build-system: start adding a headless build

Right now this doesn't do a thing, but it gives us a nice target that
has far fewer dependencies and should contain enough parts to download
stuff from a divecomputer and then sync that with cloud storage.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

CMakeLists.txt

@@ -52,8 +52,8 @@ option(FTDISUPPORT "enable support for libftdi based serial" OFF)
 # Options regarding What should we build on subsurface
 option(MAKE_TESTS "Make the tests" ON)
 
-SET(SUBSURFACE_TARGET_EXECUTABLE "DesktopExecutable" CACHE STRING "The type of application, DesktopExecutable or MobileExecutable")
-LIST(APPEND SUBSURFACE_ACCEPTED_EXECUTABLES  "DesktopExecutable" "MobileExecutable")
+SET(SUBSURFACE_TARGET_EXECUTABLE "DesktopExecutable" CACHE STRING "The type of application, DesktopExecutable, MobileExecutable, or DownloaderExecutable")
+LIST(APPEND SUBSURFACE_ACCEPTED_EXECUTABLES  "DesktopExecutable" "MobileExecutable" "DownloaderExecutable")
 SET_PROPERTY(CACHE SUBSURFACE_TARGET_EXECUTABLE PROPERTY STRINGS ${SUBSURFACE_ACCEPTED_EXECUTABLES})
 
 #verify if Platform is correct and warn on wxit with example.
@@ -199,6 +199,11 @@ elseif (SUBSURFACE_TARGET_EXECUTABLE MATCHES "MobileExecutable")
 
 	message(STATUS "Building Subsurface-mobile requires BT support")
 	set(BTSUPPORT ON)
+elseif (SUBSURFACE_TARGET_EXECUTABLE MATCHES "DownloaderExecutable")
+	set(SUBSURFACE_TARGET subsurface-downloader)
+	set(BTSUPPORT ON)
+	add_definitions(-DSUBSURFACE_DOWNLOADER)
+	message(STATUS "building the embedded Subsurface-downloader app")
 endif()
 
 if(ANDROID)
@@ -269,13 +274,17 @@ endif()
 set(QT_FIND_COMPONENTS Core Concurrent Widgets Network Svg Positioning Quick Location ${QT_EXTRA_COMPONENTS})
 if (SUBSURFACE_TARGET_EXECUTABLE MATCHES "DesktopExecutable")
 	find_package(Qt5 5.9.1 REQUIRED COMPONENTS ${QT_FIND_COMPONENTS} LinguistTools Test QuickTest)
-else()
+elseif (SUBSURFACE_TARGET_EXECUTABLE MATCHES "MobileExecutable")
 	# Kirigami 5.62 and newer require at least Qt 5.12
 	if(ANDROID)
 		find_package(Qt5 5.12 REQUIRED COMPONENTS ${QT_FIND_COMPONENTS} LinguistTools)
 	else()
 		find_package(Qt5 5.12 REQUIRED COMPONENTS ${QT_FIND_COMPONENTS} LinguistTools Test QuickTest)
 	endif()
+elseif (SUBSURFACE_TARGET_EXECUTABLE MATCHES "DownloaderExecutable")
+	# let's pick a version that's not ancient
+	find_package(Qt5 5.12 REQUIRED COMPONENTS ${QT_FIND_COMPONENTS})
+	set(MAKE_TESTS OFF)
 endif()
 foreach(_QT_COMPONENT ${QT_FIND_COMPONENTS})
 	list(APPEND QT_LIBRARIES Qt5::${_QT_COMPONENT})
@@ -286,7 +295,9 @@ endif()
 
 #set up the subsurface_link_libraries variable
 set(SUBSURFACE_LINK_LIBRARIES ${SUBSURFACE_LINK_LIBRARIES} ${LIBDIVECOMPUTER_LIBRARIES} ${LIBGIT2_LIBRARIES} ${LIBUSB_LIBRARIES} ${LIBMTP_LIBRARIES})
+if (NOT SUBSURFACE_TARGET_EXECUTABLE MATCHES "DownloaderExecutable")
 	qt5_add_resources(SUBSURFACE_RESOURCES subsurface.qrc map-widget/qml/map-widget.qrc)
+endif()
 
 # hack to build successfully on LGTM
 if(DEFINED ENV{LGTM_SRC})
@@ -294,13 +305,17 @@ if(DEFINED ENV{LGTM_SRC})
 endif()
 
 # include translations
+if (NOT SUBSURFACE_TARGET_EXECUTABLE MATCHES "DownloaderExecutable")
 add_subdirectory(translations)
+endif()
 add_subdirectory(core)
 add_subdirectory(qt-models)
 add_subdirectory(commands)
+if (NOT SUBSURFACE_TARGET_EXECUTABLE MATCHES "DownloaderExecutable")
 add_subdirectory(profile-widget)
 add_subdirectory(map-widget)
 add_subdirectory(mobile-widgets)
+endif()
 add_subdirectory(backend-shared)
 
 if (SUBSURFACE_TARGET_EXECUTABLE MATCHES "DesktopExecutable")
@@ -370,6 +385,17 @@ elseif (SUBSURFACE_TARGET_EXECUTABLE MATCHES "DesktopExecutable")
 	add_dependencies(subsurface_profile subsurface_generated_ui)
 	add_dependencies(subsurface_models_desktop subsurface_generated_ui)
 	add_dependencies(subsurface_generated_ui version)
+elseif (SUBSURFACE_TARGET_EXECUTABLE MATCHES "DownloaderExecutable")
+	set(DOWNLOADER_APP
+		subsurface-downloader-main.cpp
+	)
+	source_group("Downloader App" FILES ${DOWNLOADER_APP})
+	add_executable(${SUBSURFACE_TARGET} MACOSX_BUNDLE WIN32 ${SUBSURFACE_PKG} ${DOWNLOADER_APP} ${SUBSURFACE_RESOURCES})
+	target_link_libraries(
+		${SUBSURFACE_TARGET}
+		subsurface_corelib
+		${SUBSURFACE_LINK_LIBRARIES}
+	)
 endif()
 
 add_dependencies(subsurface_corelib version)

core/divefilter.cpp

@@ -5,7 +5,7 @@
 #include "gettextfromc.h"
 #include "qthelper.h"
 #include "subsurface-qt/divelistnotifier.h"
-#ifndef SUBSURFACE_MOBILE
+#if !defined(SUBSURFACE_MOBILE) && !defined(SUBSURFACE_DOWNLOADER)
 #include "desktop-widgets/mapwidget.h"
 #include "desktop-widgets/mainwindow.h"
 #include "desktop-widgets/divelistview.h"
@@ -103,7 +103,7 @@ bool DiveFilter::showDive(const struct dive *d) const
 			   [d] (const filter_constraint &c) { return filter_constraint_match_dive(c, d); });
 }
 
-#ifndef SUBSURFACE_MOBILE
+#if !defined(SUBSURFACE_MOBILE) && !defined(SUBSURFACE_DOWNLOADER)
 void DiveFilter::startFilterDiveSites(QVector<dive_site *> ds)
 {
 	if (++diveSiteRefCount > 1) {

core/qthelper.cpp

@@ -419,6 +419,8 @@ QString getUserAgent()
 	// replace all other ':' with ' ' so that this is easy to parse
 #ifdef SUBSURFACE_MOBILE
 	QString userAgent = QString("Subsurface-mobile:%1(%2):").arg(subsurface_mobile_version()).arg(subsurface_canonical_version());
+#elif SUBSURFACE_DOWNLOADER
+	QString userAgent = QString("Subsurface-downloader:%1:").arg(subsurface_canonical_version());
 #else
 	QString userAgent = QString("Subsurface:%1:").arg(subsurface_canonical_version());
 #endif

core/subsurfacestartup.c

@@ -132,7 +132,11 @@ void print_version()
 	static bool version_printed = false;
 	if (version_printed)
 		return;
+#if defined(SUBSURFACE_DOWNLOADER)
+	printf("Subsurface-downloader v%s,\n", subsurface_git_version());
+#else
 	printf("Subsurface v%s,\n", subsurface_git_version());
+#endif
 	printf("built with libdivecomputer v%s\n", dc_version(NULL));
 	print_qt_versions();
 	int git_maj, git_min, git_rev;

subsurface-downloader-main.cpp

@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: GPL-2.0
+/* main.c */
+#include "core/downloadfromdcthread.h" // for fill_computer_list
+#include "core/errorhelper.h"
+#include "core/parse.h"
+#include "core/qthelper.h"
+#include "core/subsurfacestartup.h"
+#include "core/settings/qPref.h"
+#include "core/tag.h"
+#include "core/dive.h"
+
+#include <QApplication>
+#include <QLoggingCategory>
+#include <QStringList>
+#include <git2.h>
+
+static bool filesOnCommandLine = false;
+static void messageHandler(QtMsgType type, const QMessageLogContext &ctx, const QString &msg);
+
+int main(int argc, char **argv)
+{
+	qInstallMessageHandler(messageHandler);
+	// we always run this in verbose mode as there is no UI
+	verbose = 1;
+
+	// now let's say Hi
+	print_version();
+
+	// supporting BT makes sense when used with an iPhone and an rfcomm BT device?
+	QLoggingCategory::setFilterRules(QStringLiteral("qt.bluetooth* = true"));
+
+	int i;
+	bool no_filenames = true;
+	std::unique_ptr<QApplication> app(new QApplication(argc, argv));
+	QStringList files;
+	QStringList importedFiles;
+	QStringList arguments = QCoreApplication::arguments();
+
+	const char *default_directory = system_default_directory();
+	const char *default_filename = system_default_filename();
+	subsurface_mkdir(default_directory);
+
+	if (subsurface_user_is_root() && !force_root) {
+		printf("You are running Subsurface as root. This is not recommended.\n");
+		printf("If you insist to do so, run with option --allow_run_as_root.\n");
+		exit(0);
+	}
+	git_libgit2_init();
+	setup_system_prefs();
+	copy_prefs(&default_prefs, &prefs);
+
+	// now handle the arguments
+	for (i = 1; i < arguments.length(); i++) {
+		QString a = arguments.at(i);
+		if (a.isEmpty())
+			continue;
+		if (a.at(0) == '-') {
+			parse_argument(qPrintable(a));
+			continue;
+		}
+		if (imported) {
+			importedFiles.push_back(a);
+		} else {
+			no_filenames = false;
+			files.push_back(a);
+		}
+	}
+	fill_computer_list();
+	parse_xml_init();
+	taglist_init_global();
+
+	if (no_filenames) {
+		if (prefs.default_file_behavior == LOCAL_DEFAULT_FILE) {
+			QString defaultFile(prefs.default_filename);
+			if (!defaultFile.isEmpty())
+				files.push_back(QString(prefs.default_filename));
+		} else if (prefs.default_file_behavior == CLOUD_DEFAULT_FILE) {
+			QString cloudURL;
+			if (getCloudURL(cloudURL) == 0)
+				files.push_back(cloudURL);
+		}
+	}
+	filesOnCommandLine = !files.isEmpty() || !importedFiles.isEmpty();
+	if (!files.isEmpty())
+		qDebug() << "loading dive data from" << files;
+	print_files();
+	if (!quit) {
+		// do something
+		;
+	}
+	taglist_free(g_tag_list);
+	parse_xml_exit();
+	free((void *)default_directory);
+	free((void *)default_filename);
+
+	// Sync struct preferences to disk
+	qPref::sync();
+
+	free_prefs();
+	return 0;
+}
+
+// install this message handler primarily so that the Windows build can log to files
+void messageHandler(QtMsgType type, const QMessageLogContext &, const QString &msg)
+{
+	QByteArray localMsg = msg.toUtf8();
+	switch (type) {
+	case QtDebugMsg:
+		fprintf(stdout, "%s\n", localMsg.constData());
+		break;
+	case QtInfoMsg:
+		fprintf(stdout, "%s\n", localMsg.constData());
+		break;
+	case QtWarningMsg:
+		fprintf(stderr, "%s\n", localMsg.constData());
+		break;
+	case QtCriticalMsg:
+		fprintf(stderr, "%s\n", localMsg.constData());
+		break;
+	case QtFatalMsg:
+		fprintf(stderr, "%s\n", localMsg.constData());
+		abort();
+	}
+}