/****************************************************************************
**
** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the QtNetwork module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** 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.
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** 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 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
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** 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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** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
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****************************************************************************/

#include "qnetworkaccessbackend_p.h"
#include "qnetworkaccessmanager_p.h"
#include "qnetworkrequest.h"
#include "qnetworkreply.h"
#include "qnetworkreply_p.h"
#include "QtCore/qhash.h"
#include "QtCore/qmutex.h"

#include "qnetworkaccesscachebackend_p.h"
#include "qabstractnetworkcache.h"

QT_BEGIN_NAMESPACE

static bool factoryDataShutdown = false;
class QNetworkAccessBackendFactoryData: public QList<QNetworkAccessBackendFactory *>
{
public:
    QNetworkAccessBackendFactoryData() : mutex(QMutex::Recursive) { }
    ~QNetworkAccessBackendFactoryData()
    {
        QMutexLocker locker(&mutex); // why do we need to lock?
        factoryDataShutdown = true;
    }

    QMutex mutex;
};
Q_GLOBAL_STATIC(QNetworkAccessBackendFactoryData, factoryData)

QNetworkAccessBackendFactory::QNetworkAccessBackendFactory()
{
    QMutexLocker locker(&factoryData()->mutex);
    factoryData()->prepend(this);
}

QNetworkAccessBackendFactory::~QNetworkAccessBackendFactory()
{
    if (!factoryDataShutdown) {
        QMutexLocker locker(&factoryData()->mutex);
        factoryData()->removeAll(this);
    }
}

QNetworkAccessBackend *QNetworkAccessManagerPrivate::findBackend(QNetworkAccessManager::Operation op,
                                                                 const QNetworkRequest &request)
{
    QNetworkRequest::CacheLoadControl mode =
        static_cast<QNetworkRequest::CacheLoadControl>(
            request.attribute(QNetworkRequest::CacheLoadControlAttribute,
                              QNetworkRequest::PreferNetwork).toInt());
    if (mode == QNetworkRequest::AlwaysCache
        && (op == QNetworkAccessManager::GetOperation
        || op == QNetworkAccessManager::HeadOperation)) {
        QNetworkAccessBackend *backend = new QNetworkAccessCacheBackend;
        backend->manager = this;
        return backend;
    }

    if (!factoryDataShutdown) {
        QMutexLocker locker(&factoryData()->mutex);
        QNetworkAccessBackendFactoryData::ConstIterator it = factoryData()->constBegin(),
                                                           end = factoryData()->constEnd();
        while (it != end) {
            QNetworkAccessBackend *backend = (*it)->create(op, request);
            if (backend) {
                backend->manager = this;
                return backend; // found a factory that handled our request
            }
            ++it;
        }
    }
    return 0;
}

QNetworkAccessBackend::QNetworkAccessBackend()
    : manager(0)
    , reply(0)
{
}

QNetworkAccessBackend::~QNetworkAccessBackend()
{
}

void QNetworkAccessBackend::upstreamReadyRead()
{
    // do nothing
}

void QNetworkAccessBackend::downstreamReadyWrite()
{
    // do nothing
}

void QNetworkAccessBackend::copyFinished(QIODevice *)
{
    // do nothing
}

void QNetworkAccessBackend::ignoreSslErrors()
{
    // do nothing
}

void QNetworkAccessBackend::fetchSslConfiguration(QSslConfiguration &) const
{
    // do nothing
}

void QNetworkAccessBackend::setSslConfiguration(const QSslConfiguration &)
{
    // do nothing
}

QNetworkCacheMetaData QNetworkAccessBackend::fetchCacheMetaData(const QNetworkCacheMetaData &) const
{
    return QNetworkCacheMetaData();
}

QNetworkAccessManager::Operation QNetworkAccessBackend::operation() const
{
    return reply->operation;
}

QNetworkRequest QNetworkAccessBackend::request() const
{
    return reply->request;
}

#ifndef QT_NO_NETWORKPROXY
QList<QNetworkProxy> QNetworkAccessBackend::proxyList() const
{
    return reply->proxyList;
}
#endif

QAbstractNetworkCache *QNetworkAccessBackend::networkCache() const
{
    if (!manager)
        return 0;
    return manager->networkCache;
}

void QNetworkAccessBackend::setCachingEnabled(bool enable)
{
    reply->setCachingEnabled(enable);
}

bool QNetworkAccessBackend::isCachingEnabled() const
{
    return reply->isCachingEnabled();
}

qint64 QNetworkAccessBackend::upstreamBytesAvailable() const
{
    return reply->writeBuffer.size();
}

void QNetworkAccessBackend::upstreamBytesConsumed(qint64 count)
{
    // remove count bytes from the write buffer
    reply->consume(count);
}

QByteArray QNetworkAccessBackend::readUpstream()
{
    // ### this is expensive. Consider making QRingBuffer::peekAll keep the buffer it returns
    return reply->writeBuffer.peek(upstreamBytesAvailable());
}

qint64 QNetworkAccessBackend::nextDownstreamBlockSize() const
{
    return reply->nextDownstreamBlockSize();
}

qint64 QNetworkAccessBackend::downstreamBytesToConsume() const
{
    return reply->writeBuffer.size();
}

void QNetworkAccessBackend::writeDownstreamData(const QByteArray &data)
{
    reply->feed(data);
}

void QNetworkAccessBackend::writeDownstreamData(QIODevice *data)
{
    reply->feed(data);
}

QVariant QNetworkAccessBackend::header(QNetworkRequest::KnownHeaders header) const
{
    return reply->q_func()->header(header);
}

void QNetworkAccessBackend::setHeader(QNetworkRequest::KnownHeaders header, const QVariant &value)
{
    reply->setCookedHeader(header, value);
}

bool QNetworkAccessBackend::hasRawHeader(const QByteArray &headerName) const
{
    return reply->q_func()->hasRawHeader(headerName);
}

QByteArray QNetworkAccessBackend::rawHeader(const QByteArray &headerName) const
{
    return reply->q_func()->rawHeader(headerName);
}

QList<QByteArray> QNetworkAccessBackend::rawHeaderList() const
{
    return reply->q_func()->rawHeaderList();
}

void QNetworkAccessBackend::setRawHeader(const QByteArray &headerName, const QByteArray &headerValue)
{
    reply->setRawHeader(headerName, headerValue);
}

QVariant QNetworkAccessBackend::attribute(QNetworkRequest::Attribute code) const
{
    return reply->q_func()->attribute(code);
}

void QNetworkAccessBackend::setAttribute(QNetworkRequest::Attribute code, const QVariant &value)
{
    if (value.isValid())
        reply->attributes.insert(code, value);
    else
        reply->attributes.remove(code);
}
QUrl QNetworkAccessBackend::url() const
{
    return reply->url;
}

void QNetworkAccessBackend::setUrl(const QUrl &url)
{
    reply->url = url;
}

void QNetworkAccessBackend::finished()
{
    reply->finished();
}

void QNetworkAccessBackend::error(QNetworkReply::NetworkError code, const QString &errorString)
{
    reply->error(code, errorString);
}

#ifndef QT_NO_NETWORKPROXY
void QNetworkAccessBackend::proxyAuthenticationRequired(const QNetworkProxy &proxy,
                                                        QAuthenticator *authenticator)
{
    manager->proxyAuthenticationRequired(this, proxy, authenticator);
}
#endif

void QNetworkAccessBackend::authenticationRequired(QAuthenticator *authenticator)
{
    manager->authenticationRequired(this, authenticator);
}

void QNetworkAccessBackend::metaDataChanged()
{
    reply->metaDataChanged();
}

void QNetworkAccessBackend::redirectionRequested(const QUrl &target)
{
    reply->redirectionRequested(target);
}

void QNetworkAccessBackend::sslErrors(const QList<QSslError> &errors)
{
#ifndef QT_NO_OPENSSL
    reply->sslErrors(errors);
#else
    Q_UNUSED(errors);
#endif
}

QT_END_NAMESPACE