/*
 * This file is part of the Flowee project
 * Copyright (C) 2025 Tom Zander <tom@flowee.org>
 *
 * 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 "FeedDataProvider.h"
#include <utils/Logger.h>

#include <FloweePay.h>
#include <QFile>
#include <QFileInfo>
#include <QJsonArray>
#include <QJsonObject>
#include <QJsonDocument>
#include <QNetworkRequest>
#include <QTimer>
#include <QUrl>
#include <QCoreApplication>

constexpr const char *FEED = "https://flowee.org/v/index.json";
constexpr const char *FLOWEE_JSON = "social-feed-flowee.json";

FeedDataProvider::FeedDataProvider(QObject *parent)
    : QObject(parent)
{
    QFileInfo info(FLOWEE_JSON);
    bool useOld = info.exists();
    if (useOld) {
        m_lastCheck = info.lastModified();
        readFeed();
    }
    if (m_lastCheck.isNull()
               || m_lastCheck.msecsTo(QDateTime::currentDateTime()) > 4 * 60 * 60 * 1000) {
        QTimer::singleShot(10, this, SLOT(start()));
    }
}

void FeedDataProvider::start()
{
    QUrl uri(FEED);
    QNetworkRequest req(uri);
    auto app = QCoreApplication::instance();
    QString useragent = QString("%1%2/%3")
            .arg(app->organizationName(),
                 app->applicationName(),
                 app->applicationVersion());
    req.setHeader(QNetworkRequest::UserAgentHeader, useragent);

    if (m_lastCheck.isNull())
        m_reply = FloweePay::instance()->network()->get(req);
    else
        m_reply = FloweePay::instance()->network()->head(req);
    logInfo() << "fetching social feed file from:" << FEED;
    connect(m_reply, SIGNAL(finished()), this, SLOT(downloadFinished()));
    connect(m_reply, SIGNAL(errorOccurred(QNetworkReply::NetworkError)),
            this, SLOT(errored(QNetworkReply::NetworkError)));
    connect(m_reply, SIGNAL(sslErrors(QList<QSslError>)),
            this, SLOT(sslErrors(QList<QSslError>)));
}

void FeedDataProvider::downloadFinished()
{
    assert(m_reply);
    if (m_reply->operation() == QNetworkAccessManager::HeadOperation) {
        auto lastModified = m_reply->header(QNetworkRequest::LastModifiedHeader);
        m_reply->deleteLater();
        m_reply = nullptr;
        // check if the server has a newer one.
        if (lastModified.toDateTime() > m_lastCheck) {
            m_lastCheck = QDateTime();
            assert(m_lastCheck.isNull());
            start(); // this will now do a download of the actual data.
        }
        return;
    }
    auto data = m_reply->readAll();
    m_reply->deleteLater();
    m_reply = nullptr;
    QFile feed(FLOWEE_JSON);
    if (feed.open(QIODevice::WriteOnly)) {
        feed.write(data);
        feed.close();
    }
    readFeed();
}

void FeedDataProvider::readFeed()
{
    QFile feed(FLOWEE_JSON);
    if (!feed.open(QIODevice::ReadOnly))
        return;
    auto data = feed.readAll();
    feed.close();
    QJsonDocument doc = QJsonDocument::fromJson(data);
    if (doc.isNull()) {
        logWarning() << "Parsing error of social json";
        return;
    }
    m_listItems.clear();
    QJsonArray list = doc.array();
    for (auto i = list.begin(); i != list.end(); ++i) {
        auto obj = i->toObject();
        auto text = obj["text"];
        if (!text.isString()) {
            logWarning() << "Skipping item in JSON, missing text attribute";
            continue;
        }
        auto *item = new ListItem(this);
        item->m_text = text.toString();
        item->m_url = obj["url"].toString();
        item->m_videoLength = obj["length"].toString();
        item->m_title = obj["title"].toString();
        auto date = obj["date"].toString();
        item->m_date = QDate::fromString(date, Qt::ISODate);

        m_listItems.append(item);
    }

    emit listItemsChanged();
}

QList<ListItem *> FeedDataProvider::listItems() const
{
    return m_listItems;
}

void FeedDataProvider::errored(QNetworkReply::NetworkError err)
{
    // TODO
}

void FeedDataProvider::sslErrors(const QList<QSslError> &errors)
{
    // TODO
}


// ------------------------------------

ListItem::ListItem(QObject *parent)
    : QObject(parent)
{
}

QDate ListItem::date() const
{
    return m_date;
}

QString ListItem::videoLength() const
{
    return m_videoLength;
}

QString ListItem::text() const
{
    return m_text;
}

QString ListItem::title() const
{
    return m_title;
}

QString ListItem::url() const
{
    return m_url;
}