#include <QNetworkReply>
#include <QNetworkRequest>
#include <QJsonDocument>
#include <QJsonObject>
#include <QJsonArray>
#include <QRegularExpression>

#include "webdownloader.h"

WebDownloader::WebDownloader(QObject *parent) : QObject(parent) {
    mAccessMgr = new QNetworkAccessManager(this);
    connect(mAccessMgr, &QNetworkAccessManager::finished, this, &WebDownloader::dlFinished);
}

void WebDownloader::fetchData(QString artist, QString album){
    mArtist = artist;
    mAlbum = album;
    QString artistQ = QString("artist:%1").arg(artist);
    QByteArray peq = QUrl::toPercentEncoding(artistQ);
    QString url = QString("https://musicbrainz.org/ws/2/release/?query=%1&fmt=json&limit=100").arg(QString(peq));
    QUrl aUrl(url);
    QNetworkRequest req(aUrl);
    req.setHeader(QNetworkRequest::UserAgentHeader, "Beetplayer/1.0.0 (beetplayer@d-tor.org");
    mAccessMgr->get(req);
}

void WebDownloader::dlFinished(QNetworkReply *reply){
    mData.clear();
    mOtherData.clear();
    mArtistId.clear();
    mAlternateArtists.clear();
    QRegularExpression yearRE("(\\d{4})");
    QByteArray res = reply->readAll();
    QJsonDocument jDoc = QJsonDocument::fromJson(res);
    QJsonObject docObj = jDoc.object();
    QJsonArray relArr = docObj.value("releases").toArray();
    QJsonArray::const_iterator it = std::find_if(relArr.constBegin(), relArr.constEnd(), [this](auto c) {
        QString title = c.toObject().value("title").toString().toLower();
        return title == mAlbum;
    });
    if(it != relArr.constEnd()){
        QJsonValue titleRes = *it;
        QString curId = titleRes.toObject().value("release-group").toObject().value("id").toString();
        if(!mData.contains(curId)){
            mData << curId;
        }
        QString aId = titleRes.toObject().value("artist-credit").toArray().at(0).toObject().value("artist").toObject().value("id").toString();
        mArtistId = aId;
        std::for_each(relArr.constBegin(), relArr.constEnd(), [this, aId, yearRE](auto c){
            QString id = c.toObject().value("artist-credit").toArray().at(0).toObject().value("artist").toObject().value("id").toString();
            QString linkId = c.toObject().value("release-group").toObject().value("id").toString();
            QString title = c.toObject().value("title").toString().toLower();
            if(id == aId){
                QString primary = c.toObject().value("release-group").toObject().value("primary-type").toString().toLower();
                auto secondary = c.toObject().value("release-group").toObject().value("secondary-types").toArray();
                if(secondary.count()){
                    return;
                }
                QString status = c.toObject().value("status").toString().toLower();
                if(primary == "album" && status == "official"){
                    QString date = c.toObject().value("date").toString();
                    int year = -1;
                    QRegularExpressionMatch match = yearRE.match(date);
                    if(match.hasMatch()){
                        year = match.captured(0).toInt();
                    }
                    auto otherIt = mOtherData.constEnd();
                    if(year != -1){
                        otherIt = std::find_if(mOtherData.constBegin(), mOtherData.constEnd(), [linkId](auto c){
                           return c.at(0).toString() == linkId;
                        });
                        if(otherIt == mOtherData.constEnd()){
                            QVariantList cur = QVariantList() << linkId << title << year;
                            mOtherData.append(cur);
                        }
                    }
                }
            }
        });
    }else{
        std::for_each(relArr.constBegin(), relArr.constEnd(), [this](auto c){
            QString disamb = c.toObject().value("artist-credit").toArray().at(0).toObject().value("artist").toObject().value("disambiguation").toString();
            QString name = c.toObject().value("artist-credit").toArray().at(0).toObject().value("artist").toObject().value("name").toString();
            QString linkId = c.toObject().value("artist-credit").toArray().at(0).toObject().value("artist").toObject().value("id").toString();
            QString t;
            if(!disamb.isEmpty()){
                t = QString("%1 (%2)").arg(name).arg(disamb);
            }else{
                t = name;
            }
            mAlternateArtists.insert(linkId, t);
        });
    }
    reply->deleteLater();
    emit done();
}