/**
 * UGENE - Integrated Bioinformatics Tools.
 * Copyright (C) 2008-2023 UniPro <ugene@unipro.ru>
 * http://ugene.net
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301, USA.
 */

#include "HttpFileAdapter.h"

#include <QMutex>
#include <QNetworkAccessManager>
#include <QNetworkReply>
#include <QNetworkRequest>
#include <QUrl>

#include <U2Core/AppContext.h>
#include <U2Core/AppSettings.h>
#include <U2Core/Log.h>
#include <U2Core/NetworkConfiguration.h>
#include <U2Core/U2SafePoints.h>

#include "ZlibAdapter.h"

namespace U2 {

#define MAX_GET_LENGTH 3000

HttpFileAdapterFactory::HttpFileAdapterFactory(QObject* o)
    : IOAdapterFactory(o) {
    name = tr("HTTP file");
}

IOAdapter* HttpFileAdapterFactory::createIOAdapter() {
    return new HttpFileAdapter(this);
}

GzippedHttpFileAdapterFactory::GzippedHttpFileAdapterFactory(QObject* obj /* = 0 */)
    : HttpFileAdapterFactory(obj) {
    name = tr("HTTP GZIP adaptor");
}

IOAdapter* GzippedHttpFileAdapterFactory::createIOAdapter() {
    return new ZlibAdapter(new HttpFileAdapter(this));
}

QNetworkProxy HttpFileAdapterFactory::getProxyByUrl(const QUrl& url) const {
    NetworkConfiguration* nc = AppContext::getAppSettings()->getNetworkConfiguration();
    return nc->getProxyByUrl(url);
}

HttpFileAdapter::HttpFileAdapter(HttpFileAdapterFactory* factory, QObject* o)
    : IOAdapter(factory, o), is_cached(false), begin_ptr(-1), end_ptr(0),
      reply(nullptr), badstate(false), is_downloaded(false), downloaded(0), total(0) {
    chunk_list.push_back(QByteArray(CHUNKSIZE, char(0)));
    netManager = new QNetworkAccessManager(this);
}
HttpFileAdapter::~HttpFileAdapter() {
    if (isOpen())
        close();
    delete netManager;
    netManager = nullptr;
}
bool HttpFileAdapter::open(const GUrl& url_, IOAdapterMode m) {
    SAFE_POINT(m == IOAdapterMode_Read, QString("Illegal IO mode: %1").arg(m), false);

    QUrl url(url_.getURLString().trimmed());
    if (!url.isValid()) {
        return false;
    }
    bool https = url.scheme() == "https";
    if (!url.scheme().isEmpty() && !https && url.scheme() != "http") {
        return false;
    }
    gurl = url_;
    init();

    auto httpFileAdapterFactory = qobject_cast<HttpFileAdapterFactory*>(getFactory());
    QNetworkProxy proxy = httpFileAdapterFactory->getProxyByUrl(url);
    return open(url, proxy);
}

bool HttpFileAdapter::open(const QUrl& url, const QNetworkProxy& p) {
    SAFE_POINT(!isOpen(), "Adapter is already opened!", false);

    if (reply) {
        close();
    }
    netManager->setProxy(p);
    connect(netManager, SIGNAL(proxyAuthenticationRequired(const QNetworkProxy&, QAuthenticator*)), this, SLOT(onProxyAuthenticationRequired(const QNetworkProxy&, QAuthenticator*)));
    if (url.toString().length() > MAX_GET_LENGTH) {
        QStringList splittedStrings = url.toString().split(RemoteRequestConfig::HTTP_BODY_SEPARATOR);
        if (splittedStrings.count() > 1) {
            SAFE_POINT(2 == splittedStrings.count(), tr("Incorrect url string has been passed to HttpFileAdapter::open()"), false);
            const QString& headerString = splittedStrings.at(0);
            postData = splittedStrings.at(1).toLatin1();
            QNetworkRequest netRequest(headerString);
            reply = netManager->post(netRequest, postData);
        } else {
            QNetworkRequest netRequest(url);
            reply = netManager->post(netRequest, "");
        }
    } else {
        QString urlString = url.toString();
        urlString = urlString.replace(RemoteRequestConfig::HTTP_BODY_SEPARATOR, "&");
        QNetworkRequest netRequest(urlString);
        reply = netManager->get(netRequest);
    }
    coreLog.details(tr("GET %1").arg(reply->url().toString()));
    connect(reply, SIGNAL(readyRead()), this, SLOT(add_data()), Qt::DirectConnection);
    connect(reply, SIGNAL(downloadProgress(qint64, qint64)), this, SLOT(progress(qint64, qint64)), Qt::DirectConnection);  //+
    connect(reply, SIGNAL(finished()), this, SLOT(done()), Qt::DirectConnection);
    return true;
}

void HttpFileAdapter::close() {
    SAFE_POINT(isOpen(), "Adapter is not opened!", );

    if (!isOpen()) {
        return;
    }
    assert(reply);
    reply->abort();
    delete reply;
    reply = nullptr;
    gurl = GUrl();
    init();
}

qint64 HttpFileAdapter::readBlock(char* data, qint64 size) {
    SAFE_POINT(isOpen(), "Adapter is not opened!", 0);
    if (badstate) {
        return -1;
    }
    assert(data);
    assert(CHUNKSIZE != end_ptr);
    size = waitData(size);

    if (badstate) {
        return -1;
    }

    rwmut.lock();
    qint64 write_offs = 0;
    while (write_offs < size) {
        qint64 howmuch = qMin(size - write_offs, (qint64)firstChunkContains());
        readFromChunk(data + write_offs, howmuch);
        write_offs += howmuch;
    }

    rwmut.unlock();
    return size;
}

qint64 HttpFileAdapter::writeBlock(const char*, qint64) {
    FAIL("Operation is not supported!", 0);
}

bool HttpFileAdapter::skip(qint64 nBytes) {
    SAFE_POINT(isOpen(), "Adapter is not opened!", false);

    nBytes = waitData(nBytes);
    rwmut.lock();

    if (nBytes < 0) {
        assert(-nBytes <= CHUNKSIZE);
        if (begin_ptr >= -nBytes) {
            begin_ptr += nBytes;
        } else {
            if (!is_cached) {
                rwmut.unlock();
                return false;
            }
            chunk_list.prepend(cache);
            begin_ptr = CHUNKSIZE - (-nBytes - begin_ptr);
            is_cached = false;
        }
    } else {
        rwmut.unlock();
        return nBytes == skipAhead(nBytes);
    }
    rwmut.unlock();
    return true;
}

qint64 HttpFileAdapter::left() const {
    return (is_downloaded ? stored() : -1);
}

void HttpFileAdapter::init() {
    reply = nullptr;
    badstate = false;
    is_downloaded = false;
    is_cached = false;
    end_ptr = 0;
    chunk_list.clear();
    chunk_list.append(QByteArray(CHUNKSIZE, 0));
    loop.exit();
}

void HttpFileAdapter::add_data() {
    rwmut.lock();
    if (isEmpty()) {
        begin_ptr = 0;
    }
    int howmuch = CHUNKSIZE - end_ptr;
    int got = reply->read(chunk_list.last().data() + end_ptr, howmuch);

    if (got < 0) {
        badstate = true;
    } else if (got < howmuch) {
        end_ptr += got;
    } else {
        do {
            QByteArray newchunck(CHUNKSIZE, (char)0);
            got = reply->read(newchunck.data(), CHUNKSIZE);

            if (got < 0) {
                badstate = true;
                break;
            }
            chunk_list.append(newchunck);
        } while (got == CHUNKSIZE);
        end_ptr = got;
    }
    //    cond.wakeOne();
    loop.exit();
    rwmut.unlock();
}

qint64 HttpFileAdapter::stored() const {
    return (singleChunk() ? firstChunkContains() : firstChunkContains() + end_ptr + (chunk_list.size() - 2) * CHUNKSIZE);
}

void HttpFileAdapter::readFromChunk(char* data, int size) {
    assert(size <= firstChunkContains());
    assert(!isEmpty());

    memcpy(data, chunk_list.first().data() + begin_ptr, size);
    if (begin_ptr + size == CHUNKSIZE) {
        popFront();
    } else {
        begin_ptr += size;
    }
}

void HttpFileAdapter::skipFromChunk(qint64 nbytes) {
    assert(nbytes <= firstChunkContains());
    assert(!isEmpty());

    if (begin_ptr + nbytes == CHUNKSIZE) {
        popFront();
    } else {
        begin_ptr += nbytes;
    }
}

void HttpFileAdapter::popFront() {
    if (singleChunk()) {
        cache = chunk_list.first();
        Empty();
    } else {
        begin_ptr = 0;
        cache = chunk_list.takeFirst();
        is_cached = true;
    }
}

qint64 HttpFileAdapter::skipAhead(qint64 nBytes) {
    assert(nBytes >= 0);
    nBytes = qMin(nBytes, stored());
    qint64 skip_offs = 0;
    while (skip_offs < nBytes) {
        int howmuch = qMin(nBytes - skip_offs, (qint64)firstChunkContains());
        skipFromChunk(howmuch);
        skip_offs += howmuch;
    }
    return nBytes;
}

qint64 HttpFileAdapter::waitData(qint64 until) {
    while (!is_downloaded && (until > stored())) {
        loop.exec();
    }
    return qMin(until, stored());
}

void HttpFileAdapter::done() {
    QString locationHeaderValue = reply->header(QNetworkRequest::LocationHeader).toString();
    if (!locationHeaderValue.isEmpty()) {
        QUrl redirectUrl(locationHeaderValue);
        chunk_list.clear();
        close();
        coreLog.details(tr("Redirecting to %1").arg(locationHeaderValue));
        QString fullRedirectUrl(redirectUrl.toString());
        if (!postData.isEmpty()) {
            fullRedirectUrl = redirectUrl.toString() + RemoteRequestConfig::HTTP_BODY_SEPARATOR + postData;
        }
        open(fullRedirectUrl, netManager->proxy());
        return;
    }
    is_downloaded = true;
    badstate = reply->error() != QNetworkReply::NoError;
    loop.exit();
}

int HttpFileAdapter::getProgress() const {
    return (total ? (int)(100 * (float)downloaded / total) : -1);
}

void HttpFileAdapter::progress(qint64 done_, qint64 total_) {
    downloaded = done_;
    total = total_;
}

QString HttpFileAdapter::errorString() const {
    CHECK(errorMessage.isEmpty(), errorMessage);
    if (reply && reply->error() != QNetworkReply::NoError) {
        return reply->errorString();
    }
    return "";
}

void HttpFileAdapter::onProxyAuthenticationRequired(const QNetworkProxy& proxy, QAuthenticator* auth) {
    auth->setUser(proxy.user());
    auth->setPassword(proxy.password());
    disconnect(this, SLOT(onProxyAuthenticationRequired(const QNetworkProxy&, QAuthenticator*)));
}

}  // namespace U2
