/*
 * Copyright (c) 2015-2017 Alex Spataru <alex_spataru@outlook.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include <QDebug>
#include <QSettings>
#include "QJoysticks.h"
#include "jsbackend/SDL_Joysticks.h"
#include "jsbackend/VirtualJoystick.h"

QJoysticks::QJoysticks()
{
	/* Initialize input methods */
	m_sdlJoysticks = new SDL_Joysticks(this);
	m_virtualJoystick = new VirtualJoystick(this);

	/* Configure SDL joysticks */
	connect(sdlJoysticks(), &SDL_Joysticks::POVEvent, this, &QJoysticks::POVEvent);
	connect(sdlJoysticks(), &SDL_Joysticks::axisEvent, this, &QJoysticks::axisEvent);
	connect(sdlJoysticks(), &SDL_Joysticks::buttonEvent, this, &QJoysticks::buttonEvent);
	connect(sdlJoysticks(), &SDL_Joysticks::countChanged, this, &QJoysticks::updateInterfaces);

	/* Configure virtual joysticks */
	connect(virtualJoystick(), &VirtualJoystick::povEvent, this, &QJoysticks::POVEvent);
	connect(virtualJoystick(), &VirtualJoystick::axisEvent, this, &QJoysticks::axisEvent);
	connect(virtualJoystick(), &VirtualJoystick::buttonEvent, this, &QJoysticks::buttonEvent);
	connect(virtualJoystick(), &VirtualJoystick::enabledChanged, this, &QJoysticks::updateInterfaces);

	/* React to own signals to create QML signals */
	connect(this, &QJoysticks::POVEvent, this, &QJoysticks::onPOVEvent);
	connect(this, &QJoysticks::axisEvent, this, &QJoysticks::onAxisEvent);
	connect(this, &QJoysticks::buttonEvent, this, &QJoysticks::onButtonEvent);

	/* Configure the settings */
	m_sortJoyticks = 0;
	m_settings = new QSettings(qApp->organizationName(), qApp->applicationName());
	m_settings->beginGroup("Blacklisted Joysticks");
}

QJoysticks::~QJoysticks()
{
	delete m_settings;
	delete m_sdlJoysticks;
	delete m_virtualJoystick;
}

/**
 * Returns the one and only instance of this class
 */
QJoysticks *QJoysticks::getInstance()
{
	static QJoysticks joysticks;
	return &joysticks;
}

/**
 * Returns the number of joysticks that are attached to the computer and/or
 * registered with the \c QJoysticks system.
 *
 * \note This count also includes the virtual joystick (if its enabled)
 */
int QJoysticks::count() const
{
	return inputDevices().count();
}

/**
 * Returns the number of joysticks that are not blacklisted.
 * This can be considered the "effective" number of joysticks.
 */
int QJoysticks::nonBlacklistedCount()
{
	int cnt = count();

	for (int i = 0; i < count(); ++i)
		if (isBlacklisted(i))
			--cnt;

	return cnt;
}

/**
 * Returns a list with the names of all registered joystick.
 *
 * \note This list also includes the blacklisted joysticks
 * \note This list also includes the virtual joystick (if its enabled)
 */
QStringList QJoysticks::deviceNames() const
{
	QStringList names;

	foreach (QJoystickDevice *joystick, inputDevices())
		names.append(joystick->name);

	return names;
}

/**
 * Returns the POV value for the given joystick \a index and \a pov ID
 */
int QJoysticks::getPOV(const int index, const int pov)
{
	if (joystickExists(index))
		return getInputDevice(index)->povs.at(pov);

	return -1;
}

/**
 * Returns the axis value for the given joystick \a index and \a axis ID
 */
double QJoysticks::getAxis(const int index, const int axis)
{
	if (joystickExists(index))
		return getInputDevice(index)->axes.at(axis);

	return 0;
}

/**
 * Returns the button value for the given joystick \a index and \a button ID
 */
bool QJoysticks::getButton(const int index, const int button)
{
	if (joystickExists(index))
		return getInputDevice(index)->buttons.at(button);

	return false;
}

/**
 * Returns the number of axes that the joystick at the given \a index has.
 */
int QJoysticks::getNumAxes(const int index)
{
	if (joystickExists(index))
		return getInputDevice(index)->axes.count();

	return -1;
}

/**
 * Returns the number of POVs that the joystick at the given \a index has.
 */
int QJoysticks::getNumPOVs(const int index)
{
	if (joystickExists(index))
		return getInputDevice(index)->povs.count();

	return -1;
}

/**
 * Returns the number of buttons that the joystick at the given \a index has.
 */
int QJoysticks::getNumButtons(const int index)
{
	if (joystickExists(index))
		return getInputDevice(index)->buttons.count();

	return -1;
}

/**
 * Returns \c true if the joystick at the given \a index is blacklisted.
 */
bool QJoysticks::isBlacklisted(const int index)
{
	if (joystickExists(index))
		return inputDevices().at(index)->blacklisted;

	return true;
}

/**
 * Returns \c true if the joystick at the given \a index is valid, otherwise,
 * the function returns \c false and warns the user through the console.
 */
bool QJoysticks::joystickExists(const int index)
{
	return (index >= 0) && (count() > index);
}

/**
 * Returns the name of the given joystick
 */
QString QJoysticks::getName(const int index)
{
	if (joystickExists(index))
		return m_devices.at(index)->name;

	return "Invalid Joystick";
}

/**
 * Returns a pointer to the SDL joysticks system.
 * This can be used if you need to get more information regarding the joysticks
 * registered and managed with SDL.
 */
SDL_Joysticks *QJoysticks::sdlJoysticks() const
{
	return m_sdlJoysticks;
}

/**
 * Returns a pointer to the virtual joystick system.
 * This can be used if you need to get more information regarding the virtual
 * joystick or want to change its properties directly.
 *
 * \note You can also change the properties of the virtual joysticks using the
 *       functions of the \c QJoysticks system class
 */
VirtualJoystick *QJoysticks::virtualJoystick() const
{
	return m_virtualJoystick;
}

/**
 * Returns a pointer to the device at the given \a index.
 */
QJoystickDevice *QJoysticks::getInputDevice(const int index)
{
	if (joystickExists(index))
		return inputDevices().at(index);

	return Q_NULLPTR;
}

/**
 * Returns a pointer to a list containing all registered joysticks.
 * This can be used for advanced hacks or just to get all properties of each
 * joystick.
 */
QList<QJoystickDevice *> QJoysticks::inputDevices() const
{
	return m_devices;
}

/**
 * If \a sort is set to true, then the device list will put all blacklisted
 * joysticks at the end of the list
 */
void QJoysticks::setSortJoysticksByBlacklistState(bool sort)
{
	if (m_sortJoyticks != sort)
	{
		m_sortJoyticks = sort;
		updateInterfaces();
	}
}

/**
 * Blacklists or whitelists the joystick at the given \a index.
 *
 * \note This function does not have effect if the given joystick does not exist
 * \note Once the joystick is blacklisted, the joystick list will be updated
 */
void QJoysticks::setBlacklisted(const int index, bool blacklisted)
{
	Q_ASSERT(joystickExists(index));

	/* Netrualize the joystick */
	if (blacklisted)
	{
		for (int i = 0; i < getNumAxes(index); ++i)
			emit axisChanged(index, i, 0);

		for (int i = 0; i < getNumButtons(index); ++i)
			emit buttonChanged(index, i, false);

		for (int i = 0; i < getNumPOVs(index); ++i)
			emit povChanged(index, i, 0);
	}

	/* See if blacklist value was actually changed */
	bool changed = m_devices.at(index)->blacklisted != blacklisted;

	/* Save settings */
	m_devices.at(index)->blacklisted = blacklisted;
	m_settings->setValue(getName(index), blacklisted);

	/* Re-scan joysticks if blacklist value has changed */
	if (changed)
		updateInterfaces();
}

/**
 * 'Rescans' for new/removed joysticks and registers them again.
 */
void QJoysticks::updateInterfaces()
{
	m_devices.clear();

	/* Put blacklisted joysticks at the bottom of the list */
	if (m_sortJoyticks)
	{
		/* Register non-blacklisted SDL joysticks */
		foreach (QJoystickDevice *joystick, sdlJoysticks()->joysticks())
		{
			joystick->blacklisted = m_settings->value(joystick->name, false).toBool();
			if (!joystick->blacklisted)
				addInputDevice(joystick);
		}

		/* Register the virtual joystick (if its not blacklisted) */
		if (virtualJoystick()->joystickEnabled())
		{
			QJoystickDevice *joystick = virtualJoystick()->joystick();
			joystick->blacklisted = m_settings->value(joystick->name, false).toBool();

			if (!joystick->blacklisted)
			{
				addInputDevice(joystick);
				virtualJoystick()->setJoystickID(inputDevices().count() - 1);
			}
		}

		/* Register blacklisted SDL joysticks */
		foreach (QJoystickDevice *joystick, sdlJoysticks()->joysticks())
		{
			joystick->blacklisted = m_settings->value(joystick->name, false).toBool();
			if (joystick->blacklisted)
				addInputDevice(joystick);
		}

		/* Register the virtual joystick (if its blacklisted) */
		if (virtualJoystick()->joystickEnabled())
		{
			QJoystickDevice *joystick = virtualJoystick()->joystick();
			joystick->blacklisted = m_settings->value(joystick->name, false).toBool();

			if (joystick->blacklisted)
			{
				addInputDevice(joystick);
				virtualJoystick()->setJoystickID(inputDevices().count() - 1);
			}
		}
	}

	/* Sort normally */
	else
	{
		/* Register SDL joysticks */
		foreach (QJoystickDevice *joystick, sdlJoysticks()->joysticks())
		{
			addInputDevice(joystick);
			joystick->blacklisted = m_settings->value(joystick->name, false).toBool();
		}

		/* Register virtual joystick */
		if (virtualJoystick()->joystickEnabled())
		{
			QJoystickDevice *joystick = virtualJoystick()->joystick();
			joystick->blacklisted = m_settings->value(joystick->name, false).toBool();

			addInputDevice(joystick);
			virtualJoystick()->setJoystickID(inputDevices().count() - 1);
		}
	}

	emit countChanged();
}

/**
 * Changes the axis value range of the virtual joystick.
 *
 * Take into account that maximum axis values supported by the \c QJoysticks
 * system is from \c -1 to \c 1.
 */
void QJoysticks::setVirtualJoystickRange(qreal range)
{
	virtualJoystick()->setAxisRange(range);
}

/**
 * Enables or disables the virtual joystick
 */
void QJoysticks::setVirtualJoystickEnabled(bool enabled)
{
	virtualJoystick()->setJoystickEnabled(enabled);
}

void QJoysticks::setVirtualJoystickAxisSensibility(qreal sensibility)
{
	virtualJoystick()->setAxisSensibility(sensibility);
}

/**
 * Removes all the registered joysticks and emits appropriate signals.
 */
void QJoysticks::resetJoysticks()
{
	m_devices.clear();
	emit countChanged();
}

/**
 * Registers the given \a device to the \c QJoysticks system
 */
void QJoysticks::addInputDevice(QJoystickDevice *device)
{
	Q_ASSERT(device);
	m_devices.append(device);
}

/**
 * Configures the QML-friendly signal based on the information given by the
 * \a event data and updates the joystick values
 */
void QJoysticks::onPOVEvent(const QJoystickPOVEvent &e)
{
	if (e.joystick == nullptr)
		return;

	if (!isBlacklisted(e.joystick->id))
	{
		if (e.pov < getInputDevice(e.joystick->id)->povs.count())
		{
			getInputDevice(e.joystick->id)->povs[e.pov] = e.angle;
			emit povChanged(e.joystick->id, e.pov, e.angle);
		}
	}
}

/**
 * Configures the QML-friendly signal based on the information given by the
 * \a event data and updates the joystick values
 */
void QJoysticks::onAxisEvent(const QJoystickAxisEvent &e)
{
	if (e.joystick == nullptr)
		return;

	if (!isBlacklisted(e.joystick->id))
	{
		if (e.axis < getInputDevice(e.joystick->id)->axes.count())
		{
			getInputDevice(e.joystick->id)->axes[e.axis] = e.value;
			emit axisChanged(e.joystick->id, e.axis, e.value);
		}
	}
}

/**
 * Configures the QML-friendly signal based on the information given by the
 * \a event data and updates the joystick values
 */
void QJoysticks::onButtonEvent(const QJoystickButtonEvent &e)
{
	if (e.joystick == nullptr)
		return;

	if (!isBlacklisted(e.joystick->id))
	{
		if (e.button < getInputDevice(e.joystick->id)->buttons.count())
		{
			getInputDevice(e.joystick->id)->buttons[e.button] = e.pressed;
			emit buttonChanged(e.joystick->id, e.button, e.pressed);
		}
	}
}