#include "xx.h"
#include "xprivate.h"
#include "cvt.h"
#include <QDebug>
#include <QSocketNotifier>

///////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////


static ScreenInfo initScreenInfo(const OutputInfo *oi, const ModeMap &om)
{
	ScreenInfo si;
	si.position = oi->position;
	si.name = oi->modelName;
	si.output = oi->outputName;
	si.isProjector = (oi->outputType == Projector::Yes);
	if (oi->mode != nullptr) {
		si.currentResolution = QSize(QSize(int(oi->mode->width), int(oi->mode->height)));
	}
	for (int i = 0; i < oi->output->nmode; ++i) {
		if (om.contains(oi->output->modes[i])) {
			auto m = om.value(oi->output->modes[i]);
			const QSize size(int(m->width), int(m->height));
			if (!si.modes.contains(size)) {
				si.modes.append(size);
			}
			if (i == 0 && oi->output->npreferred > 0) {
				si.preferredResolution = size;
			}
		}
	}
	return si;
}

ScreenSetup * ScreenSetup::_instance = nullptr;

static int errorHandlerX(Display*)
{
	exit(1);
}

ScreenSetup::ScreenSetup() : a(new XPrivate())
{
	int event_base_return, error_base_return;
	if (!XRRQueryExtension(a->_display, &event_base_return, &error_base_return)) {
		qDebug() << "No XRANDR extension found";
		exit(1);
	}
	updateScreenResources();
	XRRSelectInput(a->_display, DefaultRootWindow(a->_display), RROutputChangeNotifyMask);
	//XSync(a->_display, False);
	XSetIOErrorHandler((XIOErrorHandler) errorHandlerX);
	_socketNotifier = new QSocketNotifier(qintptr(ConnectionNumber(a->_display)), QSocketNotifier::Read);
	connect(_socketNotifier, &QSocketNotifier::activated, [=](int) {
		XEvent ev;
		qDebug() << "Socket Event";
		while (XPending(a->_display) > 0) {
			XNextEvent(a->_display, &ev);
			if (ev.type - event_base_return != RRNotify) {
				qDebug() << "Received unknown X event";
				continue;
			}
			qDebug() << "Got Change Event";
			XRROutputChangeNotifyEvent *oce = reinterpret_cast<XRROutputChangeNotifyEvent*>(&ev);
			XRRScreenResources *sr = XRRGetScreenResources(oce->display, oce->window);
			if (sr == nullptr) {
				emit outputConfigChanged(ConnectionEvent::Unknown);
				continue;
			}
			XRROutputInfo *oi = XRRGetOutputInfo(a->_display, sr, oce->output);
			if (oi == nullptr) {
				XRRFreeScreenResources(sr);
				emit outputConfigChanged(ConnectionEvent::Unknown);
				continue;
			}
			if (oi->connection == RR_Connected) {
				emit outputConfigChanged(ConnectionEvent::Connected);
			} else if (oi->connection == RR_Disconnected) {
				emit outputConfigChanged(ConnectionEvent::Disconnected);
			} else {
				emit outputConfigChanged(ConnectionEvent::Unknown);
			}
			XRRFreeOutputInfo(oi);
			XRRFreeScreenResources(sr);
		}
	});


}

static double toVertRefresh(const XRRModeInfo *mode)
{
	if (mode->hTotal > 0 && mode->vTotal > 0)
		return (double(mode->dotClock) /	(double(mode->hTotal) * double(mode->vTotal)));
	return 0;
}

//___________________________________________________________________________
void ScreenSetup::updateScreenResources()
{
	a->updateScreenResources();
}

QMap<QString, ScreenInfo> ScreenSetup::getScreenPositions() const
{
	QMap<QString, ScreenInfo> ret;
	for (auto oi : a->_outputMap) {
		ret.insert(oi->outputName, initScreenInfo(oi, a->_modeMap));
	}
	return ret;
}

/**
 * Create common modes and add them to all outputs.
 * Make sure every output has some variant of the most commonly
 * used modes.
 */
void ScreenSetup::initModes()
{
	// First copy typical resolutions to all outputs
#define RES(x,y) (((y) << 16) | (x))
	QSet<quint32> wanted;
	wanted << RES(1280, 720) << RES(1280, 800) << RES(1920, 1080);
	for (XRRModeInfo *mode : a->_modeMap) {
		if (toVertRefresh(mode) < 58 || toVertRefresh(mode) > 61)
			continue; // Play it safe and consider only those for copying that are 60Hz
		wanted.remove(RES(mode->width, mode->height));
		// Make sure all outputs got it
		for (OutputInfo *info : a->_outputMap) {
			if (a->getOutputModeForResolution(info->output, mode->width, mode->height))
				continue;
			XRRAddOutputMode(a->_display, info->id, mode->id);
		}
	}
#undef RES
	// Create those that no output supported
	for (auto res : wanted) {
		unsigned int x = res & 0xffff;
		unsigned int y = res >> 16;
		createMode(x, y, 60, QString::asprintf("%ux%u", x, y));
	}
	if (!wanted.isEmpty()) {
		updateScreenResources();
	}
	// Finally copy all those the projector supports to other outputs
	for (auto key : a->_outputMap.keys()) {
		OutputInfo *oi = a->_outputMap[key];
		if (oi->outputType == Projector::Yes) {
			a->copyModesToAll(key, oi->output->nmode);
		}
	}
	updateScreenResources();
}

static QSize getTotalSizeHorz(const QList<QSize> &list)
{
	QSize ret(0, 0);
	for (auto e : list) {
		ret.rwidth() += e.width();
		ret.rheight() = qMax(ret.height(), e.height());
	}
	return ret;
}

ScreenMode ScreenSetup::getCurrentMode()
{
	bool notAtOrigin = false;
	for (auto oi : a->_outputMap) {
		if (oi->mode != nullptr) {
			if (oi->crtc->x != 0 || oi->crtc->y != 0) {
				notAtOrigin = true;
			}
		}
	}
	if (a->_outputMap.size() == 1)
		return ScreenMode::Single;
	if (a->_outputMap.size() > 2)
		return ScreenMode::Advanced;
	if (notAtOrigin)
		return ScreenMode::Dual;
	return ScreenMode::Clone;
}

ScreenMode ScreenSetup::setDefaultMode(bool dryRun)
{
	if (a->_outputMap.size() == 1) // Only one output exists, do nothing
		return ScreenMode::Single;
	QMap<QString, OutputInfo*> screenMap;
	QMap<QString, OutputInfo*> projectorMap;
	for (auto o : a->_outputMap) {
		qDebug() << o->outputName << quint32(o->outputType);
		if (o->outputType == Projector::Yes) {
			projectorMap.insert(o->outputName, o);
		} else {
			screenMap.insert(o->outputName, o);
		}
	}
	auto projectors = projectorMap.values();
	auto screens = screenMap.values();
	qDebug() << projectors.size() << "projectors," << screens.size() << "screens.";
	QList<QSize> outputSizes = a->getTotalSize(projectors, screens);
	if (outputSizes.isEmpty())
		return ScreenMode::Advanced; // Dunno lol
	QSize screenSize = getTotalSizeHorz(outputSizes);
	if (!dryRun) {
		a->createCrtcBackup();
		XGrabServer(a->_display);
		a->disconnectAllCrtcs();
		// Set new screen size
		a->setScreenSize(screenSize);
	}

	qDebug() << "Virtual screen size:" << screenSize << "with" << outputSizes.size() << "different screens.";

	int offset = 0;
	for (int i = 0; i < outputSizes.size(); ++i) {
		const QSize &size = outputSizes.at(i);
		if (i < projectors.size()) {
			a->setOutputResolution(projectors.at(i), offset, 0, size, dryRun);
		}
		if (i < screens.size()) {
			a->setOutputResolution(screens.at(i), offset, 0, size, dryRun);
		}
		offset += size.width();
	}
	if (!dryRun) {
		XUngrabServer(a->_display);
		XSync(a->_display, False);
	}
	updateScreenResources(); // Re-Read
	if (outputSizes.size() == 1) // One output size, at least 2 outputs in total -- clone mode
		return ScreenMode::Clone;
	if (outputSizes.size() == 2 && a->_outputMap.size() == 2) // Two outputs, two sizes -- extended
		return ScreenMode::Dual;
	return ScreenMode::Advanced; // Must be more than 2 outputs -> something more involved
}

//___________________________________________________________________________
bool ScreenSetup::createMode(unsigned int resX, unsigned int resY, float refresh, QString name)
{
	QByteArray ba = name.toLocal8Bit();
	mode *mode = vert_refresh(int(resX), int(resY), refresh, 0, 0, 0);
	if (mode == nullptr)
		return false;
	XRRModeInfo m;
	memset(&m, 0, sizeof(m));
	m.width     = static_cast<unsigned int>(mode->hr);
	m.height    = static_cast<unsigned int>(mode->vr);
	m.dotClock  = static_cast<unsigned long>(mode->pclk) * 1000ul * 1000ul;
	m.hSyncStart= static_cast<unsigned int>(mode->hss);
	m.hSyncEnd  = static_cast<unsigned int>(mode->hse);
	m.hTotal    = static_cast<unsigned int>(mode->hfl);
	m.hSkew     = 0;
	m.vSyncStart= static_cast<unsigned int>(mode->vss);
	m.vSyncEnd  = static_cast<unsigned int>(mode->vse);
	m.vTotal    = static_cast<unsigned int>(mode->vfl);
	m.id        = 0;
	m.name      = ba.data();
	m.nameLength= static_cast<unsigned int>(ba.length());
	m.modeFlags     = RR_VSyncPositive | RR_HSyncNegative;
	free(mode);

	for (XRRModeInfo *mode : a->_modeMap) {
		if (mode->width == m.width && mode->height == m.height && mode->dotClock == m.dotClock)
			return true; // Already exists, return true?
	}

	RRMode xid = XRRCreateMode(a->_display, DefaultRootWindow(a->_display), &m);
	qDebug() << "Return value of create was" << xid;
	// Immediately add to all screens
	for (OutputInfo *info : a->_outputMap) {
		XRRAddOutputMode(a->_display, info->id, xid);
	}
	return true;
}

//___________________________________________________________________________
ScreenSetup::~ScreenSetup()
{
	delete a;
}

bool ScreenSetup::setCenteredClone()
{
	a->createCrtcBackup();
	XRRModeInfo *fallback = nullptr;
	for (auto m : a->_modeMap) {
		if (m->width == 1024 && m->height == 768) {
			fallback = m;
			break;
		}
	}
	XGrabServer(a->_display);
	a->disconnectAllCrtcs();
	QSize screenSize;
	bool ok = false;
	for (auto oi : a->_outputMap) {
		auto mode = a->getPreferredMode(oi, fallback);
		if (mode != nullptr) {
			if (mode->width > screenSize.width()) {
				screenSize.setWidth(mode->width);
			}
			if (mode->height > screenSize.height()) {
				screenSize.setHeight(mode->height);
			}
			// TODO: CENTER
			const int x = (screenSize.width() - mode->width) / 2;
			const int y = (screenSize.height() - mode->height) / 2;
			ok = a->setOutputResolution(oi, 0, 0, QSize(int(mode->width), int(mode->height))) || ok;
		}
	}
	a->setScreenSize(screenSize);
	XUngrabServer(a->_display);
	XSync(a->_display, False);
	return ok;
}

bool ScreenSetup::setClone(const QSize &resolution)
{
	a->createCrtcBackup();
	XGrabServer(a->_display);
	a->disconnectAllCrtcs();
	a->setScreenSize(resolution);
	bool ok = false;
	for (auto oi : a->_outputMap) {
		ok = a->setOutputResolution(oi, 0, 0, resolution) || ok;
	}
	XUngrabServer(a->_display);
	XSync(a->_display, False);
	return ok;
}

bool ScreenSetup::setCustom(const QList<QPair<QSize, QList<QString>>> &list)
{
	QList<QSize> sizes;
	for (auto e : list) {
		if (e.second.isEmpty())
			continue;
		sizes.append(e.first);
	}
	if (sizes.isEmpty())
		return false;
	a->createCrtcBackup();
	auto screenSize = getTotalSizeHorz(sizes);
	if (screenSize.isEmpty())
		return false;
	XGrabServer(a->_display);
	a->disconnectAllCrtcs();
	a->setScreenSize(screenSize);
	int x = 0;
	bool ok = false;
	for (auto e : list) {
		if (e.second.isEmpty())
			continue;
		const QSize &res = e.first;
		for (auto outputName : e.second) {
			for (auto oi : a->_outputMap) {
				if (oi->outputName != outputName)
					continue;
				ok = a->setOutputResolution(oi, x, 0, res) || ok;
			}
		}
		x += res.width();
	}
	XUngrabServer(a->_display);
	XSync(a->_display, False);
	return ok;
}

void ScreenSetup::revertChanges()
{
	if (a->_crtcBackup.isEmpty())
		return;
	qDebug() << "Starting revert";
	XGrabServer(a->_display);
	a->disconnectAllCrtcs();
	QSize screenSize;
	for (auto e : a->_crtcBackup) {
		if (e->mode == None || !a->_modeMap.contains(e->mode))
			continue;
		screenSize = screenSize.expandedTo(QSize(e->x + int(a->_modeMap[e->mode]->width), e->y + int(a->_modeMap[e->mode]->height)));
	}
	a->setScreenSize(screenSize);
	for (CrtcMap::iterator it = a->_crtcBackup.begin(); it != a->_crtcBackup.end(); ++it) {
		auto e = it.value();
		if (e->mode == None)
			continue;
		XRRSetCrtcConfig(a->_display, a->_screenResources, it.key(), CurrentTime,
			e->x, e->y, e->mode, e->rotation, e->outputs, e->noutput);
	}
	XUngrabServer(a->_display);
	XSync(a->_display, False);
}

static bool modeBiggerThan(const QSize &a, const QSize &b)
{
	if (a.width() > b.width())
		return true;
	return a.width() == b.width() && a.height() > b.height();
}

ResolutionVector ScreenSetup::getCommonModes() const
{
	QHash<QPair<quint32, quint32>, QSet<RROutput>> matches;
	for (auto oi : a->_outputMap) {
		for (int i = 0; i < oi->output->nmode; ++i) {
			if (!a->_modeMap.contains(oi->output->modes[i]))
				continue;
			const auto mode = a->_modeMap[oi->output->modes[i]];
			const QPair<quint32, quint32> pair = qMakePair(mode->width, mode->height);
			matches[pair].insert(oi->id);
		}
	}
	ResolutionVector ret;
	for (auto it = matches.begin(); it != matches.end(); ++it) {
		if (it.value().size() == a->_outputMap.size()) {
			ret.append(QSize(int(it.key().first), int(it.key().second)));
		}
	}
	qSort(ret.begin(), ret.end(), modeBiggerThan);
	return ret;
}

/**
 * Return number of connected (no active) outputs according to last query
 */
int ScreenSetup::getOutputCount() const
{
	return a->_outputMap.size();
}

/**
 * Query currently connected number of outputs
 */
int ScreenSetup::queryCurrentOutputCount() const
{
	auto sr = XRRGetScreenResourcesCurrent(a->_display, DefaultRootWindow(a->_display));
	if (sr == nullptr)
		return 0;
	int count = 0;
	for (int i = 0; i < sr->noutput; ++i) {
		XRROutputInfo* info = XRRGetOutputInfo(a->_display, sr, sr->outputs[i]);
		if (info == nullptr)
			continue;
		if (info->connection != RR_Disconnected) {
			count++;
		}
		XRRFreeOutputInfo(info);
	}
	XRRFreeScreenResources(sr);
	return count;
}

const ResolutionVector &ScreenSetup::getVirtualResolutions() const
{
	return a->_resolutions;
}