/***************************************************************************
    qgsmaprender.h  -  class for rendering map layer set
    ----------------------
    begin                : January 2006
    copyright            : (C) 2006 by Martin Dobias
    email                : wonder.sk at gmail dot 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 QGSMAPRENDER_H
#define QGSMAPRENDER_H

#include <QMutex>
#include <QSize>
#include <QStringList>
#include <QVector>
#include <QPainter>

#include "qgis.h"
#include "qgsrectangle.h"
#include "qgsrendercontext.h"
#include "qgsfeature.h"

class QDomDocument;
class QDomNode;
class QPainter;

class QgsMapToPixel;
class QgsMapLayer;
class QgsMapRenderer;
class QgsScaleCalculator;
class QgsCoordinateReferenceSystem;
class QgsDistanceArea;
class QgsVectorLayer;

class QgsPalLayerSettings;
class QgsDiagramLayerSettings;

class CORE_EXPORT QgsLabelPosition
{
  public:
    QgsLabelPosition( int id, double r, const QVector< QgsPoint >& corners, const QgsRectangle& rect, double w, double h, const QString& layer, const QString& labeltext, const QFont& labelfont, bool upside_down, bool diagram = false, bool pinned = false ):
        featureId( id ), rotation( r ), cornerPoints( corners ), labelRect( rect ), width( w ), height( h ), layerID( layer ), labelText( labeltext ), labelFont( labelfont ), upsideDown( upside_down ), isDiagram( diagram ), isPinned( pinned ) {}
    QgsLabelPosition(): featureId( -1 ), rotation( 0 ), labelRect( QgsRectangle() ), width( 0 ), height( 0 ), layerID( "" ), labelText( "" ), labelFont( QFont() ), upsideDown( false ), isDiagram( false ), isPinned( false ) {}
    int featureId;
    double rotation;
    QVector< QgsPoint > cornerPoints;
    QgsRectangle labelRect;
    double width;
    double height;
    QString layerID;
    QString labelText;
    QFont labelFont;
    bool upsideDown;
    bool isDiagram;
    bool isPinned;
};

/** Labeling engine interface.
 * \note Added in QGIS v1.4
 */
class CORE_EXPORT QgsLabelingEngineInterface
{
  public:

    virtual ~QgsLabelingEngineInterface() {}

    //! called when we're going to start with rendering
    virtual void init( QgsMapRenderer* mp ) = 0;
    //! called to find out whether the layer is used for labeling
    virtual bool willUseLayer( QgsVectorLayer* layer ) = 0;
    //! clears all PAL layer settings for registered layers
    //! @note: this method was added in version 1.9
    virtual void clearActiveLayers() = 0;
    //! clears data defined objects from PAL layer settings for a registered layer
    //! @note: this method was added in version 1.9
    virtual void clearActiveLayer( QgsVectorLayer* layer ) = 0;
    //! called when starting rendering of a layer
    //! @note: this method was added in version 1.6
    virtual int prepareLayer( QgsVectorLayer* layer, QSet<int>& attrIndices, QgsRenderContext& ctx ) = 0;
    //! returns PAL layer settings for a registered layer
    //! @note: this method was added in version 1.9
    virtual QgsPalLayerSettings& layer( const QString& layerName ) = 0;
    //! adds a diagram layer to the labeling engine
    virtual int addDiagramLayer( QgsVectorLayer* layer, QgsDiagramLayerSettings* s )
    { Q_UNUSED( layer ); Q_UNUSED( s ); return 0; }
    //! called for every feature
    virtual void registerFeature( QgsVectorLayer* layer, QgsFeature& feat, const QgsRenderContext& context = QgsRenderContext() ) = 0;
    //! called for every diagram feature
    virtual void registerDiagramFeature( QgsVectorLayer* layer, QgsFeature& feat, const QgsRenderContext& context = QgsRenderContext() )
    { Q_UNUSED( layer ); Q_UNUSED( feat ); Q_UNUSED( context ); }
    //! called when the map is drawn and labels should be placed
    virtual void drawLabeling( QgsRenderContext& context ) = 0;
    //! called when we're done with rendering
    virtual void exit() = 0;
    //! return infos about labels at a given (map) position
    //! @note: this method was added in version 1.7
    virtual QList<QgsLabelPosition> labelsAtPosition( const QgsPoint& p ) = 0;
    //! return infos about labels within a given (map) rectangle
    //! @note: this method was added in version 1.9
    virtual QList<QgsLabelPosition> labelsWithinRect( const QgsRectangle& r ) = 0;

    //! called when passing engine among map renderers
    virtual QgsLabelingEngineInterface* clone() = 0;
};

struct CORE_EXPORT QgsLayerCoordinateTransform
{
  QString srcAuthId;
  QString destAuthId;
  int srcDatumTransform; //-1 if unknown or not specified
  int destDatumTransform;
};

/** \ingroup core
 * A non GUI class for rendering a map layer set onto a QPainter.
 */

class CORE_EXPORT QgsMapRenderer : public QObject
{
    Q_OBJECT

  public:

    /**Output units for pen width and point marker width/height*/
    enum OutputUnits
    {
      Millimeters,
      Pixels
      //MAP_UNITS probably supported in future versions
    };

    /** Blending modes enum defining the available composition modes that can
     * be used when rendering a layer
     */
    enum BlendMode
    {
      BlendNormal,
      BlendLighten,
      BlendScreen,
      BlendDodge,
      BlendAddition,
      BlendDarken,
      BlendMultiply,
      BlendBurn,
      BlendOverlay,
      BlendSoftLight,
      BlendHardLight,
      BlendDifference,
      BlendSubtract
    };

    //! constructor
    QgsMapRenderer();

    //! destructor
    ~QgsMapRenderer();

    //! starts rendering
    //! @ param forceWidthScale Force a specific scale factor for line widths and marker sizes. Automatically calculated from output device DPI if 0
    void render( QPainter* painter, double* forceWidthScale = 0 );

    //! sets extent and checks whether suitable (returns false if not)
    bool setExtent( const QgsRectangle& extent );

    //! returns current extent
    QgsRectangle extent() const;

    const QgsMapToPixel* coordinateTransform() { return &( mRenderContext.mapToPixel() ); }

    //! Scale denominator
    double scale() const { return mScale; }
    /**Sets scale for scale based visibility. Normally, the scale is calculated automatically. This
     function is only used to force a preview scale (e.g. for print composer)*/
    void setScale( double scale ) {mScale = scale;}
    double mapUnitsPerPixel() const { return mMapUnitsPerPixel; }

    int width() const { return mSize.width(); };
    int height() const { return mSize.height(); };

    //! Recalculate the map scale
    void updateScale();

    QGis::UnitType mapUnits() const;
    void setMapUnits( QGis::UnitType u );

    //! sets whether map image will be for overview
    void enableOverviewMode( bool isOverview = true ) { mOverview = isOverview; }

    void setOutputSize( QSize size, int dpi );
    void setOutputSize( QSizeF size, double dpi );

    //!accessor for output dpi
    double outputDpi();
    //!accessor for output size
    QSize outputSize();
    QSizeF outputSizeF();

    /**
     * @brief transform bounding box from layer's CRS to output CRS
     * @see layerToMapCoordinates( QgsMapLayer* theLayer, QgsRectangle rect ) if you want to transform a rectangle
     * @return a bounding box (aligned rectangle) containing the transformed extent
     */
    QgsRectangle layerExtentToOutputExtent( QgsMapLayer* theLayer, QgsRectangle extent );

    /**
     * @brief transform bounding box from output CRS to layer's CRS
     * @see mapToLayerCoordinates( QgsMapLayer* theLayer,QgsRectangle rect ) if you want to transform a rectangle
     * @return a bounding box (aligned rectangle) containing the transformed extent
     */
    QgsRectangle outputExtentToLayerExtent( QgsMapLayer* theLayer, QgsRectangle extent );

    /**
     * @brief transform point coordinates from layer's CRS to output CRS
     * @return the transformed point
     */
    QgsPoint layerToMapCoordinates( QgsMapLayer* theLayer, QgsPoint point );

    /**
     * @brief transform rectangle from layer's CRS to output CRS
     * @see layerExtentToOutputExtent() if you want to transform a bounding box
     * @return the transformed rectangle
     */
    QgsRectangle layerToMapCoordinates( QgsMapLayer* theLayer, QgsRectangle rect );

    /**
     * @brief transform point coordinates from output CRS to layer's CRS
     * @return the transformed point
     */
    QgsPoint mapToLayerCoordinates( QgsMapLayer* theLayer, QgsPoint point );

    /**
     * @brief transform rectangle from output CRS to layer's CRS
     * @see outputExtentToLayerExtent() if you want to transform a bounding box
     * @return the transformed rectangle
     */
    QgsRectangle mapToLayerCoordinates( QgsMapLayer* theLayer, QgsRectangle rect );

    //! sets whether to use projections for this layer set
    void setProjectionsEnabled( bool enabled );

    //! returns true if projections are enabled for this layer set
    bool hasCrsTransformEnabled() const;

    //! sets destination coordinate reference system
    void setDestinationCrs( const QgsCoordinateReferenceSystem& crs, bool refreshCoordinateTransformInfo = true );

    //! returns CRS of destination coordinate reference system
    const QgsCoordinateReferenceSystem& destinationCrs() const;

    void setOutputUnits( OutputUnits u ) {mOutputUnits = u;}

    OutputUnits outputUnits() const {return mOutputUnits;}

    //! returns current extent of layer set
    QgsRectangle fullExtent();

    //! returns current layer set
    QStringList& layerSet();

    //! change current layer set
    void setLayerSet( const QStringList& layers );

    //! updates extent of the layer set
    void updateFullExtent();

    //! read settings
    bool readXML( QDomNode & theNode );

    //! write settings
    bool writeXML( QDomNode & theNode, QDomDocument & theDoc );

    //! Accessor for render context
    QgsRenderContext* rendererContext() {return &mRenderContext;}

    //! Labeling engine (NULL if there's no custom engine)
    //! \note Added in QGIS v1.4
    QgsLabelingEngineInterface* labelingEngine() { return mLabelingEngine; }

    //! Set labeling engine. Previous engine (if any) is deleted.
    //! Takes ownership of the engine.
    //! Added in QGIS v1.4
    void setLabelingEngine( QgsLabelingEngineInterface* iface );

    //! Returns a QPainter::CompositionMode corresponding to a BlendMode
    //! Added in 1.9
    static QPainter::CompositionMode getCompositionMode( const QgsMapRenderer::BlendMode &blendMode );
    //! Returns a BlendMode corresponding to a QPainter::CompositionMode
    //! Added in 1.9
    static QgsMapRenderer::BlendMode getBlendModeEnum( const QPainter::CompositionMode &blendMode );

    void addLayerCoordinateTransform( const QString& layerId, const QString& srcAuthId, const QString& destAuthId, int srcDatumTransform = -1, int destDatumTransform = -1 );
    void clearLayerCoordinateTransforms();

    const QgsCoordinateTransform* transformation( const QgsMapLayer *layer ) const;

  signals:

    void drawingProgress( int current, int total );

    /** This signal is emitted when CRS transformation is enabled/disabled.
     *  @param flag true if transformation is enabled.
     *  @deprecated Use hasCrsTransformEnabledChanged( bool flag )
     *              to avoid conflict with method of the same name). */
#ifndef Q_MOC_RUN
    Q_DECL_DEPRECATED
#endif
    void hasCrsTransformEnabled( bool flag );

    /** This signal is emitted when CRS transformation is enabled/disabled.
     *  @param flag true if transformation is enabled.
     *  @note Added in 2.1 */
    void hasCrsTransformEnabledChanged( bool flag );

    void destinationSrsChanged();

    void updateMap();

    void mapUnitsChanged();

    //! emitted when layer's draw() returned false
    void drawError( QgsMapLayer* );

    //! Notifies higher level components to show the datum transform dialog and add a QgsLayerCoordinateTransformInfo for that layer
    void datumTransformInfoRequested( const QgsMapLayer* ml, const QString& srcAuthId, const QString& destAuthId ) const;

  public slots:

    //! called by signal from layer current being drawn
    void onDrawingProgress( int current, int total );

  protected:

    //! adjust extent to fit the pixmap size
    void adjustExtentToSize();

    /** Convenience function to project an extent into the layer source
     * CRS, but also split it into two extents if it crosses
     * the +/- 180 degree line. Modifies the given extent to be in the
     * source CRS coordinates, and if it was split, returns true, and
     * also sets the contents of the r2 parameter
     */
    bool splitLayersExtent( QgsMapLayer* layer, QgsRectangle& extent, QgsRectangle& r2 );

    //! indicates drawing in progress
    static bool mDrawing;

    //! map units per pixel
    double mMapUnitsPerPixel;

    //! Map scale denominator at its current zoom level
    double mScale;

    //! scale calculator
    QgsScaleCalculator * mScaleCalculator;

    //! current extent to be drawn
    QgsRectangle mExtent;
    //
    /** Last extent to we drew so we know if we can
        used layer render caching or not. Note there are no
        accessors for this as it is intended to internal
        use only.
        @note added in QGIS 1.4 */
    QgsRectangle mLastExtent;

    //! indicates whether it's map image for overview
    bool mOverview;

    QSizeF mSize;

    //! detemines whether on the fly projection support is enabled
    bool mProjectionsEnabled;

    //! destination spatial reference system of the projection
    QgsCoordinateReferenceSystem* mDestCRS;

    //! stores array of layers to be rendered (identified by string)
    QStringList mLayerSet;

    //! full extent of the layer set
    QgsRectangle mFullExtent;

    //! tool for measuring
    QgsDistanceArea* mDistArea;

    //!Encapsulates context of rendering
    QgsRenderContext mRenderContext;

    //!Output units
    OutputUnits mOutputUnits;

    //! Labeling engine (NULL by default)
    QgsLabelingEngineInterface* mLabelingEngine;

    //! Locks rendering loop for concurrent draws
    QMutex mRenderMutex;

    QHash< QString, QgsLayerCoordinateTransform > mLayerCoordinateTransformInfo;

};

#endif

