/*  This file is part of the KDE libraries
    Copyright (C) 2022 Ivailo Monev <xakepa10@gmail.com>

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License version 2, as published by the Free Software Foundation.

    This library 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
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
*/

#include "http.h"
#include "kdebug.h"
#include "kcomponentdata.h"
#include "khttpheader.h"

#include <QCoreApplication>

#include <sys/types.h>
#include <unistd.h>

// TODO: maybe caching

static inline QString HTTPMIMEType(const QString &contenttype)
{
    const QList<QString> splitcontenttype = contenttype.split(QLatin1Char(';'));
    if (splitcontenttype.isEmpty()) {
        return QString::fromLatin1("application/octet-stream");
    }
    return splitcontenttype.at(0);
}

static inline QString HTTPCharset(const QString &contenttype)
{
    const QList<QString> splitcontenttype = contenttype.split(QLatin1Char(';'));
    if (splitcontenttype.size() < 2) {
        return QString();
    }
    return splitcontenttype.at(1);
}

size_t curlWriteCallback(char *ptr, size_t size, size_t nmemb, void *userdata)
{
    HttpProtocol* httpprotocol = static_cast<HttpProtocol*>(userdata);
    if (!httpprotocol) {
        return 0;
    }
    // emit MIME before data
    if (httpprotocol->firstchunk) {
        httpprotocol->slotMIME();
        httpprotocol->firstchunk = false;
    }
    // size should always be 1
    Q_ASSERT(size == 1);
    httpprotocol->slotData(ptr, nmemb);
    return nmemb;
}

int curlProgressCallback(void *userdata, double dltotal, double dlnow, double ultotal, double ulnow)
{
    HttpProtocol* httpprotocol = static_cast<HttpProtocol*>(userdata);
    if (!httpprotocol) {
        return CURLE_BAD_FUNCTION_ARGUMENT;
    }
    httpprotocol->slotProgress(dlnow, dltotal);
    return CURLE_OK;
}

int curlHeaderCallback(void *ptr, size_t size, size_t nmemb, void *userdata)
{
    HttpProtocol* httpprotocol = static_cast<HttpProtocol*>(userdata);
    if (!httpprotocol) {
        return 0;
    }
    // size should always be 1
    Q_ASSERT(size == 1);
    httpprotocol->headerdata.append(static_cast<char*>(ptr), nmemb);
    return nmemb;
}

extern "C" int Q_DECL_EXPORT kdemain(int argc, char **argv)
{
    QCoreApplication app(argc, argv);
    KComponentData componentData("kio_http", "kdelibs4");
    (void)KGlobal::locale();

    kDebug(7103) << "Starting" << ::getpid();

    if (argc != 4) {
        ::fprintf(stderr, "Usage: kio_http protocol domain-socket1 domain-socket2\n");
        ::exit(-1);
    }

    HttpProtocol slave(argv[2], argv[3]);
    slave.dispatchLoop();

    kDebug(7103) << "Done";
    return 0;
}

HttpProtocol::HttpProtocol(const QByteArray &pool, const QByteArray &app)
    : SlaveBase("http", pool, app), firstchunk(true), m_curl(nullptr)
{
    m_curl = curl_easy_init();
    if (!m_curl) {
        kWarning(7103) << "Could not create context";
        return;
    }

    curl_easy_setopt(m_curl, CURLOPT_FOLLOWLOCATION, 1L);
    curl_easy_setopt(m_curl, CURLOPT_MAXREDIRS, 10L);
    curl_easy_setopt(m_curl, CURLOPT_TIMEOUT, 30L);
    curl_easy_setopt(m_curl, CURLOPT_WRITEDATA, this);
    curl_easy_setopt(m_curl, CURLOPT_WRITEFUNCTION, curlWriteCallback);
    curl_easy_setopt(m_curl, CURLOPT_NOPROGRESS, 0L); // otherwise the progress callback is not called
    curl_easy_setopt(m_curl, CURLOPT_PROGRESSDATA, this);
    curl_easy_setopt(m_curl, CURLOPT_PROGRESSFUNCTION, curlProgressCallback);
    curl_easy_setopt(m_curl, CURLOPT_HEADERDATA, this);
    curl_easy_setopt(m_curl, CURLOPT_HEADERFUNCTION, curlHeaderCallback);
}

HttpProtocol::~HttpProtocol()
{
    if (m_curl) {
        curl_easy_cleanup(m_curl);
    }
}

void HttpProtocol::get(const KUrl &url)
{
    kDebug(7103) << "URL" << url.prettyUrl();

    if (Q_UNLIKELY(!m_curl)) {
        error(KIO::ERR_OUT_OF_MEMORY, QString::fromLatin1("Null context"));
        return;
    }

    firstchunk = true;
    headerdata.clear();
    const QByteArray urlbytes = url.prettyUrl().toLocal8Bit();
    curl_easy_setopt(m_curl, CURLOPT_URL, urlbytes.constData());

    kDebug(7103) << "Metadata" << allMetaData();
    struct curl_slist *curllist = NULL;
    // metadata from scheduler
    if (hasMetaData(QLatin1String("Languages"))) {
        curllist = curl_slist_append(curllist, QByteArray("Accept-Language: ") + metaData("Languages").toAscii());
    }
    if (hasMetaData(QLatin1String("Charsets"))) {
        curllist = curl_slist_append(curllist, QByteArray("Accept-Charset: ") + metaData("Charsets").toAscii());
    }
    if (hasMetaData(QLatin1String("UserAgent"))) {
        const QByteArray useragentbytes = metaData("UserAgent").toAscii();
        curl_easy_setopt(m_curl, CURLOPT_USERAGENT, useragentbytes.constData());
    }
    if (hasMetaData(QLatin1String("UseProxy"))) {
        const QByteArray proxybytes = metaData("UseProxy").toAscii();
        curl_easy_setopt(m_curl, CURLOPT_PROXY, proxybytes.constData());
    }
    // optional user-supplied metadata
    if (hasMetaData(QLatin1String("referrer"))) {
        curllist = curl_slist_append(curllist, QByteArray("Referrer: ") + metaData("referrer").toAscii());
    }
    if (hasMetaData(QLatin1String("accept"))) {
        curllist = curl_slist_append(curllist, QByteArray("Accept: ") + metaData("accept").toAscii());
    }
    CURLcode curlresult = curl_easy_setopt(m_curl, CURLOPT_HTTPHEADER, curllist);
    if (curlresult != CURLE_OK) {
        curl_slist_free_all(curllist);
        kWarning(7103) << "Error" << curl_easy_strerror(curlresult);
        error(KIO::ERR_COULD_NOT_CONNECT, curl_easy_strerror(curlresult));
        return;
    }

    curlresult = curl_easy_perform(m_curl);
    if (curlresult != CURLE_OK) {
        curl_slist_free_all(curllist);
        kWarning(7103) << "Error" << curl_easy_strerror(curlresult);
        error(KIO::ERR_COULD_NOT_CONNECT, curl_easy_strerror(curlresult));
        return;
    }

    if (hasMetaData(QLatin1String("PropagateHttpHeader"))) {
        const QString httpheaders = QString::fromAscii(headerdata.constData(), headerdata.size());
        kDebug(7103) << "HTTP headers" << httpheaders;
        setMetaData(QString::fromLatin1("HTTP-Headers"), httpheaders);
    }

    KHTTPHeader httpheader;
    httpheader.parseHeader(headerdata);
    setMetaData(QString::fromLatin1("modified"), httpheader.get(QLatin1String("Last-Modified")));

    curl_slist_free_all(curllist);
    finished();
}

void HttpProtocol::slotMIME()
{
    char *curlcontenttype = nullptr;
    CURLcode curlresult = curl_easy_getinfo(m_curl, CURLINFO_CONTENT_TYPE, &curlcontenttype);
    if (curlresult == CURLE_OK) {
        const QString httpmimetype = HTTPMIMEType(QString::fromAscii(curlcontenttype));
        kDebug(7103) << "MIME type" << httpmimetype;
        mimeType(httpmimetype);

        const QString httpcharset = HTTPCharset(QString::fromAscii(curlcontenttype));
        kDebug(7103) << "charset" << httpcharset;
        setMetaData(QString::fromLatin1("charset"), httpcharset);
    } else {
        kWarning(7103) << "Could not get info" << curl_easy_strerror(curlresult);
    }
}

void HttpProtocol::slotData(const char* curldata, const size_t curldatasize)
{
    data(QByteArray::fromRawData(curldata, curldatasize));
}

void HttpProtocol::slotProgress(qint64 received, qint64 total)
{
    kDebug(7103) << "Received" << received << "from" << total;
    emit processedSize(static_cast<KIO::filesize_t>(received));
    emit totalSize(static_cast<KIO::filesize_t>(total));
}

#include "moc_http.cpp"