////////////////////////////////////////////////////////////
//
// SFML - Simple and Fast Multimedia Library
// Copyright (C) 2007-2025 Laurent Gomila (laurent@sfml-dev.org)
//
// This software is provided 'as-is', without any express or implied warranty.
// In no event will the authors be held liable for any damages arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it freely,
// subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented;
//    you must not claim that you wrote the original software.
//    If you use this software in a product, an acknowledgment
//    in the product documentation would be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such,
//    and must not be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source distribution.
//
////////////////////////////////////////////////////////////

#pragma once

////////////////////////////////////////////////////////////
// Headers
////////////////////////////////////////////////////////////
#include <SFML/Graphics/Export.hpp>

#include <SFML/Graphics/Glyph.hpp>
#include <SFML/Graphics/Rect.hpp>
#include <SFML/Graphics/Texture.hpp>

#include <SFML/System/Vector2.hpp>

#include <filesystem>
#include <memory>
#include <string>
#include <string_view>
#include <unordered_map>
#include <vector>

#include <cstddef>
#include <cstdint>


namespace sf
{
class InputStream;

////////////////////////////////////////////////////////////
/// \brief Class for loading and manipulating character fonts
///
////////////////////////////////////////////////////////////
class SFML_GRAPHICS_API Font
{
public:
    ////////////////////////////////////////////////////////////
    /// \brief Holds various information about a font
    ///
    ////////////////////////////////////////////////////////////
    struct Info
    {
        std::string family; //!< The font family
    };

    ////////////////////////////////////////////////////////////
    /// \brief Default constructor
    ///
    /// Construct an empty font that does not contain any glyphs.
    ///
    ////////////////////////////////////////////////////////////
    Font() = default;

    ////////////////////////////////////////////////////////////
    /// \brief Construct the font from a file
    ///
    /// The supported font formats are: TrueType, Type 1, CFF,
    /// OpenType, SFNT, X11 PCF, Windows FNT, BDF, PFR and Type 42.
    /// Note that this function knows nothing about the standard
    /// fonts installed on the user's system, thus you can't
    /// load them directly.
    ///
    /// \warning SFML cannot preload all the font data in this
    /// function, so the file has to remain accessible until
    /// the `sf::Font` object opens a new font or is destroyed.
    ///
    /// \param filename Path of the font file to open
    ///
    /// \throws sf::Exception if opening was unsuccessful
    ///
    /// \see `openFromFile`, `openFromMemory`, `openFromStream`
    ///
    ////////////////////////////////////////////////////////////
    explicit Font(const std::filesystem::path& filename);

    ////////////////////////////////////////////////////////////
    /// \brief Construct the font from a file in memory
    ///
    /// The supported font formats are: TrueType, Type 1, CFF,
    /// OpenType, SFNT, X11 PCF, Windows FNT, BDF, PFR and Type 42.
    ///
    /// \warning SFML cannot preload all the font data in this
    /// function, so the buffer pointed by `data` has to remain
    /// valid until the `sf::Font` object opens a new font or
    /// is destroyed.
    ///
    /// \param data        Pointer to the file data in memory
    /// \param sizeInBytes Size of the data to load, in bytes
    ///
    /// \throws sf::Exception if loading was unsuccessful
    ///
    /// \see `openFromFile`, `openFromMemory`, `openFromStream`
    ///
    ////////////////////////////////////////////////////////////
    Font(const void* data, std::size_t sizeInBytes);

    ////////////////////////////////////////////////////////////
    /// \brief Construct the font from a custom stream
    ///
    /// The supported font formats are: TrueType, Type 1, CFF,
    /// OpenType, SFNT, X11 PCF, Windows FNT, BDF, PFR and Type 42.
    /// Warning: SFML cannot preload all the font data in this
    /// function, so the contents of `stream` have to remain
    /// valid as long as the font is used.
    ///
    /// \warning SFML cannot preload all the font data in this
    /// function, so the stream has to remain accessible until
    /// the `sf::Font` object opens a new font or is destroyed.
    ///
    /// \param stream Source stream to read from
    ///
    /// \throws sf::Exception if loading was unsuccessful
    ///
    /// \see `openFromFile`, `openFromMemory`, `openFromStream`
    ///
    ////////////////////////////////////////////////////////////
    explicit Font(InputStream& stream);

    ////////////////////////////////////////////////////////////
    /// \brief Open the font from a file
    ///
    /// The supported font formats are: TrueType, Type 1, CFF,
    /// OpenType, SFNT, X11 PCF, Windows FNT, BDF, PFR and Type 42.
    /// Note that this function knows nothing about the standard
    /// fonts installed on the user's system, thus you can't
    /// load them directly.
    ///
    /// \warning SFML cannot preload all the font data in this
    /// function, so the file has to remain accessible until
    /// the `sf::Font` object opens a new font or is destroyed.
    ///
    /// \param filename Path of the font file to load
    ///
    /// \return `true` if opening succeeded, `false` if it failed
    ///
    /// \see `openFromMemory`, `openFromStream`
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] bool openFromFile(const std::filesystem::path& filename);

    ////////////////////////////////////////////////////////////
    /// \brief Open the font from a file in memory
    ///
    /// The supported font formats are: TrueType, Type 1, CFF,
    /// OpenType, SFNT, X11 PCF, Windows FNT, BDF, PFR and Type 42.
    ///
    /// \warning SFML cannot preload all the font data in this
    /// function, so the buffer pointed by `data` has to remain
    /// valid until the `sf::Font` object opens a new font or
    /// is destroyed.
    ///
    /// \param data        Pointer to the file data in memory
    /// \param sizeInBytes Size of the data to load, in bytes
    ///
    /// \return `true` if opening succeeded, `false` if it failed
    ///
    /// \see `openFromFile`, `openFromStream`
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] bool openFromMemory(const void* data, std::size_t sizeInBytes);

    ////////////////////////////////////////////////////////////
    /// \brief Open the font from a custom stream
    ///
    /// The supported font formats are: TrueType, Type 1, CFF,
    /// OpenType, SFNT, X11 PCF, Windows FNT, BDF, PFR and Type 42.
    ///
    /// \warning SFML cannot preload all the font data in this
    /// function, so the stream has to remain accessible until
    /// the `sf::Font` object opens a new font or is destroyed.
    ///
    /// \param stream Source stream to read from
    ///
    /// \return `true` if opening succeeded, `false` if it failed
    ///
    /// \see `openFromFile`, `openFromMemory`
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] bool openFromStream(InputStream& stream);

    ////////////////////////////////////////////////////////////
    /// \brief Get the font information
    ///
    /// \return A structure that holds the font information
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] const Info& getInfo() const;

    ////////////////////////////////////////////////////////////
    /// \brief Retrieve a glyph of the font
    ///
    /// If the font is a bitmap font, not all character sizes
    /// might be available. If the glyph is not available at the
    /// requested size, an empty glyph is returned.
    ///
    /// You may want to use `hasGlyph` to determine if the
    /// glyph exists before requesting it. If the glyph does not
    /// exist, a font specific default is returned.
    ///
    /// Be aware that using a negative value for the outline
    /// thickness will cause distorted rendering.
    ///
    /// \param codePoint        Unicode code point of the character to get
    /// \param characterSize    Reference character size
    /// \param bold             Retrieve the bold version or the regular one?
    /// \param outlineThickness Thickness of outline (when != 0 the glyph will not be filled)
    ///
    /// \return The glyph corresponding to `codePoint` and `characterSize`
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] const Glyph& getGlyph(char32_t codePoint, unsigned int characterSize, bool bold, float outlineThickness = 0) const;

    ////////////////////////////////////////////////////////////
    /// \brief Determine if this font has a glyph representing the requested code point
    ///
    /// Most fonts only include a very limited selection of glyphs from
    /// specific Unicode subsets, like Latin, Cyrillic, or Asian characters.
    ///
    /// While code points without representation will return a font specific
    /// default character, it might be useful to verify whether specific
    /// code points are included to determine whether a font is suited
    /// to display text in a specific language.
    ///
    /// \param codePoint Unicode code point to check
    ///
    /// \return `true` if the codepoint has a glyph representation, `false` otherwise
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] bool hasGlyph(char32_t codePoint) const;

    ////////////////////////////////////////////////////////////
    /// \brief Get the kerning offset of two glyphs
    ///
    /// The kerning is an extra offset (negative) to apply between two
    /// glyphs when rendering them, to make the pair look more "natural".
    /// For example, the pair "AV" have a special kerning to make them
    /// closer than other characters. Most of the glyphs pairs have a
    /// kerning offset of zero, though.
    ///
    /// \param first         Unicode code point of the first character
    /// \param second        Unicode code point of the second character
    /// \param characterSize Reference character size
    /// \param bold          Retrieve the bold version or the regular one?
    ///
    /// \return Kerning value for `first` and `second`, in pixels
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] float getKerning(std::uint32_t first, std::uint32_t second, unsigned int characterSize, bool bold = false) const;

    ////////////////////////////////////////////////////////////
    /// \brief Get the line spacing
    ///
    /// Line spacing is the vertical offset to apply between two
    /// consecutive lines of text.
    ///
    /// \param characterSize Reference character size
    ///
    /// \return Line spacing, in pixels
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] float getLineSpacing(unsigned int characterSize) const;

    ////////////////////////////////////////////////////////////
    /// \brief Get the position of the underline
    ///
    /// Underline position is the vertical offset to apply between the
    /// baseline and the underline.
    ///
    /// \param characterSize Reference character size
    ///
    /// \return Underline position, in pixels
    ///
    /// \see `getUnderlineThickness`
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] float getUnderlinePosition(unsigned int characterSize) const;

    ////////////////////////////////////////////////////////////
    /// \brief Get the thickness of the underline
    ///
    /// Underline thickness is the vertical size of the underline.
    ///
    /// \param characterSize Reference character size
    ///
    /// \return Underline thickness, in pixels
    ///
    /// \see `getUnderlinePosition`
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] float getUnderlineThickness(unsigned int characterSize) const;

    ////////////////////////////////////////////////////////////
    /// \brief Retrieve the texture containing the loaded glyphs of a certain size
    ///
    /// The contents of the returned texture changes as more glyphs
    /// are requested, thus it is not very relevant. It is mainly
    /// used internally by `sf::Text`.
    ///
    /// \param characterSize Reference character size
    ///
    /// \return Texture containing the glyphs of the requested size
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] const Texture& getTexture(unsigned int characterSize) const;

    ////////////////////////////////////////////////////////////
    /// \brief Enable or disable the smooth filter
    ///
    /// When the filter is activated, the font appears smoother
    /// so that pixels are less noticeable. However if you want
    /// the font to look exactly the same as its source file,
    /// you should disable it.
    /// The smooth filter is enabled by default.
    ///
    /// \param smooth `true` to enable smoothing, `false` to disable it
    ///
    /// \see `isSmooth`
    ///
    ////////////////////////////////////////////////////////////
    void setSmooth(bool smooth);

    ////////////////////////////////////////////////////////////
    /// \brief Tell whether the smooth filter is enabled or not
    ///
    /// \return `true` if smoothing is enabled, `false` if it is disabled
    ///
    /// \see `setSmooth`
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] bool isSmooth() const;

private:
    ////////////////////////////////////////////////////////////
    /// \brief Structure defining a row of glyphs
    ///
    ////////////////////////////////////////////////////////////
    struct Row
    {
        Row(unsigned int rowTop, unsigned int rowHeight) : top(rowTop), height(rowHeight)
        {
        }

        unsigned int width{}; //!< Current width of the row
        unsigned int top;     //!< Y position of the row into the texture
        unsigned int height;  //!< Height of the row
    };

    ////////////////////////////////////////////////////////////
    // Types
    ////////////////////////////////////////////////////////////
    using GlyphTable = std::unordered_map<std::uint64_t, Glyph>; //!< Table mapping a codepoint to its glyph

    ////////////////////////////////////////////////////////////
    /// \brief Structure defining a page of glyphs
    ///
    ////////////////////////////////////////////////////////////
    struct Page
    {
        explicit Page(bool smooth);

        GlyphTable       glyphs;     //!< Table mapping code points to their corresponding glyph
        Texture          texture;    //!< Texture containing the pixels of the glyphs
        unsigned int     nextRow{3}; //!< Y position of the next new row in the texture
        std::vector<Row> rows;       //!< List containing the position of all the existing rows
    };

    ////////////////////////////////////////////////////////////
    /// \brief Free all the internal resources
    ///
    ////////////////////////////////////////////////////////////
    void cleanup();

    ////////////////////////////////////////////////////////////
    /// \brief Open from stream and print errors with custom message
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] bool openFromStreamImpl(InputStream& stream, std::string_view type);

    ////////////////////////////////////////////////////////////
    /// \brief Find or create the glyphs page corresponding to the given character size
    ///
    /// \param characterSize Reference character size
    ///
    /// \return The glyphs page corresponding to \a characterSize
    ///
    ////////////////////////////////////////////////////////////
    Page& loadPage(unsigned int characterSize) const;

    ////////////////////////////////////////////////////////////
    /// \brief Load a new glyph and store it in the cache
    ///
    /// \param codePoint        Unicode code point of the character to load
    /// \param characterSize    Reference character size
    /// \param bold             Retrieve the bold version or the regular one?
    /// \param outlineThickness Thickness of outline (when != 0 the glyph will not be filled)
    ///
    /// \return The glyph corresponding to `codePoint` and `characterSize`
    ///
    ////////////////////////////////////////////////////////////
    Glyph loadGlyph(char32_t codePoint, unsigned int characterSize, bool bold, float outlineThickness) const;

    ////////////////////////////////////////////////////////////
    /// \brief Find a suitable rectangle within the texture for a glyph
    ///
    /// \param page Page of glyphs to search in
    /// \param size Width and height of the rectangle
    ///
    /// \return Found rectangle within the texture
    ///
    ////////////////////////////////////////////////////////////
    IntRect findGlyphRect(Page& page, Vector2u size) const;

    ////////////////////////////////////////////////////////////
    /// \brief Make sure that the given size is the current one
    ///
    /// \param characterSize Reference character size
    ///
    /// \return `true` on success, `false` if any error happened
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] bool setCurrentSize(unsigned int characterSize) const;

    ////////////////////////////////////////////////////////////
    // Types
    ////////////////////////////////////////////////////////////
    struct FontHandles;
    using PageTable = std::unordered_map<unsigned int, Page>; //!< Table mapping a character size to its page (texture)

    ////////////////////////////////////////////////////////////
    // Member data
    ////////////////////////////////////////////////////////////
    std::shared_ptr<FontHandles> m_fontHandles;    //!< Shared information about the internal font instance
    bool                         m_isSmooth{true}; //!< Status of the smooth filter
    Info                         m_info;           //!< Information about the font
    mutable PageTable            m_pages;          //!< Table containing the glyphs pages by character size
    mutable std::vector<std::uint8_t> m_pixelBuffer; //!< Pixel buffer holding a glyph's pixels before being written to the texture
    std::shared_ptr<InputStream> m_stream; //!< Stream for openFromFile and openFromMemory
};

} // namespace sf


////////////////////////////////////////////////////////////
/// \class sf::Font
/// \ingroup graphics
///
/// Fonts can be opened from a file, from memory or from a custom
/// stream, and supports the most common types of fonts. See
/// the openFromFile function for the complete list of supported formats.
///
/// Once it is opened, a `sf::Font` instance provides three
/// types of information about the font:
/// \li Global metrics, such as the line spacing
/// \li Per-glyph metrics, such as bounding box or kerning
/// \li Pixel representation of glyphs
///
/// Fonts alone are not very useful: they hold the font data
/// but cannot make anything useful of it. To do so you need to
/// use the `sf::Text` class, which is able to properly output text
/// with several options such as character size, style, color,
/// position, rotation, etc.
/// This separation allows more flexibility and better performances:
/// indeed a `sf::Font` is a heavy resource, and any operation on it
/// is slow (often too slow for real-time applications). On the other
/// side, a `sf::Text` is a lightweight object which can combine the
/// glyphs data and metrics of a `sf::Font` to display any text on a
/// render target.
/// Note that it is also possible to bind several `sf::Text` instances
/// to the same `sf::Font`.
///
/// It is important to note that the `sf::Text` instance doesn't
/// copy the font that it uses, it only keeps a reference to it.
/// Thus, a `sf::Font` must not be destructed while it is
/// used by a `sf::Text` (i.e. never write a function that
/// uses a local `sf::Font` instance for creating a text).
///
/// Usage example:
/// \code
/// // Open a new font
/// const sf::Font font("arial.ttf");
///
/// // Create a text which uses our font
/// sf::Text text1(font);
/// text1.setCharacterSize(30);
/// text1.setStyle(sf::Text::Regular);
///
/// // Create another text using the same font, but with different parameters
/// sf::Text text2(font);
/// text2.setCharacterSize(50);
/// text2.setStyle(sf::Text::Italic);
/// \endcode
///
/// Apart from opening font files, and passing them to instances
/// of `sf::Text`, you should normally not have to deal directly
/// with this class. However, it may be useful to access the
/// font metrics or rasterized glyphs for advanced usage.
///
/// Note that if the font is a bitmap font, it is not scalable,
/// thus not all requested sizes will be available to use. This
/// needs to be taken into consideration when using `sf::Text`.
/// If you need to display text of a certain size, make sure the
/// corresponding bitmap font that supports that size is used.
///
/// \see `sf::Text`
///
////////////////////////////////////////////////////////////
