#include <iostream>
#include <regex>

#include <QtWidgets/QApplication>
#include <QtGui/QWindow>
#include <QtWidgets/QMainWindow>
#include <QtWebEngineWidgets/QWebEngineView>
#include <QtWidgets/QWidget>
#include <QtWidgets/QLayout>
#include <QtWidgets/QLabel>
#include <QtWidgets/QMenu>
#include <QtGui/QKeyEvent>
#include <QtX11Extras/QX11Info>
#include <X11/Xlib.h>


bool is_valid_url(const std::string & url);
void open_url(const std::string & url);
void search();
void page_scroll(int scroll);
class Main;
void get_window_id();
uint32_t parent_id = 0;

bool is_valid_url(const std::string & url) {
	std::regex r(".*://.*\\..*");
	std::smatch m;

	return std::regex_match(url, m, r);
}

QWebEngineView * web;
Main * view;
Display * dpy;

class Main : public QMainWindow {
	protected:
		void keyPressEvent(QKeyEvent * event) {
			if (event->text() == "o")
				search();
			else if (event->text() == "j")
				page_scroll(20);
			else if (event->text() == "k")
				page_scroll(-20);
			else if (event->text() == "H")
				web->back();
			else if (event->text() == "L")
				web->forward();
			else if (event->text() == "r")
				web->reload();
		}
};

std::string read_from_dmenu() {
	std::string output;

	std::string cmd = "printf '' | dmenu -p 'open: ' -w ";
	cmd += std::to_string(view->winId());

	FILE * f = popen(cmd.c_str(), "r");

	char string[8092] = {0};
	fgets(string, 8092, f);
	fclose(f);

	if (string[0] != 0) {
		output = string;
		output.pop_back();
	}

	return output;
}

void open_url(const std::string & url) {
	web->load(QString::fromStdString(url));
}

void search() {
	auto url = read_from_dmenu();

	if (url.empty())
		return;

	if (is_valid_url(url)) {
		open_url(url);
		return;
	}

	if (is_valid_url("https://" + url)) {
		open_url("https://" + url);
		return;
	}

	open_url("https://duckduckgo.com/?q=" + url);
}

void page_scroll(int scroll) {
	std::string js = "window.scrollBy(0, " + std::to_string(scroll) + ");";
	web->page()->runJavaScript(QString::fromStdString(js));
}

void help(char *arg0) {
	std::cout << arg0 << '\n';
	std::cout << "-e [xid] - embed in other X window\n";
}

int
main(int argc, char **argv) {
	QApplication app(argc, argv);
	view = new Main();
	web = new QWebEngineView();
	std::cout << getenv("WWW_HOME") << '\n';
	web->load(QUrl(getenv("WWW_HOME")));

	if (argc == 3) {
		if (argv[1] == std::string("-e")) {
			dpy = XOpenDisplay(NULL);
			parent_id = std::stoi(argv[2]);
			XReparentWindow(dpy, view->winId(), parent_id, 0, 0);
			XFlush(dpy);
		} else {
			help(argv[0]);
		}
	} else if (argc != 1) {
		help(argv[0]);
	}

	view->show();
	view->setCentralWidget(web);

	web->connect(web, &QWebEngineView::titleChanged, [&](const QString & title) {
			view->setWindowTitle(title);
	});

	if (parent_id != 0) {
		web->setContextMenuPolicy(Qt::CustomContextMenu);
		web->connect(web,
				&QWebEngineView::customContextMenuRequested, [&](){
				auto menu = web->page()->createStandardContextMenu();
				menu->popup(QCursor::pos());
				return menu;
				});
	}

	return app.exec();
}