subsurface/qt-mobile/gpslocation.cpp

#include "qt-mobile/gpslocation.h"
#include "qt-mobile/qmlmanager.h"
#include "pref.h"
#include "dive.h"
#include "helpers.h"
#include <time.h>
#include <QDebug>
#include <QVariant>

GpsLocation::GpsLocation(QObject *parent)
{
	// create a QSettings object that's separate from the main application settings
	QSettings *geoSettings = new QSettings(QSettings::NativeFormat, QSettings::UserScope,
					       QString("org.subsurfacedivelog"), QString("subsurfacelocation"), this);
	gpsSource = QGeoPositionInfoSource::createDefaultSource(parent);
	if (gpsSource != 0) {
		QString msg = QString("have position source %1").arg(gpsSource->sourceName());
		connect(gpsSource, SIGNAL(positionUpdated(QGeoPositionInfo)), this, SLOT(newPosition(QGeoPositionInfo)));
		connect(gpsSource, SIGNAL(updateTimeout()), this, SLOT(updateTimeout()));
	} else {
		status("don't have GPS source");
	}
}

void GpsLocation::serviceEnable(bool toggle)
{
	if (!gpsSource) {
		if (toggle)
			status("Can't start location service, no location source available");
		return;
	}
	if (toggle) {
		gpsSource->startUpdates();
		status("Starting Subsurface GPS service");
	} else {
		gpsSource->stopUpdates();
		status("Stopping Subsurface GPS service");
	}
}

#define MINTIME 600
#define MINDIST 200

void GpsLocation::newPosition(QGeoPositionInfo pos)
{
	time_t lastTime;
	QGeoCoordinate lastCoord;
	QString msg("received new position %1");
	status(qPrintable(msg.arg(pos.coordinate().toString())));
	int nr = geoSettings.value("count", 0).toInt();
	if (nr) {
		lastCoord.setLatitude(geoSettings.value(QString("gpsFix%1_lat").arg(nr)).toInt() / 1000000.0);
		lastCoord.setLongitude(geoSettings.value(QString("gpsFix%1_lon").arg(nr)).toInt() / 1000000.0);
		time_t lastTime = geoSettings.value(QString("gpsFix%1_time").arg(nr)).toULongLong();
	}
	// if we have no record stored or if at least 10 minutes have passed or we moved at least 200m
	if (!nr || pos.timestamp().toTime_t() > lastTime + MINTIME || lastCoord.distanceTo(pos.coordinate()) > MINDIST) {
		geoSettings.setValue("count", nr + 1);
		geoSettings.setValue(QString("gpsFix%1_time").arg(nr), pos.timestamp().toTime_t());
		geoSettings.setValue(QString("gpsFix%1_lat").arg(nr), rint(pos.coordinate().latitude() * 1000000));
		geoSettings.setValue(QString("gpsFix%1_lon").arg(nr), rint(pos.coordinate().longitude() * 1000000));
		geoSettings.sync();
	}
}

void GpsLocation::updateTimeout()
{
	status("request to get new position timed out");
}

void GpsLocation::status(QString msg)
{
	qDebug() << msg;
	qmlUiShowMessage(qPrintable(msg));
}

struct gpsTracker {
	degrees_t latitude;
	degrees_t longitude;
	time_t when;
};

static void copy_gps_location(struct gpsTracker *gps, struct dive *d)
{
	struct dive_site *ds = get_dive_site_by_uuid(d->dive_site_uuid);
	ds->latitude = gps->latitude;
	ds->longitude = gps->longitude;
}

#define SAME_GROUP 6 * 3600 /* six hours */
bool GpsLocation::applyLocations()
{
	int i;
	bool changed = false;
	int last = 0;
	int cnt = geoSettings.value("count", 0).toInt();
	if (cnt == 0)
		return false;

	// create a table with the GPS information
	struct gpsTracker *gpsTable = (struct gpsTracker *)calloc(cnt, sizeof(struct gpsTracker));
	for (int i = 0; i < cnt; i++) {
		gpsTable[i].latitude.udeg = geoSettings.value(QString("gpsFix%1_lat").arg(i)).toInt();
		gpsTable[i].longitude.udeg = geoSettings.value(QString("gpsFix%1_lon").arg(i)).toInt();
		gpsTable[i].when = geoSettings.value(QString("gpsFix%1_time").arg(i)).toULongLong();
	}

	// now walk the dive table and see if we can fill in missing gps data
	struct dive *d;
	for_each_dive(i, d) {
		if (dive_has_gps_location(d))
			continue;
		for (int j = last; j < cnt; j++) {
			if (time_during_dive_with_offset(d, gpsTable[j].when, SAME_GROUP)) {
				if (verbose)
					qDebug() << "processing gpsfix @" << get_dive_date_string(gpsTable[j].when) <<
						    "which is withing six hours of dive from" <<
						    get_dive_date_string(d->when) << "until" <<
						    get_dive_date_string(d->when + d->duration.seconds);
				/*
				 * If position is fixed during dive. This is the good one.
				 * Asign and mark position, and end gps_location loop
				 */
				if (time_during_dive_with_offset(d, gpsTable[j].when, 0)) {
					if (verbose)
						qDebug() << "gpsfix is during the dive, pick that one";
					copy_gps_location(gpsTable + j, d);
					changed = true;
					last = j;
					break;
				} else {
					/*
					 * If it is not, check if there are more position fixes in SAME_GROUP range
					 */
					if (j + 1 < cnt && time_during_dive_with_offset(d, gpsTable[j+1].when, SAME_GROUP)) {
						if (verbose)
							qDebug() << "look at the next gps fix @" << get_dive_date_string(gpsTable[j+1].when);
						/* first let's test if this one is during the dive */
						if (time_during_dive_with_offset(d, gpsTable[j+1].when, 0)) {
							if (verbose)
								qDebug() << "which is during the dive, pick that one";
							copy_gps_location(gpsTable + j + 1, d);
							changed = true;
							last = j + 1;
							break;
						}
						/* we know the gps fixes are sorted; if they are both before the dive, ignore the first,
						 * if theay are both after the dive, take the first,
						 * if the first is before and the second is after, take the closer one */
						if (gpsTable[j+1].when < d->when) {
							if (verbose)
								qDebug() << "which is closer to the start of the dive, do continue with that";
							continue;
						} else if (gpsTable[j].when > d->when + d->duration.seconds) {
							if (verbose)
								qDebug() << "which is even later after the end of the dive, so pick the previous one";
							copy_gps_location(gpsTable + j, d);
							changed = true;
							last = j;
							break;
						} else {
							/* ok, gpsfix is before, nextgpsfix is after */
							if (d->when - gpsTable[j].when <= gpsTable[j+1].when - (d->when + d->duration.seconds)) {
								if (verbose)
									qDebug() << "pick the one before as it's closer to the start";
								copy_gps_location(gpsTable + j, d);
								changed = true;
								last = j;
								break;
							} else {
								if (verbose)
									qDebug() << "pick the one after as it's closer to the start";
								copy_gps_location(gpsTable + j + 1, d);
								changed = true;
								last = j + 1;
								break;
							}
						}
					/*
					 * If no more positions in range, the actual is the one. Asign, mark and end loop.
					 */
					} else {
						if (verbose)
							qDebug() << "which seems to be the best one for this dive, so pick it";
						copy_gps_location(gpsTable + j, d);
						changed = true;
						last = j;
						break;
					}
				}
			} else {
				/* If position is out of SAME_GROUP range and in the future, mark position for
				 * next dive iteration and end the gps_location loop
				 */
				if (gpsTable[j].when >= d->when + d->duration.seconds + SAME_GROUP) {
					last = j;
					break;
				}
			}

		}
	}
}