/****************************************************************************
**
** Copyright (C) 2013 Jolla Ltd, author: <robin.burchell@jollamobile.com>
** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL21$
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** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
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** use the contact form at http://qt.digia.com/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 or version 3 as published by the Free
** Software Foundation and appearing in the file LICENSE.LGPLv21 and
** LICENSE.LGPLv3 included in the packaging of this file. Please review the
** following information to ensure the GNU Lesser General Public License
** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
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**
** In addition, as a special exception, Digia gives you certain additional
** rights. These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
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****************************************************************************/


#include <policy/resource.h>
#include <policy/resources.h>
#include <policy/resource-set.h>

#include "resourcepolicyint.h"
#include "resourcepolicyimpl.h"

#include <QMap>
#include <QByteArray>
#include <QString>

static int clientid = 0;

ResourcePolicyInt::ResourcePolicyInt(QObject *parent)
    : QObject(parent)
    , m_acquired(0)
    , m_status(Initial)
    , m_video(0)
    , m_available(false)
    , m_resourceSet(0)
{
    const char *resourceClass = "player";

    QByteArray envVar = qgetenv("NEMO_RESOURCE_CLASS_OVERRIDE");
    if (!envVar.isEmpty()) {
        QString data(envVar);
        // Only allow few resource classes
        if (data == "navigator" ||
            data == "call"      ||
            data == "camera"    ||
            data == "game"      ||
            data == "player"    ||
            data == "event")
            resourceClass = envVar.constData();
    }

#ifdef RESOURCE_DEBUG
    qDebug() << "##### Using resource class " << resourceClass;
#endif

    m_resourceSet = new ResourcePolicy::ResourceSet(resourceClass, this);
    m_resourceSet->setAlwaysReply();

    connect(m_resourceSet, SIGNAL(resourcesGranted(QList<ResourcePolicy::ResourceType>)),
            this, SLOT(handleResourcesGranted()));
    connect(m_resourceSet, SIGNAL(resourcesDenied()),
            this, SLOT(handleResourcesDenied()));
    connect(m_resourceSet, SIGNAL(resourcesReleased()),
            this, SLOT(handleResourcesReleased()));
    connect(m_resourceSet, SIGNAL(lostResources()),
            this, SLOT(handleResourcesLost()));
    connect(m_resourceSet, SIGNAL(resourcesReleasedByManager()),
            this, SLOT(handleResourcesReleasedByManager()));

    connect(m_resourceSet, SIGNAL(resourcesBecameAvailable(const QList<ResourcePolicy::ResourceType>)),
            this, SLOT(handleResourcesBecameAvailable(const QList<ResourcePolicy::ResourceType>)));

    ResourcePolicy::AudioResource *audioResource = new ResourcePolicy::AudioResource(resourceClass);

    audioResource->setProcessID(QCoreApplication::applicationPid());
    audioResource->setStreamTag("media.name", "*");
    m_resourceSet->addResourceObject(audioResource);
    m_resourceSet->update();
}

ResourcePolicyInt::~ResourcePolicyInt()
{
    delete m_resourceSet;
    m_resourceSet = 0;
#ifdef RESOURCE_DEBUG
    qDebug() << "##### Tearing down singleton.";
#endif
}

void ResourcePolicyInt::addClient(ResourcePolicyImpl *client)
{
    clientEntry entry;
    entry.id = clientid++;
    entry.client = client;
    entry.status = Initial;
    entry.videoEnabled = false;
    m_clients.insert(entry.client, entry);
#ifdef RESOURCE_DEBUG
    qDebug() << "##### Add client " << client << " : " << entry.id;
#endif
}

void ResourcePolicyInt::removeClient(ResourcePolicyImpl *client)
{
    QMap<const ResourcePolicyImpl*, clientEntry>::iterator i = m_clients.find(client);
    if (i != m_clients.end()) {
#ifdef RESOURCE_DEBUG
        qDebug() << "##### Remove client " << client << " : " << i.value().id;
#endif
        if (i.value().status == GrantedResource)
            --m_acquired;
        m_clients.erase(i);
    }

    if (m_acquired == 0 && m_status != Initial) {
#ifdef RESOURCE_DEBUG
        qDebug() << "##### Remove client, acquired = 0, release";
#endif
        m_resourceSet->release();
        m_status = Initial;
    }
}

bool ResourcePolicyInt::isVideoEnabled(const ResourcePolicyImpl *client) const
{
    QMap<const ResourcePolicyImpl*, clientEntry>::const_iterator i = m_clients.find(client);
    if (i != m_clients.constEnd())
        return i.value().videoEnabled;

    return false;
}

void ResourcePolicyInt::setVideoEnabled(const ResourcePolicyImpl *client, bool videoEnabled)
{
    bool update = false;

    QMap<const ResourcePolicyImpl*, clientEntry>::iterator i = m_clients.find(client);
    if (i != m_clients.end()) {
        if (videoEnabled == i.value().videoEnabled)
            return;

        if (videoEnabled) {
            if (m_video > 0) {
                i.value().videoEnabled = true;
            } else {
                m_resourceSet->addResource(ResourcePolicy::VideoPlaybackType);
                update = true;
            }
            ++m_video;
        } else {
            --m_video;
            i.value().videoEnabled = false;
            if (m_video == 0) {
                m_resourceSet->deleteResource(ResourcePolicy::VideoPlaybackType);
                update = true;
            }
        }
    }

    if (update)
        m_resourceSet->update();
}

void ResourcePolicyInt::acquire(const ResourcePolicyImpl *client)
{
    QMap<const ResourcePolicyImpl*, clientEntry>::iterator i = m_clients.find(client);
    if (i != m_clients.end()) {
#ifdef RESOURCE_DEBUG
        qDebug() << "##### " << i.value().id << ": ACQUIRE";
#endif
        if (i.value().status == Initial) {

            if (m_status == RequestedResource) {
                i.value().status = RequestedResource;
#ifdef RESOURCE_DEBUG
                qDebug() << "##### " << i.value().id << ": Already requesting, set client as RequestResource and return";
#endif
                return;
            }

            if (m_status == GrantedResource) {
                ++m_acquired;
#ifdef RESOURCE_DEBUG
                qDebug() << "##### " << i.value().id << ": Already granted, set as GrantedResource and return";
#endif
                i.value().status = GrantedResource;
                emit i.value().client->resourcesGranted();
                return;
            }
        } else if (i.value().status == RequestedResource) {
#ifdef RESOURCE_DEBUG
            qDebug() << "##### " << i.value().id << ": Already requesting, return";
#endif
            return;
        } else {
#ifdef RESOURCE_DEBUG
            qDebug() << "##### " << i.value().id << ": Already granted, return ";
#endif
            return;
        }
        i.value().status = RequestedResource;
        m_status = RequestedResource;

#ifdef RESOURCE_DEBUG
        qDebug() << "##### " << i.value().id << ": ACQUIRE call resourceSet->acquire()";
#endif
        // If m_status was Initial this is the first time resources are requested,
        // so let's actually do the acquiring
        m_resourceSet->acquire();
    }
}

void ResourcePolicyInt::release(const ResourcePolicyImpl *client)
{
    QMap<const ResourcePolicyImpl*, clientEntry>::iterator i = m_clients.find(client);
    if (i != m_clients.end()) {
        if (i.value().status == GrantedResource) {
            i.value().status = Initial;
            --m_acquired;
#ifdef RESOURCE_DEBUG
            qDebug() << "##### " << i.value().id << ": RELEASE, acquired (" << m_acquired << ")";
#endif
            emit i.value().client->resourcesReleased();
        }
    }

    if (m_acquired == 0 && m_status != Initial) {
#ifdef RESOURCE_DEBUG
        qDebug() << "##### " << i.value().id << ": RELEASE call resourceSet->release()";
#endif
        m_resourceSet->release();
        m_status = Initial;
    }
}

bool ResourcePolicyInt::isGranted(const ResourcePolicyImpl *client) const
{
    QMap<const ResourcePolicyImpl*, clientEntry>::const_iterator i = m_clients.find(client);
    if (i != m_clients.constEnd()) {
#ifdef RESOURCE_DEBUG
            qDebug() << "##### " << i.value().id << ": IS GRANTED, status: " << i.value().status;
#endif
        return i.value().status == GrantedResource;
    }

    return false;
}

bool ResourcePolicyInt::isAvailable() const
{
#ifdef RESOURCE_DEBUG
            qDebug() << "##### isAvailable " << m_available;
#endif
    return m_available;
}

void ResourcePolicyInt::handleResourcesGranted()
{
    m_status = GrantedResource;
    QMap<const ResourcePolicyImpl*, clientEntry>::iterator i = m_clients.begin();
    while (i != m_clients.end()) {
        if (i.value().status == RequestedResource) {
            ++m_acquired;
#ifdef RESOURCE_DEBUG
            qDebug() << "##### " << i.value().id << ": HANDLE GRANTED, acquired (" << m_acquired << ") emitting resourcesGranted()";
#endif
            i.value().status = GrantedResource;
            emit i.value().client->resourcesGranted();
        }
        ++i;
    }
}

void ResourcePolicyInt::handleResourcesDenied()
{
    m_status = Initial;
    m_acquired = 0;
    QMap<const ResourcePolicyImpl*, clientEntry>::iterator i = m_clients.begin();
    while (i != m_clients.end()) {
        if (i.value().status == RequestedResource) {
#ifdef RESOURCE_DEBUG
            qDebug() << "##### " << i.value().id << ": HANDLE DENIED, acquired (" << m_acquired << ") emitting resourcesDenied()";
#endif
            i.value().status = Initial;
            emit i.value().client->resourcesDenied();
        }
        // Do we need to act for clients that are in granted state?
        ++i;
    }
}

void ResourcePolicyInt::handleResourcesReleased()
{
    m_status = Initial;
    m_acquired = 0;
    QMap<const ResourcePolicyImpl*, clientEntry>::iterator i = m_clients.begin();
    while (i != m_clients.end()) {
        if (i.value().status == GrantedResource) {
#ifdef RESOURCE_DEBUG
            qDebug() << "##### " << i.value().id << ": HANDLE RELEASED, acquired (" << m_acquired << ") emitting resourcesReleased()";
#endif
            i.value().status = Initial;
            emit i.value().client->resourcesReleased();
        }
        ++i;
    }
}

void ResourcePolicyInt::handleResourcesLost()
{
    // If resources were granted switch to acquiring state,
    // so that if the resources are freed elsewhere we
    // will acquire them again properly.
    if (m_status == GrantedResource)
        m_status = RequestedResource;

    m_acquired = 0;

    QMap<const ResourcePolicyImpl*, clientEntry>::iterator i = m_clients.begin();
    while (i != m_clients.end()) {
        if (i.value().status == GrantedResource) {
#ifdef RESOURCE_DEBUG
            qDebug() << "##### " << i.value().id << ": HANDLE LOST, acquired (" << m_acquired << ") emitting resourcesLost()";
#endif
            i.value().status = RequestedResource;
            emit i.value().client->resourcesLost();
        }
        ++i;
    }
}

void ResourcePolicyInt::handleResourcesReleasedByManager()
{
    if (m_status != Initial)
        m_status = Initial;

    m_acquired = 0;

    QMap<const ResourcePolicyImpl*, clientEntry>::iterator i = m_clients.begin();
    while (i != m_clients.end()) {
        if (i.value().status != Initial) {
#ifdef RESOURCE_DEBUG
            qDebug() << "##### " << i.value().id << ": HANDLE RELEASEDBYMANAGER, acquired (" << m_acquired << ") emitting resourcesLost()";
#endif
            i.value().status = Initial;
            emit i.value().client->resourcesLost();
        }
        ++i;
    }
}

void ResourcePolicyInt::handleResourcesBecameAvailable(const QList<ResourcePolicy::ResourceType> &resources)
{
    bool available = false;

    for (int i = 0; i < resources.size(); ++i) {
        if (resources.at(i) == ResourcePolicy::AudioPlaybackType)
            available = true;
    }

    availabilityChanged(available);
}

void ResourcePolicyInt::availabilityChanged(bool available)
{
    if (available == m_available)
        return;

    m_available = available;

    QMap<const ResourcePolicyImpl*, clientEntry>::const_iterator i = m_clients.constBegin();
    while (i != m_clients.constEnd()) {
#ifdef RESOURCE_DEBUG
        qDebug() << "##### " << i.value().id << ": emitting availabilityChanged(" << m_available << ")";
#endif
        emit i.value().client->availabilityChanged(m_available);
        ++i;
    }
}
