/********************************************************************
 KWin - the KDE window manager
 This file is part of the KDE project.

Copyright (C) 2014 Martin Gräßlin <mgraesslin@kde.org>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program 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 General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*********************************************************************/
#include "shell_interface.h"
#include "display.h"
#include "surface_interface.h"

#include <QTimer>

namespace KWin
{
namespace WaylandServer
{

static const quint32 s_version = 1;

const struct wl_shell_interface ShellInterface::s_interface = {
    ShellInterface::createSurfaceCallback
};

ShellInterface::ShellInterface(Display *display, QObject *parent)
    : QObject(parent)
    , m_display(display)
    , m_shell(nullptr)
{
}

ShellInterface::~ShellInterface()
{
    destroy();
}

void ShellInterface::create()
{
    Q_ASSERT(!m_shell);
    m_shell = wl_global_create(*m_display, &wl_shell_interface, s_version, this, &ShellInterface::bind);
}

void ShellInterface::destroy()
{
    if (!m_shell) {
        return;
    }
    wl_global_destroy(m_shell);
    m_shell = nullptr;
}

void ShellInterface::bind(wl_client *client, void *data, uint32_t version, uint32_t id)
{
    reinterpret_cast<ShellInterface*>(data)->bind(client, version, id);
}

void ShellInterface::bind(wl_client *client, uint32_t version, uint32_t id)
{
    wl_resource *shell = wl_resource_create(client, &wl_shell_interface, qMin(version, s_version), id);
    if (!shell) {
        wl_client_post_no_memory(client);
        return;
    }
    wl_resource_set_implementation(shell, &ShellInterface::s_interface, this, nullptr);
}

void ShellInterface::createSurfaceCallback(wl_client *client, wl_resource *resource, uint32_t id, wl_resource *surface)
{
    ShellInterface *s = reinterpret_cast<ShellInterface*>(wl_resource_get_user_data(resource));
    s->createSurface(client, wl_resource_get_version(resource), id,
                     reinterpret_cast<SurfaceInterface*>(wl_resource_get_user_data(surface)));
}

void ShellInterface::createSurface(wl_client *client, uint32_t version, uint32_t id, SurfaceInterface *surface)
{
    auto it = std::find_if(m_surfaces.constBegin(), m_surfaces.constEnd(),
        [surface](ShellSurfaceInterface *s) {
            return surface == s->surface();
        }
    );
    if (it != m_surfaces.constBegin()) {
        wl_resource_post_error(surface->surface(), WL_DISPLAY_ERROR_INVALID_OBJECT, "ShellSurface already created");
        return;
    }
    ShellSurfaceInterface *shellSurface = new ShellSurfaceInterface(this, surface);
    m_surfaces << shellSurface;
    connect(shellSurface, &ShellSurfaceInterface::destroyed, this,
        [this, shellSurface] {
            m_surfaces.removeAll(shellSurface);
        }
    );
    shellSurface->create(client, version, id);
    emit surfaceCreated(shellSurface);
}

/*********************************
 * ShellSurfaceInterface
 *********************************/

const struct wl_shell_surface_interface ShellSurfaceInterface::s_interface = {
    ShellSurfaceInterface::pongCallback,
    ShellSurfaceInterface::moveCallback,
    ShellSurfaceInterface::resizeCallback,
    ShellSurfaceInterface::setToplevelCallback,
    ShellSurfaceInterface::setTransientCallback,
    ShellSurfaceInterface::setFullscreenCallback,
    ShellSurfaceInterface::setPopupCalback,
    ShellSurfaceInterface::setMaximizedCallback,
    ShellSurfaceInterface::setTitleCallback,
    ShellSurfaceInterface::setClassCallback
};

ShellSurfaceInterface::ShellSurfaceInterface(ShellInterface *shell, SurfaceInterface *parent)
    : QObject(parent)
    , m_surface(parent)
    , m_shell(shell)
    , m_shellSurface(nullptr)
    , m_client(nullptr)
    , m_clientPid(0)
    , m_clientUser(0)
    , m_clientGroup(0)
    , m_title()
    , m_windowClass(QByteArray())
    , m_pingTimer(new QTimer(this))
    , m_fullscreen(false)
    , m_toplevel(false)
{
    m_pingTimer->setSingleShot(true);
    m_pingTimer->setInterval(1000);
    connect(m_pingTimer, &QTimer::timeout, this, &ShellSurfaceInterface::pingTimeout);
    connect(this, &ShellSurfaceInterface::fullscreenChanged, this,
        [this] (bool fullscreen) {
            if (!fullscreen) {
                return;
            }
            setToplevel(false);
        }
    );
    connect(this, &ShellSurfaceInterface::toplevelChanged, this,
        [this] (bool toplevel) {
            if (!toplevel) {
                return;
            }
            setFullscreen(false);
        }
    );
}

ShellSurfaceInterface::~ShellSurfaceInterface()
{
    if (m_shellSurface) {
        wl_resource_destroy(m_shellSurface);
    }
}

void ShellSurfaceInterface::create(wl_client *client, quint32 version, quint32 id)
{
    Q_ASSERT(!m_client);
    Q_ASSERT(!m_shellSurface);
    m_shellSurface = wl_resource_create(client, &wl_shell_surface_interface, version, id);
    if (!m_shellSurface) {
        wl_client_post_no_memory(client);
        return;
    }
    m_client = client;
    wl_client_get_credentials(m_client, &m_clientPid, &m_clientUser, &m_clientGroup);

    wl_resource_set_implementation(m_shellSurface, &ShellSurfaceInterface::s_interface, this, ShellSurfaceInterface::unbind);
}

void ShellSurfaceInterface::unbind(wl_resource *r)
{
    ShellSurfaceInterface *s = cast(r);
    s->m_shellSurface = nullptr;
    s->deleteLater();
}

void ShellSurfaceInterface::pongCallback(wl_client *client, wl_resource *resource, uint32_t serial)
{
    ShellSurfaceInterface *s = cast(resource);
    Q_ASSERT(client == s->m_client);
    s->pong(serial);
}

void ShellSurfaceInterface::pong(quint32 serial)
{
    if (m_pingTimer->isActive() && serial == m_pingSerial) {
        m_pingTimer->stop();
        emit pongReceived();
    }
}

void ShellSurfaceInterface::ping()
{
    if (m_pingTimer->isActive()) {
        return;
    }
    m_pingSerial = m_shell->display()->nextSerial();
    wl_shell_surface_send_ping(m_shellSurface, m_pingSerial);
    wl_client_flush(m_client);
    m_pingTimer->start();
}

void ShellSurfaceInterface::setPingTimeout(uint msec)
{
    m_pingTimer->setInterval(msec);
}

bool ShellSurfaceInterface::isPinged() const
{
    return m_pingTimer->isActive();
}

void ShellSurfaceInterface::requestSize(const QSize &size)
{
    // TODO: what about the edges?
    wl_shell_surface_send_configure(m_shellSurface, 0, size.width(), size.height());
    wl_client_flush(m_client);
}

void ShellSurfaceInterface::moveCallback(wl_client *client, wl_resource *resource, wl_resource *seat, uint32_t serial)
{
    Q_UNUSED(seat)
    Q_UNUSED(serial)
    ShellSurfaceInterface *s = cast(resource);
    Q_ASSERT(client == s->m_client);
    // TODO: implement
}

void ShellSurfaceInterface::resizeCallback(wl_client *client, wl_resource *resource, wl_resource *seat, uint32_t serial, uint32_t edges)
{
    Q_UNUSED(seat)
    Q_UNUSED(serial)
    Q_UNUSED(edges)
    ShellSurfaceInterface *s = cast(resource);
    Q_ASSERT(client == s->m_client);
    // TODO: implement
}

void ShellSurfaceInterface::setToplevelCallback(wl_client *client, wl_resource *resource)
{
    ShellSurfaceInterface *s = cast(resource);
    Q_ASSERT(client == s->m_client);
    s->setToplevel(true);
}

void ShellSurfaceInterface::setToplevel(bool toplevel)
{
    if (m_toplevel == toplevel) {
        return;
    }
    m_toplevel = toplevel;
    emit toplevelChanged(m_toplevel);
}

void ShellSurfaceInterface::setTransientCallback(wl_client *client, wl_resource *resource, wl_resource *parent,
                                                 int32_t x, int32_t y, uint32_t flags)
{
    Q_UNUSED(parent)
    Q_UNUSED(x)
    Q_UNUSED(y)
    Q_UNUSED(flags)
    ShellSurfaceInterface *s = cast(resource);
    Q_ASSERT(client == s->m_client);
    // TODO: implement
}

void ShellSurfaceInterface::setFullscreenCallback(wl_client *client, wl_resource *resource, uint32_t method,
                                                  uint32_t framerate, wl_resource *output)
{
    Q_UNUSED(method)
    Q_UNUSED(framerate)
    Q_UNUSED(output)
    ShellSurfaceInterface *s = cast(resource);
    Q_ASSERT(client == s->m_client);
    // TODO: add method, framerate and output
    s->setFullscreen(true);
}

void ShellSurfaceInterface::setFullscreen(bool fullscreen)
{
    if (m_fullscreen == fullscreen) {
        return;
    }
    m_fullscreen = fullscreen;
    emit fullscreenChanged(m_fullscreen);
}

void ShellSurfaceInterface::setPopupCalback(wl_client *client, wl_resource *resource, wl_resource *seat, uint32_t serial,
                                            wl_resource *parent, int32_t x, int32_t y, uint32_t flags)
{
    Q_UNUSED(seat)
    Q_UNUSED(serial)
    Q_UNUSED(parent)
    Q_UNUSED(x)
    Q_UNUSED(y)
    Q_UNUSED(flags)
    ShellSurfaceInterface *s = cast(resource);
    Q_ASSERT(client == s->m_client);
    // TODO: implement
}

void ShellSurfaceInterface::setMaximizedCallback(wl_client *client, wl_resource *resource, wl_resource *output)
{
    Q_UNUSED(output)
    ShellSurfaceInterface *s = cast(resource);
    Q_ASSERT(client == s->m_client);
    // TODO: implement
}

void ShellSurfaceInterface::setTitleCallback(wl_client *client, wl_resource *resource, const char *title)
{
    ShellSurfaceInterface *s = cast(resource);
    Q_ASSERT(client == s->m_client);
    s->setTitle(QString::fromUtf8(title));
}

void ShellSurfaceInterface::setTitle(const QString &title)
{
    if (m_title == title) {
        return;
    }
    m_title = title;
    emit titleChanged(m_title);
}

void ShellSurfaceInterface::setClassCallback(wl_client *client, wl_resource *resource, const char *class_)
{
    ShellSurfaceInterface *s = cast(resource);
    Q_ASSERT(client == s->m_client);
    s->setWindowClass(QByteArray(class_));
}

void ShellSurfaceInterface::setWindowClass(const QByteArray &windowClass)
{
    if (m_windowClass == windowClass) {
        return;
    }
    m_windowClass = windowClass;
    emit windowClassChanged(m_windowClass);
}

}
}