//##########################################################################
//#                                                                        #
//#                              CLOUDCOMPARE                              #
//#                                                                        #
//#  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; version 2 or later of the License.      #
//#                                                                        #
//#  This program 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.                          #
//#                                                                        #
//#          COPYRIGHT: EDF R&D / TELECOM ParisTech (ENST-TSI)             #
//#                                                                        #
//##########################################################################

#ifndef CC_DB_ROOT_HEADER
#define CC_DB_ROOT_HEADER

//Qt
#include "ccPointCloud.h"
#include <QAbstractItemModel>
#include <QPoint>
#include <QTreeView>

//qCC_db
#include <ccHObject.h>

//System
#include <unordered_set>

class QAction;
class QStandardItemModel;

class ccPropertiesTreeDelegate;
class ccHObject;

//! Precise statistics about current selection
struct dbTreeSelectionInfo
{
	size_t selCount = 0;
	size_t sfCount = 0;
	size_t colorCount = 0;
	size_t normalsCount = 0;
	size_t octreeCount = 0;
	size_t cloudCount = 0;
	size_t gridCound = 0;
	size_t groupCount = 0;
	size_t polylineCount = 0;
	size_t planeCount = 0;
	size_t meshCount = 0;
	size_t primitiveCount = 0;
	size_t imageCount = 0;
	size_t sensorCount = 0;
	size_t gblSensorCount = 0;
	size_t cameraSensorCount = 0;
	size_t kdTreeCount = 0;
};

//! Custom QTreeView widget (for advanced selection behavior)
class ccCustomQTreeView : public QTreeView
{
	Q_OBJECT
	
public:

	//! Default constructor
	explicit ccCustomQTreeView(QWidget* parent) : QTreeView(parent) {}

protected:

	//inherited from QTreeView
	QItemSelectionModel::SelectionFlags selectionCommand(const QModelIndex& index, const QEvent* event=nullptr) const override;
};

//! GUI database tree root
class ccDBRoot : public QAbstractItemModel
{
	Q_OBJECT

public:

	//! Default constructor
	/** \param dbTreeWidget widget for DB tree display
		\param propertiesTreeWidget widget for selected entity's properties tree display
		\param parent widget QObject parent
	**/
	ccDBRoot(ccCustomQTreeView* dbTreeWidget, QTreeView* propertiesTreeWidget, QObject* parent = nullptr);

	//! Destructor
	~ccDBRoot() override;

	//! Returns associated root object
	ccHObject* getRootEntity();

	//! Hides properties view
	void hidePropertiesView();
	//! Updates properties view
	void updatePropertiesView();

	//! Adds an element to the DB tree
	void addElement(ccHObject* object, bool autoExpand = true);

	//! Removes an element from the DB tree
	/** Automatically calls prepareDisplayForRefresh on the object.
	**/
	void removeElement(ccHObject* object);

	//! Removes several elements at once from the DB tree
	/** Faster than multiple calls to removeElement.
		Automatically calls prepareDisplayForRefresh on the objects.
		\warning The input container will be cleared.
	**/
	void removeElements(ccHObject::Container& objects);

	//! Finds an element in DB
	ccHObject* find(int uniqueID) const;

	//! Returns the number of selected entities in DB tree (optionally with a given type)
	int countSelectedEntities(CC_CLASS_ENUM filter = CC_TYPES::OBJECT);

	//! Returns selected entities in DB tree (optionally with a given type and additional information)
	size_t getSelectedEntities(	ccHObject::Container& selectedEntities,
								CC_CLASS_ENUM filter = CC_TYPES::OBJECT,
								dbTreeSelectionInfo* info = nullptr);

	//! Expands tree at a given node
	void expandElement(ccHObject* object, bool state);

	//! Unselects a given entity
	void unselectEntity(ccHObject* obj);

	//! Unselects all entities
	void unselectAllEntities();

	//! Unloads all entities
	void unloadAll();

	//inherited from QAbstractItemModel
	QVariant data(const QModelIndex &index, int role) const override;
	QModelIndex index(int row, int column, const QModelIndex &parentIndex = QModelIndex()) const override;
	QModelIndex index(ccHObject* object);
	QModelIndex parent(const QModelIndex &index) const override;
	int rowCount(const QModelIndex &parent = QModelIndex()) const override;
	int columnCount(const QModelIndex &parent = QModelIndex()) const override;
	Qt::ItemFlags flags(const QModelIndex &index) const override;
	bool setData(const QModelIndex &index, const QVariant &value, int role = Qt::EditRole) override;
	Qt::DropActions supportedDropActions() const override;
	bool dropMimeData(const QMimeData* data, Qt::DropAction action, int row, int column, const QModelIndex& parent) override;
	QMap<int,QVariant> itemData(const QModelIndex& index) const override;
	Qt::DropActions supportedDragActions() const override { return Qt::MoveAction; }

	void changeSelection(const QItemSelection & selected, const QItemSelection & deselected);
	void reflectObjectPropChange(ccHObject* obj);
	void redrawCCObject(ccHObject* object);
	void redrawCCObjectAndChildren(ccHObject* object);
	void updateCCObject(ccHObject* object);
	void deleteSelectedEntities();

	//! Selects a given entity
	/** If ctrl is pressed by the user at the same time,
		previous selection will be simply updated accordingly.
		\param obj entity to select
		\param forceAdditiveSelection whether to force additive selection (just as if CTRL key is pressed) or not
	**/
	void selectEntity(ccHObject* obj, bool forceAdditiveSelection = false);

	//! Selects multiple entities at once (shortcut to the other version)
	/** \param entIDs list of the IDs of the entities to select
	**/
	void selectEntities(std::unordered_set<int> entIDs);

	//! Selects multiple entities at once
	/** \param entities set of the entities to 'select'
		\param incremental whether to 'add' the input set to the selected entities set or to use it as replacement
	**/
	void selectEntities(const ccHObject::Container& entities, bool incremental = false);

private:
	//! Entity property that can be toggled
	enum TOGGLE_PROPERTY {	TG_ENABLE,
							TG_VISIBLE,
							TG_COLOR,
							TG_SF,
							TG_NORMAL,
							TG_MATERIAL,
							TG_3D_NAME };

	//! Toggles a given property (enable state, visibility, normal, color, SF, etc.) on selected entities
	void toggleSelectedEntitiesProperty(TOGGLE_PROPERTY prop);

	void showContextMenu(const QPoint&);

	void expandBranch();
	void collapseBranch();
	void gatherRecursiveInformation();
	void sortChildrenAZ();
	void sortChildrenZA();
	void sortChildrenType();
	void selectByTypeAndName();

	inline void toggleSelectedEntities()			{ toggleSelectedEntitiesProperty(TG_ENABLE); }
	inline void toggleSelectedEntitiesVisibility()	{ toggleSelectedEntitiesProperty(TG_VISIBLE); }
	inline void toggleSelectedEntitiesColor()		{ toggleSelectedEntitiesProperty(TG_COLOR); }
	inline void toggleSelectedEntitiesNormals()		{ toggleSelectedEntitiesProperty(TG_NORMAL); }
	inline void toggleSelectedEntitiesSF()			{ toggleSelectedEntitiesProperty(TG_SF); }
	inline void toggleSelectedEntitiesMat()         { toggleSelectedEntitiesProperty(TG_MATERIAL); }
	inline void toggleSelectedEntities3DName()      { toggleSelectedEntitiesProperty(TG_3D_NAME); }

	void addEmptyGroup();
	void alignCameraWithEntityDirect() { alignCameraWithEntity(false); }
	void alignCameraWithEntityIndirect() { alignCameraWithEntity(true); }
	void enableBubbleViewMode();
	void editLabelScalarValue();

Q_SIGNALS:
	void selectionChanged();
	void dbIsEmpty();
	void dbIsNotEmptyAnymore();

protected:

	//! Aligns the camera with the currently selected entity
	/** \param reverse whether to use the entity's normal (false) or its inverse (true)
	**/
	void alignCameraWithEntity(bool reverse);

	//! Shows properties view for a given element
	void showPropertiesView(ccHObject* obj);

	//! Entities sorting schemes
	enum SortRules { SORT_A2Z, SORT_Z2A, SORT_BY_TYPE };

	//! Sorts selected entities children
	void sortSelectedEntitiesChildren(SortRules rule);

	//! Expands or collapses hovered item
	void expandOrCollapseHoveredBranch(bool expand);

	//! Selects objects by type and/or name
    void selectChildrenByTypeAndName(CC_CLASS_ENUM type,
                                     bool typeIsExclusive = true,
                                     QString name = QString(),
                                     bool nameIsRegex = false);

	//! Associated DB root
	ccHObject* m_treeRoot;

	//! Associated widget for DB tree
	QTreeView* m_dbTreeWidget;

	//! Associated widget for selected entity's properties tree
	QTreeView* m_propertiesTreeWidget;

	//! Selected entity's properties data model
	QStandardItemModel* m_propertiesModel;
	//! Selected entity's properties delegate
	ccPropertiesTreeDelegate* m_ccPropDelegate;

	//! Context menu action: expand tree branch
	QAction* m_expandBranch;
	//! Context menu action: collapse tree branch
	QAction* m_collapseBranch;
	//! Context menu action: gather (recursive) information on selected entities
	QAction* m_gatherInformation;
	//! Context menu action: sort children in alphabetical order
	QAction* m_sortChildrenAZ;
	//! Context menu action: sort children in reverse alphabetical order
	QAction* m_sortChildrenZA;
	//! Context menu action: sort children by type
	QAction* m_sortChildrenType;
	//! Context menu action: select object by type and/or by name
	QAction* m_selectByTypeAndName;
	//! Context menu action: delete selected entities
	QAction* m_deleteSelectedEntities;
	//! Context menu action: enabled/disable selected entities
	QAction* m_toggleSelectedEntities;
	//! Context menu action: hide/show selected entities
	QAction* m_toggleSelectedEntitiesVisibility;
	//! Context menu action: hide/show selected entities color
	QAction* m_toggleSelectedEntitiesColor;
	//! Context menu action: hide/show selected entities normals
	QAction* m_toggleSelectedEntitiesNormals;
	//! Context menu action: hide/show selected entities materials/textures
	QAction* m_toggleSelectedEntitiesMat;
	//! Context menu action: hide/show selected entities SF
	QAction* m_toggleSelectedEntitiesSF;
	//! Context menu action: hide/show selected entities 3D name
	QAction* m_toggleSelectedEntities3DName;	
	//! Context menu action: add empty group
	QAction* m_addEmptyGroup;
	//! Context menu action: use 3-points labels or planes to orient camera
	QAction* m_alignCameraWithEntity;
	//! Context menu action: reverse of m_alignCameraWithEntity
	QAction* m_alignCameraWithEntityReverse;
	//! Context menu action: enable bubble-view (on a sensor)
	QAction* m_enableBubbleViewMode;
	//! Context menu action: change current scalar value (via a 2D label)
	QAction* m_editLabelScalarValue;

	//! Last context menu pos
	QPoint m_contextMenuPos;
};

#endif