/***************************************************************************
    qgslabelfeature.h
    ---------------------
    begin                : December 2015
    copyright            : (C) 2015 by Martin Dobias
    email                : wonder dot 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 QGSLABELFEATURE_H
#define QGSLABELFEATURE_H

#define SIP_NO_FILE

#include "qgis_core.h"
#include "qgspallabeling.h"
#include "geos_c.h"
#include "qgsgeos.h"
#include "qgsmargins.h"
#include "pal.h"

namespace pal
{
  class LabelInfo;
}

class QgsAbstractLabelProvider;
class QgsRenderContext;
class QgsGeometry;


/**
 * \ingroup core
 * \brief The QgsLabelFeature class describes a feature that
 * should be used within the labeling engine. Those may be the usual textual labels,
 * diagrams, or any other custom type of map annotations (generated by custom
 * label providers).
 *
 * Instances only contain data relevant to the labeling engine (geometry, label size etc.)
 * necessary for the layout. Rendering of labels is done by label providers.
 *
 * Individual label providers may create subclasses of QgsLabelFeature in order to add
 * more data to the instances that will be later used for drawing of labels.
 *
 * \note this class is not a part of public API yet. See notes in QgsLabelingEngine
 * \note not available in Python bindings
 * \since QGIS 2.12
 */
class CORE_EXPORT QgsLabelFeature
{
  public:

    //! Create label feature, takes ownership of the geometry instance
    QgsLabelFeature( QgsFeatureId id, geos::unique_ptr geometry, QSizeF size );
    //! Clean up geometry and curved label info (if present)
    virtual ~QgsLabelFeature();

    //! Identifier of the label (unique within the parent label provider)
    QgsFeatureId id() const { return mId; }

    //! Gets access to the associated geometry
    GEOSGeometry *geometry() const { return mGeometry.get(); }

    /**
     * Sets the label's obstacle geometry, if different to the feature geometry.
     * This can be used to override the shape of the feature for obstacle detection, e.g., to
     * buffer around a point geometry to prevent labels being placed too close to the
     * point itself. It not set, the feature's geometry is used for obstacle detection.
     * Ownership of obstacle geometry is transferred.
     * \see obstacleGeometry()
     * \since QGIS 2.14
     */
    void setObstacleGeometry( geos::unique_ptr obstacleGeom );

    /**
     * Returns the label's obstacle geometry, if different to the feature geometry.
     * \see setObstacleGeometry()
     * \since QGIS 2.14
     */
    GEOSGeometry *obstacleGeometry() const { return mObstacleGeometry.get(); }

    /**
     * Sets the label's permissible zone geometry. If set, the feature's label MUST be fully contained
     * within this zone, and the feature will not be labeled if no candidates can be generated which
     * are not contained within the zone.
     * \param geometry permissible zone geometry. If an invalid QgsGeometry is passed then no zone limit
     * will be applied to the label candidates (this is the default behavior).
     * \see permissibleZone()
     * \since QGIS 3.0
     */
    void setPermissibleZone( const QgsGeometry &geometry );

    /**
     * Returns the label's permissible zone geometry. If a valid geometry is returned, the feature's label
     * MUST be fully contained within this zone, and the feature will not be labeled if no candidates can be
     * generated which are not contained within the zone.
     * \see setPermissibleZone()
     * \see permissibleZonePrepared()
     * \since QGIS 3.0
     */
    QgsGeometry permissibleZone() const { return mPermissibleZone; }

    /**
     * Returns a GEOS prepared geometry representing the label's permissibleZone().
     * \see permissibleZone()
     * \since QGIS 3.0
     */
    //TODO - remove when QgsGeometry caches GEOS preparedness
    const GEOSPreparedGeometry *permissibleZonePrepared() const { return mPermissibleZoneGeosPrepared.get(); }

    //! Size of the label (in map units)
    QSizeF size() const { return mSize; }

    /**
     * Sets the visual margin for the label feature. The visual margin represents a margin
     * within the label which should not be considered when calculating the positions of candidates
     * for the label feature. It is used in certain label placement modes to adjust the position
     * of candidates so that they all appear to be at visually equal distances from a point feature.
     * For instance, this can be used to place labels which sit above a point so that their baseline
     * rather then the descender of the label is at a preset distance from the point.
     * \param margin visual margins for label
     * \see visualMargin()
     */
    void setVisualMargin( const QgsMargins &margin ) { mVisualMargin = margin; }

    /**
     * Returns the visual margin for the label feature.
     * \see setVisualMargin() for details
     */
    const QgsMargins &visualMargin() const { return mVisualMargin; }

    /**
     * Sets the size of the rendered symbol associated with this feature. This size is taken into
     * account in certain label placement modes to avoid placing labels over the rendered
     * symbol for this feature.
     * \see symbolSize()
     */
    void setSymbolSize( QSizeF size ) { mSymbolSize = size; }

    /**
     * Returns the size of the rendered symbol associated with this feature, if applicable.
     * This size is taken into account in certain label placement modes to avoid placing labels over
     * the rendered symbol for this feature. The size will only be set for labels associated
     * with a point feature.
     * \see symbolSize()
     */
    const QSizeF &symbolSize() const { return mSymbolSize; }

    /**
     * Returns the feature's labeling priority.
     * \returns feature's priority, as a value between 0 (highest priority)
     * and 1 (lowest priority). Returns -1.0 if feature will use the layer's default priority.
     * \see setPriority
     */
    double priority() const { return mPriority; }

    /**
     * Sets the priority for labeling the feature.
     * \param priority feature's priority, as a value between 0 (highest priority)
     * and 1 (lowest priority). Set to -1.0 to use the layer's default priority
     * for this feature.
     * \see priority
     */
    void setPriority( double priority ) { mPriority = priority; }

    /**
     * Returns the label's z-index. Higher z-index labels are rendered on top of lower
     * z-index labels.
     * \see setZIndex()
     * \since QGIS 2.14
     */
    double zIndex() const { return mZIndex; }

    /**
     * Sets the label's z-index. Higher z-index labels are rendered on top of lower
     * z-index labels.
     * \param zIndex z-index for label
     * \see zIndex()
     * \since QGIS 2.14
     */
    void setZIndex( double zIndex ) { mZIndex = zIndex; }

    //! Whether the label should use a fixed position instead of being automatically placed
    bool hasFixedPosition() const { return mHasFixedPosition; }
    //! Sets whether the label should use a fixed position instead of being automatically placed
    void setHasFixedPosition( bool enabled ) { mHasFixedPosition = enabled; }
    //! Coordinates of the fixed position (relevant only if hasFixedPosition() returns TRUE)
    QgsPointXY fixedPosition() const { return mFixedPosition; }
    //! Sets coordinates of the fixed position (relevant only if hasFixedPosition() returns TRUE)
    void setFixedPosition( const QgsPointXY &point ) { mFixedPosition = point; }

    //! Whether the label should use a fixed angle instead of using angle from automatic placement
    bool hasFixedAngle() const { return mHasFixedAngle; }
    //! Sets whether the label should use a fixed angle instead of using angle from automatic placement
    void setHasFixedAngle( bool enabled ) { mHasFixedAngle = enabled; }
    //! Angle in degrees of the fixed angle (relevant only if hasFixedAngle() returns TRUE)
    double fixedAngle() const { return mFixedAngle; }
    //! Sets angle in degrees of the fixed angle (relevant only if hasFixedAngle() returns TRUE)
    void setFixedAngle( double angle ) { mFixedAngle = angle; }

    /**
     * Returns whether the quadrant for the label is fixed.
     * Applies to "around point" placement strategy.
     * \see setHasFixedQuadrant
     * \see quadOffset
     */
    bool hasFixedQuadrant() const { return mHasFixedQuadrant; }

    /**
     * Sets whether the quadrant for the label must be respected. This can be used
     * to fix the quadrant for specific features when using an "around point" placement.
     * \see hasFixedQuadrant
     * \see quadOffset
     */
    void setHasFixedQuadrant( bool enabled ) { mHasFixedQuadrant = enabled; }

    /**
     * Applies to "offset from point" placement strategy and "around point" (in case hasFixedQuadrant() returns TRUE).
     * Determines which side of the point to use.
     * For X coordinate, values -1, 0, 1 mean left, center, right.
     * For Y coordinate, values -1, 0, 1 mean above, center, below.
     */
    QPointF quadOffset() const { return mQuadOffset; }

    /**
     * Set which side of the point to use
     * \see quadOffset
     */
    void setQuadOffset( QPointF quadOffset ) { mQuadOffset = quadOffset; }

    /**
     * Applies only to "offset from point" placement strategy.
     * What offset (in map units) to use from the point
     */
    QgsPointXY positionOffset() const { return mPositionOffset; }

    /**
     * Applies only to "offset from point" placement strategy.
     * Set what offset (in map units) to use from the point
     */
    void setPositionOffset( const QgsPointXY &offset ) { mPositionOffset = offset; }

    /**
     * Returns the offset type, which determines how offsets and distance to label
     * behaves. Support depends on which placement mode is used for generating
     * label candidates.
     * \see setOffsetType()
     */
    QgsPalLayerSettings::OffsetType offsetType() const { return mOffsetType; }

    /**
     * Sets the offset type, which determines how offsets and distance to label
     * behaves. Support depends on which placement mode is used for generating
     * label candidates.
     * \see offsetType()
     */
    void setOffsetType( QgsPalLayerSettings::OffsetType type ) { mOffsetType = type; }

    /**
     * Applies to "around point" placement strategy or linestring features.
     * Distance of the label from the feature (in map units)
     */
    double distLabel() const { return mDistLabel; }

    /**
     * Applies to "around point" placement strategy or linestring features.
     * Set distance of the label from the feature (in map units)
     */
    void setDistLabel( double dist ) { mDistLabel = dist; }

    /**
     * Returns the priority ordered list of predefined positions for label candidates. This property
     * is only used for OrderedPositionsAroundPoint placements.
     * \see setPredefinedPositionOrder()
     */
    QVector< QgsPalLayerSettings::PredefinedPointPosition > predefinedPositionOrder() const { return mPredefinedPositionOrder; }

    /**
     * Sets the priority ordered list of predefined positions for label candidates. This property
     * is only used for OrderedPositionsAroundPoint placements.
     * \see predefinedPositionOrder()
     */
    void setPredefinedPositionOrder( const QVector< QgsPalLayerSettings::PredefinedPointPosition > &order ) { mPredefinedPositionOrder = order; }

    /**
     * Applies only to linestring features - after what distance (in map units)
     * the labels should be repeated (0 = no repetitions)
     */
    double repeatDistance() const { return mRepeatDistance; }

    /**
     * Applies only to linestring features - set after what distance (in map units)
     * the labels should be repeated (0 = no repetitions)
     */
    void setRepeatDistance( double dist ) { mRepeatDistance = dist; }

    //! Whether label should be always shown (sets very high label priority)
    bool alwaysShow() const { return mAlwaysShow; }
    //! Sets whether label should be always shown (sets very high label priority)
    void setAlwaysShow( bool enabled ) { mAlwaysShow = enabled; }

    /**
     * Returns whether the feature will act as an obstacle for labels.
     * \returns TRUE if feature is an obstacle
     * \see setIsObstacle
     */
    bool isObstacle() const { return mIsObstacle; }

    /**
     * Sets whether the feature will act as an obstacle for labels.
     * \param enabled whether feature will act as an obstacle
     * \see isObstacle
     */
    void setIsObstacle( bool enabled ) { mIsObstacle = enabled; }

    /**
     * Returns the obstacle factor for the feature. The factor controls the penalty
     * for labels overlapping this feature.
     * \see setObstacleFactor
     */
    double obstacleFactor() const { return mObstacleFactor; }

    /**
     * Sets the obstacle factor for the feature. The factor controls the penalty
     * for labels overlapping this feature.
     * \param factor larger factors ( > 1.0 ) will result in labels
     * which are less likely to cover this feature, smaller factors ( < 1.0 ) mean labels
     * are more likely to cover this feature (where required)
     * \see obstacleFactor
     */
    void setObstacleFactor( double factor ) { mObstacleFactor = factor; }

    /**
     * Returns the feature's arrangement flags.
     * \see setArrangementFlags
     */
    pal::LineArrangementFlags arrangementFlags() const { return mArrangementFlags; }

    /**
     * Sets the feature's arrangement flags.
     * \param flags arrangement flags
     * \see arrangementFlags
     */
    void setArrangementFlags( pal::LineArrangementFlags flags ) { mArrangementFlags = flags; }

    /**
     * Text of the label
     *
     * Used also if "merge connected lines to avoid duplicate labels" is enabled
     * to identify which features may be merged.
     */
    QString labelText() const { return mLabelText; }
    //! Sets text of the label
    void setLabelText( const QString &text ) { mLabelText = text; }

    //! Gets additional infor required for curved label placement. Returns NULLPTR if not set
    pal::LabelInfo *curvedLabelInfo() const { return mInfo; }
    //! takes ownership of the instance
    void setCurvedLabelInfo( pal::LabelInfo *info ) { mInfo = info; }

    //! Gets PAL layer of the label feature. Should be only used internally in PAL
    pal::Layer *layer() const { return mLayer; }
    //! Assign PAL layer to the label feature. Should be only used internally in PAL
    void setLayer( pal::Layer *layer ) { mLayer = layer; }

    //! Returns provider of this instance
    QgsAbstractLabelProvider *provider() const;

  protected:
    //! Pointer to PAL layer (assigned when registered to PAL)
    pal::Layer *mLayer = nullptr;

    //! Associated ID unique within the parent label provider
    QgsFeatureId mId;
    //! Geometry of the feature to be labelled
    geos::unique_ptr mGeometry;
    //! Optional geometry to use for label obstacles, if different to mGeometry
    geos::unique_ptr mObstacleGeometry;
    //! Optional geometry to use for label's permissible zone
    QgsGeometry mPermissibleZone;
    //! Width and height of the label
    QSizeF mSize;
    //! Visual margin of label contents
    QgsMargins mVisualMargin;
    //! Size of associated rendered symbol, if applicable
    QSizeF mSymbolSize;
    //! Priority of the label
    double mPriority;
    //! Z-index of label (higher z-index labels are rendered on top of lower z-index labels)
    double mZIndex;
    //! whether mFixedPosition should be respected
    bool mHasFixedPosition;
    //! fixed position for the label (instead of automatic placement)
    QgsPointXY mFixedPosition;
    //! whether mFixedAngle should be respected
    bool mHasFixedAngle;
    //! fixed rotation for the label (instead of automatic choice)
    double mFixedAngle;
    //! whether mQuadOffset should be respected (only for "around point" placement)
    bool mHasFixedQuadrant;
    //! whether the side of the label is fixed (only for "around point" placement)
    QPointF mQuadOffset;
    //! offset of label from the feature (only for "offset from point" placement)
    QgsPointXY mPositionOffset;
    //! distance of label from the feature (only for "around point" placement or linestrings)
    double mDistLabel;
    //! Offset type for certain placement modes
    QgsPalLayerSettings::OffsetType mOffsetType;
    //! Ordered list of predefined positions for label (only for OrderedPositionsAroundPoint placement)
    QVector< QgsPalLayerSettings::PredefinedPointPosition > mPredefinedPositionOrder;
    //! distance after which label should be repeated (only for linestrings)
    double mRepeatDistance;
    //! whether to always show label - even in case of collisions
    bool mAlwaysShow;
    //! whether the feature geometry acts as an obstacle for labels
    bool mIsObstacle;
    //! how strong is the geometry acting as obstacle
    double mObstacleFactor;
    //! text of the label
    QString mLabelText;
    //! extra information for curved labels (may be NULLPTR)
    pal::LabelInfo *mInfo = nullptr;

    pal::LineArrangementFlags mArrangementFlags = nullptr;

  private:

    //! GEOS geometry on which mPermissibleZoneGeosPrepared is based on
    geos::unique_ptr mPermissibleZoneGeos;

    // TODO - not required when QgsGeometry caches geos preparedness
    geos::prepared_unique_ptr mPermissibleZoneGeosPrepared;

};

#endif // QGSLABELFEATURE_H
