/***************************************************************************
 *                                                                         *
 *   This file is part of the Fotowall project,                            *
 *       http://www.enricoros.com/opensource/fotowall                      *
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 *   Original work                                                         *
 *      file             : mainwindow.cpp                                  *
 *      license          : GPL v3                                          *
 *      copyright notice : follows below                                   *
 *                                                                         *
 ***************************************************************************/

//        Google Image Downloader. Search and download as many images fit your search criteria
//        Copyright (C) 2009  Marco Bavagnoli - lil.deimos@gmail.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 3 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, see <http://www.gnu.org/licenses/>.

#include "GoogleImagesPictureService.h"

#include <QNetworkReply>
#include <QDebug>

namespace GoogleImagesInternal {

    struct G_PhotoDescription {
        QString href_thumbnail_at_google;   // http://www.tktpoint.it/public/zucchero01din_5.jpg
        QString href_google_thumb_download; // http://t0.gstatic.com/images
        QString ID_google_thumb;            // TkcA1QGjiRrHKM:
        QString href_original_page;         // http://www.tktpoint.it/news_dett.asp%3FIDNews%3D81
        QString desc;                       // 500 x 448 - 41k
        QString kind;                       // jpg
        QString url_t;                      // http://t0.gstatic.com/images?q=tbn:TkcA1QGjiRrHKM:http://www.tktpoint.it/public/zucchero01din_5.jpg
        int width_t;                        // 130
        int height_t;                       // 116
        QString url_o;                      // http://www.tktpoint.it/public/zucchero01din_5.jpg
        int height_o;                       // TODO parse desc
        int width_o;                        // TODO parse desc
    };

    struct Photo {
        int idx;
        G_PhotoDescription description;
        bool thumbRequested;
        QPixmap thumbnail;
        QList<QNetworkReply *> jobs;

        Photo() : idx(0), thumbRequested(false) {
        }
        ~Photo() {
            foreach (QNetworkReply * job, jobs) {
                job->disconnect(0, 0, 0);
                job->abort();
                job->deleteLater();
            }
        }
    };
}

GoogleImagesPictureService::GoogleImagesPictureService(QNetworkAccessManager * manager, QObject * parent)
  : AbstractPictureService(manager, parent)
  , m_contentType(0)
  , m_sizeType(0)
  , m_searchJob(0)
{
    // init regular expressions
    m_rxStart.setPattern("setResults[(][[]");
    // m_rxData retrieves a string with all data of the thumbnail
    m_rxData.setPattern("[[]\".*[]],");
    m_rxData.setMinimal(true);
    m_rxHref.setPattern("(http://.*)[\\\\|\"]");
    m_rxHref.setMinimal(true);
    m_rxOther.setPattern(",[\"](.*)[\"]");
    m_rxOther.setMinimal(true);
}

GoogleImagesPictureService::~GoogleImagesPictureService()
{
    dropSearch();
}

void GoogleImagesPictureService::configure(int contentType, int sizeType)
{
    m_contentType = contentType;
    m_sizeType = sizeType;
}

void GoogleImagesPictureService::searchPics(const QString & text)
{   
    // clear previous search results
    dropSearch();

    // notify about the start
    emit searchStarted();

    // build the google images search string
    QString requestString = "&q=" + QUrl::toPercentEncoding(text);
#if 1
    int startImageNumber = 0;
    requestString += "&start=" + QString::number(startImageNumber);
#endif
#if 1
    // 0=any content  1=news content  2=faces  3=photo content  4=clip art 5=line drawings
    QString content_type;
    switch (m_contentType) {
        case 0: content_type=""; break;
        case 1: content_type="news"; break;
        case 2: content_type="face"; break;
        case 3: content_type="photo"; break;
        case 4: content_type="clipart"; break;
        case 5: content_type="lineart"; break;
    }
    if (!content_type.isEmpty())
        requestString += "&imgtype=" + content_type;
#endif
#if 1
    QString image_size;
    switch (m_sizeType) {
        case 0: image_size=""; break;
        case 1: image_size="m"; break;
        case 2: image_size="l"; break;
        case 3: image_size="i"; break;
        case 4: image_size="qsvga"; break;
        case 5: image_size="vga"; break;
        case 6: image_size="svga"; break;
        case 7: image_size="xga"; break;
        case 8: image_size="2mp"; break;
        case 9: image_size="4mp"; break;
        case 10: image_size="6mp"; break;
        case 11: image_size="8mp"; break;
        case 12: image_size="10mp"; break;
        case 13: image_size="12mp"; break;
        case 14: image_size="15mp"; break;
        case 15: image_size="20mp"; break;
        case 16: image_size="40mp"; break;
        case 17: image_size="70mp"; break;
    }
    if (!image_size.isEmpty())
        requestString += "&imgsz=" + image_size;
#endif
#if 0
    switch (ui->CB_coloration->currentIndex()) {
        case 0: coloration=""; break;
        case 1: coloration="gray"; break;
        case 2: coloration="color"; break;
    }
    requestString += "&imgc=" + coloration;
#endif
#if 0
    switch (ui->CB_filter->currentIndex()) {
        case 0: safeFilter="off"; break;
        case 1: safeFilter="images"; break;
        case 2: safeFilter="active"; break;
    }
    requestString += "&safe=" + safeFilter;
#endif
#if 0
    site_search = ui->CB_domain->currentText();
    if (!site_search.isEmpty())
        requestString += "&as_sitesearch=" + site_search;
#endif

    // make request and connect to reply
    QUrl url("http://images.google.com/images");
    url.setEncodedQuery(requestString.toLatin1());
    m_searchJob = get(url);
    connect(m_searchJob, SIGNAL(finished()), this, SLOT(slotSearchJobFinished()));
}

void GoogleImagesPictureService::dropSearch()
{
    if (m_searchJob) {
        m_searchJob->disconnect(0, 0, 0);
        m_searchJob->abort();
        m_searchJob->deleteLater();
        m_searchJob = 0;
    }
    qDeleteAll(m_searchResults);
    m_searchResults.clear();
    foreach (QNetworkReply * reply, m_prefetches) {
        reply->disconnect(0, 0, 0);
        reply->abort();
        reply->deleteLater();
    }
    m_prefetches.clear();
    emit searchEnded(false);
}

bool GoogleImagesPictureService::imageInfo(int idx, QString * url, QString * title, int * width, int * height)
{
    if (idx < 0 || idx >= m_searchResults.size())
        return false;
    GoogleImagesInternal::Photo * photo = m_searchResults[idx];
    *url = photo->description.url_o;
    *title = QString(); // TODO
    *width = photo->description.width_o;
    *height = photo->description.height_o;
    return true;
}

QNetworkReply * GoogleImagesPictureService::download(int idx)
{
    if (idx < 0 || idx >= m_searchResults.size())
        return 0;

    // return an existing prefetch, if any
    if (m_prefetches.contains(idx))
        return m_prefetches.take(idx);

    // or start a new transfer
    return get(m_searchResults[idx]->description.url_o);
}

void GoogleImagesPictureService::startPrefetch(int idx)
{
#if QT_VERSION >= 0x040600
    if (idx < 0 || idx >= m_searchResults.size() || m_prefetches.contains(idx))
        return;
    m_prefetches[idx] = get(m_searchResults[idx]->description.url_o);
#else
    // no precaching with <= 4.5 since QNetworkReply::isFinished doesn't exist
    Q_UNUSED(idx);
#endif
}

void GoogleImagesPictureService::stopPrefetch(int idx)
{
    if (!m_prefetches.contains(idx))
        return;
    QNetworkReply * reply = m_prefetches.take(idx);
    reply->disconnect(0, 0, 0);
    reply->abort();
    reply->deleteLater();
}

bool GoogleImagesPictureService::parseGoogleSearchReply(const QByteArray & data)
{
    int missingImages = 99;

    // find out the start
    QString html = data;
    int pos = m_rxStart.indexIn(html);
    if (pos == -1) {
        qWarning("GoogleImagesPictureService::parseSearchReply: Something changed in the google image page html source.\nThis function must be rewritten");
        return false;
    }

    // process the html
    int idx = 0;
    html.remove(0, pos + m_rxStart.cap(0).size());
    pos = 0;
    while ((pos = m_rxData.indexIn(html, pos)) != -1 && missingImages--) {
        int pos2 = 0;
        int i = 0;

        GoogleImagesInternal::G_PhotoDescription pd;

        QString dataString = m_rxData.cap(0);
        dataString.replace("\\","\\\\");
        pos += m_rxData.matchedLength();

        // skip https images
        if (dataString.contains("https:"))
            continue;

        // Get image hrefs: (http://.*)[\\\\|\"]
        // 0 occurrence = source image href
        // 1 occurrence = href to attach to google image to retrieve thumbnail
        // 2 occurrence = source image href
        // 3 occurrence = as the 1st
        // 4 occurrence = google href for thumbnails
        while ((pos2 = m_rxHref.indexIn(dataString, pos2)) != -1) {
            switch (i) {
                case 0: pd.href_thumbnail_at_google = m_rxHref.cap(1); break;
                case 1: pd.href_original_page = m_rxHref.cap(1); break;
                case 2: pd.url_o = m_rxHref.cap(1);
                        pd.url_o = QUrl(pd.url_o).fromPercentEncoding(pd.url_o.toLocal8Bit());
                        break;
                case 3: pd.href_google_thumb_download = m_rxHref.cap(1); break;
            }
            pos2 += m_rxHref.matchedLength();
            i++;
        }

        // Get other data: ,[\"](.*)[\"]
        // cap 1 = ID image at google download image thumb
        // cap 2 = source image href
        // cap 4 = thumb x res
        // cap 5 = thumb y res
        // cap 6 = image description with some strange characters
        // cap 9 = source image values ( with x height x Kb )
        // cap 10= kind of image (jpg, png ecc)
        // cap 11= source image site
        // cap 14= source image site (same as href_google_thumb_download)
        pos2 = 0;
        i = 0;
        while ((pos2 = m_rxOther.indexIn(dataString, pos2)) != -1) {
            //qDebug() << m_rxOther.cap(0);
            switch (i) {
                case 1: pd.ID_google_thumb = m_rxOther.cap(1);
                    // Example to combine data for thumbnail:
                    // http://tbn1.google.com/images?q=tbn:jKItZeo94DSqzM:http://www.scott-eaton.com/news/uploaded_images/ecorcheZbrush-723429.jpg
                    pd.url_t = pd.href_google_thumb_download + "?q=tbn:" + pd.ID_google_thumb + pd.href_thumbnail_at_google;
                    break;
                case 2:  break;
                case 3: pd.width_t = m_rxOther.cap(1).toInt(); break;
                case 4: pd.height_t = m_rxOther.cap(1).toInt(); break;
                case 5: break;
                case 6: break;
                case 7: break;
                case 8: pd.desc = m_rxOther.cap(1);
                    pd.width_o = pd.desc.section(' ', 0, 0).toInt();
                    pd.height_o = pd.desc.section(' ', 2, 2).toInt();
                    break;
                case 9: pd.kind = m_rxOther.cap(1); break;
            }
            pos2 += m_rxOther.matchedLength();
            i++;
        }

        // create a new Photo
        GoogleImagesInternal::Photo * photo = new GoogleImagesInternal::Photo();
        photo->idx = idx++;
        photo->description = pd;
        m_searchResults.append(photo);

        // notify about the new item
        emit searchResult(photo->idx, pd.desc, pd.width_t, pd.height_t);
    }
    return true;
}

bool GoogleImagesPictureService::startNextThumbnailJobs(int count)
{
    bool finished = true;
    foreach (GoogleImagesInternal::Photo * photo, m_searchResults) {
        if (photo->thumbRequested)
            continue;

        if (count-- <= 0)
            break;

        // start the thumbnail job
        QNetworkReply * job = get(photo->description.url_t);
        connect(job, SIGNAL(finished()), this, SLOT(slotThumbJobFinished()));
        photo->jobs << job;
        photo->thumbRequested = true;
        finished = false;
    }
    return finished;
}

void GoogleImagesPictureService::slotSearchJobFinished()
{
    //QByteArray replyContent = QByteArray::fromPercentEncoding(m_searchJob->readAll());
    QByteArray replyContent = m_searchJob->readAll();
    m_searchJob->disconnect(0, 0, 0);
    m_searchJob->deleteLater();
    m_searchJob = 0;

    // TODO add a logic for pre/post image count (to fetch other images)

    // parse the search reply
    parseGoogleSearchReply(replyContent);

    // start 2 thumbnail jobs
    if (startNextThumbnailJobs(2))
        emit searchEnded(false);
}

void GoogleImagesPictureService::slotThumbJobFinished()
{
    QNetworkReply * job = static_cast<QNetworkReply *>(sender());
    QByteArray replyContent = job->readAll();
    job->deleteLater();

    // find the Photo that owns the job
    foreach (GoogleImagesInternal::Photo * photo, m_searchResults) {

        // remove the job from the photo
        if (!photo->jobs.removeAll(job))
            continue;

        // stop if network Error
        if (job->error() != QNetworkReply::NoError)
            break;

        // make pixmap from the network data
        QImage image = QImage::fromData(replyContent);
        if (image.isNull())
            break;
        photo->thumbnail = QPixmap::fromImage(image);
        emit searchThumbnail(photo->idx, photo->thumbnail);
        break;
    }

    // start a new job
    if (startNextThumbnailJobs(1))
        emit searchEnded(false);
}