mainwindow.cpp

/* Secure Shout Host Oriented Unified Talk
 * Copyright 2015-2018 Rivoreo
 *
 * 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.
 */

#include "common.h"
#include "mainwindow.h"
#include "ui_mainwindow.h"
#ifdef HAVE_OPENSSH_LIBRARY
#include "internalsshclient.h"
#endif
#include "externalsshclient.h"
#include "settingsdialog.h"
#include "connectionwindow.h"
#include "sshout/api.h"
#include "packet.h"
#include "messagelog.h"
#include <QtCore/QSettings>
#include <QtCore/QTimer>
#include <QtCore/QDataStream>
#include <QtCore/QDateTime>
#include <QtCore/QTime>
#include <QtCore/QBuffer>
#include <QtCore/qglobal.h>
#include <QtCore/QUrl>
#include <QtCore/QCryptographicHash>
#include <QtGui/QImage>
#include <QtGui/QClipboard>
#include <QtGui/QTextBlock>
#if QT_VERSION < 0x050000
#include <QtGui/QKeyEvent>
#include <QtGui/QListWidgetItem>
#include <QtGui/QFileDialog>
#include <QtGui/QMessageBox>
#include <QtGui/QScrollBar>
#include <QtGui/QDesktopServices>
#include <QtGui/QDialogButtonBox>
#include <QtGui/QPushButton>
#include <QtGui/QTreeWidget>
#else
#include <QtWidgets/QListWidgetItem>
#include <QtWidgets/QFileDialog>
#include <QtWidgets/QMessageBox>
#include <QKeyEvent>
#include <QScrollBar>
#include <QDesktopServices>
#include <QtWidgets/QTreeWidget>
#include <QtWidgets/QDialogButtonBox>
#include <QtWidgets/QPushButton>
#endif
//#include <QtGui/QRubberBand>
#include <stdio.h>
#include <QtCore/QDebug>

#define appendPlainText append

extern QString config_dir();

MainWindow::MainWindow(QWidget *parent, QSettings *config, const QString &host, quint16 port, const QString &identify_file) :
	QMainWindow(parent),
	ui(new Ui::MainWindow)
{
	ready = false;
	ui->setupUi(this);
	this->config = config;
	//setMouseTracking(true);
#ifdef HAVE_OPENSSH_LIBRARY
	use_internal_ssh_library = config->value("UseInternalSSHLibrary", false).toBool();
	if(use_internal_ssh_library) ssh_client = new InternalSSHClient(this);
	else
#endif
	ssh_client = new ExternalSSHClient(this, config->value("SSHProgramPath", DEFAULT_SSH_PROGRAM_PATH).toString());
#ifndef HAVE_OPENSSH_LIBRARY
	use_internal_ssh_library = false;
#endif
	ssh_client->set_identify_file(identify_file);
	this->host = host;
	this->port = port;
	connect(ssh_client, SIGNAL(state_changed(SSHClient::SSHState)), SLOT(ssh_state_change(SSHClient::SSHState)));
	connect(ssh_client, SIGNAL(readyRead()), SLOT(read_ssh()));
	if(use_internal_ssh_library || config->value("UseSeparateKnownHosts", false).toBool()) {
		QStringList known_hosts = config->value("KnownHosts").toStringList();
		known_hosts.removeAll(QString());
		if(known_hosts.isEmpty()) {
			QMessageBox::critical(this, tr("Configuration Error"), use_internal_ssh_library ?
				tr("Configured to use internal SSH library; but known host list is empty") :
				tr("Configured to use separate known host list; but that list is empty."));
			change_server();
			QMetaObject::invokeMethod(this, "close", Qt::QueuedConnection);
			return;
		}
		known_hosts.removeDuplicates();
		ssh_client->set_known_hosts(known_hosts);
	}
	if(!use_internal_ssh_library) {
		ExternalSSHClient *extern_ssh_client = (ExternalSSHClient *)ssh_client;
		extern_ssh_client->register_ready_read_stderr_slot(this, SLOT(read_ssh_stderr()));
		QString args = config->value("SSHArgs").toString();
		if(!args.isEmpty()) extern_ssh_client->set_extra_args(args.split(' '));
		config->beginGroup("SSHEnvironment");
		QStringList key_list = config->allKeys();
		foreach(const QString &key, key_list) {
			extern_ssh_client->setenv(key, config->value(key).toString());
		}
		config->endGroup();
	}
	send_message_on_enter = config->value("UseEnterToSendMessage", true).toBool();
	ui->action_press_enter_to_send_message->setChecked(send_message_on_enter);
	ui->action_use_html_for_sending_messages->setChecked(config->value("UseHTMLForSendingMessages", false).toBool());
	ui->textEdit_message_to_send->installEventFilter(this);
	control_key_pressed = false;
	ignore_key_event = false;
	need_reconnect = true;
	bool show_user_list = config->value("ShowUserList", true).toBool();
	ui->dockWidget_online_list->setVisible(show_user_list);
	ui->action_show_online_users->setChecked(show_user_list);
	if(show_user_list) {
		QVariant v = config->value("UserListWindowSize");
		if(!v.isNull()) ui->dockWidget_online_list->resize(v.toSize());
	}
	{
		QVariant v = config->value("WindowSize");
		if(!v.isNull()) resize(v.toSize());
	}
	if(config->value("WindowMaximized", false).toBool()) showMaximized();
	ui->textEdit_message_to_send->setFocus();
	data_stream = new QDataStream(ssh_client);
	//data_stream->setByteOrder(QDataStream::BigEndian);
	timer = new QTimer(this);
	timer->setInterval(60000);
	connect(timer, SIGNAL(timeout()), SLOT(send_request_online_users()));
	log_dir = new QDir(QString("%1/logs/%2").arg(config_dir()).arg(host));
	if(!log_dir->mkpath("images")) {
		qWarning("Cannot create image cache directory");
		QMessageBox::warning(this, QString(), tr("Failed to create image cache directory '%1'").arg(log_dir->path()));
	}
	image_cache_dir = new QDir(*log_dir);
	image_cache_dir->cd("images");
	message_log = new MessageLog;
	if(!message_log->open(log_dir->filePath("messages.db"))) {
		qWarning("Cannot open database for log");
		QMessageBox::warning(this, QString(), tr("Failed to open message log database; messages won't be logged"));
	}
	connect(ui->chat_area->verticalScrollBar(), SIGNAL(valueChanged(int)), SLOT(reset_unread_message_count_from_chat_area_vertical_scroll_bar(int)));
	unread_message_count = 0;
	ready = true;
	setAcceptDrops(true);
	update_window_title();
	apply_chat_area_config();
	connect_ssh();
}

MainWindow::~MainWindow()
{
	delete ui;
	delete ssh_client;
	delete data_stream;
	delete timer;
}

void MainWindow::show() {
	if(!ready) return;
	return QWidget::show();
}

void MainWindow::keyPressEvent(QKeyEvent *e) {
	//qDebug("function: MainWindow::keyPressEvent(%p)", e);
	if(focusWidget() == ui->textEdit_message_to_send) {
		bool show_tip = true;
		int key = e->key();
		//qDebug("key = 0x%x", key);
		switch(key) {
			case Qt::Key_Control:
				show_tip = false;
				control_key_pressed = true;
				break;
			case Qt::Key_Enter:
			case Qt::Key_Return:
				show_tip = false;
				if(send_message_on_enter) {
					if(control_key_pressed) ui->textEdit_message_to_send->insertPlainText("\n");
					else send_message();
					ignore_key_event = true;
				} else if(control_key_pressed) {
					send_message();
					ignore_key_event = true;
				}
				break;
			case Qt::Key_Backspace:
				show_tip = false;
				break;
			case Qt::Key_Up:
				if(ui->textEdit_message_to_send->document()->isEmpty()) {
					//qDebug("should dup");
					ui->textEdit_message_to_send->setHtml(last_message_html);
				}
				break;

		}
		if(show_tip) ui->statusbar->showMessage(tr("Press %1 to send").arg(send_message_on_enter ? tr("Enter") : tr("Ctrl-Enter")), 2000);
	}
}

void MainWindow::keyReleaseEvent(QKeyEvent *e) {
	//qDebug("function: MainWindow::keyReleaseEvent(%p)", e);
	if(focusWidget() == ui->textEdit_message_to_send) {
		int key = e->key();
		//qDebug("key = 0x%x", key);
		if(key == Qt::Key_Control) control_key_pressed = false;
	}
}

bool MainWindow::eventFilter(QObject *o, QEvent *e) {
	//qDebug("function: MainWindow::eventFilter(%p, %p)", o, e);
	if(o != ui->textEdit_message_to_send) return QObject::eventFilter(o, e);
	if(e->type() != QEvent::KeyPress) return QObject::eventFilter(o, e);
	keyPressEvent(static_cast<QKeyEvent *>(e));
	if(!ignore_key_event) return false;
	ignore_key_event = false;
	return true;
}

void MainWindow::save_ui_layout() {
	bool show_user_list = ui->dockWidget_online_list->isVisible();
	config->setValue("ShowUserList", show_user_list);
	bool is_maximized = isMaximized();
	config->setValue("WindowMaximized", is_maximized);
	if(!is_maximized) config->setValue("WindowSize", size());
	if(show_user_list) {
		config->setValue("UserListWindowSize", ui->dockWidget_online_list->size());
	}
}

void MainWindow::closeEvent(QCloseEvent *e) {
	need_reconnect = false;
	ssh_client->disconnect();
	message_log->close();
	if(ready) save_ui_layout();
	e->accept();
}

void MainWindow::connect_ssh() {
	if(!ssh_client->connect(host, port, DEFAULT_SSH_USER_NAME, "api")) {
		ui->statusbar->showMessage(tr("Cannot connect"), 10000);
	}
}

/*
QString MainWindow::create_random_hex_string(int len) {
	//char buffer[len * 2];
	QByteArray buffer;
	//buffer.resize(len * 2);
	//int i = 0;
	//while(i < len) {
	while(len-- > 0) {
		//QString::number(qrand() & 0xff, 0x10);
		char n = qrand() & 0xff;
		buffer.append(QByteArray(&n, 1).toHex());
	}
	return QString::fromLatin1(buffer);
}
*/

void MainWindow::print_image(const QByteArray &data, QByteArray &file_name_buffer) {
	QImage image;
	if(!image.loadFromData(data, "JPEG")) {
		ui->chat_area->appendPlainText(tr("[Failed to load image]") + "\n");
		return;
	}

	QString image_file_name;
	QFile image_file;
/*
	do {
		image_file_name = create_random_hex_string(16) + ".jpg";
		image_file.setFileName(image_cache_dir->filePath(image_file_name));
	} while(image_file.exists());
*/
	image_file_name = QCryptographicHash::hash(data, QCryptographicHash::Sha1).toHex() + ".jpg";
	image_file.setFileName(image_cache_dir->filePath(image_file_name));
	if(image_file.exists()) {
		ui->statusbar->showMessage(tr("Image file '%1' is already exist, skipping write").arg(image_file_name), 10000);
	} else {
		if(!image_file.open(QIODevice::WriteOnly)) {
			ui->chat_area->appendPlainText(tr("[Failed to save image, %1]").arg(image_file.errorString()));
			return;
		}
		if(image_file.write(data) < data.length()) {
			ui->chat_area->appendPlainText(tr("[File %1 short write]").arg(image_file_name));
			image_file.close();
			return;
		}
		image_file.close();
	}
	file_name_buffer = image_file_name.toUtf8();
	QUrl url(image_file.fileName());
	url.setScheme("file");
	//qDebug() << url;

	QTextDocument *doc = ui->chat_area->document();
	doc->addResource(QTextDocument::ImageResource, url, image);
	QTextCursor cursor = ui->chat_area->textCursor();
	//cursor.insertImage(image);
	QTextImageFormat image_format;
	image_format.setWidth(image.width());
	image_format.setHeight(image.height());
	image_format.setName(url.toString());
	cursor.movePosition(QTextCursor::End);
	cursor.insertImage(image_format);
	ui->chat_area->setTextCursor(cursor);
}

void MainWindow::print_message(const QDateTime &dt, const QString &msg_from, const QString &msg_to, quint8 msg_type, const QByteArray &message) {
	QTime t = dt.time();
	QString tag = (msg_to.isEmpty() || msg_to == QString("GLOBAL")) ?
		QString("%1 %2").arg(msg_from).arg(t.toString("H:mm:ss")) :
		tr("%1 to %2 %3").arg(msg_from).arg(msg_to).arg(t.toString("H:mm:ss"));
	QScrollBar *chat_area_scroll_bar = ui->chat_area->verticalScrollBar();
	bool should_scroll = chat_area_scroll_bar->value() >= chat_area_scroll_bar->maximum();
	QTextCursor cursor = ui->chat_area->textCursor();
	cursor.movePosition(QTextCursor::End);
	ui->chat_area->setTextCursor(cursor);
	ui->chat_area->insertPlainText("\n");
	QByteArray image_file_name;
	switch(msg_type) {
		case SSHOUT_API_MESSAGE_TYPE_PLAIN:
			ui->chat_area->insertPlainText(tag + "\n" + QString::fromUtf8(message));
			break;
		case SSHOUT_API_MESSAGE_TYPE_RICH:
			ui->chat_area->insertPlainText(tag + "\n");
			ui->chat_area->insertHtml(QString::fromUtf8(message));
			break;
		case SSHOUT_API_MESSAGE_TYPE_IMAGE:
			ui->chat_area->insertPlainText(tag + "\n");
			print_image(message, image_file_name);
			break;
	}
	apply_chat_area_config();
	ui->chat_area->append(QString());
	if(should_scroll) chat_area_scroll_bar->setValue(chat_area_scroll_bar->maximum());
	ui->chat_area->horizontalScrollBar()->setValue(0);
	if(msg_from != my_user_name && (!isActiveWindow() || !should_scroll)) {
		unread_message_count++;
		update_window_title();
		config->beginGroup("Notification");
		if(config->value("UseWindowAlert", false).toBool()) QApplication::alert(this);
		config->endGroup();
	}
	message_log->append_message(dt, msg_from, msg_to, msg_type,
		msg_type == SSHOUT_API_MESSAGE_TYPE_IMAGE ? image_file_name : message);
}

void MainWindow::send_hello() {
	quint32 length = 1 + 6 + 2;
	quint8 type = SSHOUT_API_HELLO;
	quint16 version = 1;
	*data_stream << length;
	*data_stream << type;
	data_stream->writeRawData("SSHOUT", 6);
	*data_stream << version;
}

void MainWindow::send_message(const QString &to_user, quint8 message_type, const QByteArray &message) {
	if(!ssh_client->is_connected()) {
		ui->statusbar->showMessage(tr("Cannot send message, server is not connected"));
		return;
	}
	QByteArray to_user_bytes = to_user.toUtf8();
	if(to_user_bytes.length() > 32) {
		qWarning("MainWindow::send_message: user name too long");
		return;
	}
	quint8 to_user_len = to_user_bytes.length();
	quint32 message_len = message.length();
	quint32 packet_length = 1 + 1 + to_user_len + 1 + 4 + message_len;
	quint8 packet_type = SSHOUT_API_SEND_MESSAGE;
	*data_stream << packet_length;
	*data_stream << packet_type;
	*data_stream << to_user_len;
	data_stream->writeRawData(to_user_bytes.data(), to_user_len);
	*data_stream << message_type;
	*data_stream << message_len;
	data_stream->writeRawData(message.data(), message_len);

}

void MainWindow::send_message() {
	qDebug("slot: MainWindow::send_message()");
	bool use_html = ui->action_use_html_for_sending_messages->isChecked();
	QString message = use_html ? ui->textEdit_message_to_send->toHtml() : ui->textEdit_message_to_send->toPlainText();
	if(message.isEmpty()) return;

	QByteArray message_bytes = message.toUtf8();

	ui->statusbar->showMessage(tr("Sending message"), 1000);
	// TODO: get user name from current selection of user list
	//QString ui->listWidget_online_users->currentItem()
	send_message("GLOBAL", use_html ? SSHOUT_API_MESSAGE_TYPE_RICH : SSHOUT_API_MESSAGE_TYPE_PLAIN, message_bytes);

	last_message_html = ui->textEdit_message_to_send->toHtml();
	ui->textEdit_message_to_send->clear();
}

void MainWindow::send_image(const QImage &image) {
	QDialog preview_dialog(this);
	QVBoxLayout layout(&preview_dialog);
	QLabel image_label(&preview_dialog);
	image_label.setPixmap(QPixmap::fromImage(image));
	layout.addWidget(&image_label);
	QDialogButtonBox button_box(Qt::Horizontal, &preview_dialog);
	button_box.addButton(QDialogButtonBox::Ok)->setFocus();
	button_box.addButton(QDialogButtonBox::Cancel)->setAutoDefault(false);
	layout.addWidget(&button_box);
	preview_dialog.setWindowTitle(tr("Preview"));
	preview_dialog.connect(&button_box, SIGNAL(accepted()), SLOT(accept()));
	preview_dialog.connect(&button_box, SIGNAL(rejected()), SLOT(reject()));
	if(!preview_dialog.exec()) return;
	QByteArray data;
	QBuffer buffer(&data, this);
	buffer.open(QIODevice::WriteOnly);
	int quality = -1;
	if(config->value("OverrideDefaultJPEGQuality", false).toBool()) {
		quality = config->value("JPEGQuality", -1).toInt();
	}
	if(!image.save(&buffer, "JPEG", quality)) {
		QMessageBox::critical(this, QString(), tr("Cannot export the image as JPEG"));
		return;
	}
	buffer.close();
	send_message("GLOBAL", SSHOUT_API_MESSAGE_TYPE_IMAGE, data);
}

void MainWindow::add_user_item(const QString &user_name, QList<UserIdAndHostName> *logins) {
	QListWidgetItem *item;
	QList<QListWidgetItem *> orig_items = ui->listWidget_online_users->findItems(user_name, Qt::MatchFixedString | Qt::MatchCaseSensitive);
	int exists = orig_items.length();
	if(exists) {
		Q_ASSERT(exists == 1);
		item = orig_items[0];
	} else {
		item = new QListWidgetItem(user_name);
		item->setFlags(Qt::ItemIsSelectable | Qt::ItemIsEnabled);
	}
	item->setData((int)Qt::UserRole, QVariant::fromValue((void *)logins));
	if(!exists) ui->listWidget_online_users->addItem(item);
}

void MainWindow::remove_offline_user_items(const QSet<QString> &keep_set) {
	QList<QListWidgetItem *> items = ui->listWidget_online_users->findItems("*", Qt::MatchWildcard);
	//qDebug() << items;
	foreach(QListWidgetItem *i, items) {
		if(keep_set.contains(i->text())) continue;
		delete (QList<UserIdAndHostName> *)i->data((int)Qt::UserRole).value<void *>();
		delete i;
	}
}

void MainWindow::update_user_list(const UserInfo *users, unsigned int count) {
	QSet<QString> user_set;
	QHash<QString, QList<UserIdAndHostName> > user_logins;
	my_user_name.clear();
	for(unsigned int i=0; i<count; i++) {
		const UserInfo *p = users + i;
		if(my_user_name.isEmpty() && p->id == my_id) my_user_name = p->user_name;
		user_set << p->user_name;
		user_logins[p->user_name] << (UserIdAndHostName){ p->id, p->host_name };
	}
	remove_offline_user_items(user_set);
	foreach(const QString &user, user_set) {
		add_user_item(user, new QList<UserIdAndHostName>(user_logins[user]));
	}
}

void MainWindow::send_request_online_users() {
	quint32 length = 1;
	quint8 type = SSHOUT_API_GET_ONLINE_USER;
	*data_stream << length;
	*data_stream << type;
}

void MainWindow::update_user_state(const QString &user, quint8 state) {
	ui->chat_area->appendPlainText(tr("%1 is %2\n").arg(user).arg(state ? tr("joined") : tr("left")));
	if(state) {
		send_request_online_users();
		timer->start();
	} else {
		QList<QListWidgetItem *> items = ui->listWidget_online_users->findItems(user, Qt::MatchFixedString | Qt::MatchCaseSensitive);
		//qDebug() << items;
		if(items.isEmpty()) return;
		Q_ASSERT(items.count() == 1);
		delete (QList<UserIdAndHostName> *)items[0]->data((int)Qt::UserRole).value<void *>();
		delete items[0];
	}
}

void MainWindow::print_error(quint32 error_code, const QString &error_message) {
	qDebug("MainWindow::print_error(%u, const QString &)", (unsigned int)error_code);
	ui->chat_area->appendPlainText(tr("Error from server: %1").arg(error_message) + "\n");
}

void MainWindow::apply_chat_area_config() {
	//qDebug("function: MainWindow::apply_chat_area_config()");
	//qDebug() << ui->chat_area->currentCharFormat().font() << ui->chat_area->currentCharFormat().fontPointSize();
	QVariant font_from_config = config->value("Text/DefaultFontFamily");
	QFont font = font_from_config.isNull() ? ui->chat_area->font() : font_from_config.value<QFont>();
	int font_size = config->value("Text/DefaultFontSize").toInt();
	if(font_size > 0) font.setPointSize(font_size);
	ui->chat_area->setFont(font);
	ui->chat_area->setCurrentCharFormat(QTextCharFormat());
}

void MainWindow::ssh_state_change(SSHClient::SSHState state) {
	qDebug("slot: MainWindow::ssh_state_change(%d)", state);
	switch(state) {
		case SSHClient::DISCONNECTED:
			//ui->statusbar->showMessage(tr("Disconnected"));
			timer->stop();
			if(need_reconnect) QTimer::singleShot(10000, this, SLOT(connect_ssh()));
			break;
		case SSHClient::CONNECTIING:
			if(use_internal_ssh_library) ui->statusbar->showMessage(tr("Connecting"));
			break;
		case SSHClient::AUTHENTICATING:
			if(use_internal_ssh_library) ui->statusbar->showMessage(tr("Authenticating"));
			break;
		case SSHClient::AUTHENTICATED:
			ui->statusbar->showMessage(tr("Connected"));
			send_hello();
			break;
	}
}

void MainWindow::read_ssh() {
	//qDebug("slot: MainWindow::read_ssh()");
	while(ssh_client->bytesAvailable() > 0) {
#if 0
		QByteArray data = sshout_get_packet(ssh_client);
		if(data.isEmpty()) {
			//ssh_client->disconnect();
			return;
		}
#else
		QByteArray data;
		switch(sshout_get_packet(ssh_client, &data)) {
			case SSHOUT_GET_PACKET_SUCCESS:
				break;
			case SSHOUT_GET_PACKET_INCOMPLETE:
				continue;
			case SSHOUT_GET_PACKET_READ_ERROR:
				ssh_client->disconnect();
				return;
			case SSHOUT_GET_PACKET_SHORT_READ:
				ssh_client->disconnect();
				return;
			case SSHOUT_GET_PACKET_TOO_LONG:
				ssh_client->disconnect();
				return;
			case SSHOUT_GET_PACKET_TOO_SHORT:
				ssh_client->disconnect();
				return;
		}
#endif
		QDataStream stream(&data, QIODevice::ReadOnly);
		quint8 packet_type;
		stream >> packet_type;
		switch(packet_type) {
			case SSHOUT_API_PASS:
				qDebug("SSHOUT_API_PASS received");
				if(data.mid(1, 6) != QString("SSHOUT")) {
					qWarning("Magic mismatch");
					ui->chat_area->appendPlainText(tr("Magic mismatch"));
					need_reconnect = false;
					ssh_client->disconnect();
					return;
				}
				stream.skipRawData(6);
				quint16 version;
				stream >> version;
				if(version != 1) {
					qWarning("Version mismatch (%hu != 1)", version);
					ui->chat_area->appendPlainText(tr("Version mismatch (%1 != 1)").arg(version));
					need_reconnect = false;
					ssh_client->disconnect();
					return;
				}
				send_request_online_users();
				timer->start();
				break;
			case SSHOUT_API_ONLINE_USERS_INFO:
				qDebug("SSHOUT_API_ONLINE_USERS_INFO received");
				{
					quint16 my_id;
					stream >> my_id;
					this->my_id = my_id;
					quint16 count;
					stream >> count;
					UserInfo users[count];
					unsigned int i = 0;
					//while(count-- > 0) {
					while(i < count) {
						quint16 id;
						quint8 user_name_len, host_name_len;
						stream >> id;
						stream >> user_name_len;
						char user_name[user_name_len];
						stream.readRawData(user_name, user_name_len);
						stream >> host_name_len;
						char host_name[host_name_len];
						stream.readRawData(host_name, host_name_len);
						UserInfo *p = users + i++;
						p->id = id;
						p->user_name = QString::fromUtf8(user_name, user_name_len);
						p->host_name = QString::fromUtf8(host_name, host_name_len);
					}
					update_user_list(users, count);
				}
				break;
			case SSHOUT_API_RECEIVE_MESSAGE:
				qDebug("SSHOUT_API_RECEIVE_MESSAGE received");
				{
					quint64 time;
					stream >> time;
					quint8 from_user_len;
					stream >> from_user_len;
					if(1 + 8 + 1 + from_user_len + 1 + 1 + 4 > data.length()) {
						qWarning("malformed SSHOUT_API_RECEIVE_MESSAGE packet: from_user_len %hhu too large", from_user_len);
						ssh_client->disconnect();
						return;
					}
					char from_user[from_user_len];
					stream.readRawData(from_user, from_user_len);
					quint8 to_user_len;
					stream >> to_user_len;
					if(1 + 8 + 1 + from_user_len + 1 + to_user_len + 1 + 4 > data.length()) {
						qWarning("malformed SSHOUT_API_RECEIVE_MESSAGE packet: to_user_len %hhu too large", to_user_len);
						ssh_client->disconnect();
						return;
					}
					char to_user[to_user_len];
					stream.readRawData(to_user, to_user_len);
					quint8 msg_type;
					stream >> msg_type;
					quint32 msg_len;
					stream >> msg_len;
					qDebug() << data.length() << time << from_user_len << to_user_len << msg_type;
					if(1 + 8 + 1 + (int)from_user_len + 1 + (int)to_user_len + 1 + 4 + (int)msg_len > data.length()) {
						qWarning("malformed SSHOUT_API_RECEIVE_MESSAGE packet: msg_len %hhu too large", msg_len);
						//ssh_client->disconnect();
						return;
					}
					qDebug() << msg_len;
					print_message(QDateTime::fromTime_t(time),
						      QString::fromUtf8(from_user, from_user_len),
						      QString::fromUtf8(to_user, to_user_len),
						      msg_type,
						      data.mid(1 + 8 + 1 + from_user_len + 1 + to_user_len + 1 + 4, msg_len));
				}
				break;
			case SSHOUT_API_USER_STATE_CHANGE:
				qDebug("SSHOUT_API_USER_STATE_CHANGE received");
				{
					qDebug("length: %d", data.length());
					quint8 state;
					stream >> state;
					quint8 user_name_len;
					stream >> user_name_len;
					if(1 + 1 + 1 + (int)user_name_len > data.length()) {
						qWarning("malformed SSHOUT_API_USER_STATE_CHANGE packet: user_name_len %hhu too large", user_name_len);
						ssh_client->disconnect();
						return;
					}
					update_user_state(QString::fromUtf8(data.mid(3, user_name_len)), state);
				}
				break;
			case SSHOUT_API_ERROR:
				qDebug("SSHOUT_API_ERROR received");
				{
					quint32 error_code;
					stream >> error_code;
					quint32 error_msg_len;
					stream >> error_msg_len;
					if(1 + 4 + 4 + (int)error_msg_len > data.length()) {
						qWarning("malformed SSHOUT_API_ERROR packet: error_msg_len %hhu too large", error_msg_len);
						ssh_client->disconnect();
						return;
					}
					print_error(error_code, QString::fromUtf8(data.mid(9, error_msg_len)));
				}
				break;
			case SSHOUT_API_MOTD:
				qDebug("SSHOUT_API_MOTD received");
				quint32 length;
				stream >> length;
				if(length > (unsigned int)data.length() - 1 - 4) {
					qWarning("malformed packet: member size %u out of packet size %d", length, data.length());
					ssh_client->disconnect();
					return;
				}
				//if(data[5 + length - 1] == '\n') length--;
				if(data[5 + length - 1] != '\n') {
					data.append('\n');
					length++;
				}
				ui->chat_area->append(QString::fromUtf8(data.mid(5, length)));
				break;
		}
	}
}

void MainWindow::read_ssh_stderr() {
	//qDebug("slot: MainWindow::read_ssh_stderr()");
	if(use_internal_ssh_library) return;
	ExternalSSHClient *extern_ssh_client = (ExternalSSHClient *)ssh_client;
	while(extern_ssh_client->can_read_line_from_stderr()) {
		QByteArray data = extern_ssh_client->read_line_from_stderr();
		int len = data.count();
		if(!len) return;
		fputs(data.data(), stderr);
		if(data[len - 1] == '\n') data.resize(len - 1);
		ui->statusbar->showMessage(QString::fromLocal8Bit(data), 10000);
	}
}

void MainWindow::set_send_message_on_enter(bool v) {
	//qDebug("slot: MainWindow::set_send_message_on_enter(%s)", v ? "true" : "false");
	send_message_on_enter = v;
	config->setValue("UseEnterToSendMessage", v);
}

void MainWindow::settings() {
	SettingsDialog d(this, config);
	if(!d.exec()) return;
	apply_chat_area_config();
}

void MainWindow::change_server() {
	ConnectionWindow *w = new ConnectionWindow(NULL, config);
	w->show();
	close();
}

void MainWindow::set_use_html(bool v) {
	config->setValue("UseHTMLForSendingMessages", v);
}

void MainWindow::send_image() {
	QFileDialog d(this, tr("Choose an image to upload"));
	d.setAcceptMode(QFileDialog::AcceptOpen);
	d.setFileMode(QFileDialog::ExistingFile);
	d.setOption(QFileDialog::DontUseNativeDialog);
	if(d.exec()) {
		QString path = d.selectedFiles()[0];
		qDebug() << path;
		QImage image(path);
		if(image.isNull()) {
			QMessageBox::critical(this, QString(), tr("Cannot load file '%1' as an image").arg(path));
			return;
		}
		send_image(image);
	}
}

void MainWindow::open_project_page() {
	QDesktopServices::openUrl(QUrl(PROJECT_PAGE_URL));
}

void MainWindow::show_about() {
	QMessageBox d(this);
	d.setWindowTitle(tr("About"));
	d.setText("<h3>Secure Shout Host Oriented Unified Talk</h3>Copyright 2018 Rivoreo<br/><br/>" +
		tr("This program is free software; you are free to change and redistribute it; see the source for copying conditions.") + "<br/>" +
		tr("There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE."));
	d.exec();
}

void MainWindow::show_chat_area_context_menu(const QPoint &p) {
	//qDebug("slot: MainWindow::show_chat_area_context_menu(QPoint(%d, %d))", p.x(), p.y());
	//QMenu *menu = ui->chat_area->createStandardContextMenu(p);
	QMenu *menu = new QMenu(this);
	QAction *open_image_action = NULL;
	QAction *copy_image_action = NULL;
	QTextCursor cursor = ui->chat_area->cursorForPosition(p);
	if(cursor.block().text() == QString(QChar(0xfffc))) {
		//menu->addAction(tr("&Open image"), this, SLOT(open_image_from_chat_area()));
		//pos_in_chat_area = p;
		//open_image_action = new QAction(tr("&Open image"), this);
		//menu->insertAction(NULL, open_image_action);
		open_image_action = menu->addAction(tr("&Open Image"));
		copy_image_action = menu->addAction(tr("Copy &Image"));
	}
	menu->addAction(tr("&Copy") + "	" + QKeySequence(QKeySequence::Copy).toString(), ui->chat_area, SLOT(copy()))->setEnabled(cursor.hasComplexSelection());
/*
	if(ui->chat_area->interactionFlags() & Qt::LinksAccessibleByKeyboard || (ui->chat_area->interactionFlags() & Qt::LinksAccessibleByMouse)) {
		menu->addAction(tr("Copy &Link Location"), this, SLOT(copy_link_from_chat_area()))->setEnabled(is_url(ui->chat_area, cursor.position()));
	}
*/
	menu->addAction(tr("Select All") + "	" + QKeySequence(QKeySequence::SelectAll).toString(), ui->chat_area, SLOT(selectAll()))->setEnabled(!ui->chat_area->document()->isEmpty());
	QAction *triggered_action = menu->exec(ui->chat_area->mapToGlobal(p));
	if(triggered_action) {
		if(triggered_action == open_image_action) {
			QUrl url(cursor.charFormat().toImageFormat().name());
			ui->statusbar->showMessage(tr("Opening %1").arg(url.toString()), 10000);
			QDesktopServices::openUrl(url);
		} else if(triggered_action == copy_image_action) {
			QUrl url(cursor.charFormat().toImageFormat().name());
			QVariant v = ui->chat_area->document()->resource(QTextDocument::ImageResource, url);
			if(v.isNull()) {
				ui->statusbar->showMessage(tr("Failed to copy image: invalid image"), 10000);
			} else {
				QImage image = v.value<QImage>();
				QApplication::clipboard()->setImage(image);
			}
		}
	}
	//delete open_image_action;
	delete menu;
	//delete current_cursor_in_chat_area;
	//current_cursor_in_chat_area = NULL;
}

void MainWindow::update_window_title() {
	if(unread_message_count) setWindowTitle(QString("[%1] %2 - SSHOUT").arg(unread_message_count).arg(host));
	else setWindowTitle(QString("%1 - SSHOUT").arg(host));
}

void MainWindow::reset_unread_message_count() {
	unread_message_count = 0;
	update_window_title();
}

void MainWindow::reset_unread_message_count_from_chat_area_vertical_scroll_bar(int scroll_bar_value) {
	qDebug("slot: MainWindow::reset_unread_message_count_from_chat_area_vertical_scroll_bar(%d)", scroll_bar_value);
	if(scroll_bar_value < ui->chat_area->verticalScrollBar()->maximum()) return;
	if(!isActiveWindow()) return;
	reset_unread_message_count();
}

void MainWindow::changeEvent(QEvent *e) {
	if(e->type() != QEvent::ActivationChange) return;
	if(!isActiveWindow()) return;
	QScrollBar *chat_area_scroll_bar = ui->chat_area->verticalScrollBar();
	if(chat_area_scroll_bar->value() < chat_area_scroll_bar->maximum()) return;
	reset_unread_message_count();
}

void MainWindow::show_sessions_of_user(QListWidgetItem *item_from_list) {
	//qDebug("slot: MainWindow::show_sessions_of_user(%p)", item_from_list);
	QList<UserIdAndHostName> *sessions = (QList<UserIdAndHostName> *)item_from_list->data(Qt::UserRole).value<void *>();
	if(sessions->isEmpty()) {
		qWarning("MainWindow::show_sessions_of_user: session list empty");
		return;
	}
	QTreeWidget *tree_widget = new QTreeWidget;
	tree_widget->setAttribute(Qt::WA_DeleteOnClose);
	tree_widget->setColumnCount(2);
	tree_widget->setHeaderLabels(QStringList() << "ID" << "Host");
	//int height = tree_widget->header()->height();
	foreach(const UserIdAndHostName &id_and_host_name, *sessions) {
		QTreeWidgetItem *item = new QTreeWidgetItem;
		item->setText(0, QString::number(id_and_host_name.id));
		item->setText(1, id_and_host_name.host_name);
		tree_widget->addTopLevelItem(item);
		qDebug("%d", id_and_host_name.host_name.length());
	}
	//tree_widget->setContextMenuPolicy(Qt::CustomContextMenu);
	//connect(tree_widget, SIGNAL(customContextMenuRequested(QPoint)), SLOT(show_session_list_context_menu(QPoint)));
	tree_widget->setWindowTitle(tr("Active Sessions of User %1").arg(item_from_list->text()));
	tree_widget->resizeColumnToContents(0);
	//tree_widget->resizeColumnToContents(1);
	//int width = tree_widget->columnWidth(0) + tree_widget->columnWidth(1);
	tree_widget->setGeometry(x() + (width() - 240) / 2, y() + (height() - 160) / 2, 240, 160);
	QEventLoop event_loop;
	connect(tree_widget, SIGNAL(destroyed()), &event_loop, SLOT(quit()));
	tree_widget->show();
	event_loop.exec();
	//qDebug("end of MainWindow::show_sessions_of_user");
}

void MainWindow::dragEnterEvent(QDragEnterEvent *e) {
	//qDebug("function: MainWindow::dragEnterEvent(%p)", e);
	const QMimeData *data = e->mimeData();
	//qDebug() << data->hasHtml() << data->hasImage() << data->hasUrls();
	if(!data->hasImage() && !data->hasUrls()) return;
	e->acceptProposedAction();
	ui->statusbar->showMessage(tr("Dropping to send image"));
}

void MainWindow::dragLeaveEvent(QDragLeaveEvent *e) {
	qDebug("function: MainWindow::dragLeaveEvent(%p)", e);
	if(!e->isAccepted()) return;
	//ui->statusbar->clearMessage();
}

void MainWindow::dropEvent(QDropEvent *e) {
	qDebug("function: dropEvent(%p)", e);
	const QMimeData *data = e->mimeData();
	//qDebug() << data->hasHtml() << data->hasImage() << data->hasUrls();
	if(data->hasImage()) send_image(qvariant_cast<QImage>(data->imageData()));
	else if(data->hasUrls()) {
		QUrl url = data->urls()[0];
		if(url.scheme() != QString("file")) {
			ui->statusbar->showMessage(tr("Can't load '%1' as image: only local files are supported").arg(url.toString()), 10000);
			return;
		}
		QImage image(url.toString(QUrl::RemoveScheme));
		if(image.isNull()) {
			QString error_string = tr("Cannot load file '%1' as an image").arg(url.toString());
			ui->statusbar->showMessage(error_string, 10000);
			QMessageBox::critical(this, QString(), error_string);
			return;
		}
		send_image(image);
	}
}