/***************************************************************************
 *                                                                         *
 *   This file is part of the Fotowall project,                            *
 *       http://www.enricoros.com/opensource/fotowall                      *
 *                                                                         *
 *   Copyright (C) 2007-2009 by Enrico Ros <enrico.ros@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 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

#include "FlickrPictureService.h"
#include <QNetworkReply>
#include <QNetworkRequest>
#include <QXmlStreamAttributes>
#include <QXmlStreamReader>

namespace FlickrInternal {
    struct F_PhotoDescription {
        QString id;         // 3743354066
        QString owner;      // 22046259@N04
        QString secret;     // b0ba1ca158
        QString server;     // 2646
        QString farm;       // 3
        QString title;      // Rescale Test 1
        bool ispublic;      // 1
        bool isfriend;      // 0
        bool isfamily;      // 0
        QUrl url_t;         // http://farm3.static.flickr.com/2548/3744077174_3f6efa0789_t.jpg
        int height_t;       // 100
        int width_t;        // 75
        QUrl url_o;         // http://farm3.static.flickr.com/2548/3744077174_296535ff22_o.jpg
        int height_o;       // 3000
        int width_o;        // 4000
    };

    struct Photo {
        int idx;
        F_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();
            }
        }
    };
}

FlickrPictureService::FlickrPictureService(const QString & apiKey, QNetworkAccessManager * manager, QObject * parent)
  : AbstractPictureService(manager, parent)
  , m_apiKey(apiKey)
  , m_searchJob(0)
{
}

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

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

    // notify about the start
    emit searchStarted();

    // make request and connect to reply
    KeyValueList options;
    options << KeyValue("text", text);
    options << KeyValue("extras", "url_t,url_o");
    m_searchJob = flickrApiCall("flickr.photos.search", options);
    connect(m_searchJob, SIGNAL(finished()), this, SLOT(slotSearchJobFinished()));
    //connect(m_searchJob, SIGNAL(error(QNetworkReply::NetworkError)), this, SLOT(...);
    //connect(m_searchJob, SIGNAL(downloadProgress(qint64, qint64)), this, SLOT(slotdownloadProgress(qint64, qint64)));
}

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

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

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

    // read response
    int idx = 0;
    QXmlStreamReader sr(replyContent);
    while (!sr.atEnd()) {
        sr.readNext();
        if (sr.isStartElement() && sr.name().toString() == "photo") {

            // create the F_PhotoDescription
            FlickrInternal::F_PhotoDescription pd;
            QXmlStreamAttributes attribs = sr.attributes();
            pd.id = attribs.value("id").toString();
            pd.owner = attribs.value("owner").toString();
            pd.secret = attribs.value("secret").toString();
            pd.server = attribs.value("server").toString();
            pd.farm = attribs.value("farm").toString();
            pd.title = attribs.value("title").toString();
            pd.ispublic = attribs.value("ispublic").toString() != "0";
            pd.isfriend = attribs.value("isfriend").toString() != "0";
            pd.isfamily = attribs.value("isfamily").toString() != "0";
            pd.url_t = attribs.value("url_t").toString();
            pd.height_t = attribs.value("height_t").toString().toUInt();
            pd.width_t = attribs.value("width_t").toString().toUInt();
            pd.url_o = attribs.value("url_o").toString();
            pd.height_o = attribs.value("height_o").toString().toUInt();
            pd.width_o = attribs.value("width_o").toString().toUInt();

            // if no original, use standard url (info on http://www.flickr.com/services/api/misc.urls.html)
            if (pd.url_o.isEmpty())
                pd.url_o = QString("http://farm%1.static.flickr.com/%2/%3_%4.jpg").arg(pd.farm).arg(pd.server).arg(pd.id).arg(pd.secret);

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

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

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

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

    // find the Photo that owns the job
    foreach (FlickrInternal::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);
}

bool FlickrPictureService::startNextThumbnailJobs(int count)
{
    bool finished = true;
    foreach (FlickrInternal::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;
}

QNetworkReply * FlickrPictureService::flickrApiCall(const QString & method, const KeyValueList & params)
{
    // build URL with method+apikey+params
    QUrl url("http://api.flickr.com/services/rest/");
    KeyValueList fullList;
    fullList.append(KeyValue("method", method));
    fullList.append(KeyValue("api_key", m_apiKey));
#if QT_VERSION >= 0x040500
    fullList.append(params);
#else
    foreach (const KeyValue & param, params)
        fullList.append(param);
#endif
    url.setQueryItems(fullList);
    return get(url);
}