/***************************************************************************
    qgsidentifymenu.h  -  menu to be used in identify map tool
    ---------------------
    begin                : August 2014
    copyright            : (C) 2014 by Denis Rouzaud
    email                : denis.rouzaud@gmail.com
 ***************************************************************************
 *                                                                         *
 *   This program 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 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

#ifndef QGSIDENTIFYMENU_H
#define QGSIDENTIFYMENU_H

#include <QMenu>

#include "qgsmaplayeractionregistry.h"
#include "qgsmaptoolidentify.h"
#include "qgis_gui.h"
#include "qgis.h"

#ifndef SIP_RUN
/// \cond PRIVATE
class CustomActionRegistry : public QgsMapLayerActionRegistry
{
    Q_OBJECT

  public:

    CustomActionRegistry() = default;
    // remove all actions
    void clear() { mMapLayerActionList.clear(); }
};
///\endcond
#endif

/**
 * \ingroup gui
 * \brief The QgsIdentifyMenu class builds a menu to be used with identify results (\see QgsMapToolIdentify).
 * It is customizable and can display attribute actions (\see QgsAction) as well as map layer actions (\see QgsMapLayerAction).
 * It can also embed custom map layer actions, defined for this menu exclusively.
 * If used in a QgsMapToolIdentify, it is accessible via QgsMapToolIdentify::identifyMenu() and can be customized in the map tool sub-class.
 */
class GUI_EXPORT QgsIdentifyMenu : public QMenu
{

    Q_OBJECT

  public:
    enum MenuLevel
    {
      LayerLevel,
      FeatureLevel
    };

    struct ActionData
    {
      //! Constructor for ActionData
      ActionData() = default;

      ActionData( QgsMapLayer *layer, QgsMapLayerAction *mapLayerAction = nullptr )
        : mIsValid( true )
        , mAllResults( !layer )
        , mIsExternalAction( nullptr != mapLayerAction )
        , mLayer( layer )
        , mMapLayerAction( mapLayerAction )
      {}

      ActionData( QgsMapLayer *layer, QgsFeatureId fid, QgsMapLayerAction *mapLayerAction = nullptr )
        : mIsValid( true )
        , mIsExternalAction( nullptr != mapLayerAction )
        , mLayer( layer )
        , mFeatureId( fid )
        , mLevel( FeatureLevel )
        , mMapLayerAction( mapLayerAction )
      {}

      bool mIsValid = false;
      bool mAllResults = false;
      bool mIsExternalAction = false;
      QgsMapLayer *mLayer = nullptr;
      QgsFeatureId mFeatureId = 0;
      QgsIdentifyMenu::MenuLevel mLevel = LayerLevel;
      QgsMapLayerAction *mMapLayerAction = nullptr;
    };

    /**
     * \brief QgsIdentifyMenu is a menu to be used to choose within a list of QgsMapTool::IdentifyReults
     */
    explicit QgsIdentifyMenu( QgsMapCanvas *canvas );

    ~QgsIdentifyMenu() override;

    //! define if the menu executed can return multiple results (e.g. all results or all identified features of a vector layer)
    void setAllowMultipleReturn( bool multipleReturn ) { mAllowMultipleReturn = multipleReturn;}
    bool allowMultipleReturn() { return mAllowMultipleReturn;}

    //! define if the menu will be shown with a single idetify result
    void setExecWithSingleResult( bool execWithSingleResult ) { mExecWithSingleResult = execWithSingleResult;}
    bool execWithSingleResult() { return mExecWithSingleResult;}

    /**
     * Sets an expression context scope used to resolve underlying actions.
     *
     * \since QGIS 3.0
     */
    void setExpressionContextScope( const QgsExpressionContextScope &scope );

    /**
     * Returns an expression context scope used to resolve underlying actions.
     *
     * \since QGIS 3.0
     */
    QgsExpressionContextScope expressionContextScope() const;

    /**
     * \brief define if attribute actions(1) and map layer actions(2) can be listed and run from the menu
     * \note custom actions will be shown in any case if they exist.
     * \note (1) attribute actions are defined by the user in the layer properties \see QgsAction
     * \note (2) map layer actions are built-in c++ actions or actions which are defined by a Python plugin \see QgsMapLayerActionRegistry
     */
    void setShowFeatureActions( bool showFeatureActions ) { mShowFeatureActions = showFeatureActions; }
    bool showFeatureActions() { return mShowFeatureActions;}

    /**
     * \brief setResultsIfExternalAction if set to false (default) the menu will not return any results if an external action has been triggered
     * \note external action can be either custom actions or feature / map layer actions (\see setShowFeatureActions)
     */
    void setResultsIfExternalAction( bool resultsIfExternalAction ) {mResultsIfExternalAction = resultsIfExternalAction;}
    bool resultsIfExternalAction() {return mResultsIfExternalAction;}

    /**
     * Defines the maximum number of layers displayed in the menu (default is 10).
     * \note 0 is unlimited.
     */
    void setMaxLayerDisplay( int maxLayerDisplay );
    int maxLayerDisplay() {return mMaxLayerDisplay;}

    /**
     * Defines the maximum number of features displayed in the menu for vector layers (default is 10).
     * \note 0 is unlimited.
     */
    void setMaxFeatureDisplay( int maxFeatureDisplay );
    int maxFeatureDisplay() {return mMaxFeatureDisplay;}

    //! adds a new custom action to the menu
    void addCustomAction( QgsMapLayerAction *action ) {mCustomActionRegistry.addMapLayerAction( action );}

    //! remove all custom actions from the menu to be built
    void removeCustomActions();

    /**
     * \brief exec
     * \param idResults the list of identify results to choose within
     * \param pos the position where the menu will be executed
     */
    QList<QgsMapToolIdentify::IdentifyResult> exec( const QList<QgsMapToolIdentify::IdentifyResult> &idResults, QPoint pos );

  protected:
    void closeEvent( QCloseEvent *e ) override;

  private slots:
    void handleMenuHover();
    void deleteRubberBands();
    void layerDestroyed();
    void triggerMapLayerAction();

  private:

    //! adds a raster layer in the menu being built
    void addRasterLayer( QgsMapLayer *layer );

    /**
     * adds a vector layer and its results in the menu being built
     * if singleLayer is true, results will be displayed on the top level item (not in QMenu with the layer name)
     */
    void addVectorLayer( QgsVectorLayer *layer, const QList<QgsMapToolIdentify::IdentifyResult> &results, bool singleLayer = false );

    //! get the lists of results corresponding to an action in the menu
    QList<QgsMapToolIdentify::IdentifyResult> results( QAction *action, bool &externalAction );

    QgsMapCanvas *mCanvas = nullptr;
    QList<QgsHighlight *> mRubberBands;
    bool mAllowMultipleReturn;
    bool mExecWithSingleResult;
    bool mShowFeatureActions;
    bool mResultsIfExternalAction;
    int mMaxLayerDisplay;
    int mMaxFeatureDisplay;

    QgsExpressionContextScope mExpressionContextScope;

    // name of the action to be displayed for feature default action, if other actions are shown
    QString mDefaultActionName;

    // custom menu actions regirstry
    CustomActionRegistry mCustomActionRegistry;

    // map layers with their results, this is the odering of the menu
    QMap <QgsMapLayer *, QList<QgsMapToolIdentify::IdentifyResult> > mLayerIdResults;
};

Q_DECLARE_METATYPE( QgsIdentifyMenu::ActionData )

#endif // QGSIDENTIFYMENU_H