/*
 * Copyright (C) 2013, 2014 Nicolas Bonnefon and other contributors
 *
 * This file is part of glogg.
 *
 * glogg 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.
 *
 * glogg 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 glogg.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef QUICKFINDMUX_H
#define QUICKFINDMUX_H

#include <memory>
#include <vector>

#include <QObject>
#include <QString>

#include "quickfindpattern.h"

// Interface representing a widget searchable in both direction.
class SearchableWidgetInterface {
  public:
    virtual void searchForward() = 0;
    virtual void searchBackward() = 0;

    virtual void incrementallySearchForward() = 0;
    virtual void incrementallySearchBackward() = 0;
    virtual void incrementalSearchStop() = 0;
    virtual void incrementalSearchAbort() = 0;
};

// Interface representing the selector. It will be called and asked
// who the search have to be forwarded to.
class QuickFindMuxSelectorInterface {
  public:
    // Return the searchable widget to use.
    SearchableWidgetInterface* getActiveSearchable() const
    { return doGetActiveSearchable(); }
    // Return the list of all possible searchables, this
    // is done on registration in order to establish
    // listeners on all searchables.
    std::vector<QObject*> getAllSearchables() const
    { return doGetAllSearchables(); }
  protected:
    virtual SearchableWidgetInterface* doGetActiveSearchable() const = 0;
    virtual std::vector<QObject*> doGetAllSearchables() const = 0;
};

class QFNotification;

// Represents a multiplexer (unique application wise) dispatching the
// Quick Find search from the UI to the relevant view.
// It is also its responsability to determine if an incremental search
// must be performed and to react accordingly.
class QuickFindMux : public QObject
{
  Q_OBJECT

  public:

    enum QFDirection {
        Forward,
        Backward,
    };

    // Construct the multiplexer, taking a reference to the pattern
    QuickFindMux( std::shared_ptr<QuickFindPattern> pattern );

    // Register a new selector, which will be called and asked
    // who the search have to be forwarded to.
    // The selector is called immediately when registering to get the list of
    // searchables.
    // The previous selector and its associated views are automatically
    // deregistered.
    // A null selector is accepted, in this case QFM functionalities are
    // disabled until a valid selector is registered.
    void registerSelector( const QuickFindMuxSelectorInterface* selector );

    // Set the direction that will be used by the search when searching
    // forward.
    void setDirection( QFDirection direction );

  signals:
    void patternChanged( const QString& );
    void notify( const QFNotification& );
    void clearNotification();

  public slots:
    // Signal the current pattern must be altered (will start an incremental
    // search if the options are configured in such a way).
    void setNewPattern( const QString& new_pattern, bool ignore_case );

    // Signal the current pattern must be altered and is confirmed
    // (will stop an incremental search if needed)
    void confirmPattern( const QString& new_pattern, bool ignore_case );

    // Signal the user cancelled the search
    // (used for incremental only)
    void cancelSearch();

    // Starts a search in the specified direction
    void searchNext();
    void searchPrevious();

    // Idem but ignore the direction and always search in the
    // specified direction
    void searchForward();
    void searchBackward();

  private slots:
    void changeQuickFind( const QString& new_pattern,
            QuickFindMux::QFDirection new_direction );
    void notifyPatternChanged();

  private:
    const QuickFindMuxSelectorInterface* selector_;

    // The (application wide) quick find pattern
    std::shared_ptr<QuickFindPattern> pattern_;

    QFDirection currentDirection_;

    std::vector<QObject*> registeredSearchables_;

    SearchableWidgetInterface* getSearchableWidget() const;
    void registerSearchable( QObject* searchable );
    void unregisterAllSearchables();
};

#endif