#pragma once

#include <optional>

#include <QDateTime>
#include <QDebug>
#include <QDomDocument>
#include <QList>
#include <QString>
#include <QUrl>

#include "atomchannelimage.h"
#include "atomitem.h"

class QXmlStreamReader;

// TODO: mark items as read in all user channels

#define GADGET_PROPERTY(type, name) \
protected: \
    Q_PROPERTY(const type name READ get_##name WRITE set_##name) \
public: \
    const type &get_##name() const \
    { \
        return m_##name; \
    } \
    void set_##name(const type &name) \
    { \
        m_##name = name; \
    } \
\
protected: \
    type m_##name

class DbItem
{
    Q_GADGET

    GADGET_PROPERTY(std::optional<qlonglong>, id);

    static constexpr auto dateFormat = Qt::DateFormat::RFC2822Date;

public:
    explicit DbItem(const QDomNode &node);

public:
    void init(const QMetaObject &mo, const QDomNode &node);
};

class Channel : public DbItem
{
    Q_GADGET

    GADGET_PROPERTY(QString, title);
    GADGET_PROPERTY(QUrl, link);

public:
    explicit Channel(const QDomNode &node);

public:
    bool isValid() const;
};

// TODO: <image>

class Item : public DbItem
{
    Q_GADGET

    GADGET_PROPERTY(QString, title);
    GADGET_PROPERTY(QUrl, link);
    GADGET_PROPERTY(QStringList, category);
    GADGET_PROPERTY(QString, guid);
    GADGET_PROPERTY(QDateTime, pubDate);
    GADGET_PROPERTY(QString, description);
    GADGET_PROPERTY(QString, content);

public:
    explicit Item(const QDomNode &node);

public:
    bool isValid() const;
};

class AtomChannel
{
public:
    // TODO: move to interface
    static inline const QString xmlTag{"channel"};

public:
    explicit AtomChannel(QXmlStreamReader *xmlReader);

public:
    // TODO: update db data if differs. here and everywhere (item, user, etc)
    /*!
     * \brief getDbId - check if channel with corresponding `link` exists in db
     * and return db id if any
     * \return id on success, 0 otherwise
     */
    std::optional<int> getDbId();

    /*!
     * \brief createInDb - create channel in db
     * \return new channel id on success, 0 otherwise
     */
    std::optional<int> createInDb();

    /*!
     * \brief getOrInsertDbId - get existing channel id or try to create a new
     * channel and get its id
     * \return existing or new channel id on success, 0 otherwise
     */
    std::optional<int> getOrInsertDbId();

    /*!
     * \brief syncDbItems - create items in db if not exist
     * \return list of new items ids
     */
    QList<int> syncDbItems();

public:
    /*!
     * \brief m_id - cache db m_id
     */
    std::optional<int> m_id{0};

    QString title;
    /*!
     * \brief link - field called `link` in atom xml. Points to feed itself
     */
    QUrl link;
    QString description;
    QDateTime lastBuildDate;
    QLocale::Language language;
    // ...
    // TODO: shared_ptr
    AtomChannelImage image;
    QList<AtomItem> items;
};

QDebug operator<<(QDebug debug, const AtomChannel &channel);
QDebug operator<<(QDebug debug, const Channel &channel);
QDebug operator<<(QDebug debug, const Item &item);