/***************************************************************************
  qgstextformat.h
  ---------------
   begin                : May 2020
   copyright            : (C) Nyall Dawson
   email                : nyall dot dawson 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 QGSTEXTFORMAT_H
#define QGSTEXTFORMAT_H

#include "qgis_sip.h"
#include "qgis_core.h"
#include "qgis.h"
#include "qgstextbuffersettings.h"
#include "qgstextbackgroundsettings.h"
#include "qgstextshadowsettings.h"
#include "qgstextmasksettings.h"
#include "qgsstringutils.h"
#include "qgsscreenproperties.h"

#include <QSharedDataPointer>

class QMimeData;
class QgsTextSettingsPrivate;

/**
 * \class QgsTextFormat
  * \ingroup core
  * \brief Container for all settings relating to text rendering.
  * \note QgsTextFormat objects are implicitly shared.
 */
class CORE_EXPORT QgsTextFormat
{
  public:

    /**
     * Default constructor for QgsTextFormat. Creates a text format initially
     * set to an invalid state (see isValid()).
     */
    QgsTextFormat();

    QgsTextFormat( const QgsTextFormat &other );

    QgsTextFormat &operator=( const QgsTextFormat &other );

    ~QgsTextFormat();

    bool operator==( const QgsTextFormat &other ) const;
    bool operator!=( const QgsTextFormat &other ) const;

    /**
     * Returns TRUE if the format is valid.
     *
     * A default constructed QgsTextFormat is invalid, until at least one or more properties
     * have been set on the format. An invalid state can be used as a representation of a "not set"
     * text format, e.g. for indicating that a default text format should be used.
     *
     * \note Calling any setter on a QgsTextFormat object will automatically set the format as valid.
     *
     * \see setValid()
     * \since QGIS 3.16
     */
    bool isValid() const;

    /**
     * Sets the format to a valid state, without changing any of the default format settings.
     *
     * \see isValid()
     * \since QGIS 3.16
     */
    void setValid();

    /**
     * Returns a reference to the text buffer settings.
     * \see setBuffer()
     */
    QgsTextBufferSettings &buffer();

    /**
     * Returns a reference to the text buffer settings.
     * \see setBuffer()
     */
    SIP_SKIP QgsTextBufferSettings buffer() const { return mBufferSettings; }

    /**
     * Sets the text's buffer settings.
     * \param bufferSettings buffer settings
     * \see buffer()
     */
    void setBuffer( const QgsTextBufferSettings &bufferSettings );

    /**
     * Returns a reference to the text background settings.
     * \see setBackground()
     */
    QgsTextBackgroundSettings &background();

    /**
     * Returns a reference to the text background settings.
     * \see setBackground()
     */
    SIP_SKIP QgsTextBackgroundSettings background() const { return mBackgroundSettings; }

    /**
     * Sets the text's background settings.q
     * \param backgroundSettings background settings
     * \see background()
     */
    void setBackground( const QgsTextBackgroundSettings &backgroundSettings );

    /**
     * Returns a reference to the text drop shadow settings.
     * \see setShadow()
     */
    QgsTextShadowSettings &shadow();

    /**
     * Returns a reference to the text drop shadow settings.
     * \see setShadow()
     */
    SIP_SKIP QgsTextShadowSettings shadow() const { return mShadowSettings; }

    /**
     * Sets the text's drop shadow settings.
     * \param shadowSettings shadow settings
     * \see shadow()
     */
    void setShadow( const QgsTextShadowSettings &shadowSettings );

    /**
     * Returns a reference to the masking settings.
     * \see setMask()
     */
    QgsTextMaskSettings &mask();

    /**
     * Returns a reference to the masking settings.
     * Masks may be defined in contexts where the text is rendered over some map layers, for labeling especially.
     * \see setMask()
     * \since QGIS 3.12
     */
    SIP_SKIP QgsTextMaskSettings mask() const { return mMaskSettings; }

    /**
     * Sets the text's masking settings.
     * Masks may be defined in contexts where the text is rendered over some map layers, for labeling especially.
     * \param maskSettings mask settings
     * \see mask()
     * \since QGIS 3.12
     */
    void setMask( const QgsTextMaskSettings &maskSettings );

    /**
     * Returns the font used for rendering text. Note that the size of the font
     * is not used, and size() should be called instead to determine the size
     * of rendered text.
     * \see scaledFont()
     * \see setFont()
     * \see namedStyle()
     * \see toQFont()
     */
    QFont font() const;

    /**
     * Returns a font with the size scaled to match the format's size settings (including
     * units and map unit scale) for a specified render context.
     * \param context destination render context
     * \param scaleFactor optional font size scaling factor. It is recommended to set this to
     * QgsTextRenderer::calculateScaleFactorForFormat() and then manually scale painter devices or calculations
     * based on the resultant font metrics. Failure to do so will result in poor quality text rendering
     * at small font sizes.
     * \param isZeroSize will be set to true if the font is scaled down to a near 0 size, and nothing should be rendered. Not available in Python bindings.
     * \returns font with scaled size
     * \see font()
     * \see size()
     */
    QFont scaledFont( const QgsRenderContext &context, double scaleFactor = 1.0, bool *isZeroSize SIP_PYARGREMOVE = nullptr ) const;

    /**
     * Sets the font used for rendering text. Note that the size of the font
     * is not used, and setSize() should be called instead to explicitly set the size
     * of rendered text.
     * \param font desired font
     * \see font()
     * \see setNamedStyle()
     * \see fromQFont()
     */
    void setFont( const QFont &font );

    /**
     * Returns the named style for the font used for rendering text (e.g., "bold").
     * \see setNamedStyle()
     * \see font()
     */
    QString namedStyle() const;

    /**
     * Sets the named style for the font used for rendering text.
     * \param style named style, e.g., "bold"
     * \see namedStyle()
     * \see setFont()
     */
    void setNamedStyle( const QString &style );

    /**
     * Returns TRUE if the format is set to force a bold style.
     *
     * \warning Unlike setting a font's style via setNamedStyle(), this will ensure that a font is
     * always rendered in bold regardless of whether the font family actually has a bold variant. A
     * "faux bold" effect will be emulated, which may result in poor quality font rendering. For this
     * reason it is greatly preferred to call setNamedStyle() instead.
     *
     * \see setForcedBold()
     * \since QGIS 3.26
     */
    bool forcedBold() const;

    /**
     * Sets whether the format is set to force a bold style.
     *
     * \warning Unlike setting a font's style via setNamedStyle(), this will ensure that a font is
     * always rendered in bold regardless of whether the font family actually has a bold variant. A
     * "faux bold" effect will be emulated, which may result in poor quality font rendering. For this
     * reason it is greatly preferred to call setNamedStyle() instead.
     *
     * \see forcedBold()
     * \since QGIS 3.26
     */
    void setForcedBold( bool forced );

    /**
     * Returns TRUE if the format is set to force an italic style.
     *
     * \warning Unlike setting a font's style via setNamedStyle(), this will ensure that a font is
     * always rendered in italic regardless of whether the font family actually has an italic variant. A
     * "faux italic" slanted text effect will be emulated, which may result in poor quality font rendering. For this
     * reason it is greatly preferred to call setNamedStyle() instead.
     *
     * \see setForcedItalic()
     * \since QGIS 3.26
     */
    bool forcedItalic() const;

    /**
     * Sets whether the format is set to force an italic style.
     *
     * \warning Unlike setting a font's style via setNamedStyle(), this will ensure that a font is
     * always rendered in italic regardless of whether the font family actually has an italic variant. A
     * "faux italic" slanted text effect will be emulated, which may result in poor quality font rendering. For this
     * reason it is greatly preferred to call setNamedStyle() instead.
     *
     * \see forcedItalic()
     * \since QGIS 3.26
     */
    void setForcedItalic( bool forced );

    /**
     * Returns the list of font families to use when restoring the text format, in order of precedence.
     *
     * \warning The list of families returned by this method is ONLY used when restoring the text format
     * from serialized versions, and will not affect the current font() familily used by the format.
     *
     * \see setFamilies()
     * \since QGIS 3.20
     */
    QStringList families() const;

    /**
     * Sets a list of font \a families to use for the text format, in order of precedence.
     *
     * When restoring serialized versions of the text format then the first matching font family
     * from this list will be used for the text format. This provides a way to specify a list of possible
     * font families which are used as fallbacks if a family isn't available on a particular QGIS install (CSS style).
     *
     * \warning The list of families set by calling this method is ONLY used when restoring the text format
     * from serialized versions, and will not affect the current font() familily used by the format.
     *
     * \see families()
     * \since QGIS 3.20
     */
    void setFamilies( const QStringList &families );

    /**
     * Returns the size for rendered text. Units are retrieved using sizeUnit().
     * \see setSize()
     * \see sizeUnit()
     */
    double size() const;

    /**
     * Sets the size for rendered text.
     * \param size size of rendered text. Units are set using setSizeUnit()
     * \see size()
     * \see setSizeUnit()
     */
    void setSize( double size );

    /**
     * Returns the units for the size of rendered text.
     * \see size()
     * \see setSizeUnit()
     * \see sizeMapUnitScale()
     */
    Qgis::RenderUnit sizeUnit() const;

    /**
     * Sets the units for the size of rendered text.
     * \param unit size units
     * \see setSize()
     * \see sizeUnit()
     * \see setSizeMapUnitScale()
     */
    void setSizeUnit( Qgis::RenderUnit unit );

    /**
     * Returns the map unit scale object for the size. This is only used if the
     * sizeUnit() is set to QgsUnitTypes::RenderMapUnit.
     * \see setSizeMapUnitScale()
     * \see sizeUnit()
     */
    QgsMapUnitScale sizeMapUnitScale() const;

    /**
     * Sets the map unit scale object for the size. This is only used if the
     * sizeUnit() is set to QgsUnitTypes::RenderMapUnit.
     * \see sizeMapUnitScale()
     * \see setSizeUnit()
     */
    void setSizeMapUnitScale( const QgsMapUnitScale &scale );

    /**
     * Returns the color that text will be rendered in.
     * \see setColor()
     */
    QColor color() const;

    /**
     * Sets the color that text will be rendered in.
     * \param color text color
     * \see color()
     */
    void setColor( const QColor &color );

    /**
     * Returns the text's opacity. The opacity is a double value between 0 (fully transparent) and 1 (totally
     * opaque).
     * \see setOpacity()
     */
    double opacity() const;

    /**
     * Multiply opacity by \a opacityFactor.
     *
     * This method multiplies the opacity of all the labeling elements (text, shadow, buffer etc.)
     * by \a opacityFactor effectively changing the opacity of the whole labeling.
     *
     * \since QGIS 3.32
     */
    void multiplyOpacity( double opacityFactor );

    /**
     * Sets the text's opacity.
     * \param opacity opacity as a double value between 0 (fully transparent) and 1 (totally
     * opaque)
     * \see opacity()
     */
    void setOpacity( double opacity );

    /**
     * Returns the text's stretch factor.
     *
     * The stretch factor matches a condensed or expanded version of the font or applies a stretch
     * transform that changes the width of all characters in the font by factor percent.
     *
     * For example, a factor of 150 results in all characters in the font being 1.5 times
     * (ie. 150%) wider. The minimum stretch factor is 1, and the maximum stretch factor is 4000.
     *
     * \see setStretchFactor()
     * \since QGIS 3.24
     */
    int stretchFactor() const;

    /**
     * Sets the text's stretch \a factor.
     *
     * The stretch factor matches a condensed or expanded version of the font or applies a stretch
     * transform that changes the width of all characters in the font by factor percent.
     *
     * For example, setting \a factor to 150 results in all characters in the font being 1.5 times
     * (ie. 150%) wider. The minimum stretch factor is 1, and the maximum stretch factor is 4000.
     *
     * \see stretchFactor()
     * \since QGIS 3.24
     */
    void setStretchFactor( int factor );

    /**
     * Returns the blending mode used for drawing the text.
     * \see setBlendMode()
     */
    QPainter::CompositionMode blendMode() const;

    /**
     * Sets the blending mode used for drawing the text.
     * \param mode blending mode
     * \see blendMode()
     */
    void setBlendMode( QPainter::CompositionMode mode );

    /**
     * Returns the line height for text.
     *
     * If lineHeightUnit() is QgsUnitTypes::RenderPercentage (the default), then this is a number representing
     * the leading between lines as a multiplier of line height (where 0 - 1.0 represents 0 to 100% of text line height).
     * Otherwise the line height is an absolute measurement in lineHeightUnit().
     *
     * \see setLineHeight()
     * \see lineHeightUnit()
     */
    double lineHeight() const;

    /**
     * Sets the line height for text.
     *
     * If lineHeightUnit() is QgsUnitTypes::RenderPercentage (the default), then \a height is a number representing
     * the leading between lines as a multiplier of line height (where 0 - 1.0 represents 0 to 100% of text line height).
     * Otherwise \a height is an absolute measurement in lineHeightUnit().
     *
     * \see lineHeight()
     * \see setLineHeightUnit()
     */
    void setLineHeight( double height );

    /**
     * Returns the units for the line height for text.
     *
     * \see setLineHeightUnit()
     * \see lineHeight()
     *
     * \since QGIS 3.28
     */
    Qgis::RenderUnit lineHeightUnit() const;

    /**
     * Sets the \a unit for the line height for text.
     *
     * \see lineHeightUnit()
     * \see setLineHeight()
     *
     * \since QGIS 3.28
     */
    void setLineHeightUnit( Qgis::RenderUnit unit );

    /**
     * Returns the distance for tab stops.
     *
     * \see tabStopDistanceUnit()
     * \see setTabStopDistance()
     *
     * \since QGIS 3.38
     */
    double tabStopDistance() const;

    /**
     * Sets the \a distance for tab stops. The units are specified using setTabStopDistanceUnit().
     *
     * \see tabStopDistance()
     * \see setTabStopDistanceUnit()
     *
     * \since QGIS 3.38
     */
    void setTabStopDistance( double distance );

    /**
     * Returns the units for the tab stop distance.
     *
     * \see tabStopDistance()
     * \see setTabStopDistanceUnit()
     *
     * \since QGIS 3.38
     */
    Qgis::RenderUnit tabStopDistanceUnit() const;

    /**
     * Sets the \a unit used for the tab stop distance.
     *
     * \see setTabStopDistance()
     * \see tabStopDistanceUnit()
     *
     * \since QGIS 3.38
     */
    void setTabStopDistanceUnit( Qgis::RenderUnit unit );

    /**
     * Returns the map unit scale object for the tab stop distance. This is only used if the
     * tab stop distance is set to Qgis::RenderUnit::MapUnits.
     *
     * \see setTabStopDistanceMapUnitScale()
     * \see tabStopDistanceUnit()
     *
     * \since QGIS 3.38
     */
    QgsMapUnitScale tabStopDistanceMapUnitScale() const;

    /**
     * Sets the map unit \a scale object for the tab stop distance. This is only used if the
     * tab stop distance is set to Qgis::RenderUnit::MapUnits.
     *
     * \see tabStopDistanceMapUnitScale()
     * \see setTabStopDistanceUnit()
     *
     * \since QGIS 3.38
     */
    void setTabStopDistanceMapUnitScale( const QgsMapUnitScale &scale );

    /**
     * Returns the orientation of the text.
     * \see setOrientation()
     * \since QGIS 3.10
     */
    Qgis::TextOrientation orientation() const;

    /**
     * Sets the \a orientation for the text.
     * \see orientation()
     * \since QGIS 3.10
     */
    void setOrientation( Qgis::TextOrientation orientation );

    /**
     * Returns the text capitalization style.
     *
     * \see setCapitalization()
     * \since QGIS 3.16
     */
    Qgis::Capitalization capitalization() const;

    /**
     * Sets the text \a capitalization style.
     *
     * \see capitalization()
     * \since QGIS 3.16
     */
    void setCapitalization( Qgis::Capitalization capitalization );

    /**
     * Returns TRUE if text should be treated as a HTML document and HTML tags should be used for formatting
     * the rendered text.
     *
     * \warning Only a small subset of HTML formatting is supported. Currently this is restricted to:
     *
     * - text color formatting
     * - strikethrough
     * - underline
     * - overline
     *
     * \see setAllowHtmlFormatting()
     * \since QGIS 3.14
     */
    bool allowHtmlFormatting() const;

    /**
     * Sets whether text should be treated as a HTML document and HTML tags should be used for formatting
     * the rendered text.
     *
     * \warning Only a small subset of HTML formatting is supported. Currently this is restricted to:
     *
     * - text color formatting
     * - strikethrough
     * - underline
     * - overline
     *
     * \see allowHtmlFormatting()
     * \since QGIS 3.14
     */
    void setAllowHtmlFormatting( bool allow );

    /**
     * Returns the background color for text previews.
     * \see setPreviewBackgroundColor()
     * \since QGIS 3.10
     */
    QColor previewBackgroundColor() const;

    /**
     * Sets the background \a color that text will be rendered on for previews.
     * \see previewBackgroundColor()
     * \since QGIS 3.10
     */
    void setPreviewBackgroundColor( const QColor &color );

    /**
     * Reads settings from a layer's custom properties (for QGIS 2.x projects).
     * \param layer source vector layer
     */
    void readFromLayer( QgsVectorLayer *layer );

    /**
     * Read settings from a DOM element.
     * \see writeXml()
     */
    void readXml( const QDomElement &elem, const QgsReadWriteContext &context );

    /**
     * Write settings into a DOM element.
     * \see readXml()
     */
    QDomElement writeXml( QDomDocument &doc, const QgsReadWriteContext &context ) const;

    /**
     * Returns new mime data representing the text format settings.
     * Caller takes responsibility for deleting the returned object.
     * \see fromMimeData()
     */
    QMimeData *toMimeData() const SIP_FACTORY;

    /**
     * Returns a text format matching the settings from an input \a font.
     * Unlike setFont(), this method also handles the size and size units
     * from \a font.
     * \see toQFont()
     * \since QGIS 3.2
     */
    static QgsTextFormat fromQFont( const QFont &font );

    /**
     * Returns a QFont matching the relevant settings from this text format.
     * Unlike font(), this method also handles the size and size units
     * from the text format.
     * \see fromQFont()
     * \since QGIS 3.2
     */
    QFont toQFont() const;

    /**
     * Attempts to parse the provided mime \a data as a QgsTextFormat.
     * If data can be parsed as a text format, \a ok will be set to TRUE.
     * \see toMimeData()
     */
    static QgsTextFormat fromMimeData( const QMimeData *data, bool *ok SIP_OUT = nullptr );

    /**
     * Returns TRUE if any component of the font format requires advanced effects
     * such as blend modes, which require output in raster formats to be fully respected.
     */
    bool containsAdvancedEffects() const;

    /**
     * Returns TRUE if the specified font was found on the system, or FALSE
     * if the font was not found and a replacement was used instead.
     * \see resolvedFontFamily()
     */
    bool fontFound() const { return mTextFontFound; }

    /**
     * Returns the family for the resolved font, ie if the specified font
     * was not found on the system this will return the name of the replacement
     * font.
     * \see fontFound()
     */
    QString resolvedFontFamily() const { return mTextFontFamily; }

    /**
     * Returns a reference to the format's property collection, used for data defined overrides.
     * \see setDataDefinedProperties()
     * \since QGIS 3.10
     */
    QgsPropertyCollection &dataDefinedProperties();

    /**
     * Returns a reference to the format's property collection, used for data defined overrides.
     * \see setDataDefinedProperties()
     * \note not available in Python bindings
     * \since QGIS 3.10
     */
    const QgsPropertyCollection &dataDefinedProperties() const SIP_SKIP;

    /**
     * Returns all field names referenced by the configuration (e.g. from data defined properties).
     * \since QGIS 3.14
     */
    QSet<QString> referencedFields( const QgsRenderContext &context ) const;

    /**
     * Sets the format's property collection, used for data defined overrides.
     * \param collection property collection. Existing properties will be replaced.
     * \see dataDefinedProperties()
     * \since QGIS 3.10
     */
    void setDataDefinedProperties( const QgsPropertyCollection &collection );

    /**
     * Updates the format by evaluating current values of data defined properties.
     * \since QGIS 3.10
     */
    void updateDataDefinedProperties( QgsRenderContext &context );

    /**
    * Returns a pixmap preview for a text \a format.
    * \param format text format
    * \param size target pixmap size
    * \param previewText text to render in preview, or empty for default text
    * \param padding space between icon edge and color ramp
    * \param screen can be used to specify the destination screen properties for the icon. This allows the icon to be generated using the correct DPI and device pixel ratio for the target screen (since QGIS 3.32)
    * \since QGIS 3.10
    */
    static QPixmap textFormatPreviewPixmap( const QgsTextFormat &format, QSize size, const QString &previewText = QString(), int padding = 0, const QgsScreenProperties &screen = QgsScreenProperties() );

    /**
     * Returns a CSS string representing the specified text format as closely as possible.
     * \param pointToPixelMultiplier scaling factor to apply to convert point sizes to pixel font sizes.
     * The CSS returned by this function will always use pixels for font sizes, so this parameter
     * should be set to a suitable value to convert point sizes to pixels (e.g., taking into account
     * destination DPI)
     * \returns partial CSS string, e.g., "line-height: 120%;"
     * \since QGIS 3.34
     */
    QString asCSS( double pointToPixelMultiplier = 1.0 ) const;

  private:

    QgsTextBufferSettings mBufferSettings;
    QgsTextBackgroundSettings mBackgroundSettings;
    QgsTextShadowSettings mShadowSettings;
    QgsTextMaskSettings mMaskSettings;

    QString mTextFontFamily;
    bool mTextFontFound = true;

    QSharedDataPointer<QgsTextSettingsPrivate> d;

};

Q_DECLARE_METATYPE( QgsTextFormat )

#endif // QGSTEXTFORMAT_H
