src/main.cpp

#include <QApplication>
#include <QFileDialog>
#include <QMessageBox>
#include <QMdiSubWindow>
#include <QStackedWidget>
#include <QCloseEvent>
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "version.h"
#include "ui/canvas.h"
#include "document.h"
#include "settingseditor/settingseditor.h"
#include "widgets/colorselectdialog.h"

static const QDir LOCALE_DIR {":/locale"};

class ModelSubWindow : public QMdiSubWindow
{
	Q_OBJECT
public:
	const ModelId modelId;
	ModelSubWindow(ModelId modelId, QWidget* widget) :
		QMdiSubWindow{widget},
		modelId{modelId}
	{
	}
protected:
	void closeEvent(QCloseEvent* event) override
	{
		event->ignore();
	}
};

static void doQtRegistrations()
{
	QCoreApplication::setApplicationName(::appName);
	QCoreApplication::setOrganizationName("hecknology.net");
	QCoreApplication::setOrganizationDomain("hecknology.net");
	qRegisterMetaTypeStreamOperators<Library>("Library");
	qRegisterMetaTypeStreamOperators<Libraries>("Libraries");
}

template<typename BaseType, typename MemberType, typename DataType>
struct MemberData
{
	std::size_t member;
	DataType payload;
	constexpr MemberType memberInstance(BaseType* instance) const
	{
		return *reinterpret_cast<MemberType*>(reinterpret_cast<char*>(instance) + this->member);
	}
};

class ModelData : public QObject
{
	Q_OBJECT
public:
	ModelData(QObject* parent) : QObject {parent} {}
	std::unique_ptr<Canvas> canvas;
	std::unique_ptr<QItemSelectionModel> itemSelectionModel;
	std::unique_ptr<EditTools> tools;
	Model* model;
};
#include "main.moc"

static constexpr MemberData<Ui_MainWindow, QAction*, gl::RenderStyle> renderStyleButtons[] = {
	{ offsetof(Ui_MainWindow, actionRenderStyleNormal), gl::RenderStyle::Normal },
	{ offsetof(Ui_MainWindow, actionRenderStyleBfc), gl::RenderStyle::BfcRedGreen },
	{ offsetof(Ui_MainWindow, actionRenderStyleRandom), gl::RenderStyle::RandomColors },
	{ offsetof(Ui_MainWindow, actionRenderStylePickScene), gl::RenderStyle::PickScene },
};

static std::optional<ModelId> openModelFromPath(
	const QString& path,
	const LibraryManager* libraries,
	DocumentManager* documents,
	QWidget* parent)
{
	QString errorString;
	QTextStream errorStream{&errorString};
	const std::optional<ModelId> modelIdOpt = documents->openModel(
		path,
		errorStream,
		OpenType::ManuallyOpened);
	if (modelIdOpt.has_value()) {
		const DocumentManager::MissingDependencies missing = documents->loadDependenciesForAllModels(*libraries);
		if (not missing.empty()) {
			QMessageBox::warning(
				parent,
				QObject::tr("Problem loading references"),
				errorStringFromMissingDependencies(missing));
		}
	}
	else {
		QMessageBox::critical(
			parent,
			QObject::tr("Problem opening file"),
			QObject::tr("Could not open %1: %2").arg(quoted(path), errorString)
		);
	}
	return modelIdOpt;
}

static QString getOpenModelPath(QWidget* parent)
{
	return QFileDialog::getOpenFileName(
		parent,
		QObject::tr("Open model"),
		"",
		QObject::tr("LDraw models (*.ldr *.dat)"));
}

static const QString localeCode(const QString& locale)
{
	if (locale == "system") {
		return QLocale::system().name();
	}
	else {
		return locale;
	}
}

/**
 * @brief Changes the application language to the specified language
 */
static void changeLanguage(const QString& locale, QTranslator* translator)
{
	if (not locale.isEmpty()) {
		const QString localeCode = ::localeCode(locale);
		QLocale::setDefault({localeCode});
		qApp->removeTranslator(translator);
		const QString path = LOCALE_DIR.filePath(localeCode + ".qm");
		const bool loadSuccessful = translator->load(path);
		if (loadSuccessful)
		{
			qApp->installTranslator(translator);
		}
	}
}

ModelData* findModelData(DocumentManager* documents, ModelId modelId)
{
	return documents->findPayload<ModelData>(modelId);
}

static ModelSubWindow* currentModelSubWindow(Ui_MainWindow* ui)
{
	return qobject_cast<ModelSubWindow*>(ui->mdiArea->activeSubWindow());
}

static ModelData* currentModelData(Ui_MainWindow* ui, DocumentManager* documents)
{
	if (auto* const activeSubWindow = currentModelSubWindow(ui)) {
		return findModelData(documents, activeSubWindow->modelId);
	}
	else {
		return nullptr;
	}
}

static Model* currentModelBody(Ui_MainWindow* ui, DocumentManager* documents)
{
	if (auto* const activeSubWindow = currentModelSubWindow(ui)) {
		return documents->getModelById(activeSubWindow->modelId);
	}
	else {
		return nullptr;
	}
}

static std::optional<ModelId> findCurrentModelId(Ui_MainWindow* ui)
{
	ModelSubWindow* activeSubWindow = qobject_cast<ModelSubWindow*>(ui->mdiArea->activeSubWindow());
	if (activeSubWindow != nullptr) {
		return activeSubWindow->modelId;
	}
	else {
		return {};
	}
}

/**
 * @brief Updates the title of the main window so to contain the app's name
 * and version as well as the open document name.
 */
static QString title()
{
	QString title = ::appName;
	title += " ";
	title += fullVersionString();
	return title;
}

static ColorTable loadColors(const LibraryManager* libraries)
{
	QTextStream errors;
	return libraries->loadColorTable(errors);
}

static QString tabName(const QFileInfo& fileInfo)
{
	QString result = fileInfo.baseName();
	if (result.isEmpty()) {
		result = QObject::tr("<unnamed>");
	}
	return result;
}

void rebuildRecentFilesMenu(QMenu* menu, const QStringList& strings, QWidget* parent)
{
	menu->clear();
	for (const QString& path : strings) {
		QAction* action = new QAction{path, parent};
		action->setData(path);
		menu->addAction(action);
	}
}

template<typename Fn>
static void forModel(const DocumentManager* documents, Fn&& fn)
{
	forValueInMap(*documents, [&fn](const DocumentManager::ModelInfo& info)
	{
		ModelData* modelSpecificData = qobject_cast<ModelData*>(info.payload);
		if (modelSpecificData != nullptr) {
			fn(&info, modelSpecificData);
		}
	});
}

static void updateRenderPreferences(
	Ui_MainWindow* ui,
	const gl::RenderPreferences* renderPreferences,
	const DocumentManager* documents)
{
	forModel(documents, [&renderPreferences](const void*, const ModelData* data){
		if (data->canvas != nullptr) {
			data->canvas->setRenderPreferences(*renderPreferences);
		}
	});
	for (auto data : ::renderStyleButtons) {
		QAction* action = data.memberInstance(ui);
		action->setChecked(renderPreferences->style == data.payload);
	}
	ui->actionDrawAxes->setChecked(renderPreferences->drawAxes);
};

static gl::RenderPreferences loadRenderPreferences(Configuration* settings)
{
	return gl::RenderPreferences{
		.style = static_cast<gl::RenderStyle>(settings->renderStyle()),
		.mainColor = settings->mainColor(),
		.backgroundColor = settings->backgroundColor(),
		.selectedColor = settings->selectedColor(),
		.lineThickness = settings->lineThickness(),
		.lineAntiAliasing = settings->lineAntiAliasing(),
		.drawAxes = settings->drawAxes(),
	};
}

void initializeTools(Ui_MainWindow* ui, QWidget* parent)
{
	const struct
	{
		QString name, tooltip;
		QPixmap icon;
		QWidget* widget;
	} editingModesInfo[] = {
		{
			.name = QObject::tr("Select"),
			.tooltip = QObject::tr("Select elements from the model."),
			.icon = {":/icons/navigate-outline.png"},
			//.widget = this->objectEditor,
		},
		{
			.name = QObject::tr("Draw"),
			.tooltip = QObject::tr("Draw new elements into the model."),
			.icon = {":/icons/pencil-outline.png"},
			.widget = nullptr,
		},
	};
	for (int i = 0; i < countof(editingModesInfo); ++i) {
		const auto& editingModeInfo = editingModesInfo[i];
		QAction* action = new QAction{editingModeInfo.name, parent};
		action->setCheckable(true);
		action->setChecked(i == 0);
		action->setData(static_cast<EditingMode>(i));
		action->setToolTip(editingModeInfo.tooltip);
		action->setIcon(QPixmap{editingModeInfo.icon});
		ui->editingModesToolBar->addAction(action);
		QWidget* widget = editingModeInfo.widget;
		if (widget == nullptr) {
			widget = new QWidget{parent};
		}
		ui->toolWidgetStack->addWidget(widget);
	}
}

constexpr bool sortModelIndexesByRow(const QModelIndex& a, const QModelIndex& b)
{
	return a.row() < b.row();
}

std::vector<int> rows(const QModelIndexList& indexList)
{
	std::vector<int> result;
	result.reserve(indexList.size());
	for (const QModelIndex& index : indexList)
	{
		result.push_back(index.row());
	}
	return result;
}

int main(int argc, char *argv[])
{
	doQtRegistrations();
	QApplication app{argc, argv};
	QMainWindow mainWindow;
	Ui_MainWindow ui;
	DocumentManager documents;
	QString currentLanguage = "en";
	QTranslator translator{&mainWindow};
	Configuration settings;
	LibraryManager libraries{&mainWindow};
	QByteArray documentSplitterState;
	QStringList recentlyOpenedFiles;
	ColorTable colorTable;
	gl::RenderPreferences renderPreferences;
	ui.setupUi(&mainWindow);
	const uiutilities::KeySequenceMap defaultKeyboardShortcuts =
		uiutilities::makeKeySequenceMap(uiutilities::collectActions(&mainWindow));
	const auto saveSettings = [&]{
		settings.setMainWindowGeometry(mainWindow.saveGeometry());
		settings.setRecentFiles(recentlyOpenedFiles);
		settings.setMainSplitterState(documentSplitterState);
		settings.setRenderStyle(static_cast<int>(renderPreferences.style));
		settings.setDrawAxes(renderPreferences.drawAxes);
		libraries.storeToSettings(&settings);
	};
	const auto updateRecentlyOpenedDocumentsMenu = [&]{
		rebuildRecentFilesMenu(ui.menuRecentFiles, recentlyOpenedFiles, &mainWindow);
		for (QAction* action : ui.menuRecentFiles->findChildren<QAction*>()) {
			QString path = action->data().toString();
			QObject::connect(
				action,
				&QAction::triggered,
				[path, &libraries, &documents, &mainWindow]() {
					openModelFromPath(path, &libraries, &documents, &mainWindow);
				}
			);
		}
	};
	static constexpr auto executeAction = [&](
		Model* model, const ModelAction& action
	) {
		std::visit(overloaded{
			[model](const AppendToModel& action){
				model->append(action.newElement);
			},
			[model](const DeleteFromModel& action){
				model->remove(action.position);
			},
		}, action);
	};
	const auto restoreSettings = [&]{
		recentlyOpenedFiles = settings.recentFiles();
		documentSplitterState = settings.mainSplitterState();
		renderPreferences = loadRenderPreferences(&settings);
		changeLanguage(settings.locale(), &translator);
		libraries.restoreFromSettings(&settings);
		updateRecentlyOpenedDocumentsMenu();
		colorTable = loadColors(&libraries);
		updateRenderPreferences(&ui, &renderPreferences, &documents);
		ui.mdiArea->setViewMode(static_cast<QMdiArea::ViewMode>(settings.viewMode()));
		ui.retranslateUi(&mainWindow);
	};
	const auto addRecentlyOpenedFile = [&](const QString& path){
		constexpr int maxRecentlyOpenedFiles = 10;
		recentlyOpenedFiles.removeAll(path);
		recentlyOpenedFiles.insert(0, path);
		while (recentlyOpenedFiles.size() > maxRecentlyOpenedFiles)
		{
			recentlyOpenedFiles.removeLast();
		}
		saveSettings();
		updateRecentlyOpenedDocumentsMenu();
	};
	const auto openModelForEditing = [&](const ModelId modelId){
		Model* model = documents.getModelById(modelId);
		if (model != nullptr) {
			ModelData* data = new ModelData(&documents);
			data->tools = std::make_unique<EditTools>(model, colorTable);
			data->canvas = std::make_unique<Canvas>(model, data->tools.get(), &documents, colorTable);
			data->itemSelectionModel = std::make_unique<QItemSelectionModel>(model);
			data->model = model;
			QObject::connect(
				data->tools.get(),
				&EditTools::modelAction,
				std::bind(executeAction, model, std::placeholders::_1));
			QObject::connect(data->itemSelectionModel.get(), &QItemSelectionModel::selectionChanged,
				[modelId, &documents](
				const QItemSelection& selected,
				const QItemSelection& deselected)
			{
				ModelData* data = findModelData(&documents, modelId);
				if (data != nullptr) {
					auto resolveIndex = [&data](const QModelIndex& index){
						return data->model->idAt(index.row());
					};
					auto resolve = [&resolveIndex](const QItemSelection& selection)
					{
						return fn::map<QSet<ModelId>>(selection.indexes(), resolveIndex);
					};
					data->canvas->handleSelectionChange(resolve(selected), resolve(deselected));
				}
			});
			data->canvas->setRenderPreferences(renderPreferences);
			QObject::connect(
				data->tools.get(),
				&EditTools::newStatusText,
				[&](const QString& newStatusText) {
					mainWindow.statusBar()->showMessage(newStatusText);
				});
			const QFileInfo fileInfo{*documents.modelPath(modelId)};
			QMdiSubWindow* subWindow = ui.mdiArea->addSubWindow(data->canvas.get());
			subWindow->setWindowTitle(tabName(fileInfo));
			subWindow->show();
		}
	};
	QObject::connect(ui.actionNew, &QAction::triggered, [&]{
		openModelForEditing(documents.newModel());
	});
	QObject::connect(ui.actionOpen, &QAction::triggered, [&]{
		const QString path = getOpenModelPath(&mainWindow);
		if (not path.isEmpty())
		{
			const std::optional<ModelId> id = openModelFromPath(path, &libraries, &documents, &mainWindow);
			if (id.has_value()) {
				openModelForEditing(id.value());
				addRecentlyOpenedFile(path);
			}
		}
	});
	QObject::connect(ui.actionSettingsEditor, &QAction::triggered, [&]{
		SettingsEditor settingsEditor{&settings, defaultKeyboardShortcuts, &mainWindow};
		const int result = settingsEditor.exec();
		if (result == QDialog::Accepted)
		{
			restoreSettings();
		}
	});
	QObject::connect(ui.actionQuit, &QAction::triggered, &mainWindow, &QMainWindow::close);
	QObject::connect(ui.actionAdjustGridToView, &QAction::triggered, [&]{
		if (ModelData* data = currentModelData(&ui, &documents)) {
			adjustGridToView(data->canvas.get());
		}
	});
	QObject::connect(ui.actionClose, &QAction::triggered, [&ui, &documents]{
		if (ModelData* data = currentModelData(&ui, &documents)) {
			// TODO
		}
	});
	const auto save = [&](ModelId modelId){
		QString error;
		QTextStream errorStream{&error};
		const bool succeeded = documents.saveModel(modelId, errorStream);
		if (not succeeded)
		{
			QMessageBox::critical(&mainWindow, QObject::tr("Save error"), error);
		}
		else
		{
			const QString* pathPtr = documents.modelPath(modelId);
			if (pathPtr != nullptr) {
				addRecentlyOpenedFile(*pathPtr);
			}
		}
	};
	const auto actionSaveAs = [&]{
		const std::optional<ModelId> modelId = findCurrentModelId(&ui);
		if (modelId.has_value())
		{
			const QString* pathPtr = documents.modelPath(*modelId);
			QString defaultPath = (pathPtr != nullptr) ? *pathPtr : "";
			const QString newPath = QFileDialog::getSaveFileName(
				&mainWindow,
				QObject::tr("Save as…"),
				QFileInfo{defaultPath}.absoluteDir().path(), 
				QObject::tr("LDraw files (*.ldr *dat);;All files (*)")
			);
			if (not newPath.isEmpty()) {
				QString error;
				QTextStream errorStream{&error};
				documents.setModelPath(*modelId, newPath, libraries, errorStream);
				QMdiSubWindow* const subWindow = ui.mdiArea->currentSubWindow();
				if (subWindow != nullptr) {
					subWindow->setWindowTitle(tabName(QFileInfo{newPath}));
				}
				save(*modelId);
			}
		}
	};
	QObject::connect(ui.actionSaveAs, &QAction::triggered, actionSaveAs);
	QObject::connect(ui.actionSave, &QAction::triggered, [&]{
		const std::optional<ModelId> modelId = findCurrentModelId(&ui);
		if (modelId.has_value()) {
			const QString* path = documents.modelPath(*modelId);
			if (path == nullptr or path->isEmpty()) {
				actionSaveAs();
			}
			else {
				save(*modelId);
			}
		}
	});
	QObject::connect(ui.actionDelete, &QAction::triggered, [&]{
		if (Model* model = currentModelBody(&ui, &documents)) {
			std::vector<int> selectedRows = rows(ui.modelListView->selectionModel()->selectedRows());
			std::sort(selectedRows.begin(), selectedRows.end(), std::greater<int>{});
			for (int row : selectedRows) {
				executeAction(model, DeleteFromModel{.position = row});
			}
		}
	});
	QObject::connect(ui.actionDrawAxes, &QAction::triggered, [&](bool drawAxes){
		renderPreferences.drawAxes = drawAxes;
		saveSettings();
		updateRenderPreferences(&ui, &renderPreferences, &documents);
	});
	for (auto data : ::renderStyleButtons) {
		QAction* action = data.memberInstance(&ui);
		QObject::connect(action, &QAction::triggered, [&, data]{
			renderPreferences.style = data.payload;
			saveSettings();
			updateRenderPreferences(&ui, &renderPreferences, &documents);
		});
	}
	const auto checkEditingModeAction = [&ui](EditingMode mode) {
		for (QAction* action : ui.editingModesToolBar->actions()) {
			action->setChecked(action->data().value<EditingMode>() == mode);
		}
	};
	initializeTools(&ui, &mainWindow);
	for (QAction* action : ui.editingModesToolBar->actions()) {
		QObject::connect(action, &QAction::triggered, [&, action]{
			if (ModelData* data = currentModelData(&ui, &documents)) {
				const EditingMode mode = action->data().value<EditingMode>();
				data->tools->setEditMode(mode);
				checkEditingModeAction(mode);
			}
		});
	}
	QObject::connect(ui.mdiArea, &QMdiArea::subWindowActivated,
	[&](QMdiSubWindow* subWindow) {
		ModelSubWindow* modelSubWindow = qobject_cast<ModelSubWindow*>(subWindow);
		if (modelSubWindow != nullptr) {
			if (ModelData* data = documents.findPayload<ModelData>(modelSubWindow->modelId)) {
				checkEditingModeAction(data->tools->currentEditingMode());
				if (data->itemSelectionModel != nullptr) {
					ui.modelListView->setModel(data->model);
					ui.modelListView->setSelectionModel(data->itemSelectionModel.get());
				}
			}
		}
	});
	mainWindow.setWindowTitle(title());
	mainWindow.restoreGeometry(settings.mainWindowGeometry());
	restoreSettings();
	updateRenderPreferences(&ui, &renderPreferences, &documents);
	mainWindow.show();
	const int result = app.exec();
	saveSettings();
	return result;
}