qthelper.cpp

#include "qthelper.h"
#include "helpers.h"
#include "gettextfromc.h"
#include "statistics.h"
#include "usersurvey.h"
#include "membuffer.h"
#include "subsurfacesysinfo.h"
#include "version.h"
#include "divecomputer.h"
#include "time.h"
#include "gettextfromc.h"
#include <sys/time.h>
#include <exif.h>
#include "file.h"
#include <QFile>
#include <QRegExp>
#include <QDir>
#include <QDebug>
#include <QSettings>
#include <QStandardPaths>
#include <QJsonDocument>
#include <QJsonArray>
#include <QJsonObject>
#include <QNetworkReply>
#include <QNetworkRequest>
#include <QNetworkAccessManager>
#include <QUrlQuery>
#include <QEventLoop>
#include <QDateTime>
#include <QSaveFile>
#include <QDir>
#include <QImageReader>
#include <QtConcurrent>
#include "divepicturewidget.h"

#include <libxslt/documents.h>

const char *existing_filename;
static QString shortDateFormat;
static QString dateFormat;
static QString timeFormat;
static QLocale loc;

#if defined(Q_OS_WIN) && QT_VERSION < 0x050000
static QByteArray encodeUtf8(const QString &fname)
{
	return fname.toUtf8();
}

static QString decodeUtf8(const QByteArray &fname)
{
	return QString::fromUtf8(fname);
}
#endif

#define translate(_context, arg) trGettext(arg)
static const QString DEGREE_SIGNS("dD" UTF8_DEGREE);

QString weight_string(int weight_in_grams)
{
	QString str;
	if (get_units()->weight == units::KG) {
		int gr = weight_in_grams % 1000;
		int kg = weight_in_grams / 1000;
		if (kg >= 20.0) {
			str = QString("0");
		} else {
			str = QString("%1.%2").arg(kg).arg((unsigned)(gr) / 100);
		}
	} else {
		double lbs = grams_to_lbs(weight_in_grams);
		str = QString("%1").arg(lbs, 0, 'f', lbs >= 40.0 ? 0 : 1);
	}
	return (str);
}

extern "C" const char *printGPSCoords(int lat, int lon)
{
	unsigned int latdeg, londeg;
	unsigned int latmin, lonmin;
	double latsec, lonsec;
	QString lath, lonh, result;

	if (!lat && !lon)
		return strdup("");

	lath = lat >= 0 ? translate("gettextFromC", "N") : translate("gettextFromC", "S");
	lonh = lon >= 0 ? translate("gettextFromC", "E") : translate("gettextFromC", "W");
	lat = abs(lat);
	lon = abs(lon);
	latdeg = lat / 1000000U;
	londeg = lon / 1000000U;
	latmin = (lat % 1000000U) * 60U;
	lonmin = (lon % 1000000U) * 60U;
	latsec = (latmin % 1000000) * 60;
	lonsec = (lonmin % 1000000) * 60;
	result.sprintf("%u%s%02d\'%06.3f\"%s %u%s%02d\'%06.3f\"%s",
		       latdeg, UTF8_DEGREE, latmin / 1000000, latsec / 1000000, lath.toUtf8().data(),
		       londeg, UTF8_DEGREE, lonmin / 1000000, lonsec / 1000000, lonh.toUtf8().data());
	return strdup(result.toUtf8().data());
}

/**
* Try to parse in a generic manner a coordinate.
*/
static bool parseCoord(const QString& txt, int& pos, const QString& positives,
		       const QString& negatives, const QString& others,
		       double& value)
{
	bool numberDefined = false, degreesDefined = false,
		minutesDefined = false, secondsDefined = false;
	double number = 0.0;
	int posBeforeNumber = pos;
	int sign = 0;
	value = 0.0;
	while (pos < txt.size()) {
		if (txt[pos].isDigit()) {
			if (numberDefined)
				return false;
			QRegExp numberRe("(\\d+(?:[\\.,]\\d+)?).*");
			if (!numberRe.exactMatch(txt.mid(pos)))
				return false;
			number = numberRe.cap(1).toDouble();
			numberDefined = true;
			posBeforeNumber = pos;
			pos += numberRe.cap(1).size() - 1;
		} else if (positives.indexOf(txt[pos]) >= 0) {
			if (sign != 0)
				return false;
			sign = 1;
			if (degreesDefined || numberDefined) {
				//sign after the degrees =>
				//at the end of the coordinate
				++pos;
				break;
			}
		} else if (negatives.indexOf(txt[pos]) >= 0) {
			if (sign != 0) {
				if (others.indexOf(txt[pos]) >= 0)
					//special case for the '-' sign => next coordinate
					break;
				return false;
			}
			sign = -1;
			if (degreesDefined || numberDefined) {
				//sign after the degrees =>
				//at the end of the coordinate
				++pos;
				break;
			}
		} else if (others.indexOf(txt[pos]) >= 0) {
			//we are at the next coordinate.
			break;
		} else if (DEGREE_SIGNS.indexOf(txt[pos]) >= 0 ||
			   (txt[pos].isSpace() && !degreesDefined && numberDefined)) {
			if (!numberDefined)
				return false;
			if (degreesDefined) {
				//next coordinate => need to put back the number
				pos = posBeforeNumber;
				numberDefined = false;
				break;
			}
			value += number;
			numberDefined = false;
			degreesDefined = true;
		} else if (txt[pos] == '\'' || (txt[pos].isSpace() && !minutesDefined && numberDefined)) {
			if (!numberDefined || minutesDefined)
				return false;
			value += number / 60.0;
			numberDefined = false;
			minutesDefined = true;
		} else if (txt[pos] == '"' || (txt[pos].isSpace() && !secondsDefined && numberDefined)) {
			if (!numberDefined || secondsDefined)
				return false;
			value += number / 3600.0;
			numberDefined = false;
			secondsDefined = true;
		} else {
			return false;
		}
		++pos;
	}
	if (!degreesDefined && numberDefined) {
		value = number; //just a single number => degrees
	} else if (!minutesDefined && numberDefined) {
		value += number / 60.0;
	} else if (!secondsDefined && numberDefined) {
		value += number / 3600.0;
	} else if (numberDefined) {
		return false;
	}
	if (sign == -1) value *= -1.0;
	return true;
}

/**
* Parse special coordinate formats that cannot be handled by parseCoord.
*/
static bool parseSpecialCoords(const QString& txt, double& latitude, double& longitude) {
	QRegExp xmlFormat("(-?\\d+(?:\\.\\d+)?)\\s+(-?\\d+(?:\\.\\d+)?)");
	if (xmlFormat.exactMatch(txt)) {
		latitude = xmlFormat.cap(1).toDouble();
		longitude = xmlFormat.cap(2).toDouble();
		return true;
	}
	return false;
}

bool parseGpsText(const QString &gps_text, double *latitude, double *longitude)
{
	static const QString POS_LAT = QString("+N") + translate("gettextFromC", "N");
	static const QString NEG_LAT = QString("-S") + translate("gettextFromC", "S");
	static const QString POS_LON = QString("+E") + translate("gettextFromC", "E");
	static const QString NEG_LON = QString("-W") + translate("gettextFromC", "W");

	//remove the useless spaces (but keep the ones separating numbers)
	static const QRegExp SPACE_CLEANER("\\s*([" + POS_LAT + NEG_LAT + POS_LON +
		NEG_LON + DEGREE_SIGNS + "'\"\\s])\\s*");
	const QString normalized = gps_text.trimmed().toUpper().replace(SPACE_CLEANER, "\\1");

	if (normalized.isEmpty()) {
		*latitude = 0.0;
		*longitude = 0.0;
		return true;
	}
	if (parseSpecialCoords(normalized, *latitude, *longitude))
		return true;
	int pos = 0;
	return parseCoord(normalized, pos, POS_LAT, NEG_LAT, POS_LON + NEG_LON, *latitude) &&
		parseCoord(normalized, pos, POS_LON, NEG_LON, "", *longitude) &&
		pos == normalized.size();
}

#if 0 // we'll need something like this for the dive site management, eventually
bool gpsHasChanged(struct dive *dive, struct dive *master, const QString &gps_text, bool *parsed_out)
{
	double latitude, longitude;
	int latudeg, longudeg;
	bool ignore;
	bool *parsed = parsed_out ?: &ignore;
	*parsed = true;

	/* if we have a master and the dive's gps address is different from it,
	 * don't change the dive */
	if (master && (master->latitude.udeg != dive->latitude.udeg ||
		       master->longitude.udeg != dive->longitude.udeg))
		return false;

	if (!(*parsed = parseGpsText(gps_text, &latitude, &longitude)))
		return false;

	latudeg = rint(1000000 * latitude);
	longudeg = rint(1000000 * longitude);

	/* if dive gps didn't change, nothing changed */
	if (dive->latitude.udeg == latudeg && dive->longitude.udeg == longudeg)
		return false;
	/* ok, update the dive and mark things changed */
	dive->latitude.udeg = latudeg;
	dive->longitude.udeg = longudeg;
	return true;
}
#endif

QList<int> getDivesInTrip(dive_trip_t *trip)
{
	QList<int> ret;
	int i;
	struct dive *d;
	for_each_dive (i, d) {
		if (d->divetrip == trip) {
			ret.push_back(get_divenr(d));
		}
	}
	return ret;
}

// we need this to be uniq, but also make sure
// it doesn't change during the life time of a Subsurface session
// oh, and it has no meaning whatsoever - that's why we have the
// silly initial number and increment by 3 :-)
int dive_getUniqID(struct dive *d)
{
	static QSet<int> ids;
	static int maxId = 83529;

	int id = d->id;
	if (id) {
		if (!ids.contains(id)) {
			qDebug() << "WTF - only I am allowed to create IDs";
			ids.insert(id);
		}
		return id;
	}
	maxId += 3;
	id = maxId;
	Q_ASSERT(!ids.contains(id));
	ids.insert(id);
	return id;
}


static xmlDocPtr get_stylesheet_doc(const xmlChar *uri, xmlDictPtr, int, void *, xsltLoadType)
{
	QFile f(QLatin1String(":/xslt/") + (const char *)uri);
	if (!f.open(QIODevice::ReadOnly)) {
		if (verbose > 0) {
			qDebug() << "cannot open stylesheet" << QLatin1String(":/xslt/") + (const char *)uri;
			return NULL;
		}
	}
	/* Load and parse the data */
	QByteArray source = f.readAll();

	xmlDocPtr doc = xmlParseMemory(source, source.size());
	return doc;
}

extern "C" xsltStylesheetPtr get_stylesheet(const char *name)
{
	// this needs to be done only once, but doesn't hurt to run every time
	xsltSetLoaderFunc(get_stylesheet_doc);

	// get main document:
	xmlDocPtr doc = get_stylesheet_doc((const xmlChar *)name, NULL, 0, NULL, XSLT_LOAD_START);
	if (!doc)
		return NULL;

	//	xsltSetGenericErrorFunc(stderr, NULL);
	xsltStylesheetPtr xslt = xsltParseStylesheetDoc(doc);
	if (!xslt) {
		xmlFreeDoc(doc);
		return NULL;
	}

	return xslt;
}

extern "C" void picture_load_exif_data(struct picture *p)
{
	EXIFInfo exif;
	memblock mem;

	if (readfile(p->filename, &mem) <= 0)
		goto picture_load_exit;
	if (exif.parseFrom((const unsigned char *)mem.buffer, (unsigned)mem.size) != PARSE_EXIF_SUCCESS)
		goto picture_load_exit;
	p->longitude.udeg= lrint(1000000.0 * exif.GeoLocation.Longitude);
	p->latitude.udeg  = lrint(1000000.0 * exif.GeoLocation.Latitude);

picture_load_exit:
	free(mem.buffer);
	return;
}

extern "C" void picture_get_timestamp(char *filename, timestamp_t *t)
{
	EXIFInfo exif;
	memblock mem;
	int retval;

	if (readfile(filename, &mem) <= 0)
		return;
	retval = exif.parseFrom((const unsigned char *)mem.buffer, (unsigned)mem.size);
	free(mem.buffer);
	if (retval != PARSE_EXIF_SUCCESS)
		return;
	*t = exif.epoch();
	return;
}

extern "C" const char *system_default_directory(void)
{
	static char filename[PATH_MAX];

	if (!*filename) {
		enum QStandardPaths::StandardLocation location;
#if QT_VERSION >= 0x050400
		location = QStandardPaths::AppDataLocation;
#else
		location = QStandardPaths::DataLocation;
#endif
		QString name = QStandardPaths::standardLocations(location).first();
		QDir dir(name);
		dir.mkpath(name);
		// Why no "dir.encodeName()"? Crazy Qt
		strncpy(filename, QFile::encodeName(name), PATH_MAX-1);
	}
	return filename;
}

extern "C" char *get_file_name(const char *fileName)
{
	QFileInfo fileInfo(fileName);
	return strdup(fileInfo.fileName().toUtf8());
}

extern "C" void copy_image_and_overwrite(const char *cfileName, const char *cnewName)
{
	QString fileName = QString::fromUtf8(cfileName);
	QString newName = QString::fromUtf8(cnewName);
	newName += QFileInfo(cfileName).fileName();
	QFile file(newName);
	if (file.exists())
		file.remove();
	QFile::copy(fileName, newName);
}

extern "C" bool string_sequence_contains(const char *string_sequence, const char *text)
{
	if (same_string(text, "") || same_string(string_sequence, ""))
		return false;

	QString stringSequence(string_sequence);
	QStringList strings = stringSequence.split(",", QString::SkipEmptyParts);
	Q_FOREACH (const QString& string, strings) {
		if (string.trimmed().compare(QString(text).trimmed(), Qt::CaseInsensitive) == 0)
			return true;
	}
	return false;
}

static bool lessThan(const QPair<QString, int> &a, const QPair<QString, int> &b)
{
	return a.second < b.second;
}

void selectedDivesGasUsed(QVector<QPair<QString, int> > &gasUsedOrdered)
{
	int i, j;
	struct dive *d;
	QMap<QString, int> gasUsed;
	for_each_dive (i, d) {
		if (!d->selected)
			continue;
		volume_t diveGases[MAX_CYLINDERS] = {};
		get_gas_used(d, diveGases);
		for (j = 0; j < MAX_CYLINDERS; j++)
			if (diveGases[j].mliter) {
				QString gasName = gasname(&d->cylinder[j].gasmix);
				gasUsed[gasName] += diveGases[j].mliter;
			}
	}
	Q_FOREACH(const QString& gas, gasUsed.keys()) {
		gasUsedOrdered.append(qMakePair(gas, gasUsed[gas]));
	}
	qSort(gasUsedOrdered.begin(), gasUsedOrdered.end(), lessThan);
}

QString getUserAgent()
{
	QString arch;
	// fill in the system data - use ':' as separator
	// replace all other ':' with ' ' so that this is easy to parse
	QString userAgent = QString("Subsurface:%1:").arg(subsurface_version());
	userAgent.append(SubsurfaceSysInfo::prettyOsName().replace(':', ' ') + ":");
	arch = SubsurfaceSysInfo::buildCpuArchitecture().replace(':', ' ');
	userAgent.append(arch);
	if (arch == "i386")
		userAgent.append("/" + SubsurfaceSysInfo::currentCpuArchitecture());
	userAgent.append(":" + uiLanguage(NULL));
	return userAgent;

}

QString uiLanguage(QLocale *callerLoc)
{
	QSettings s;
	s.beginGroup("Language");

	if (!s.value("UseSystemLanguage", true).toBool()) {
		loc = QLocale(s.value("UiLanguage", QLocale().uiLanguages().first()).toString());
	} else {
		loc = QLocale(QLocale().uiLanguages().first());
	}

	QString uiLang = loc.uiLanguages().first();
	s.endGroup();

	// there's a stupid Qt bug on MacOS where uiLanguages doesn't give us the country info
	if (!uiLang.contains('-') && uiLang != loc.bcp47Name()) {
		QLocale loc2(loc.bcp47Name());
		loc = loc2;
		uiLang = loc2.uiLanguages().first();
	}
	if (callerLoc)
		*callerLoc = loc;

	// the short format is fine
	// the long format uses long weekday and month names, so replace those with the short ones
	// for time we don't want the time zone designator and don't want leading zeroes on the hours
	shortDateFormat = loc.dateFormat(QLocale::ShortFormat);
	dateFormat = loc.dateFormat(QLocale::LongFormat);
	dateFormat.replace("dddd,", "ddd").replace("dddd", "ddd").replace("MMMM", "MMM");
	// special hack for Swedish as our switching from long weekday names to short weekday names
	// messes things up there
	dateFormat.replace("'en' 'den' d:'e'", " d");
	timeFormat = loc.timeFormat();
	timeFormat.replace("(t)", "").replace(" t", "").replace("t", "").replace("hh", "h").replace("HH", "H").replace("'kl'.", "");
	timeFormat.replace(".ss", "").replace(":ss", "").replace("ss", "");
	return uiLang;
}

QLocale getLocale()
{
	return loc;
}

QString getDateFormat()
{
	return dateFormat;
}
void set_filename(const char *filename, bool force)
{
	if (!force && existing_filename)
		return;
	free((void *)existing_filename);
	if (filename)
		existing_filename = strdup(filename);
	else
		existing_filename = NULL;
}

const QString get_dc_nickname(const char *model, uint32_t deviceid)
{
	const DiveComputerNode *existNode = dcList.getExact(model, deviceid);

	if (existNode && !existNode->nickName.isEmpty())
		return existNode->nickName;
	else
		return model;
}

QString get_depth_string(int mm, bool showunit, bool showdecimal)
{
	if (prefs.units.length == units::METERS) {
		double meters = mm / 1000.0;
		return QString("%1%2").arg(meters, 0, 'f', (showdecimal && meters < 20.0) ? 1 : 0).arg(showunit ? translate("gettextFromC", "m") : "");
	} else {
		double feet = mm_to_feet(mm);
		return QString("%1%2").arg(feet, 0, 'f', 0).arg(showunit ? translate("gettextFromC", "ft") : "");
	}
}

QString get_depth_string(depth_t depth, bool showunit, bool showdecimal)
{
	return get_depth_string(depth.mm, showunit, showdecimal);
}

QString get_depth_unit()
{
	if (prefs.units.length == units::METERS)
		return QString("%1").arg(translate("gettextFromC", "m"));
	else
		return QString("%1").arg(translate("gettextFromC", "ft"));
}

QString get_weight_string(weight_t weight, bool showunit)
{
	QString str = weight_string(weight.grams);
	if (get_units()->weight == units::KG) {
		str = QString("%1%2").arg(str).arg(showunit ? translate("gettextFromC", "kg") : "");
	} else {
		str = QString("%1%2").arg(str).arg(showunit ? translate("gettextFromC", "lbs") : "");
	}
	return (str);
}

QString get_weight_unit()
{
	if (prefs.units.weight == units::KG)
		return QString("%1").arg(translate("gettextFromC", "kg"));
	else
		return QString("%1").arg(translate("gettextFromC", "lbs"));
}

/* these methods retrieve used gas per cylinder */
static unsigned start_pressure(cylinder_t *cyl)
{
	return cyl->start.mbar ?: cyl->sample_start.mbar;
}

static unsigned end_pressure(cylinder_t *cyl)
{
	return cyl->end.mbar ?: cyl->sample_end.mbar;
}

QString get_cylinder_used_gas_string(cylinder_t *cyl, bool showunit)
{
	int decimals;
	const char *unit;
	double gas_usage;
	/* Get the cylinder gas use in mbar */
	gas_usage = start_pressure(cyl) - end_pressure(cyl);
	/* Can we turn it into a volume? */
	if (cyl->type.size.mliter) {
		gas_usage = bar_to_atm(gas_usage / 1000);
		gas_usage *= cyl->type.size.mliter;
		gas_usage = get_volume_units(gas_usage, &decimals, &unit);
	} else {
		gas_usage = get_pressure_units(gas_usage, &unit);
		decimals = 0;
	}
	// translate("gettextFromC","%.*f %s"
	return QString("%1 %2").arg(gas_usage, 0, 'f', decimals).arg(showunit ? unit : "");
}

QString get_temperature_string(temperature_t temp, bool showunit)
{
	if (temp.mkelvin == 0) {
		return ""; //temperature not defined
	} else if (prefs.units.temperature == units::CELSIUS) {
		double celsius = mkelvin_to_C(temp.mkelvin);
		return QString("%1%2%3").arg(celsius, 0, 'f', 1).arg(showunit ? (UTF8_DEGREE) : "").arg(showunit ? translate("gettextFromC", "C") : "");
	} else {
		double fahrenheit = mkelvin_to_F(temp.mkelvin);
		return QString("%1%2%3").arg(fahrenheit, 0, 'f', 1).arg(showunit ? (UTF8_DEGREE) : "").arg(showunit ? translate("gettextFromC", "F") : "");
	}
}

QString get_temp_unit()
{
	if (prefs.units.temperature == units::CELSIUS)
		return QString(UTF8_DEGREE "C");
	else
		return QString(UTF8_DEGREE "F");
}

QString get_volume_string(volume_t volume, bool showunit, int mbar)
{
	const char *unit;
	int decimals;
	double value = get_volume_units(volume.mliter, &decimals, &unit);
	if (mbar) {
		// we are showing a tank size
		// fix the weird imperial way of denominating size and provide
		// reasonable number of decimals
		if (prefs.units.volume == units::CUFT)
			value *= bar_to_atm(mbar / 1000.0);
		decimals = (value > 20.0) ? 0 : (value > 2.0) ? 1 : 2;
	}
	return QString("%1%2").arg(value, 0, 'f', decimals).arg(showunit ? unit : "");
}

QString get_volume_unit()
{
	const char *unit;
	(void) get_volume_units(0, NULL, &unit);
	return QString(unit);
}

QString get_pressure_string(pressure_t pressure, bool showunit)
{
	if (prefs.units.pressure == units::BAR) {
		double bar = pressure.mbar / 1000.0;
		return QString("%1%2").arg(bar, 0, 'f', 1).arg(showunit ? translate("gettextFromC", "bar") : "");
	} else {
		double psi = mbar_to_PSI(pressure.mbar);
		return QString("%1%2").arg(psi, 0, 'f', 0).arg(showunit ? translate("gettextFromC", "psi") : "");
	}
}

QString getSubsurfaceDataPath(QString folderToFind)
{
	QString execdir;
	QDir folder;

	// first check if we are running in the build dir, so the path that we
	// are looking for is just a  subdirectory of the execution path;
	// this also works on Windows as there we install the dirs
	// under the application path
	execdir = QCoreApplication::applicationDirPath();
	folder = QDir(execdir.append(QDir::separator()).append(folderToFind));
	if (folder.exists())
		return folder.absolutePath();

	// next check for the Linux typical $(prefix)/share/subsurface
	execdir = QCoreApplication::applicationDirPath();
	if (execdir.contains("bin")) {
		folder = QDir(execdir.replace("bin", "share/subsurface/").append(folderToFind));
		if (folder.exists())
			return folder.absolutePath();
	}
	// then look for the usual locations on a Mac
	execdir = QCoreApplication::applicationDirPath();
	folder = QDir(execdir.append("/../Resources/share/").append(folderToFind));
	if (folder.exists())
		return folder.absolutePath();
	execdir = QCoreApplication::applicationDirPath();
	folder = QDir(execdir.append("/../Resources/").append(folderToFind));
	if (folder.exists())
		return folder.absolutePath();
	return QString("");
}

int gettimezoneoffset(timestamp_t when)
{
	QDateTime dt1, dt2;
	if (when == 0)
		dt1 = QDateTime::currentDateTime();
	else
		dt1 = QDateTime::fromMSecsSinceEpoch(when * 1000);
	dt2 = dt1.toUTC();
	dt1.setTimeSpec(Qt::UTC);
	return dt2.secsTo(dt1);
}

int parseTemperatureToMkelvin(const QString &text)
{
	int mkelvin;
	QString numOnly = text;
	numOnly.replace(",", ".").remove(QRegExp("[^-0-9.]"));
	if (numOnly.isEmpty())
		return 0;
	double number = numOnly.toDouble();
	switch (prefs.units.temperature) {
	case units::CELSIUS:
		mkelvin = C_to_mkelvin(number);
		break;
	case units::FAHRENHEIT:
		mkelvin = F_to_mkelvin(number);
		break;
	default:
		mkelvin = 0;
	}
	return mkelvin;
}

QString get_dive_duration_string(timestamp_t when, QString hourText, QString minutesText)
{
	int hrs, mins;
	mins = (when + 59) / 60;
	hrs = mins / 60;
	mins -= hrs * 60;

	QString displayTime;
	if (hrs)
		displayTime = QString("%1%2%3%4").arg(hrs).arg(hourText).arg(mins, 2, 10, QChar('0')).arg(minutesText);
	else
		displayTime = QString("%1%2").arg(mins).arg(minutesText);

	return displayTime;
}

QString get_dive_date_string(timestamp_t when)
{
	QDateTime ts;
	ts.setMSecsSinceEpoch(when * 1000L);
	return loc.toString(ts.toUTC(), dateFormat + " " + timeFormat);
}

QString get_short_dive_date_string(timestamp_t when)
{
	QDateTime ts;
	ts.setMSecsSinceEpoch(when * 1000L);
	return loc.toString(ts.toUTC(), shortDateFormat + " " + timeFormat);
}

const char *get_dive_date_c_string(timestamp_t when)
{
	QString text = get_dive_date_string(when);
	return strdup(text.toUtf8().data());
}

QString get_trip_date_string(timestamp_t when, int nr)
{
	struct tm tm;
	utc_mkdate(when, &tm);
	if (nr != 1) {
		QString ret =  translate("gettextFromC", "%1 %2 (%3 dives)");
		return ret.arg(monthname(tm.tm_mon))
			.arg(tm.tm_year + 1900)
			.arg(nr);
	} else {
		QString ret = translate("gettextFromC", "%1 %2 (1 dive)");
		return ret.arg(monthname(tm.tm_mon))
			.arg(tm.tm_year + 1900);
	}
}

extern "C" void reverseGeoLookup(degrees_t latitude, degrees_t longitude, uint32_t uuid)
{
	QNetworkRequest request;
	QNetworkAccessManager *rgl = new QNetworkAccessManager();
	request.setUrl(QString("http://open.mapquestapi.com/nominatim/v1/reverse.php?format=json&accept-language=%1&lat=%2&lon=%3")
		       .arg(uiLanguage(NULL)).arg(latitude.udeg / 1000000.0).arg(longitude.udeg / 1000000.0));
	request.setRawHeader("Accept", "text/json");
	request.setRawHeader("User-Agent", getUserAgent().toUtf8());
	QNetworkReply *reply = rgl->get(request);
	QEventLoop loop;
	QObject::connect(reply, SIGNAL(finished()), &loop, SLOT(quit()));
	loop.exec();
	QJsonParseError errorObject;
	QJsonDocument jsonDoc = QJsonDocument::fromJson(reply->readAll(), &errorObject);
	if (errorObject.error != QJsonParseError::NoError) {
		qDebug() << errorObject.errorString();
	} else {
		QJsonObject obj = jsonDoc.object();
		QJsonObject address = obj.value("address").toObject();
		qDebug() << "found country:" << address.value("country").toString();
		struct dive_site *ds = get_dive_site_by_uuid(uuid);
		ds->notes = add_to_string(ds->notes, "countrytag: %s", address.value("country").toString().toUtf8().data());
	}
}

QHash<QString, QByteArray> hashOf;
QMutex hashOfMutex;
QHash<QByteArray, QString> localFilenameOf;

extern "C" char * hashstring(char * filename)
{
	return hashOf[QString(filename)].toHex().data();
}

void read_hashes()
{
	QFile hashfile(QString(system_default_directory()).append("/hashes"));
	if (hashfile.open(QIODevice::ReadOnly)) {
		QDataStream stream(&hashfile);
		stream >> localFilenameOf;
		hashfile.close();
	}
}

void write_hashes()
{
	QSaveFile hashfile(QString(system_default_directory()).append("/hashes"));
	if (hashfile.open(QIODevice::WriteOnly)) {
		QDataStream stream(&hashfile);
		stream << localFilenameOf;
		hashfile.commit();
	} else {
		qDebug() << "cannot open" << hashfile.fileName();
	}
}

void add_hash(const QString filename, QByteArray hash)
{
	QMutexLocker locker(&hashOfMutex);
	hashOf[filename] =  hash;
	localFilenameOf[hash] = filename;
}

QByteArray hashFile(const QString filename)
{
	QCryptographicHash hash(QCryptographicHash::Sha1);
	QFile imagefile(filename);
	imagefile.open(QIODevice::ReadOnly);
	hash.addData(&imagefile);
	add_hash(filename, hash.result());
	return hash.result();
}

void learnHash(struct picture *picture, QByteArray hash)
{
	free(picture->hash);
	QMutexLocker locker(&hashOfMutex);
	hashOf[QString(picture->filename)] = hash;
	picture->hash = strdup(hash.toHex());
}

QString localFilePath(const QString originalFilename)
{
	return localFilenameOf[hashOf[originalFilename]];
}

QString fileFromHash(char *hash)
{
	return localFilenameOf[QByteArray::fromHex(hash)];
}

void updateHash(struct picture *picture) {
	QByteArray hash = hashFile(fileFromHash(picture->hash));
	QMutexLocker locker(&hashOfMutex);
	hashOf[QString(picture->filename)] = hash;
	char *old = picture->hash;
	picture->hash = strdup(hash.toHex());
	free(old);
}

void learnImages(const QDir dir, int max_recursions, bool recursed)
{
	QDir current(dir);
	QStringList filters, files;

	if (max_recursions) {
		foreach (QString dirname, dir.entryList(QStringList(), QDir::NoDotAndDotDot | QDir::Dirs)) {
			learnImages(QDir(dir.filePath(dirname)), max_recursions - 1, true);
		}
	}

	foreach (QString format, QImageReader::supportedImageFormats()) {
		filters.append(QString("*.").append(format));
	}

	foreach (QString file, dir.entryList(filters, QDir::Files)) {
		files.append(dir.absoluteFilePath(file));
	}

	QtConcurrent::blockingMap(files, hashFile);
}