/****************************************************************************
**
** Copyright (C) 2015 The Qt Company Ltd.
** Copyright (C) 2022 Rochus Keller (me@rochus-keller.ch) for LeanQt
**
** This file is part of the QtNetwork module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL21$
** GNU Lesser General Public License Usage
** This file may be used under the terms of the GNU Lesser
** General Public License version 2.1 or version 3 as published by the Free
** Software Foundation and appearing in the file LICENSE.LGPLv21 and
** LICENSE.LGPLv3 included in the packaging of this file. Please review the
** following information to ensure the GNU Lesser General Public License
** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** As a special exception, The Qt Company gives you certain additional
** rights. These rights are described in The Qt Company LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "qnetworkrequest_p.h"

#ifndef QT_NO_NETWORKACCESS
#include "qnetworkcookie.h"
#endif
#include "qplatformdefs.h"
#include "QtCore/qshareddata.h"
#include "QtCore/qlocale.h"
#include "QtCore/qdatetime.h"

#include <ctype.h>
#ifndef QT_NO_DATESTRING
# include <stdio.h>
#endif

QT_BEGIN_NAMESPACE

static QByteArray headerName(QNetworkRequest::KnownHeaders header)
{
    switch (header) {
    case QNetworkRequest::ContentTypeHeader:
        return "Content-Type";

    case QNetworkRequest::ContentLengthHeader:
        return "Content-Length";

    case QNetworkRequest::LocationHeader:
        return "Location";

    case QNetworkRequest::LastModifiedHeader:
        return "Last-Modified";

    case QNetworkRequest::CookieHeader:
        return "Cookie";

    case QNetworkRequest::SetCookieHeader:
        return "Set-Cookie";

    case QNetworkRequest::ContentDispositionHeader:
        return "Content-Disposition";

    case QNetworkRequest::UserAgentHeader:
        return "User-Agent";

    case QNetworkRequest::ServerHeader:
        return "Server";

    // no default:
    // if new values are added, this will generate a compiler warning
    }

    return QByteArray();
}

static QByteArray headerValue(QNetworkRequest::KnownHeaders header, const QVariant &value)
{
    switch (header) {
    case QNetworkRequest::ContentTypeHeader:
    case QNetworkRequest::ContentLengthHeader:
    case QNetworkRequest::ContentDispositionHeader:
    case QNetworkRequest::UserAgentHeader:
    case QNetworkRequest::ServerHeader:
        return value.toByteArray();

    case QNetworkRequest::LocationHeader:
        switch (value.userType()) {
        case QMetaType::QUrl:
            return value.toUrl().toEncoded();

        default:
            return value.toByteArray();
        }

    case QNetworkRequest::LastModifiedHeader:
        switch (value.userType()) {
        case QMetaType::QDate:
        case QMetaType::QDateTime:
            // generate RFC 1123/822 dates:
            return QNetworkHeadersPrivate::toHttpDate(value.toDateTime());

        default:
            return value.toByteArray();
        }

#ifndef QT_NO_NETWORKACCESS
    case QNetworkRequest::CookieHeader: {
        QList<QNetworkCookie> cookies = qvariant_cast<QList<QNetworkCookie> >(value);
        if (cookies.isEmpty() && value.userType() == qMetaTypeId<QNetworkCookie>())
            cookies << qvariant_cast<QNetworkCookie>(value);

        QByteArray result;
        bool first = true;
        foreach (const QNetworkCookie &cookie, cookies) {
            if (!first)
                result += "; ";
            first = false;
            result += cookie.toRawForm(QNetworkCookie::NameAndValueOnly);
        }
        return result;
    }

    case QNetworkRequest::SetCookieHeader: {
        QList<QNetworkCookie> cookies = qvariant_cast<QList<QNetworkCookie> >(value);
        if (cookies.isEmpty() && value.userType() == qMetaTypeId<QNetworkCookie>())
            cookies << qvariant_cast<QNetworkCookie>(value);

        QByteArray result;
        bool first = true;
        foreach (const QNetworkCookie &cookie, cookies) {
            if (!first)
                result += ", ";
            first = false;
            result += cookie.toRawForm(QNetworkCookie::Full);
        }
        return result;
    }
#endif
    }

    return QByteArray();
}

static int parseHeaderName(const QByteArray &headerName)
{
    if (headerName.isEmpty())
        return -1;

    switch (tolower(headerName.at(0))) {
    case 'c':
        if (qstricmp(headerName.constData(), "content-type") == 0)
            return QNetworkRequest::ContentTypeHeader;
        else if (qstricmp(headerName.constData(), "content-length") == 0)
            return QNetworkRequest::ContentLengthHeader;
        else if (qstricmp(headerName.constData(), "cookie") == 0)
            return QNetworkRequest::CookieHeader;
        break;

    case 'l':
        if (qstricmp(headerName.constData(), "location") == 0)
            return QNetworkRequest::LocationHeader;
        else if (qstricmp(headerName.constData(), "last-modified") == 0)
            return QNetworkRequest::LastModifiedHeader;
        break;

    case 's':
        if (qstricmp(headerName.constData(), "set-cookie") == 0)
            return QNetworkRequest::SetCookieHeader;
        else if (qstricmp(headerName.constData(), "server") == 0)
            return QNetworkRequest::ServerHeader;
        break;

    case 'u':
        if (qstricmp(headerName.constData(), "user-agent") == 0)
            return QNetworkRequest::UserAgentHeader;
        break;
    }

    return -1; // nothing found
}

static QVariant parseHttpDate(const QByteArray &raw)
{
    QDateTime dt = QNetworkHeadersPrivate::fromHttpDate(raw);
    if (dt.isValid())
        return dt;
    return QVariant();          // transform an invalid QDateTime into a null QVariant
}

static QVariant parseCookieHeader(const QByteArray &raw)
{
#ifndef QT_NO_NETWORKACCESS
    QList<QNetworkCookie> result;
    QList<QByteArray> cookieList = raw.split(';');
    foreach (const QByteArray &cookie, cookieList) {
        QList<QNetworkCookie> parsed = QNetworkCookie::parseCookies(cookie.trimmed());
        if (parsed.count() != 1)
            return QVariant();  // invalid Cookie: header

        result += parsed;
    }

    return QVariant::fromValue(result);
#else
	return QVariant();
#endif
}

static QVariant parseHeaderValue(QNetworkRequest::KnownHeaders header, const QByteArray &value)
{
    // header is always a valid value
    switch (header) {
    case QNetworkRequest::UserAgentHeader:
    case QNetworkRequest::ServerHeader:
    case QNetworkRequest::ContentTypeHeader:
        // copy exactly, convert to QString
        return QString::fromLatin1(value);

    case QNetworkRequest::ContentLengthHeader: {
        bool ok;
        qint64 result = value.trimmed().toLongLong(&ok);
        if (ok)
            return result;
        return QVariant();
    }

    case QNetworkRequest::LocationHeader: {
        QUrl result = QUrl::fromEncoded(value, QUrl::StrictMode);
        if (result.isValid() && !result.scheme().isEmpty())
            return result;
        return QVariant();
    }

    case QNetworkRequest::LastModifiedHeader:
        return parseHttpDate(value);

    case QNetworkRequest::CookieHeader:
        return parseCookieHeader(value);

#ifndef QT_NO_NETWORKACCESS
    case QNetworkRequest::SetCookieHeader:
        return QVariant::fromValue(QNetworkCookie::parseCookies(value));
#endif

    default:
        Q_ASSERT(0);
    }
    return QVariant();
}

QNetworkHeadersPrivate::RawHeadersList::ConstIterator
QNetworkHeadersPrivate::findRawHeader(const QByteArray &key) const
{
    RawHeadersList::ConstIterator it = rawHeaders.constBegin();
    RawHeadersList::ConstIterator end = rawHeaders.constEnd();
    for ( ; it != end; ++it)
        if (qstricmp(it->first.constData(), key.constData()) == 0)
            return it;

    return end;                 // not found
}

QNetworkHeadersPrivate::RawHeadersList QNetworkHeadersPrivate::allRawHeaders() const
{
    return rawHeaders;
}

QList<QByteArray> QNetworkHeadersPrivate::rawHeadersKeys() const
{
    QList<QByteArray> result;
    result.reserve(rawHeaders.size());
    RawHeadersList::ConstIterator it = rawHeaders.constBegin(),
                                 end = rawHeaders.constEnd();
    for ( ; it != end; ++it)
        result << it->first;

    return result;
}

void QNetworkHeadersPrivate::setRawHeader(const QByteArray &key, const QByteArray &value)
{
    if (key.isEmpty())
        // refuse to accept an empty raw header
        return;

    setRawHeaderInternal(key, value);
    parseAndSetHeader(key, value);
}

/*!
    \internal
    Sets the internal raw headers list to match \a list. The cooked headers
    will also be updated.

    If \a list contains duplicates, they will be stored, but only the first one
    is usually accessed.
*/
void QNetworkHeadersPrivate::setAllRawHeaders(const RawHeadersList &list)
{
    cookedHeaders.clear();
    rawHeaders = list;

    RawHeadersList::ConstIterator it = rawHeaders.constBegin();
    RawHeadersList::ConstIterator end = rawHeaders.constEnd();
    for ( ; it != end; ++it)
        parseAndSetHeader(it->first, it->second);
}

void QNetworkHeadersPrivate::setCookedHeader(QNetworkRequest::KnownHeaders header,
                                             const QVariant &value)
{
    QByteArray name = headerName(header);
    if (name.isEmpty()) {
        // headerName verifies that \a header is a known value
        qWarning("QNetworkRequest::setHeader: invalid header value KnownHeader(%d) received", header);
        return;
    }

    if (value.isNull()) {
        setRawHeaderInternal(name, QByteArray());
        cookedHeaders.remove(header);
    } else {
        QByteArray rawValue = headerValue(header, value);
        if (rawValue.isEmpty()) {
            qWarning("QNetworkRequest::setHeader: QVariant of type %s cannot be used with header %s",
                     value.typeName(), name.constData());
            return;
        }

        setRawHeaderInternal(name, rawValue);
        cookedHeaders.insert(header, value);
    }
}

void QNetworkHeadersPrivate::setRawHeaderInternal(const QByteArray &key, const QByteArray &value)
{
    RawHeadersList::Iterator it = rawHeaders.begin();
    while (it != rawHeaders.end()) {
        if (qstricmp(it->first.constData(), key.constData()) == 0)
            it = rawHeaders.erase(it);
        else
            ++it;
    }

    if (value.isNull())
        return;                 // only wanted to erase key

    RawHeaderPair pair;
    pair.first = key;
    pair.second = value;
    rawHeaders.append(pair);
}

void QNetworkHeadersPrivate::parseAndSetHeader(const QByteArray &key, const QByteArray &value)
{
    // is it a known header?
    const int parsedKeyAsInt = parseHeaderName(key);
    if (parsedKeyAsInt != -1) {
        const QNetworkRequest::KnownHeaders parsedKey
                = static_cast<QNetworkRequest::KnownHeaders>(parsedKeyAsInt);
        if (value.isNull()) {
            cookedHeaders.remove(parsedKey);
        } else if (parsedKey == QNetworkRequest::ContentLengthHeader
                 && cookedHeaders.contains(QNetworkRequest::ContentLengthHeader)) {
            // Only set the cooked header "Content-Length" once.
            // See bug QTBUG-15311
        } else {
            cookedHeaders.insert(parsedKey, parseHeaderValue(parsedKey, value));
        }

    }
}

// Fast month string to int conversion. This code
// assumes that the Month name is correct and that
// the string is at least three chars long.
static int name_to_month(const char* month_str)
{
    switch (month_str[0]) {
    case 'J':
        switch (month_str[1]) {
        case 'a':
            return 1;
        case 'u':
            switch (month_str[2] ) {
            case 'n':
                return 6;
            case 'l':
                return 7;
            }
        }
        break;
    case 'F':
        return 2;
    case 'M':
        switch (month_str[2] ) {
        case 'r':
            return 3;
        case 'y':
            return 5;
        }
        break;
    case 'A':
        switch (month_str[1]) {
        case 'p':
            return 4;
        case 'u':
            return 8;
        }
        break;
    case 'O':
        return 10;
    case 'S':
        return 9;
    case 'N':
        return 11;
    case 'D':
        return 12;
    }

    return 0;
}

QDateTime QNetworkHeadersPrivate::fromHttpDate(const QByteArray &value)
{
    // HTTP dates have three possible formats:
    //  RFC 1123/822      -   ddd, dd MMM yyyy hh:mm:ss "GMT"
    //  RFC 850           -   dddd, dd-MMM-yy hh:mm:ss "GMT"
    //  ANSI C's asctime  -   ddd MMM d hh:mm:ss yyyy
    // We only handle them exactly. If they deviate, we bail out.

    int pos = value.indexOf(',');
    QDateTime dt;
#ifndef QT_NO_DATESTRING
    if (pos == -1) {
        // no comma -> asctime(3) format
        dt = QDateTime::fromString(QString::fromLatin1(value), Qt::TextDate);
    } else {
        // Use sscanf over QLocal/QDateTimeParser for speed reasons. See the
        // Qt WebKit performance benchmarks to get an idea.
        if (pos == 3) {
            char month_name[4];
            int day, year, hour, minute, second;
#ifdef Q_CC_MSVC
            // Use secure version to avoid compiler warning
            if (sscanf_s(value.constData(), "%*3s, %d %3s %d %d:%d:%d 'GMT'", &day, month_name, 4, &year, &hour, &minute, &second) == 6)
#else
            // The POSIX secure mode is %ms (which allocates memory), too bleeding edge for now
            // In any case this is already safe as field width is specified.
            if (sscanf(value.constData(), "%*3s, %d %3s %d %d:%d:%d 'GMT'", &day, month_name, &year, &hour, &minute, &second) == 6)
#endif
                dt = QDateTime(QDate(year, name_to_month(month_name), day), QTime(hour, minute, second));
        } else {
            QLocale c = QLocale::c();
            // eat the weekday, the comma and the space following it
            QString sansWeekday = QString::fromLatin1(value.constData() + pos + 2);
            // must be RFC 850 date
            dt = c.toDateTime(sansWeekday, QLatin1String("dd-MMM-yy hh:mm:ss 'GMT'"));
        }
    }
#endif // QT_NO_DATESTRING

    if (dt.isValid())
        dt.setTimeSpec(Qt::UTC);
    return dt;
}

QByteArray QNetworkHeadersPrivate::toHttpDate(const QDateTime &dt)
{
    return QLocale::c().toString(dt, QLatin1String("ddd, dd MMM yyyy hh:mm:ss 'GMT'"))
        .toLatin1();
}



QT_END_NAMESPACE