/*
 * Copyright (C) by Klaas Freitag <freitag@owncloud.com>
 * Copyright (C) by Daniel Molkentin <danimo@owncloud.com>
 *
 * 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.
 */

#include <QNetworkRequest>
#include <QNetworkAccessManager>
#include <QNetworkReply>
#include <QNetworkRequest>
#include <QSslConfiguration>
#include <QBuffer>
#include <QXmlStreamReader>
#include <QStringList>
#include <QStack>
#include <QTimer>
#include <QMutex>
#include <QDebug>

#include "json.h"

#include "mirall/networkjobs.h"
#include "mirall/account.h"

#include "creds/credentialsfactory.h"
#include "creds/abstractcredentials.h"

namespace Mirall {

AbstractNetworkJob::AbstractNetworkJob(Account *account, const QString &path, QObject *parent)
    : QObject(parent)
    , _ignoreCredentialFailure(false)
    , _reply(0)
    , _account(account)
    , _path(path)
    , _timer(0)
{
}

void AbstractNetworkJob::setReply(QNetworkReply *reply)
{
    if (_reply) {
        _reply->deleteLater();
    }
    _reply = reply;
}

void AbstractNetworkJob::setTimeout(qint64 msec)
{
    qDebug() << Q_FUNC_INFO << msec;
    if (_timer)
        _timer->deleteLater();
    _timer = new QTimer(this);
    _timer->setSingleShot(true);
    connect(_timer, SIGNAL(timeout()), this, SLOT(slotTimeout()));
    _timer->start(msec);
}

void AbstractNetworkJob::resetTimeout()
{
    if( _timer ) {
        qint64 interval = _timer->interval();
        _timer->stop();
        _timer->start(interval);
    }
}

void AbstractNetworkJob::setIgnoreCredentialFailure(bool ignore)
{
    _ignoreCredentialFailure = ignore;
}

void AbstractNetworkJob::setAccount(Account *account)
{
    _account = account;
}

void AbstractNetworkJob::setPath(const QString &path)
{
    _path = path;
}

void AbstractNetworkJob::slotError(QNetworkReply::NetworkError)
{
    qDebug() << metaObject()->className() << "Error:" << _reply->errorString();
    emit networkError(_reply);
}

void AbstractNetworkJob::setupConnections(QNetworkReply *reply)
{
    connect(reply, SIGNAL(finished()), SLOT(slotFinished()));
    connect(reply, SIGNAL(error(QNetworkReply::NetworkError)),
            this, SLOT(slotError(QNetworkReply::NetworkError)));
}

QNetworkReply* AbstractNetworkJob::davRequest(const QByteArray &verb, const QString &relPath,
                                              QNetworkRequest req, QIODevice *data)
{
    return _account->davRequest(verb, relPath, req, data);
}

QNetworkReply *AbstractNetworkJob::davRequest(const QByteArray &verb, const QUrl &url, QNetworkRequest req, QIODevice *data)
{
    return _account->davRequest(verb, url, req, data);
}

QNetworkReply* AbstractNetworkJob::getRequest(const QString &relPath)
{
    return _account->getRequest(relPath);
}

QNetworkReply *AbstractNetworkJob::getRequest(const QUrl &url)
{
    return _account->getRequest(url);
}

QNetworkReply *AbstractNetworkJob::headRequest(const QString &relPath)
{
    return _account->headRequest(relPath);
}

QNetworkReply *AbstractNetworkJob::headRequest(const QUrl &url)
{
    return _account->headRequest(url);
}

void AbstractNetworkJob::slotFinished()
{
    qDebug() << _reply->error() << _reply->errorString();

    static QMutex mutex;
    AbstractCredentials *creds = _account->credentials();
    if (creds->stillValid(_reply) || _ignoreCredentialFailure) {
        finished();
    } else {
        // If other jobs that still were created from before
        // the account was put offline by the code below,
        // we do want them to fail silently while we
        // query the user
        if (mutex.tryLock()) {
            Account *a = account();
            bool fetched = creds->fetchFromUser(a);
            if (fetched) {
                a->setState(Account::Connected);
            }
            mutex.unlock();
        }
    }
    deleteLater();
}

AbstractNetworkJob::~AbstractNetworkJob() {
    _reply->deleteLater();
}

void AbstractNetworkJob::start()
{
    qDebug() << "!!!" << metaObject()->className() << "created for" << account()->url() << "querying" << path();
}

/*********************************************************************************************/

RequestEtagJob::RequestEtagJob(Account *account, const QString &path, QObject *parent)
    : AbstractNetworkJob(account, path, parent)
{
}

void RequestEtagJob::start()
{
    QNetworkRequest req;
    if (path().isEmpty() || path() == QLatin1String("/")) {
        /* For the root directory, we need to query the etags of all the sub directories
         * because, at the time I am writing this comment (Owncloud 5.0.9), the etag of the
         * root directory is not updated when the sub directories changes */
        req.setRawHeader("Depth", "1");
    } else {
        req.setRawHeader("Depth", "0");
    }
    QByteArray xml("<?xml version=\"1.0\" ?>\n"
                   "<d:propfind xmlns:d=\"DAV:\">\n"
                   "  <d:prop>\n"
                   "    <d:getetag/>\n"
                   "  </d:prop>\n"
                   "</d:propfind>\n");
    QBuffer *buf = new QBuffer(this);
    buf->setData(xml);
    buf->open(QIODevice::ReadOnly);
    // assumes ownership
    setReply(davRequest("PROPFIND", path(), req, buf));
    buf->setParent(reply());
    setupConnections(reply());

    if( reply()->error() != QNetworkReply::NoError ) {
        qDebug() << "getting etag: request network error: " << reply()->errorString();
    }
    AbstractNetworkJob::start();
}

void RequestEtagJob::finished()
{
    if (reply()->attribute(QNetworkRequest::HttpStatusCodeAttribute) == 207) {
        // Parse DAV response
        QXmlStreamReader reader(reply());
        reader.addExtraNamespaceDeclaration(QXmlStreamNamespaceDeclaration("d", "DAV:"));
        QString etag;
        while (!reader.atEnd()) {
            QXmlStreamReader::TokenType type = reader.readNext();
            if (type == QXmlStreamReader::StartElement &&
                    reader.namespaceUri() == QLatin1String("DAV:")) {
                QString name = reader.name().toString();
                if (name == QLatin1String("getetag")) {
                    etag += reader.readElementText();
                }
            }
        }
        emit etagRetreived(etag);
    }
}

/*********************************************************************************************/

MkColJob::MkColJob(Account *account, const QString &path, QObject *parent)
    : AbstractNetworkJob(account, path, parent)
{
}

void MkColJob::start()
{
    // assumes ownership
   QNetworkReply *reply = davRequest("MKCOL", path());
   setReply(reply);
   setupConnections(reply);
   AbstractNetworkJob::start();
}

void MkColJob::finished()
{
    emit finished(reply()->error());
}

/*********************************************************************************************/

LsColJob::LsColJob(Account *account, const QString &path, QObject *parent)
    : AbstractNetworkJob(account, path, parent)
{
}

void LsColJob::start()
{
    QNetworkRequest req;
    req.setRawHeader("Depth", "1");
    QByteArray xml("<?xml version=\"1.0\" ?>\n"
                   "<d:propfind xmlns:d=\"DAV:\">\n"
                   "  <d:prop>\n"
                   "    <d:resourcetype/>\n"
                   "  </d:prop>\n"
                   "</d:propfind>\n");
    QBuffer *buf = new QBuffer(this);
    buf->setData(xml);
    buf->open(QIODevice::ReadOnly);
    QNetworkReply *reply = davRequest("PROPFIND", path(), req, buf);
    buf->setParent(reply);
    setReply(reply);
    setupConnections(reply);
    AbstractNetworkJob::start();
}

void LsColJob::finished()
{
    if (reply()->attribute(QNetworkRequest::HttpStatusCodeAttribute) == 207) {
        // Parse DAV response
        QXmlStreamReader reader(reply());
        reader.addExtraNamespaceDeclaration(QXmlStreamNamespaceDeclaration("d", "DAV:"));

        QStringList folders;
        QString currentItem;

        while (!reader.atEnd()) {
            QXmlStreamReader::TokenType type = reader.readNext();
            if (type == QXmlStreamReader::StartElement &&
                    reader.namespaceUri() == QLatin1String("DAV:")) {
                QString name = reader.name().toString();
                if (name == QLatin1String("href")) {
                    currentItem = reader.readElementText();
                } else if (name == QLatin1String("collection") &&
                           !currentItem.isEmpty()) {
                    folders.append(QUrl::fromEncoded(currentItem.toLatin1()).path());
                    currentItem.clear();
                }
            }
        }
        emit directoryListing(folders);
    }
}

/*********************************************************************************************/

CheckServerJob::CheckServerJob(Account *account, bool followRedirect, QObject *parent)
    : AbstractNetworkJob(account, QLatin1String("status.php") , parent)
    , _followRedirects(followRedirect)
    , _redirectCount(0)
{
}

void CheckServerJob::start()
{
    setReply(getRequest(path()));
    setupConnections(reply());
    AbstractNetworkJob::start();
}

void CheckServerJob::slotTimeout()
{
    qDebug() << "TIMEOUT" << Q_FUNC_INFO;
    if (reply()->isRunning())
        emit timeout(reply()->url());
}

QString CheckServerJob::version(const QVariantMap &info)
{
    return info.value(QLatin1String("version")).toString();
}

QString CheckServerJob::versionString(const QVariantMap &info)
{
    return info.value(QLatin1String("versionstring")).toString();
}

bool CheckServerJob::installed(const QVariantMap &info)
{
    return info.value(QLatin1String("installed")).toBool();
}

void CheckServerJob::finished()
{
    account()->setSslConfiguration(reply()->sslConfiguration());

    // ### the qDebugs here should be exported via displayErrors() so they
    // ### can be presented to the user if the job executor has a GUI
    QUrl requestedUrl = reply()->request().url();
    QUrl redirectUrl = reply()->attribute(QNetworkRequest::RedirectionTargetAttribute).toUrl();
    if (!redirectUrl.isEmpty()) {
        _redirectCount++;
        if (requestedUrl.scheme() == QLatin1String("https") &&
                redirectUrl.scheme() == QLatin1String("http")) {
                qDebug() << Q_FUNC_INFO << "HTTPS->HTTP downgrade detected!";
        } else if (requestedUrl == redirectUrl || _redirectCount >= maxRedirects()) {
                qDebug() << Q_FUNC_INFO << "Redirect loop detected!";
        } else {
            resetTimeout();
            setReply(getRequest(redirectUrl));
            setupConnections(reply());
            return;
        }
    }

    bool success = false;
    QVariantMap status = QtJson::parse(QString::fromUtf8(reply()->readAll()), success).toMap();
    // empty or invalid response
    if (!success || status.isEmpty()) {
        qDebug() << "status.php from server is not valid JSON!";
    }

    qDebug() << "status.php returns: " << status << " " << reply()->error() << " Reply: " << reply();
    if( status.contains("installed")
            && status.contains("version")
            && status.contains("versionstring") ) {
        emit instanceFound(reply()->url(), status);
    } else {
        qDebug() << "No proper answer on " << requestedUrl;
    }
}

/*********************************************************************************************/

PropfindJob::PropfindJob(Account *account, const QString &path, QObject *parent)
    : AbstractNetworkJob(account, path, parent)
{

}

void PropfindJob::start()
{
    QList<QByteArray> properties = _properties;

    if (properties.isEmpty()) {
        properties << "allprop";
    }
    QNetworkRequest req;
    req.setRawHeader("Depth", "0");
    QByteArray propStr;
    foreach (const QByteArray &prop, properties) {
        propStr += "    <d:" + prop + " />\n";
    }
    QByteArray xml = "<?xml version=\"1.0\" ?>\n"
                     "<d:propfind xmlns:d=\"DAV:\">\n"
                     "  <d:prop>\n"
                     + propStr +
                     "  </d:prop>\n"
                     "</d:propfind>\n";

    QBuffer *buf = new QBuffer(this);
    buf->setData(xml);
    buf->open(QIODevice::ReadOnly);
    setReply(davRequest("PROPFIND", path(), req, buf));
    buf->setParent(reply());
    setupConnections(reply());
    AbstractNetworkJob::start();
}

void PropfindJob::setProperties(QList<QByteArray> properties)
{
    _properties = properties;
}

QList<QByteArray> PropfindJob::properties() const
{
    return _properties;
}

void PropfindJob::finished()
{
    int http_result_code = reply()->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();

    if (http_result_code == 207) {
        // Parse DAV response
        QXmlStreamReader reader(reply());
        reader.addExtraNamespaceDeclaration(QXmlStreamNamespaceDeclaration("d", "DAV:"));

        QVariantMap items;
        // introduced to nesting is ignored
        QStack<QString> curElement;

        while (!reader.atEnd()) {
            QXmlStreamReader::TokenType type = reader.readNext();
            if (type == QXmlStreamReader::StartElement &&
                    reader.namespaceUri() == QLatin1String("DAV:")) {
                if (curElement.isEmpty()) {
                    curElement.push(reader.name().toString());
                    items.insert(reader.name().toString(), reader.text().toString());
                }
            }
            if (type == QXmlStreamReader::EndElement &&
                    reader.namespaceUri() == QLatin1String("DAV:")) {
                if(curElement.top() == reader.name()) {
                    curElement.pop();
                }
            }

        }
        emit result(items);
    } else {
        qDebug() << "Quota request *not* successful, http result code is " << http_result_code;
    }
}

/*********************************************************************************************/

EntityExistsJob::EntityExistsJob(Account *account, const QString &path, QObject *parent)
    : AbstractNetworkJob(account, path, parent)
{
}

void EntityExistsJob::start()
{
    setReply(headRequest(path()));
    setupConnections(reply());
    AbstractNetworkJob::start();
}

void EntityExistsJob::finished()
{
    emit exists(reply());
}

/*********************************************************************************************/

CheckQuotaJob::CheckQuotaJob(Account *account, const QString &path, QObject *parent)
    : AbstractNetworkJob(account, path, parent)
{
}

void CheckQuotaJob::start()
{
    QNetworkRequest req;
    req.setRawHeader("Depth", "0");
    QByteArray xml("<?xml version=\"1.0\" ?>\n"
                   "<d:propfind xmlns:d=\"DAV:\">\n"
                   "  <d:prop>\n"
                   "    <d:quota-available-bytes/>\n"
                   "    <d:quota-used-bytes/>\n"
                   "  </d:prop>\n"
                   "</d:propfind>\n");
    QBuffer *buf = new QBuffer(this);
    buf->setData(xml);
    buf->open(QIODevice::ReadOnly);
    // assumes ownership
    setReply(davRequest("PROPFIND", path(), req, buf));
    buf->setParent(reply());
    setupConnections(reply());
    AbstractNetworkJob::start();
}

void CheckQuotaJob::finished()
{
    if (reply()->attribute(QNetworkRequest::HttpStatusCodeAttribute) == 207) {
        // Parse DAV response
        QXmlStreamReader reader(reply());
        reader.addExtraNamespaceDeclaration(QXmlStreamNamespaceDeclaration("d", "DAV:"));
        qint64 quotaAvailableBytes = 0;
        qint64 quotaUsedBytes = 0;
        while (!reader.atEnd()) {
            QXmlStreamReader::TokenType type = reader.readNext();
            if (type == QXmlStreamReader::StartElement &&
                    reader.namespaceUri() == QLatin1String("DAV:")) {
                QString name = reader.name().toString();
                if (name == QLatin1String("quota-available-bytes")) {
                    quotaAvailableBytes = reader.readElementText().toLongLong();
                } else if (name == QLatin1String("quota-used-bytes")) {
                    quotaUsedBytes = reader.readElementText().toLongLong();
                }
            }
        }
        qint64 total = quotaUsedBytes + quotaAvailableBytes;
        emit quotaRetrieved(total, quotaUsedBytes);
    }
}

} // namespace Mirall