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#include "definitiondownloader.h"

#include <utils/fileutils.h>

#include <QLatin1Char>
#include <QEventLoop>
#include <QScopedPointer>
#include <QNetworkRequest>
#include <QNetworkReply>
#include <QRegExp>

#include <utils/networkaccessmanager.h>

using namespace TextEditor;
using namespace Internal;

DefinitionDownloader::DefinitionDownloader(const QUrl &url, const QString &localPath) :
    m_url(url), m_localPath(localPath), m_status(Unknown)
{}

void DefinitionDownloader::run()
{
    Utils::NetworkAccessManager *manager = Utils::NetworkAccessManager::instance();

    int currentAttempt = 0;
    const int maxAttempts = 5;
    while (currentAttempt < maxAttempts) {
        QScopedPointer<QNetworkReply> reply(getData(manager));
        if (reply->error() != QNetworkReply::NoError) {
            m_status = NetworkError;
            return;
        }

        ++currentAttempt;
        QVariant variant = reply->attribute(QNetworkRequest::RedirectionTargetAttribute);
        if (variant.isValid() && currentAttempt < maxAttempts) {
            m_url = variant.toUrl();
        } else if (!variant.isValid()) {
            saveData(reply.data());
            return;
        }
    }
}

QNetworkReply *DefinitionDownloader::getData(QNetworkAccessManager *manager) const
{
    QNetworkRequest request(m_url);
    QNetworkReply *reply = manager->get(request);

    QEventLoop eventLoop;
    connect(reply, SIGNAL(finished()), &eventLoop, SLOT(quit()));
    eventLoop.exec();

    return reply;
}

void DefinitionDownloader::saveData(QNetworkReply *reply)
{
    const QString &urlPath = m_url.path();
    const QString &fileName =
        urlPath.right(urlPath.length() - urlPath.lastIndexOf(QLatin1Char('/')) - 1);
    Utils::FileSaver saver(m_localPath + fileName, QIODevice::Text);
    const QByteArray data = reply->readAll();
    saver.write(data);
    m_status = saver.finalize() ? Ok: WriteError;
    QString content = QString::fromUtf8(data);
    QRegExp reference(QLatin1String("context\\s*=\\s*\"[^\"]*##([^\"]+)\""));
    int index = -1;
    forever {
        index = reference.indexIn(content, index + 1);
        if (index == -1)
            break;
        emit foundReferencedDefinition(reference.cap(1));
    }
}

DefinitionDownloader::Status DefinitionDownloader::status() const
{ return m_status; }
