} else {
			return inside((double)gps_position.lat * 1.0e-7, (double)gps_position.lon * 1.0e-7,
				      baro_altitude_amsl);
		}
	}
}

bool Geofence::inside(double lat, double lon, float altitude)
{
	if (_param_geofence_mode.get() >= GEOFENCE_MAX_DISTANCES_ONLY) {
		int32_t max_horizontal_distance = _param_max_hor_distance.get();
		int32_t max_vertical_distance = _param_max_ver_distance.get();

		if (max_horizontal_distance > 0 || max_vertical_distance > 0) {
			if (_home_pos_set) {
				float dist_xy = -1.0f;
				float dist_z = -1.0f;
				get_distance_to_point_global_wgs84(lat, lon, altitude,
								   _home_pos.lat, _home_pos.lon, _home_pos.alt,
								   &dist_xy, &dist_z);

				if (max_vertical_distance > 0 && (dist_z > max_vertical_distance)) {
					if (hrt_elapsed_time(&_last_vertical_range_warning) > GEOFENCE_RANGE_WARNING_LIMIT) {
						mavlink_log_critical(_mavlinkFd, "Geofence exceeded max vertical distance by %.1f m",
								     (double)(dist_z - max_vertical_distance));
						_last_vertical_range_warning = hrt_absolute_time();
					}

					return false;
				}

				if (max_horizontal_distance > 0 && (dist_xy > max_horizontal_distance)) {
					if (hrt_elapsed_time(&_last_horizontal_range_warning) > GEOFENCE_RANGE_WARNING_LIMIT) {
						mavlink_log_critical(_mavlinkFd, "Geofence exceeded max horizontal distance by %.1f m",
								     (double)(dist_xy - max_horizontal_distance));
						_last_horizontal_range_warning = hrt_absolute_time();
					}

					return false;
				}
			}
		}
	}

	bool inside_fence = inside_polygon(lat, lon, altitude);

	if (inside_fence) {
		_outside_counter = 0;
		return inside_fence;

	} else {
		_outside_counter++;

		if (_outside_counter > _param_counter_threshold.get()) {
			return inside_fence;

		} else {
			return true;
		}
	}
}


bool Geofence::inside_polygon(double lat, double lon, float altitude)
{
	/* Return true if geofence is disabled or only checking max distances */
	if ((_param_geofence_mode.get() == GEOFENCE_OFF)
	    || (_param_geofence_mode.get() == GEOFENCE_MAX_DISTANCES_ONLY)) {
		return true;
	}

	if (valid()) {

		if (!isEmpty()) {
			/* Vertical check */
			if (altitude > _altitude_max || altitude < _altitude_min) {
				return false;
			}

			/*Horizontal check */
			/* Adaptation of algorithm originally presented as
			 * PNPOLY - Point Inclusion in Polygon Test
			 * W. Randolph Franklin (WRF) */

			bool c = false;

			struct fence_vertex_s temp_vertex_i;
			struct fence_vertex_s temp_vertex_j;

			/* Red until fence is finished */
			for (unsigned i = 0, j = _verticesCount - 1; i < _verticesCount; j = i++) {
				if (dm_read(DM_KEY_FENCE_POINTS, i, &temp_vertex_i, sizeof(struct fence_vertex_s)) != sizeof(struct fence_vertex_s)) {
					break;
				}

				if (dm_read(DM_KEY_FENCE_POINTS, j, &temp_vertex_j, sizeof(struct fence_vertex_s)) != sizeof(struct fence_vertex_s)) {
					break;
				}

				// skip vertex 0 (return point)
				if (((double)temp_vertex_i.lon >= lon) != ((double)temp_vertex_j.lon >= lon) &&
				    (lat <= (double)(temp_vertex_j.lat - temp_vertex_i.lat) * (lon - (double)temp_vertex_i.lon) /
				     (double)(temp_vertex_j.lon - temp_vertex_i.lon) + (double)temp_vertex_i.lat)) {
					c = !c;
				}

			}

			return c;

		} else {
			/* Empty fence --> accept all points */
			return true;
		}

	} else {
		/* Invalid fence --> accept all points */
		return true;
	}
}

bool
Geofence::valid()
{
	// NULL fence is valid
	if (isEmpty()) {
		return true;
	}

	// Otherwise
	if ((_verticesCount < 4) || (_verticesCount > GEOFENCE_MAX_VERTICES)) {
		warnx("Fence must have at least 3 sides and not more than %d", GEOFENCE_MAX_VERTICES - 1);
		return false;
	}

	return true;
}

void
Geofence::addPoint(int argc, char *argv[])
{
	int ix, last;
	double lon, lat;
	struct fence_vertex_s vertex;
	char *end;

	if ((argc == 1) && (strcmp("-clear", argv[0]) == 0)) {
		dm_clear(DM_KEY_FENCE_POINTS);
		publishFence(0);
		return;
	}

	if (argc < 3) {
		errx(1, "Specify: -clear | sequence latitude longitude [-publish]");
	}

	ix = atoi(argv[0]);

	if (ix >= DM_KEY_FENCE_POINTS_MAX) {
		errx(1, "Sequence must be less than %d", DM_KEY_FENCE_POINTS_MAX);
	}

	lat = strtod(argv[1], &end);
	lon = strtod(argv[2], &end);

	last = 0;

	if ((argc > 3) && (strcmp(argv[3], "-publish") == 0)) {
		last = 1;
	}

	vertex.lat = (float)lat;
	vertex.lon = (float)lon;

	if (dm_write(DM_KEY_FENCE_POINTS, ix, DM_PERSIST_POWER_ON_RESET, &vertex, sizeof(vertex)) == sizeof(vertex)) {
		if (last) {
			publishFence((unsigned)ix + 1);
		}

		return;
	}

	errx(1, "can't store fence point");
}

void
Geofence::publishFence(unsigned vertices)
{
	if (_fence_pub == -1) {
		_fence_pub = orb_advertise(ORB_ID(fence), &vertices);

	} else {
		orb_publish(ORB_ID(fence), _fence_pub, &vertices);
	}
}

int
Geofence::loadFromFile(const char *filename)
{
	FILE		*fp;
	char		line[120];
	int			pointCounter = 0;
	bool		gotVertical = false;
	const char commentChar = '#';
	int rc = ERROR;

	/* Make sure no data is left in the datamanager */
	clearDm();

	/* open the mixer definition file */
	fp = fopen(GEOFENCE_FILENAME, "r");

	if (fp == NULL) {
		return ERROR;
	}

	/* create geofence points from valid lines and store in DM */
	for (;;) {
		/* get a line, bail on error/EOF */
		if (fgets(line, sizeof(line), fp) == NULL) {
			break;
		}

		/* Trim leading whitespace */
		size_t textStart = 0;

		while ((textStart < sizeof(line) / sizeof(char)) && isspace(line[textStart])) { textStart++; }

		/* if the line starts with #, skip */
		if (line[textStart] == commentChar) {
			continue;
		}

		/* if there is only a linefeed, skip it */
		if (line[0] == '\n') {
			continue;
		}

		if (gotVertical) {
			/* Parse the line as a geofence point */
			struct fence_vertex_s vertex;

			/* if the line starts with DMS, this means that the coordinate is given as degree minute second instead of decimal degrees */
			if (line[textStart] == 'D' && line[textStart + 1] == 'M' && line[textStart + 2] == 'S') {
				/* Handle degree minute second format */
				float lat_d, lat_m, lat_s, lon_d, lon_m, lon_s;

				if (sscanf(line, "DMS %f %f %f %f %f %f", &lat_d, &lat_m, &lat_s, &lon_d, &lon_m, &lon_s) != 6) {
					warnx("Scanf to parse DMS geofence vertex failed.");
					goto error;
				}

//				warnx("Geofence DMS: %.5f %.5f %.5f ; %.5f %.5f %.5f", (double)lat_d, (double)lat_m, (double)lat_s, (double)lon_d, (double)lon_m, (double)lon_s);

				vertex.lat = lat_d + lat_m / 60.0f + lat_s / 3600.0f;
				vertex.lon = lon_d + lon_m / 60.0f + lon_s / 3600.0f;

			} else {
				/* Handle decimal degree format */
				if (sscanf(line, "%f %f", &(vertex.lat), &(vertex.lon)) != 2) {
					warnx("Scanf to parse geofence vertex failed.");
					goto error;
				}
			}

			if (dm_write(DM_KEY_FENCE_POINTS, pointCounter, DM_PERSIST_POWER_ON_RESET, &vertex, sizeof(vertex)) != sizeof(vertex)) {
				goto error;
			}

			warnx("Geofence: point: %d, lat %.5f: lon: %.5f", pointCounter, (double)vertex.lat, (double)vertex.lon);

			pointCounter++;

		} else {
			/* Parse the line as the vertical limits */
			if (sscanf(line, "%f %f", &_altitude_min, &_altitude_max) != 2) {
				goto error;
			}

			warnx("Geofence: alt min: %.4f, alt_max: %.4f", (double)_altitude_min, (double)_altitude_max);
			gotVertical = true;
		}
	}

	/* Check if import was successful */
	if (gotVertical && pointCounter > 0) {
		_verticesCount = pointCounter;
		warnx("Geofence: imported successfully");
		mavlink_log_info(_mavlinkFd, "Geofence imported");
		rc = OK;

	} else {
		warnx("Geofence: import error");
		mavlink_log_critical(_mavlinkFd, "Geofence import error");
	}

error:
	fclose(fp);
	return rc;
}

int Geofence::clearDm()
{
	dm_clear(DM_KEY_FENCE_POINTS);
	return OK;
}