#ifndef REMOTEMODEL_H

#define REMOTEMODEL_H

#include <QAbstractItemModel>

#include <QStringList>

#include <json.hpp>

class RemoteDatabase;

// List of fields stored in the JSON data

enum RemoteModelColumns

{

RemoteModelColumnName,

RemoteModelColumnType,

RemoteModelColumnUrl,

RemoteModelColumnCommitId,

RemoteModelColumnSize,

RemoteModelColumnLastModified,

RemoteModelColumnCount

};

class RemoteModelItem

{

public:

explicit RemoteModelItem(RemoteModelItem* parent = nullptr);

~RemoteModelItem();

QVariant value(RemoteModelColumns column) const;

void setValue(RemoteModelColumns column, QVariant value);

bool fetchedDirectoryList() const;

void setFetchedDirectoryList(bool fetched);

void appendChild(RemoteModelItem* item);

RemoteModelItem* child(int row) const;

RemoteModelItem* parent() const;

int childCount() const;

int row() const;

// This function assumes the JSON value it's getting passed is an array ("[{...}, {...}, {...}, ...]"). It returns a list of model items, one

// per array entry and each with the specified parent set.

static std::vector<RemoteModelItem*> loadArray(const nlohmann::json& array, RemoteModelItem* parent = nullptr);

private:

// These are just the fields from the json objects returned by the dbhub.io server

QVariant m_values[RemoteModelColumnCount];

// Child items and parent item

std::vector<RemoteModelItem*> m_children;

RemoteModelItem* m_parent;

// Indicates whether we already tried fetching a directory listing for this item. This serves two purposes:

// 1) When having an empty directory this allows us to remove the expandable flag for this item.

// 2) Between sending a network request and getting the reply this flag is already set, avoiding a second or third request being sent in the meantime.

bool m_fetchedDirectoryList;

};

class RemoteModel : public QAbstractItemModel

{

Q_OBJECT

public:

explicit RemoteModel(QObject* parent, RemoteDatabase& remote);

~RemoteModel() override;

void setNewRootDir(const QString& url, const QString& cert);

QModelIndex index(int row, int column,const QModelIndex& parent = QModelIndex()) const override;

QModelIndex parent(const QModelIndex& index) const override;

QVariant data(const QModelIndex& index, int role) const override;

QVariant headerData(int section, Qt::Orientation orientation, int role) const override;

int rowCount(const QModelIndex& parent = QModelIndex()) const override;

int columnCount(const QModelIndex& parent = QModelIndex()) const override;

bool hasChildren(const QModelIndex& parent) const override;

bool canFetchMore(const QModelIndex& parent) const override;

void fetchMore(const QModelIndex& parent) override;

// This helper function takes a model index and returns the according model item. An invalid model index is used to indicate the

// root item, so if the index is invalid the root item is returned. This means that if you need to check for actual invalid indices

// this needs to be done prior to calling this function.

const RemoteModelItem* modelIndexToItem(const QModelIndex& idx) const;

// Returns the current client certificate

const QString& currentClientCertificate() const;

signals:

// This signal is emitted whenever a directory listing has been received and parsed

void directoryListingParsed(QModelIndex parent);

private slots:

// This is called whenever a network reply containing a directory listing arrives. json contains the reply data, userdata

// contains some custom data passed to the request. In this case we expect this to be the model index of the parent tree item.

void parseDirectoryListing(const QString& text, const QVariant& userdata);

private:

// Pointer to the root item. This contains all the actual item data.

RemoteModelItem* rootItem;

// The header list is a list of column titles. It's a static list that's getting filled in the constructor.

QStringList headerList;

// Reference to the remote database object which is stored somewhere in the main window.

RemoteDatabase& remoteDatabase;

// This stores the currently used network identity so it can be used for further requests, e.g. for

// lazy population.

QString currentRootDirectory;

QString currentClientCert;

QString currentUserName;

};

#endif