/* SPDX-FileCopyrightText: 2026 Project Tick
 * SPDX-FileContributor: Project Tick
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 *   MeshMC - A Custom Launcher for Minecraft
 *   Copyright (C) 2026 Project Tick
 *
 *   This program is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

#include "ScreenshotsPage.h"
#include "ui_ScreenshotsPage.h"

#include <QModelIndex>
#include <QMutableListIterator>
#include <QMap>
#include <QSet>
#include <QFileIconProvider>
#include <QFileSystemModel>
#include <QStyledItemDelegate>
#include <QLineEdit>
#include <QRegularExpression>
#include <QEvent>
#include <QPainter>
#include <QClipboard>
#include <QKeyEvent>
#include <QMenu>

#include <Application.h>

#include "ui/dialogs/ProgressDialog.h"
#include "ui/dialogs/CustomMessageBox.h"

#include "net/NetJob.h"
#include "screenshots/ImgurUpload.h"
#include "screenshots/ImgurAlbumCreation.h"
#include "tasks/SequentialTask.h"

#include "RWStorage.h"
#include <FileSystem.h>
#include <DesktopServices.h>

typedef RWStorage<QString, QIcon> SharedIconCache;
typedef std::shared_ptr<SharedIconCache> SharedIconCachePtr;

class ThumbnailingResult : public QObject
{
	Q_OBJECT
  public slots:
	inline void emitResultsReady(const QString& path)
	{
		emit resultsReady(path);
	}
	inline void emitResultsFailed(const QString& path)
	{
		emit resultsFailed(path);
	}
  signals:
	void resultsReady(const QString& path);
	void resultsFailed(const QString& path);
};

class ThumbnailRunnable : public QRunnable
{
  public:
	ThumbnailRunnable(QString path, SharedIconCachePtr cache)
	{
		m_path = path;
		m_cache = cache;
	}
	void run()
	{
		QFileInfo info(m_path);
		if (info.isDir())
			return;
		if ((info.suffix().compare("png", Qt::CaseInsensitive) != 0))
			return;
		int tries = 5;
		while (tries) {
			if (!m_cache->stale(m_path))
				return;
			QImage image(m_path);
			if (image.isNull()) {
				QThread::msleep(500);
				tries--;
				continue;
			}
			QImage small;
			if (image.width() > image.height())
				small = image.scaledToWidth(512).scaledToWidth(
					256, Qt::SmoothTransformation);
			else
				small = image.scaledToHeight(512).scaledToHeight(
					256, Qt::SmoothTransformation);
			QPoint offset((256 - small.width()) / 2,
						  (256 - small.height()) / 2);
			QImage square(QSize(256, 256), QImage::Format_ARGB32);
			square.fill(Qt::transparent);

			QPainter painter(&square);
			painter.drawImage(offset, small);
			painter.end();

			QIcon icon(QPixmap::fromImage(square));
			m_cache->add(m_path, icon);
			m_resultEmitter.emitResultsReady(m_path);
			return;
		}
		m_resultEmitter.emitResultsFailed(m_path);
	}
	QString m_path;
	SharedIconCachePtr m_cache;
	ThumbnailingResult m_resultEmitter;
};

// this is about as elegant and well written as a bag of bricks with scribbles
// done by insane asylum patients.
class FilterModel : public QIdentityProxyModel
{
	Q_OBJECT
  public:
	explicit FilterModel(QObject* parent = 0) : QIdentityProxyModel(parent)
	{
		m_thumbnailingPool.setMaxThreadCount(4);
		m_thumbnailCache = std::make_shared<SharedIconCache>();
		m_thumbnailCache->add("placeholder", APPLICATION->getThemedIcon(
												 "screenshot-placeholder"));
		connect(&watcher, SIGNAL(fileChanged(QString)),
				SLOT(fileChanged(QString)));
		// FIXME: the watched file set is not updated when files are removed
	}
	virtual ~FilterModel()
	{
		m_thumbnailingPool.waitForDone(500);
	}
	virtual QVariant data(const QModelIndex& proxyIndex,
						  int role = Qt::DisplayRole) const
	{
		auto model = sourceModel();
		if (!model)
			return QVariant();
		if (role == Qt::DisplayRole || role == Qt::EditRole) {
			QVariant result =
				sourceModel()->data(mapToSource(proxyIndex), role);
			return result.toString().remove(QRegularExpression("\\.png$"));
		}
		if (role == Qt::DecorationRole) {
			QVariant result = sourceModel()->data(
				mapToSource(proxyIndex), QFileSystemModel::FilePathRole);
			QString filePath = result.toString();
			QIcon temp;
			if (!watched.contains(filePath)) {
				((QFileSystemWatcher&)watcher).addPath(filePath);
				((QSet<QString>&)watched).insert(filePath);
			}
			if (m_thumbnailCache->get(filePath, temp)) {
				return temp;
			}
			if (!m_failed.contains(filePath)) {
				((FilterModel*)this)->thumbnailImage(filePath);
			}
			return (m_thumbnailCache->get("placeholder"));
		}
		return sourceModel()->data(mapToSource(proxyIndex), role);
	}
	virtual bool setData(const QModelIndex& index, const QVariant& value,
						 int role = Qt::EditRole)
	{
		auto model = sourceModel();
		if (!model)
			return false;
		if (role != Qt::EditRole)
			return false;
		// FIXME: this is a workaround for a bug in QFileSystemModel, where it
		// doesn't sort after renames
		{
			((QFileSystemModel*)model)->setNameFilterDisables(true);
			((QFileSystemModel*)model)->setNameFilterDisables(false);
		}
		return model->setData(mapToSource(index), value.toString() + ".png",
							  role);
	}

  private:
	void thumbnailImage(QString path)
	{
		auto runnable = new ThumbnailRunnable(path, m_thumbnailCache);
		connect(&(runnable->m_resultEmitter), SIGNAL(resultsReady(QString)),
				SLOT(thumbnailReady(QString)));
		connect(&(runnable->m_resultEmitter), SIGNAL(resultsFailed(QString)),
				SLOT(thumbnailFailed(QString)));
		((QThreadPool&)m_thumbnailingPool).start(runnable);
	}
  private slots:
	void thumbnailReady(QString path)
	{
		emit layoutChanged();
	}
	void thumbnailFailed(QString path)
	{
		m_failed.insert(path);
	}
	void fileChanged(QString filepath)
	{
		m_thumbnailCache->setStale(filepath);
		thumbnailImage(filepath);
		// reinsert the path...
		watcher.removePath(filepath);
		watcher.addPath(filepath);
	}

  private:
	SharedIconCachePtr m_thumbnailCache;
	QThreadPool m_thumbnailingPool;
	QSet<QString> m_failed;
	QSet<QString> watched;
	QFileSystemWatcher watcher;
};

class CenteredEditingDelegate : public QStyledItemDelegate
{
  public:
	explicit CenteredEditingDelegate(QObject* parent = 0)
		: QStyledItemDelegate(parent)
	{
	}
	virtual ~CenteredEditingDelegate() {}
	virtual QWidget* createEditor(QWidget* parent,
								  const QStyleOptionViewItem& option,
								  const QModelIndex& index) const
	{
		auto widget = QStyledItemDelegate::createEditor(parent, option, index);
		auto foo = dynamic_cast<QLineEdit*>(widget);
		if (foo) {
			foo->setAlignment(Qt::AlignHCenter);
			foo->setFrame(true);
			foo->setMaximumWidth(192);
		}
		return widget;
	}
};

ScreenshotsPage::ScreenshotsPage(QString path, QWidget* parent)
	: QMainWindow(parent), ui(new Ui::ScreenshotsPage)
{
	m_model.reset(new QFileSystemModel());
	m_filterModel.reset(new FilterModel());
	m_filterModel->setSourceModel(m_model.get());
	m_model->setFilter(QDir::Files | QDir::Writable | QDir::Readable);
	m_model->setReadOnly(false);
	m_model->setNameFilters({"*.png"});
	m_model->setNameFilterDisables(false);
	m_folder = path;
	m_valid = FS::ensureFolderPathExists(m_folder);

	ui->setupUi(this);
	ui->toolBar->insertSpacer(ui->actionView_Folder);

	ui->listView->setIconSize(QSize(128, 128));
	ui->listView->setGridSize(QSize(192, 160));
	ui->listView->setSpacing(9);
	// ui->listView->setUniformItemSizes(true);
	ui->listView->setLayoutMode(QListView::Batched);
	ui->listView->setViewMode(QListView::IconMode);
	ui->listView->setResizeMode(QListView::Adjust);
	ui->listView->installEventFilter(this);
	ui->listView->setEditTriggers(QAbstractItemView::NoEditTriggers);
	ui->listView->setItemDelegate(new CenteredEditingDelegate(this));
	ui->listView->setContextMenuPolicy(Qt::CustomContextMenu);
	connect(ui->listView, &QListView::customContextMenuRequested, this,
			&ScreenshotsPage::ShowContextMenu);
	connect(ui->listView, SIGNAL(activated(QModelIndex)),
			SLOT(onItemActivated(QModelIndex)));
}

bool ScreenshotsPage::eventFilter(QObject* obj, QEvent* evt)
{
	if (obj != ui->listView)
		return QWidget::eventFilter(obj, evt);
	if (evt->type() != QEvent::KeyPress) {
		return QWidget::eventFilter(obj, evt);
	}
	QKeyEvent* keyEvent = static_cast<QKeyEvent*>(evt);
	switch (keyEvent->key()) {
		case Qt::Key_Delete:
			on_actionDelete_triggered();
			return true;
		case Qt::Key_F2:
			on_actionRename_triggered();
			return true;
		default:
			break;
	}
	return QWidget::eventFilter(obj, evt);
}

ScreenshotsPage::~ScreenshotsPage()
{
	delete ui;
}

void ScreenshotsPage::ShowContextMenu(const QPoint& pos)
{
	auto menu = ui->toolBar->createContextMenu(this, tr("Context menu"));
	menu->exec(ui->listView->mapToGlobal(pos));
	delete menu;
}

QMenu* ScreenshotsPage::createPopupMenu()
{
	QMenu* filteredMenu = QMainWindow::createPopupMenu();
	filteredMenu->removeAction(ui->toolBar->toggleViewAction());
	return filteredMenu;
}

void ScreenshotsPage::onItemActivated(QModelIndex index)
{
	if (!index.isValid())
		return;
	auto info = m_model->fileInfo(index);
	QString fileName = info.absoluteFilePath();
	DesktopServices::openFile(info.absoluteFilePath());
}

void ScreenshotsPage::on_actionView_Folder_triggered()
{
	DesktopServices::openDirectory(m_folder, true);
}

void ScreenshotsPage::on_actionUpload_triggered()
{
	auto selection = ui->listView->selectionModel()->selectedRows();
	if (selection.isEmpty())
		return;

	QList<ScreenShot::Ptr> uploaded;
	auto job =
		NetJob::Ptr(new NetJob("Screenshot Upload", APPLICATION->network()));
	if (selection.size() < 2) {
		auto item = selection.at(0);
		auto info = m_model->fileInfo(item);
		auto screenshot = std::make_shared<ScreenShot>(info);
		job->addNetAction(ImgurUpload::make(screenshot));

		m_uploadActive = true;
		ProgressDialog dialog(this);

		if (dialog.execWithTask(job.get()) != QDialog::Accepted) {
			CustomMessageBox::selectable(
				this, tr("Failed to upload screenshots!"), tr("Unknown error"),
				QMessageBox::Warning)
				->exec();
		} else {
			auto link = screenshot->m_url;
			QClipboard* clipboard = QApplication::clipboard();
			clipboard->setText(link);
			CustomMessageBox::selectable(
				this, tr("Upload finished"),
				tr("The <a href=\"%1\">link  to the uploaded screenshot</a> "
				   "has been placed in your clipboard.")
					.arg(link),
				QMessageBox::Information)
				->exec();
		}

		m_uploadActive = false;
		return;
	}

	for (auto item : selection) {
		auto info = m_model->fileInfo(item);
		auto screenshot = std::make_shared<ScreenShot>(info);
		uploaded.push_back(screenshot);
		job->addNetAction(ImgurUpload::make(screenshot));
	}
	SequentialTask task;
	auto albumTask =
		NetJob::Ptr(new NetJob("Imgur Album Creation", APPLICATION->network()));
	auto imgurAlbum = ImgurAlbumCreation::make(uploaded);
	albumTask->addNetAction(imgurAlbum);
	task.addTask(job);
	task.addTask(albumTask);
	m_uploadActive = true;
	ProgressDialog prog(this);
	if (prog.execWithTask(&task) != QDialog::Accepted) {
		CustomMessageBox::selectable(this, tr("Failed to upload screenshots!"),
									 tr("Unknown error"), QMessageBox::Warning)
			->exec();
	} else {
		auto link = QString("https://imgur.com/a/%1").arg(imgurAlbum->id());
		QClipboard* clipboard = QApplication::clipboard();
		clipboard->setText(link);
		CustomMessageBox::selectable(
			this, tr("Upload finished"),
			tr("The <a href=\"%1\">link  to the uploaded album</a> has been "
			   "placed in your clipboard.")
				.arg(link),
			QMessageBox::Information)
			->exec();
	}
	m_uploadActive = false;
}

void ScreenshotsPage::on_actionDelete_triggered()
{
	auto mbox = CustomMessageBox::selectable(
		this, tr("Are you sure?"),
		tr("This will delete all selected screenshots."), QMessageBox::Warning,
		QMessageBox::Yes | QMessageBox::No);
	std::unique_ptr<QMessageBox> box(mbox);

	if (box->exec() != QMessageBox::Yes)
		return;

	auto selected = ui->listView->selectionModel()->selectedIndexes();
	for (auto item : selected) {
		m_model->remove(item);
	}
}

void ScreenshotsPage::on_actionRename_triggered()
{
	auto selection = ui->listView->selectionModel()->selectedIndexes();
	if (selection.isEmpty())
		return;
	ui->listView->edit(selection[0]);
	// TODO: mass renaming
}

void ScreenshotsPage::openedImpl()
{
	if (!m_valid) {
		m_valid = FS::ensureFolderPathExists(m_folder);
	}
	if (m_valid) {
		QString path = QDir(m_folder).absolutePath();
		auto idx = m_model->setRootPath(path);
		if (idx.isValid()) {
			ui->listView->setModel(m_filterModel.get());
			ui->listView->setRootIndex(m_filterModel->mapFromSource(idx));
		} else {
			ui->listView->setModel(nullptr);
		}
	}
}

#include "ScreenshotsPage.moc"