/****************************************************************************
**
** Copyright (C) 2015 The Qt Company Ltd.
** Contact: http://www.qt.io/licensing/
**
** This file is part of the QtQml module 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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** Alternatively, this file may be used under the terms of the GNU Lesser
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** LICENSE.LGPLv3 included in the packaging of this file. Please review the
** following information to ensure the GNU Lesser General Public License
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**
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** rights. These rights are described in The Qt Company LGPL Exception
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****************************************************************************/

#include "qqmldebugconnection_p.h"
#include "qqmldebugclient_p.h"

#include <private/qpacketprotocol_p.h>
#include <private/qpacket_p.h>
#include <private/qobject_p.h>

#include <QtCore/qeventloop.h>
#include <QtCore/qtimer.h>
#include <QtCore/qdatastream.h>
#include <QtNetwork/qlocalserver.h>
#include <QtNetwork/qlocalsocket.h>
#include <QtNetwork/qtcpsocket.h>

QT_BEGIN_NAMESPACE

static const int protocolVersion = 1;
static const QString serverId = QLatin1String("QDeclarativeDebugServer");
static const QString clientId = QLatin1String("QDeclarativeDebugClient");

class QQmlDebugConnectionPrivate : public QObjectPrivate
{
    Q_DECLARE_PUBLIC(QQmlDebugConnection)

public:
    QQmlDebugConnectionPrivate();
    QPacketProtocol *protocol;
    QIODevice *device;
    QLocalServer *server;
    QEventLoop handshakeEventLoop;
    QTimer handshakeTimer;

    bool gotHello;
    int dataStreamVersion;
    QHash <QString, float> serverPlugins;
    QHash<QString, QQmlDebugClient *> plugins;
    QStringList removedPlugins;

    void advertisePlugins();
    void connectDeviceSignals();
    void flush();
};

QQmlDebugConnectionPrivate::QQmlDebugConnectionPrivate() :
    protocol(0), device(0), server(0), gotHello(false), dataStreamVersion(QDataStream::Qt_5_0)
{
    handshakeTimer.setSingleShot(true);
    handshakeTimer.setInterval(3000);
}

void QQmlDebugConnectionPrivate::advertisePlugins()
{
    Q_Q(QQmlDebugConnection);
    if (!q->isConnected())
        return;

    QPacket pack;
    pack << serverId << 1 << plugins.keys();
    protocol->send(pack);
    flush();
}

void QQmlDebugConnection::socketConnected()
{
    Q_D(QQmlDebugConnection);
    QPacket pack;
    pack << serverId << 0 << protocolVersion << d->plugins.keys() << d->dataStreamVersion;
    d->protocol->send(pack);
    d->flush();
}

void QQmlDebugConnection::socketDisconnected()
{
    Q_D(QQmlDebugConnection);
    d->gotHello = false;
}

void QQmlDebugConnection::protocolReadyRead()
{
    Q_D(QQmlDebugConnection);
    if (!d->gotHello) {
        QPacket pack = d->protocol->read();
        QString name;

        pack >> name;

        bool validHello = false;
        if (name == clientId) {
            int op = -1;
            pack >> op;
            if (op == 0) {
                int version = -1;
                pack >> version;
                if (version == protocolVersion) {
                    QStringList pluginNames;
                    QList<float> pluginVersions;
                    pack >> pluginNames;
                    if (!pack.atEnd())
                        pack >> pluginVersions;

                    const int pluginNamesSize = pluginNames.size();
                    const int pluginVersionsSize = pluginVersions.size();
                    for (int i = 0; i < pluginNamesSize; ++i) {
                        float pluginVersion = 1.0;
                        if (i < pluginVersionsSize)
                            pluginVersion = pluginVersions.at(i);
                        d->serverPlugins.insert(pluginNames.at(i), pluginVersion);
                    }

                    pack >> d->dataStreamVersion;
                    validHello = true;
                }
            }
        }

        if (!validHello) {
            qWarning("QQmlDebugConnection: Invalid hello message");
            QObject::disconnect(d->protocol, SIGNAL(protocolReadyRead()), this, SLOT(protocolReadyRead()));
            return;
        }
        d->gotHello = true;
        emit connected();

        QHash<QString, QQmlDebugClient *>::Iterator iter = d->plugins.begin();
        for (; iter != d->plugins.end(); ++iter) {
            QQmlDebugClient::State newState = QQmlDebugClient::Unavailable;
            if (d->serverPlugins.contains(iter.key()))
                newState = QQmlDebugClient::Enabled;
            iter.value()->stateChanged(newState);
        }

        d->handshakeTimer.stop();
        d->handshakeEventLoop.quit();
    }

    while (d->protocol->packetsAvailable()) {
        QPacket pack = d->protocol->read();
        QString name;
        pack >> name;

        if (name == clientId) {
            int op = -1;
            pack >> op;

            if (op == 1) {
                // Service Discovery
                QHash<QString, float> oldServerPlugins = d->serverPlugins;
                d->serverPlugins.clear();

                QStringList pluginNames;
                QList<float> pluginVersions;
                pack >> pluginNames;
                if (!pack.atEnd())
                    pack >> pluginVersions;

                const int pluginNamesSize = pluginNames.size();
                const int pluginVersionsSize = pluginVersions.size();
                for (int i = 0; i < pluginNamesSize; ++i) {
                    float pluginVersion = 1.0;
                    if (i < pluginVersionsSize)
                        pluginVersion = pluginVersions.at(i);
                    d->serverPlugins.insert(pluginNames.at(i), pluginVersion);
                }

                QHash<QString, QQmlDebugClient *>::Iterator iter = d->plugins.begin();
                for (; iter != d->plugins.end(); ++iter) {
                    const QString pluginName = iter.key();
                    QQmlDebugClient::State newSate = QQmlDebugClient::Unavailable;
                    if (d->serverPlugins.contains(pluginName))
                        newSate = QQmlDebugClient::Enabled;

                    if (oldServerPlugins.contains(pluginName)
                            != d->serverPlugins.contains(pluginName)) {
                        iter.value()->stateChanged(newSate);
                    }
                }
            } else {
                qWarning() << "QQmlDebugConnection: Unknown control message id" << op;
            }
        } else {
            QByteArray message;
            pack >> message;

            QHash<QString, QQmlDebugClient *>::Iterator iter = d->plugins.find(name);
            if (iter == d->plugins.end()) {
                // We can get more messages for plugins we have removed because it takes time to
                // send the advertisement message but the removal is instant locally.
                if (!d->removedPlugins.contains(name))
                    qWarning() << "QQmlDebugConnection: Message received for missing plugin"
                               << name;
            } else {
                (*iter)->messageReceived(message);
            }
        }
    }
}

void QQmlDebugConnection::handshakeTimeout()
{
    Q_D(QQmlDebugConnection);
    if (!d->gotHello) {
        qWarning() << "QQmlDebugConnection: Did not get handshake answer in time";
        d->handshakeEventLoop.quit();
    }
}

QQmlDebugConnection::QQmlDebugConnection(QObject *parent) :
    QObject(*(new QQmlDebugConnectionPrivate), parent)
{
    Q_D(QQmlDebugConnection);
    connect(&d->handshakeTimer, SIGNAL(timeout()), this, SLOT(handshakeTimeout()));
}

QQmlDebugConnection::~QQmlDebugConnection()
{
    Q_D(QQmlDebugConnection);
    QHash<QString, QQmlDebugClient*>::iterator iter = d->plugins.begin();
    for (; iter != d->plugins.end(); ++iter)
        iter.value()->stateChanged(QQmlDebugClient::NotConnected);
}

void QQmlDebugConnection::setDataStreamVersion(int dataStreamVersion)
{
    Q_D(QQmlDebugConnection);
    d->dataStreamVersion = dataStreamVersion;
}

int QQmlDebugConnection::dataStreamVersion()
{
    Q_D(QQmlDebugConnection);
    return d->dataStreamVersion;
}

bool QQmlDebugConnection::isConnected() const
{
    Q_D(const QQmlDebugConnection);
    return d->gotHello;
}

void QQmlDebugConnection::close()
{
    Q_D(QQmlDebugConnection);
    if (d->gotHello) {
        d->gotHello = false;
        d->device->close();

        QHash<QString, QQmlDebugClient*>::iterator iter = d->plugins.begin();
        for (; iter != d->plugins.end(); ++iter)
            iter.value()->stateChanged(QQmlDebugClient::NotConnected);
    }

    if (d->device) {
        d->device->deleteLater();
        d->device = 0;
    }
}

bool QQmlDebugConnection::waitForConnected(int msecs)
{
    Q_D(QQmlDebugConnection);
    QAbstractSocket *socket = qobject_cast<QAbstractSocket*>(d->device);
    if (!socket) {
        if (!d->server || (!d->server->hasPendingConnections() &&
                           !d->server->waitForNewConnection(msecs)))
            return false;
    } else if (!socket->waitForConnected(msecs)) {
        return false;
    }
    // wait for handshake
    d->handshakeTimer.start();
    d->handshakeEventLoop.exec();
    return d->gotHello;
}

QQmlDebugClient *QQmlDebugConnection::client(const QString &name) const
{
    Q_D(const QQmlDebugConnection);
    return d->plugins.value(name, 0);
}

bool QQmlDebugConnection::addClient(const QString &name, QQmlDebugClient *client)
{
    Q_D(QQmlDebugConnection);
    if (d->plugins.contains(name))
        return false;
    d->removedPlugins.removeAll(name);
    d->plugins.insert(name, client);
    d->advertisePlugins();
    return true;
}

bool QQmlDebugConnection::removeClient(const QString &name)
{
    Q_D(QQmlDebugConnection);
    if (!d->plugins.contains(name))
        return false;
    d->plugins.remove(name);
    d->removedPlugins.append(name);
    d->advertisePlugins();
    return true;
}

float QQmlDebugConnection::serviceVersion(const QString &serviceName) const
{
    Q_D(const QQmlDebugConnection);
    return d->serverPlugins.value(serviceName, -1);
}

bool QQmlDebugConnection::sendMessage(const QString &name, const QByteArray &message)
{
    Q_D(QQmlDebugConnection);
    if (!isConnected() || !d->serverPlugins.contains(name))
        return false;

    QPacket pack;
    pack << name << message;
    d->protocol->send(pack);
    d->flush();

    return true;
}

void QQmlDebugConnectionPrivate::flush()
{
    QAbstractSocket *socket = qobject_cast<QAbstractSocket*>(device);
    if (socket)
        socket->flush();
}

void QQmlDebugConnection::connectToHost(const QString &hostName, quint16 port)
{
    Q_D(QQmlDebugConnection);
    if (d->gotHello)
        close();
    QTcpSocket *socket = new QTcpSocket(this);
    d->device = socket;
    d->connectDeviceSignals();
    connect(socket, SIGNAL(connected()), this, SLOT(socketConnected()));
    connect(socket, SIGNAL(disconnected()), this, SLOT(socketDisconnected()));
    socket->connectToHost(hostName, port);
}

void QQmlDebugConnection::startLocalServer(const QString &fileName)
{
    Q_D(QQmlDebugConnection);
    if (d->gotHello)
        close();
    if (d->server)
        d->server->deleteLater();
    d->server = new QLocalServer(this);
    // QueuedConnection so that waitForNewConnection() returns true.
    connect(d->server, SIGNAL(newConnection()), this, SLOT(newConnection()), Qt::QueuedConnection);
    d->server->listen(fileName);
}

void QQmlDebugConnection::newConnection()
{
    Q_D(QQmlDebugConnection);
    delete d->device;
    QLocalSocket *socket = d->server->nextPendingConnection();
    d->server->close();
    d->device = socket;
    d->connectDeviceSignals();
    socketConnected();
}

void QQmlDebugConnectionPrivate::connectDeviceSignals()
{
    Q_Q(QQmlDebugConnection);
    delete protocol;
    protocol = new QPacketProtocol(device, q);
    QObject::connect(protocol, SIGNAL(readyRead()), q, SLOT(protocolReadyRead()));
    QObject::connect(device, SIGNAL(disconnected()), q, SLOT(socketDisconnected()));
}

QT_END_NAMESPACE