/********************************************************************
Copyright 2015  Martin Gräßlin <mgraesslin@kde.org>

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) version 3, or any
later version accepted by the membership of KDE e.V. (or its
successor approved by the membership of KDE e.V.), which shall
act as a proxy defined in Section 6 of version 3 of the license.

This library 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
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library.  If not, see <http://www.gnu.org/licenses/>.
*********************************************************************/
#include "idle_interface.h"
#include "display.h"
#include "global_p.h"
#include "resource_p.h"
#include "seat_interface.h"

#include <QTimer>

#include <functional>
#include <wayland-server.h>
#include <wayland-idle-server-protocol.h>

namespace KWayland
{
namespace Server
{

class IdleInterface::Private : public Global::Private
{
public:
    Private(IdleInterface *q, Display *d);

    int inhibitCount = 0;
    QVector<IdleTimeoutInterface*> idleTimeouts;

private:
    void bind(wl_client *client, uint32_t version, uint32_t id) override;
    static void getIdleTimeoutCallback(wl_client *client, wl_resource *resource, uint32_t id, wl_resource *seat, uint32_t timeout);

    static void unbind(wl_resource *resource);
    static Private *cast(wl_resource *r) {
        return reinterpret_cast<Private*>(wl_resource_get_user_data(r));
    }

    IdleInterface *q;
    static const struct org_kde_kwin_idle_interface s_interface;
    static const quint32 s_version;
};

class IdleTimeoutInterface::Private : public Resource::Private
{
public:
    Private(SeatInterface *seat, IdleTimeoutInterface *q, IdleInterface *manager, wl_resource *parentResource);
    ~Private();
    void setup(quint32 timeout);

    void simulateUserActivity();

    SeatInterface *seat;
    QTimer *timer = nullptr;

private:
    static void simulateUserActivityCallback(wl_client *client, wl_resource *resource);
    IdleTimeoutInterface *q_func() {
        return reinterpret_cast<IdleTimeoutInterface*>(q);
    }
    static const struct org_kde_kwin_idle_timeout_interface s_interface;
};

const quint32 IdleInterface::Private::s_version = 1;

#ifndef DOXYGEN_SHOULD_SKIP_THIS
const struct org_kde_kwin_idle_interface IdleInterface::Private::s_interface = {
    getIdleTimeoutCallback
};
#endif

IdleInterface::Private::Private(IdleInterface *q, Display *d)
    : Global::Private(d, &org_kde_kwin_idle_interface, s_version)
    , q(q)
{
}

void IdleInterface::Private::getIdleTimeoutCallback(wl_client *client, wl_resource *resource, uint32_t id, wl_resource *seat, uint32_t timeout)
{
    Private *p = cast(resource);
    SeatInterface *s = SeatInterface::get(seat);
    Q_ASSERT(s);
    IdleTimeoutInterface *idleTimeout = new IdleTimeoutInterface(s, p->q, resource);
    idleTimeout->create(p->display->getConnection(client), wl_resource_get_version(resource), id);
    if (!idleTimeout->resource()) {
        wl_resource_post_no_memory(resource);
        delete idleTimeout;
        return;
    }
    p->idleTimeouts << idleTimeout;
    QObject::connect(idleTimeout, &IdleTimeoutInterface::aboutToBeUnbound, p->q, [p, idleTimeout]() {
        p->idleTimeouts.removeOne(idleTimeout);
    });
    idleTimeout->d_func()->setup(timeout);
}

void IdleInterface::Private::bind(wl_client *client, uint32_t version, uint32_t id)
{
    auto c = display->getConnection(client);
    wl_resource *resource = c->createResource(&org_kde_kwin_idle_interface, qMin(version, s_version), id);
    if (!resource) {
        wl_client_post_no_memory(client);
        return;
    }
    wl_resource_set_implementation(resource, &s_interface, this, unbind);
    // TODO: should we track?
}

void IdleInterface::Private::unbind(wl_resource *resource)
{
    Q_UNUSED(resource)
}

IdleInterface::IdleInterface(Display *display, QObject *parent)
    : Global(new Private(this, display), parent)
{
}

IdleInterface::~IdleInterface() = default;

void IdleInterface::inhibit()
{
    Q_D();
    d->inhibitCount++;
    if (d->inhibitCount == 1) {
        emit inhibitedChanged();
    }
}

void IdleInterface::uninhibit()
{
    Q_D();
    d->inhibitCount--;
    if (d->inhibitCount == 0) {
        emit inhibitedChanged();
    }
}

bool IdleInterface::isInhibited() const
{
    Q_D();
    return d->inhibitCount > 0;
}

void IdleInterface::simulateUserActivity()
{
    Q_D();
    for (auto i : qAsConst(d->idleTimeouts)) {
        i->d_func()->simulateUserActivity();
    }
}

IdleInterface::Private *IdleInterface::d_func() const
{
    return reinterpret_cast<Private*>(d.data());
}

#ifndef DOXYGEN_SHOULD_SKIP_THIS
const struct org_kde_kwin_idle_timeout_interface IdleTimeoutInterface::Private::s_interface = {
    resourceDestroyedCallback,
    simulateUserActivityCallback
};
#endif

IdleTimeoutInterface::Private::Private(SeatInterface *seat, IdleTimeoutInterface *q, IdleInterface *manager, wl_resource *parentResource)
    : Resource::Private(q, manager, parentResource, &org_kde_kwin_idle_timeout_interface, &s_interface)
    , seat(seat)
{
}

IdleTimeoutInterface::Private::~Private() = default;

void IdleTimeoutInterface::Private::simulateUserActivityCallback(wl_client *client, wl_resource *resource)
{
    Q_UNUSED(client);
    Private *p = reinterpret_cast<Private*>(wl_resource_get_user_data(resource));
    p->simulateUserActivity();
}

void IdleTimeoutInterface::Private::simulateUserActivity()
{
    if (!timer) {
        // not yet configured
        return;
    }
    if (qobject_cast<IdleInterface*>(global)->isInhibited()) {
        // ignored while inhibited
        return;
    }
    if (!timer->isActive() && resource) {
        org_kde_kwin_idle_timeout_send_resumed(resource);
    }
    timer->start();
}

void IdleTimeoutInterface::Private::setup(quint32 timeout)
{
    if (timer) {
        return;
    }
    timer = new QTimer(q);
    timer->setSingleShot(true);
    // less than 5 sec is not idle by definition
    timer->setInterval(qMax(timeout, 5000u));
    QObject::connect(timer, &QTimer::timeout, q,
        [this] {
            if (resource) {
                org_kde_kwin_idle_timeout_send_idle(resource);
            }
        }
    );
    if (qobject_cast<IdleInterface*>(global)->isInhibited()) {
        // don't start if inhibited
        return;
    }
    timer->start();
}

IdleTimeoutInterface::IdleTimeoutInterface(SeatInterface *seat, IdleInterface *parent, wl_resource *parentResource)
    : Resource(new Private(seat, this, parent, parentResource))
{
    connect(seat, &SeatInterface::timestampChanged, this,
        [this] {
            Q_D();
            d->simulateUserActivity();
        }
    );
    connect(parent, &IdleInterface::inhibitedChanged, this,
        [this] {
            Q_D();
            if (!d->timer) {
                // not yet configured
                return;
            }
            if (qobject_cast<IdleInterface*>(d->global)->isInhibited()) {
                if (!d->timer->isActive() && d->resource) {
                    org_kde_kwin_idle_timeout_send_resumed(d->resource);
                }
                d->timer->stop();
            } else {
                d->timer->start();
            }
        }
    );
}

IdleTimeoutInterface::~IdleTimeoutInterface() = default;

IdleTimeoutInterface::Private *IdleTimeoutInterface::d_func() const
{
    return reinterpret_cast<IdleTimeoutInterface::Private*>(d.data());
}

}
}
