// For license of this file, see <project-root-folder>/LICENSE.md.

#ifndef ROOTITEM_H
#define ROOTITEM_H

#include "core/message.h"

#include <QDateTime>
#include <QFont>
#include <QIcon>

class Category;
class Feed;
class ServiceRoot;
class QAction;

namespace RootItemKind {
  // Describes the kind of the item.
  enum Kind {
    Root = 1,
    Bin = 2,
    Feed = 4,
    Category = 8,
    ServiceRoot = 16,
    LabelsRoot = 32
  };
  inline Kind operator|(Kind a, Kind b) {
    return static_cast<Kind>(static_cast<int>(a) | static_cast<int>(b));
  }

}

// Represents ROOT item of FeedsModel.
// NOTE: This class is derived to add functionality for
// all other non-root items of FeedsModel.
class RSSGUARD_DLLSPEC RootItem : public QObject {
  Q_OBJECT

  public:
    enum ReadStatus {
      Unread = 0,
      Read = 1
    };

    // Holds statuses for messages
    // to be switched importance (starred).
    enum Importance {
      NotImportant = 0,
      Important = 1
    };

    // Constructors and destructors.
    explicit RootItem(RootItem* parent_item = nullptr);
    explicit RootItem(const RootItem& other);
    virtual ~RootItem();

    // Determines if this item should be kept always in the beginning of feeds list.
    virtual QString hashCode() const;
    virtual QString additionalTooltip() const;

    // Returns list of specific actions which can be done with the item.
    // Do not include general actions here like actions: Mark as read, Update, ...
    // NOTE: Ownership of returned actions is not switched to caller, free them when needed.
    virtual QList<QAction*> contextMenu();

    // Can properties of this item be edited?
    virtual bool canBeEdited() const;

    // Performs editing of properties of this item (probably via dialog)
    // and returns result status.
    virtual bool editViaGui();

    // Can the item be deleted?
    virtual bool canBeDeleted() const;

    // Performs deletion of the item, this
    // method should NOT display any additional dialogs.
    // Returns result status.
    virtual bool deleteViaGui();

    // Performs all needed steps (DB update, remote server update)
    // to mark this item as read/unread.
    virtual bool markAsReadUnread(ReadStatus status);

    // Get ALL undeleted messages from this item in one single list.
    // This is currently used for displaying items in "newspaper mode".
    virtual QList<Message> undeletedMessages() const;

    // This method should "clean" all messages it contains.
    // What "clean" means? It means delete messages -> move them to recycle bin
    // or eventually remove them completely if there is no recycle bin functionality.
    // If this method is called on "recycle bin" instance of your
    // service account, it should "empty" the recycle bin.
    virtual bool cleanMessages(bool clear_only_read);

    // Updates counts of all/unread messages for this feed.
    virtual void updateCounts(bool including_total_count);
    virtual int row() const;
    virtual QVariant data(int column, int role) const;
    virtual Qt::ItemFlags additionalFlags() const;
    virtual bool performDragDropChange(RootItem* target_item);

    // Each item offers "counts" of messages.
    // Returns counts of messages of all child items summed up.
    virtual int countOfUnreadMessages() const;
    virtual int countOfAllMessages() const;
    inline RootItem* parent() const {
      return m_parentItem;
    }

    inline void setParent(RootItem* parent_item) {
      m_parentItem = parent_item;
    }

    inline RootItem* child(int row) {
      return m_childItems.value(row);
    }

    inline int childCount() const {
      return m_childItems.size();
    }

    inline void appendChild(RootItem* child) {
      if (child != nullptr) {
        m_childItems.append(child);
        child->setParent(this);
      }
    }

    // Access to children.
    inline QList<RootItem*> childItems() const {
      return m_childItems;
    }

    // Removes all children from this item.
    // NOTE: Children are NOT freed from the memory.
    inline void clearChildren() {
      m_childItems.clear();
    }

    inline void setChildItems(const QList<RootItem*>& child_items) {
      m_childItems = child_items;
    }

    // Removes particular child at given index.
    // NOTE: Child is NOT freed from the memory.
    bool removeChild(int index);

    bool removeChild(RootItem* child);

    // Checks whether "this" object is child (direct or indirect)
    // of the given root.
    bool isChildOf(const RootItem* root) const;

    // Is "this" item parent (direct or indirect) if given child?
    bool isParentOf(const RootItem* child) const;

    // Returns flat list of all items from subtree where this item is a root.
    // Returned list includes this item too.
    QList<RootItem*> getSubTree() const;
    QList<RootItem*> getSubTree(RootItemKind::Kind kind_of_item) const;
    QList<Category*> getSubTreeCategories() const;

    // Returns list of categories complemented by their own integer primary ID.
    QHash<int, Category*> getHashedSubTreeCategories() const;

    // Returns list of feeds complemented by their own string CUSTOM ID.
    QHash<QString, Feed*> getHashedSubTreeFeeds() const;
    QList<Feed*> getSubTreeFeeds() const;

    // Returns the service root node which is direct or indirect parent of current item.
    ServiceRoot* getParentServiceRoot() const;

    RootItemKind::Kind kind() const;
    void setKind(RootItemKind::Kind kind);

    // Each item can have icon.
    QIcon icon() const;
    void setIcon(const QIcon& icon);

    // This ALWAYS represents primary column number/ID under which
    // the item is stored in DB.
    int id() const;
    void setId(int id);

    // Each item has its title.
    QString title() const;
    void setTitle(const QString& title);

    QDateTime creationDate() const;
    void setCreationDate(const QDateTime& creation_date);

    QString description() const;
    void setDescription(const QString& description);

    // NOTE: For standard feed/category, this WILL equal to id().
    QString customId() const;
    int customNumericId() const;
    void setCustomId(const QString& custom_id);

    // Converters
    Category* toCategory() const;
    Feed* toFeed() const;
    ServiceRoot* toServiceRoot() const;

    bool keepOnTop() const;
    void setKeepOnTop(bool keep_on_top);

  private:
    RootItemKind::Kind m_kind;
    int m_id;
    QString m_customId;
    QString m_title;
    QString m_description;
    QIcon m_icon;
    QDateTime m_creationDate;
    bool m_keepOnTop;

    QList<RootItem*> m_childItems;
    RootItem* m_parentItem;
};

QDataStream& operator<<(QDataStream& out, const RootItem::Importance& myObj);
QDataStream& operator>>(QDataStream& in, RootItem::Importance& myObj);
QDataStream& operator<<(QDataStream& out, const RootItem::ReadStatus& myObj);
QDataStream& operator>>(QDataStream& in, RootItem::ReadStatus& myObj);

#endif // ROOTITEM_H
