/**
 * @file LogView/logview.h
 * @brief Implementation of the LogView module
 * @author Enar Vaikene
 *
 * Copyright (c) 2011-2019 Enar Vaikene
 *
 * This file is part of the eVaf C++ cross-platform application development framework.
 *
 * This file can be used under the terms of the GNU General Public License
 * version 3.0 as published by the Free Software Foundation and appearing in
 * the file LICENSE included in the packaging of this file. Please review the
 * the following information to ensure the GNU General Public License version
 * 3.0 requirements will be met: http://www.gnu.org/copyleft/gpl.html.
 *
 * Alternatively, this file may be used in accordance with the Commercial License
 * Agreement provided with the Software.
 */

#ifndef __LOGVIEW_LOGVIEW_H
#  define __LOGVIEW_LOGVIEW_H

#include <Plugins/iPlugin>
#include <Common/iLogger>
#include <Gui/Panel>

#include <QObject>
#include <QString>
#include <QWidget>
#include <QAbstractListModel>
#include <QQueue>
#include <QDateTime>

class QListView;
class QLabel;
class QTabWidget;
class QStatusBar;
class QEvent;

namespace eVaf {

/**
 * Module for showing messages output with the eVaf::Common::iLogger interface.
 *
 * The LogView module implements a widget that shows all the messages output with the
 * eVaf::Common::iLogger interface.
 */
namespace LogView {

/**
 * Internal implementation of the LogView module.
 */
namespace Internal {

/**
 * Data model for the log view widget
 */
class Model : public QAbstractListModel
{
    Q_OBJECT

public:

    /// One logger message
    struct Message
    {
        Message(Common::iLogger::Severity s, QString const & t, QString const & w)
            : dt(QDateTime::currentDateTime())
            , severity(s)
            , text(t)
            , simplified(t.simplified())
            , where(w)
        {}

        QDateTime dt;
        Common::iLogger::Severity severity;
        QString text;
        QString simplified;
        QString where;
    };

    Model(QObject * parent = nullptr);

    Message const & messageAt(int idx) const { return mData.at(idx); }

    virtual int rowCount(QModelIndex const & = QModelIndex()) const { return mData.size(); }

    virtual QVariant data(QModelIndex const & index, int role = Qt::DisplayRole) const;

    void addMessage(Common::iLogger::Severity severity, QString const & text, QString const & where);

    QString details(QModelIndex const & index) const;

    bool saveToFile(QString const & fileName);

    bool copyToClipboard(QModelIndex const & index);

    QString errorString() const { return mErrorString; }


signals:

    void messageAdded(QModelIndex const & index);


private: // Members

    /// Maximum number of lines in the queue
    static int const MaxLines;

    /// Human-readable texts for message severity levels
    static char const * const SeverityText[Common::iLogger::Count];

    /// Currently shown messages
    QQueue<Message> mData;

    /// Human-readable error string if the last operation failed
    QString mErrorString;


private: // Methods

    inline char const * severityText(Common::iLogger::Severity s) const;

};

/**
 * The log view widget
 *
 * The Widget class implements a widget that shows messages from one logger source.
 */
class Widget : public QWidget
{
    Q_OBJECT

public:

    Widget(QString const & source, QWidget * parent = nullptr);

    QString const & source() const { return mSource; }

    inline void addMessage(Common::iLogger::Severity severity, QString const & text, QString const & where)
    {
        mModel->addMessage(severity, text, where);
    }


private slots:

    void messageAdded(QModelIndex const & index);

    void currentChanged(QModelIndex const &, QModelIndex const &);

    void copyToClipboard();

    void saveToFile();


private:

    QString mSource;

    Model * mModel;

    bool mAutoScroll;

    QListView * wList;
    QLabel * wDetails;

};

/**
 * The log view window
 */
class Window : public Gui::Panel
{
    Q_OBJECT

public:

    Window(QString const & args, QWidget * parent = nullptr, Qt::WindowFlags flags = Qt::WindowFlags());

    virtual ~Window();

    virtual bool event(QEvent * e);


public slots:

    void loggerEvent(Common::iLogger::Severity severity, QString const & text, QString const & source, QString const & where);


private: // Methods

    void saveSettings();

    void restoreSettings();

    QString getPanelName(QString const & args) const;


private: // Members

    QString mDefSource;
    QTabWidget * wTabs;
    QHash<QString, Widget *> mLogViews;
    QStatusBar * wStatusBar;

};

/**
 * LogView module's implementation
 */
class Module : public Plugins::iPlugin
{
    Q_OBJECT
    Q_INTERFACES(eVaf::Plugins::iPlugin)

public:

    Module();

    virtual ~Module();

    virtual bool init(QString const & args);

    virtual void done();

    virtual bool isReady() const { return wWindow != nullptr; }

private: // Members

    Window * wWindow;

};

} // namespace eVaf::LogView::Internal
} // namespace eVaf::LogView
} // namespace eVaf

#endif // logview.h