/*
 * cmodlistview_moc.cpp, part of VCMI engine
 *
 * Authors: listed in file AUTHORS in main folder
 *
 * License: GNU General Public License v2.0 or later
 * Full text of license available in license.txt file, in main folder
 *
 */
#include "StdInc.h"
#include "cmodlistview_moc.h"
#include "ui_cmodlistview_moc.h"
#include "imageviewer_moc.h"
#include "../mainwindow_moc.h"

#include <QJsonArray>
#include <QCryptographicHash>
#include <QRegularExpression>

#include "cmodlistmodel_moc.h"
#include "cmodmanager.h"
#include "cdownloadmanager_moc.h"
#include "../launcherdirs.h"

#include "../../lib/CConfigHandler.h"

void CModListView::setupModModel()
{
	modModel = new CModListModel(this);
	manager = vstd::make_unique<CModManager>(modModel);
}

void CModListView::setupFilterModel()
{
	filterModel = new CModFilterModel(modModel, this);

	filterModel->setFilterKeyColumn(-1); // filter across all columns
	filterModel->setSortCaseSensitivity(Qt::CaseInsensitive); // to make it more user-friendly
	filterModel->setDynamicSortFilter(true);
}

void CModListView::setupModsView()
{
	ui->allModsView->setModel(filterModel);
	// input data is not sorted - sort it before display
	ui->allModsView->sortByColumn(ModFields::TYPE, Qt::AscendingOrder);

	ui->allModsView->header()->setSectionResizeMode(ModFields::STATUS_ENABLED, QHeaderView::Fixed);
	ui->allModsView->header()->setSectionResizeMode(ModFields::STATUS_UPDATE, QHeaderView::Fixed);

	QSettings s(Ui::teamName, Ui::appName);
	auto state = s.value("AllModsView/State").toByteArray();
	if(!state.isNull()) //read last saved settings
	{
		ui->allModsView->header()->restoreState(state);
	}
	else //default //TODO: default high-DPI scaling
	{
		ui->allModsView->setColumnWidth(ModFields::NAME, 185);
		ui->allModsView->setColumnWidth(ModFields::STATUS_ENABLED, 30);
		ui->allModsView->setColumnWidth(ModFields::STATUS_UPDATE, 30);
		ui->allModsView->setColumnWidth(ModFields::TYPE, 75);
		ui->allModsView->setColumnWidth(ModFields::SIZE, 80);
		ui->allModsView->setColumnWidth(ModFields::VERSION, 60);
	}

	ui->allModsView->setUniformRowHeights(true);

	connect(ui->allModsView->selectionModel(), SIGNAL(currentRowChanged(const QModelIndex&,const QModelIndex&)),
		this, SLOT(modSelected(const QModelIndex&,const QModelIndex&)));

	connect(filterModel, SIGNAL(modelReset()),
		this, SLOT(modelReset()));

	connect(modModel, SIGNAL(dataChanged(QModelIndex,QModelIndex)),
		this, SLOT(dataChanged(QModelIndex,QModelIndex)));
}

CModListView::CModListView(QWidget * parent)
	: QWidget(parent), settingsListener(settings.listen["launcher"]["repositoryURL"]), ui(new Ui::CModListView)
{
	settingsListener([&](const JsonNode &){ repositoriesChanged = true; });
	ui->setupUi(this);


	setupModModel();
	setupFilterModel();
	setupModsView();

	ui->progressWidget->setVisible(false);
	dlManager = nullptr;
	disableModInfo();
	if(settings["launcher"]["autoCheckRepositories"].Bool())
	{
		loadRepositories();
	}
	else
	{
		manager->resetRepositories();
	}
}

void CModListView::loadRepositories()
{
	manager->resetRepositories();
	for(auto entry : settings["launcher"]["repositoryURL"].Vector())
	{
		QString str = QString::fromUtf8(entry.String().c_str());

		// URL must be encoded to something else to get rid of symbols illegal in file names
		auto hashed = QCryptographicHash::hash(str.toUtf8(), QCryptographicHash::Md5);
		auto hashedStr = QString::fromUtf8(hashed.toHex());

		downloadFile(hashedStr + ".json", str, "repository index");
	}
}

CModListView::~CModListView()
{
	QSettings s(Ui::teamName, Ui::appName);
	s.setValue("AllModsView/State", ui->allModsView->header()->saveState());

	delete ui;
}

void CModListView::showEvent(QShowEvent * event)
{
	QWidget::showEvent(event);
	if(repositoriesChanged)
	{
		repositoriesChanged = false;
		if(settings["launcher"]["autoCheckRepositories"].Bool())
		{
			loadRepositories();
		}
	}
}

void CModListView::showModInfo()
{
	enableModInfo();
	ui->modInfoWidget->show();
	ui->hideModInfoButton->setArrowType(Qt::RightArrow);
	ui->showInfoButton->setVisible(false);
	loadScreenshots();
}

void CModListView::hideModInfo()
{
	ui->modInfoWidget->hide();
	ui->hideModInfoButton->setArrowType(Qt::LeftArrow);
	ui->hideModInfoButton->setEnabled(true);
	ui->showInfoButton->setVisible(true);
}

static QString replaceIfNotEmpty(QVariant value, QString pattern)
{
	if(value.canConvert<QStringList>())
		return pattern.arg(value.toStringList().join(", "));

	if(value.canConvert<QString>())
		return pattern.arg(value.toString());

	// all valid types of data should have been filtered by code above
	assert(!value.isValid());

	return "";
}

static QString replaceIfNotEmpty(QStringList value, QString pattern)
{
	if(!value.empty())
		return pattern.arg(value.join(", "));
	return "";
}

QString CModListView::genChangelogText(CModEntry & mod)
{
	QString headerTemplate = "<p><span style=\" font-weight:600;\">%1: </span></p>";
	QString entryBegin = "<p align=\"justify\"><ul>";
	QString entryEnd = "</ul></p>";
	QString entryLine = "<li>%1</li>";
	//QString versionSeparator = "<hr/>";

	QString result;

	QVariantMap changelog = mod.getValue("changelog").toMap();
	QList<QString> versions = changelog.keys();

	std::sort(versions.begin(), versions.end(), [](QString lesser, QString greater)
	{
		return !CModEntry::compareVersions(lesser, greater);
	});

	for(auto & version : versions)
	{
		result += headerTemplate.arg(version);
		result += entryBegin;
		for(auto & line : changelog.value(version).toStringList())
			result += entryLine.arg(line);
		result += entryEnd;
	}
	return result;
}

QString CModListView::genModInfoText(CModEntry & mod)
{
	QString prefix = "<p><span style=\" font-weight:600;\">%1: </span>"; // shared prefix
	QString lineTemplate = prefix + "%2</p>";
	QString urlTemplate = prefix + "<a href=\"%2\">%3</a></p>";
	QString textTemplate = prefix + "</p><p align=\"justify\">%2</p>";
	QString listTemplate = "<p align=\"justify\">%1: %2</p>";
	QString noteTemplate = "<p align=\"justify\">%1</p>";

	QString result;

	result += replaceIfNotEmpty(mod.getValue("name"), lineTemplate.arg(tr("Mod name")));
	result += replaceIfNotEmpty(mod.getValue("installedVersion"), lineTemplate.arg(tr("Installed version")));
	result += replaceIfNotEmpty(mod.getValue("latestVersion"), lineTemplate.arg(tr("Latest version")));

	if(mod.getValue("size").isValid())
		result += replaceIfNotEmpty(CModEntry::sizeToString(mod.getValue("size").toDouble()), lineTemplate.arg(tr("Download size")));
	result += replaceIfNotEmpty(mod.getValue("author"), lineTemplate.arg(tr("Authors")));

	if(mod.getValue("licenseURL").isValid())
		result += urlTemplate.arg(tr("License")).arg(mod.getValue("licenseURL").toString()).arg(mod.getValue("licenseName").toString());

	if(mod.getValue("contact").isValid())
		result += urlTemplate.arg(tr("Home")).arg(mod.getValue("contact").toString()).arg(mod.getValue("contact").toString());

	result += replaceIfNotEmpty(mod.getValue("depends"), lineTemplate.arg(tr("Required mods")));
	result += replaceIfNotEmpty(mod.getValue("conflicts"), lineTemplate.arg(tr("Conflicting mods")));
	result += replaceIfNotEmpty(mod.getValue("description"), textTemplate.arg(tr("Description")));

	result += "<p></p>"; // to get some empty space

	QString unknownDeps = tr("This mod can not be installed or enabled because following dependencies are not present");
	QString blockingMods = tr("This mod can not be enabled because following mods are incompatible with this mod");
	QString hasActiveDependentMods = tr("This mod can not be disabled because it is required to run following mods");
	QString hasDependentMods = tr("This mod can not be uninstalled or updated because it is required to run following mods");
	QString thisIsSubmod = tr("This is submod and it can not be installed or uninstalled separately from parent mod");

	QString notes;

	notes += replaceIfNotEmpty(findInvalidDependencies(mod.getName()), listTemplate.arg(unknownDeps));
	notes += replaceIfNotEmpty(findBlockingMods(mod.getName()), listTemplate.arg(blockingMods));
	if(mod.isEnabled())
		notes += replaceIfNotEmpty(findDependentMods(mod.getName(), true), listTemplate.arg(hasActiveDependentMods));
	if(mod.isInstalled())
		notes += replaceIfNotEmpty(findDependentMods(mod.getName(), false), listTemplate.arg(hasDependentMods));

	if(mod.getName().contains('.'))
		notes += noteTemplate.arg(thisIsSubmod);

	if(notes.size())
		result += textTemplate.arg(tr("Notes")).arg(notes);

	return result;
}

void CModListView::enableModInfo()
{
	ui->hideModInfoButton->setEnabled(true);
	ui->showInfoButton->setVisible(true);
}

void CModListView::disableModInfo()
{
	hideModInfo();
	ui->hideModInfoButton->setEnabled(false);
	ui->showInfoButton->setVisible(false);

	ui->disableButton->setVisible(false);
	ui->enableButton->setVisible(false);
	ui->installButton->setVisible(false);
	ui->uninstallButton->setVisible(false);
	ui->updateButton->setVisible(false);
}

void CModListView::dataChanged(const QModelIndex & topleft, const QModelIndex & bottomRight)
{
	selectMod(ui->allModsView->currentIndex());
}

void CModListView::selectMod(const QModelIndex & index)
{
	if(!index.isValid())
	{
		disableModInfo();
	}
	else
	{
		auto mod = modModel->getMod(index.data(ModRoles::ModNameRole).toString());

		ui->modInfoBrowser->setHtml(genModInfoText(mod));
		ui->changelogBrowser->setHtml(genChangelogText(mod));

		bool hasInvalidDeps = !findInvalidDependencies(index.data(ModRoles::ModNameRole).toString()).empty();
		bool hasBlockingMods = !findBlockingMods(index.data(ModRoles::ModNameRole).toString()).empty();
		bool hasDependentMods = !findDependentMods(index.data(ModRoles::ModNameRole).toString(), true).empty();

		ui->hideModInfoButton->setEnabled(true);
		ui->showInfoButton->setVisible(!ui->modInfoWidget->isVisible());
		ui->disableButton->setVisible(mod.isEnabled());
		ui->enableButton->setVisible(mod.isDisabled());
		ui->installButton->setVisible(mod.isAvailable() && !mod.getName().contains('.'));
		ui->uninstallButton->setVisible(mod.isInstalled() && !mod.getName().contains('.'));
		ui->updateButton->setVisible(mod.isUpdateable());

		// Block buttons if action is not allowed at this time
		// TODO: automate handling of some of these cases instead of forcing player
		// to resolve all conflicts manually.
		ui->disableButton->setEnabled(!hasDependentMods);
		ui->enableButton->setEnabled(!hasBlockingMods && !hasInvalidDeps);
		ui->installButton->setEnabled(!hasInvalidDeps);
		ui->uninstallButton->setEnabled(!hasDependentMods);
		ui->updateButton->setEnabled(!hasInvalidDeps && !hasDependentMods);

		loadScreenshots();
	}
}

void CModListView::keyPressEvent(QKeyEvent * event)
{
	if(event->key() == Qt::Key_Escape && ui->modInfoWidget->isVisible())
	{
		hideModInfo();
	}
	else
	{
		return QWidget::keyPressEvent(event);
	}
}

void CModListView::modSelected(const QModelIndex & current, const QModelIndex &)
{
	selectMod(current);
}

void CModListView::on_hideModInfoButton_clicked()
{
	if(ui->modInfoWidget->isVisible())
		hideModInfo();
	else
		showModInfo();
}

void CModListView::on_allModsView_activated(const QModelIndex & index)
{
	showModInfo();
	selectMod(index);
}

void CModListView::on_lineEdit_textChanged(const QString & arg1)
{
#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
	auto baseStr = QRegularExpression::wildcardToRegularExpression(arg1, QRegularExpression::UnanchoredWildcardConversion);
#else
	auto baseStr = QRegularExpression::wildcardToRegularExpression(arg1);
	//Hack due to lack QRegularExpression::UnanchoredWildcardConversion in Qt5
	baseStr.chop(3);
	baseStr.remove(0,5);
#endif
	QRegularExpression regExp{baseStr, QRegularExpression::CaseInsensitiveOption};
	filterModel->setFilterRegularExpression(regExp);
}

void CModListView::on_comboBox_currentIndexChanged(int index)
{
	switch(index)
	{
	case 0:
		filterModel->setTypeFilter(ModStatus::MASK_NONE, ModStatus::MASK_NONE);
		break;
	case 1:
		filterModel->setTypeFilter(ModStatus::MASK_NONE, ModStatus::INSTALLED);
		break;
	case 2:
		filterModel->setTypeFilter(ModStatus::INSTALLED, ModStatus::INSTALLED);
		break;
	case 3:
		filterModel->setTypeFilter(ModStatus::UPDATEABLE, ModStatus::UPDATEABLE);
		break;
	case 4:
		filterModel->setTypeFilter(ModStatus::ENABLED | ModStatus::INSTALLED, ModStatus::ENABLED | ModStatus::INSTALLED);
		break;
	case 5:
		filterModel->setTypeFilter(ModStatus::INSTALLED, ModStatus::ENABLED | ModStatus::INSTALLED);
		break;
	}
}

QStringList CModListView::findInvalidDependencies(QString mod)
{
	QStringList ret;
	for(QString requrement : modModel->getRequirements(mod))
	{
		if(!modModel->hasMod(requrement))
			ret += requrement;
	}
	return ret;
}

QStringList CModListView::findBlockingMods(QString modUnderTest)
{
	QStringList ret;
	auto required = modModel->getRequirements(modUnderTest);

	for(QString name : modModel->getModList())
	{
		auto mod = modModel->getMod(name);

		if(mod.isEnabled())
		{
			// one of enabled mods have requirement (or this mod) marked as conflict
			for(auto conflict : mod.getValue("conflicts").toStringList())
			{
				if(required.contains(conflict))
					ret.push_back(name);
			}
		}
	}

	return ret;
}

QStringList CModListView::findDependentMods(QString mod, bool excludeDisabled)
{
	QStringList ret;
	for(QString modName : modModel->getModList())
	{
		auto current = modModel->getMod(modName);

		if(!current.isInstalled())
			continue;

		if(current.getValue("depends").toStringList().contains(mod))
		{
			if(!(current.isDisabled() && excludeDisabled))
				ret += modName;
		}
	}
	return ret;
}

void CModListView::on_enableButton_clicked()
{
	QString modName = ui->allModsView->currentIndex().data(ModRoles::ModNameRole).toString();

	assert(findBlockingMods(modName).empty());
	assert(findInvalidDependencies(modName).empty());

	for(auto & name : modModel->getRequirements(modName))
	{
		if(modModel->getMod(name).isDisabled())
			manager->enableMod(name);
	}
	checkManagerErrors();
}

void CModListView::on_disableButton_clicked()
{
	QString modName = ui->allModsView->currentIndex().data(ModRoles::ModNameRole).toString();

	if(modModel->hasMod(modName) && modModel->getMod(modName).isEnabled())
		manager->disableMod(modName);

	checkManagerErrors();
}

void CModListView::on_updateButton_clicked()
{
	QString modName = ui->allModsView->currentIndex().data(ModRoles::ModNameRole).toString();

	assert(findInvalidDependencies(modName).empty());

	for(auto & name : modModel->getRequirements(modName))
	{
		auto mod = modModel->getMod(name);
		// update required mod, install missing (can be new dependency)
		if(mod.isUpdateable() || !mod.isInstalled())
			downloadFile(name + ".zip", mod.getValue("download").toString(), "mods");
	}
}

void CModListView::on_uninstallButton_clicked()
{
	QString modName = ui->allModsView->currentIndex().data(ModRoles::ModNameRole).toString();
	// NOTE: perhaps add "manually installed" flag and uninstall those dependencies that don't have it?

	if(modModel->hasMod(modName) && modModel->getMod(modName).isInstalled())
	{
		if(modModel->getMod(modName).isEnabled())
			manager->disableMod(modName);
		manager->uninstallMod(modName);
	}
	checkManagerErrors();
}

void CModListView::on_installButton_clicked()
{
	QString modName = ui->allModsView->currentIndex().data(ModRoles::ModNameRole).toString();

	assert(findInvalidDependencies(modName).empty());

	for(auto & name : modModel->getRequirements(modName))
	{
		auto mod = modModel->getMod(name);
		if(!mod.isInstalled())
			downloadFile(name + ".zip", mod.getValue("download").toString(), "mods");
	}
}

void CModListView::downloadFile(QString file, QString url, QString description)
{
	if(!dlManager)
	{
		dlManager = new CDownloadManager();
		ui->progressWidget->setVisible(true);
		connect(dlManager, SIGNAL(downloadProgress(qint64,qint64)),
			this, SLOT(downloadProgress(qint64,qint64)));

		connect(dlManager, SIGNAL(finished(QStringList,QStringList,QStringList)),
			this, SLOT(downloadFinished(QStringList,QStringList,QStringList)));


		QString progressBarFormat = "Downloading %s%. %p% (%v KB out of %m KB) finished";

		progressBarFormat.replace("%s%", description);
		ui->progressBar->setFormat(progressBarFormat);
	}

	dlManager->downloadFile(QUrl(url), file);
}

void CModListView::downloadProgress(qint64 current, qint64 max)
{
	// display progress, in kilobytes
	ui->progressBar->setValue(current / 1024);
	ui->progressBar->setMaximum(max / 1024);
}

void CModListView::downloadFinished(QStringList savedFiles, QStringList failedFiles, QStringList errors)
{
	QString title = "Download failed";
	QString firstLine = "Unable to download all files.\n\nEncountered errors:\n\n";
	QString lastLine = "\n\nInstall successfully downloaded?";

	// if all files were d/loaded there should be no errors. And on failure there must be an error
	assert(failedFiles.empty() == errors.empty());

	if(savedFiles.empty())
	{
		// no successfully downloaded mods
		QMessageBox::warning(this, title, firstLine + errors.join("\n"), QMessageBox::Ok, QMessageBox::Ok);
	}
	else if(!failedFiles.empty())
	{
		// some mods were not downloaded
		int result = QMessageBox::warning (this, title, firstLine + errors.join("\n") + lastLine,
		                                   QMessageBox::Yes | QMessageBox::No, QMessageBox::No );

		if(result == QMessageBox::Yes)
			installFiles(savedFiles);
	}
	else
	{
		// everything OK
		installFiles(savedFiles);
	}

	// remove progress bar after some delay so user can see that download was complete and not interrupted.
	QTimer::singleShot(1000, this, SLOT(hideProgressBar()));

	dlManager->deleteLater();
	dlManager = nullptr;
}

void CModListView::hideProgressBar()
{
	if(dlManager == nullptr) // it was not recreated meanwhile
	{
		ui->progressWidget->setVisible(false);
		ui->progressBar->setMaximum(0);
		ui->progressBar->setValue(0);
	}
}

void CModListView::installFiles(QStringList files)
{
	QStringList mods;
	QStringList images;

	// TODO: some better way to separate zip's with mods and downloaded repository files
	for(QString filename : files)
	{
		if(filename.endsWith(".zip"))
			mods.push_back(filename);
		if(filename.endsWith(".json"))
			manager->loadRepository(filename);
		if(filename.endsWith(".png"))
			images.push_back(filename);
	}
	if(!mods.empty())
		installMods(mods);

	if(!images.empty())
		loadScreenshots();
}

void CModListView::installMods(QStringList archives)
{
	QStringList modNames;

	for(QString archive : archives)
	{
		// get basename out of full file name
		//                remove path                  remove extension
		QString modName = archive.section('/', -1, -1).section('.', 0, 0);

		modNames.push_back(modName);
	}

	QStringList modsToEnable;

	// disable mod(s), to properly recalculate dependencies, if changed
	for(QString mod : boost::adaptors::reverse(modNames))
	{
		CModEntry entry = modModel->getMod(mod);
		if(entry.isInstalled())
		{
			// enable mod if installed and enabled
			if(entry.isEnabled())
				modsToEnable.push_back(mod);
		}
		else
		{
			// enable mod if m
			if(settings["launcher"]["enableInstalledMods"].Bool())
				modsToEnable.push_back(mod);
		}
	}

	// uninstall old version of mod, if installed
	for(QString mod : boost::adaptors::reverse(modNames))
	{
		if(modModel->getMod(mod).isInstalled())
			manager->uninstallMod(mod);
	}

	for(int i = 0; i < modNames.size(); i++)
		manager->installMod(modNames[i], archives[i]);

	std::function<void(QString)> enableMod;

	enableMod = [&](QString modName)
	{
		auto mod = modModel->getMod(modName);
		if(mod.isInstalled() && !mod.getValue("keepDisabled").toBool())
		{
			if(manager->enableMod(modName))
			{
				for(QString child : modModel->getChildren(modName))
					enableMod(child);
			}
		}
	};

	for(QString mod : modsToEnable)
	{
		enableMod(mod);
	}

	for(QString archive : archives)
		QFile::remove(archive);

	checkManagerErrors();
}

void CModListView::on_refreshButton_clicked()
{
	loadRepositories();
}

void CModListView::on_pushButton_clicked()
{
	delete dlManager;
	dlManager = nullptr;
	hideProgressBar();
}

void CModListView::modelReset()
{
	if(ui->modInfoWidget->isVisible())
		selectMod(filterModel->rowCount() > 0 ? filterModel->index(0, 0) : QModelIndex());
}

void CModListView::checkManagerErrors()
{
	QString errors = manager->getErrors().join('\n');
	if(errors.size() != 0)
	{
		QString title = "Operation failed";
		QString description = "Encountered errors:\n" + errors;
		QMessageBox::warning(this, title, description, QMessageBox::Ok, QMessageBox::Ok);
	}
}

void CModListView::on_tabWidget_currentChanged(int index)
{
	loadScreenshots();
}

void CModListView::loadScreenshots()
{
	if(ui->tabWidget->currentIndex() == 2 && ui->modInfoWidget->isVisible())
	{
		ui->screenshotsList->clear();
		QString modName = ui->allModsView->currentIndex().data(ModRoles::ModNameRole).toString();
		assert(modModel->hasMod(modName)); //should be filtered out by check above

		for(QString & url : modModel->getMod(modName).getValue("screenshots").toStringList())
		{
			// URL must be encoded to something else to get rid of symbols illegal in file names
			auto hashed = QCryptographicHash::hash(url.toUtf8(), QCryptographicHash::Md5);
			auto hashedStr = QString::fromUtf8(hashed.toHex());

			QString fullPath = CLauncherDirs::get().downloadsPath() + '/' + hashedStr + ".png";
			QPixmap pixmap(fullPath);
			if(pixmap.isNull())
			{
				// image file not exists or corrupted - try to redownload
				downloadFile(hashedStr + ".png", url, "screenshots");
			}
			else
			{
				// managed to load cached image
				QIcon icon(pixmap);
				QListWidgetItem * item = new QListWidgetItem(icon, QString(tr("Screenshot %1")).arg(ui->screenshotsList->count() + 1));
				ui->screenshotsList->addItem(item);
			}
		}
	}
}

void CModListView::on_screenshotsList_clicked(const QModelIndex & index)
{
	if(index.isValid())
	{
		QIcon icon = ui->screenshotsList->item(index.row())->icon();
		auto pixmap = icon.pixmap(icon.availableSizes()[0]);
		ImageViewer::showPixmap(pixmap, this);
	}
}

void CModListView::on_showInfoButton_clicked()
{
	showModInfo();
}