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#ifndef INCLUDED_VCL_INC_SALLAYOUT_HXX
#define INCLUDED_VCL_INC_SALLAYOUT_HXX

#include <iostream>
#include <list>
#include <vector>

#include <basegfx/polygon/b2dpolypolygon.hxx>
#include <i18nlangtag/languagetag.hxx>
#include <tools/gen.hxx>
#include <vcl/dllapi.h>
#include <vcl/vclenum.hxx> // for typedef sal_UCS4
#include <vcl/devicecoordinate.hxx>

#include "salglyphid.hxx"

#define MAX_FALLBACK 16

typedef unsigned short LanguageType;

class SalGraphics;
class PhysicalFontFace;
enum class SalLayoutFlags;
namespace vcl {
    class TextLayoutCache;
}

// used for managing runs e.g. for BiDi, glyph and script fallback
class VCL_PLUGIN_PUBLIC ImplLayoutRuns
{
private:
    int                 mnRunIndex;
    std::vector<int>    maRuns;

public:
            ImplLayoutRuns() { mnRunIndex = 0; maRuns.reserve(8); }

    void    Clear()             { maRuns.clear(); }
    void    AddPos( int nCharPos, bool bRTL );
    void    AddRun( int nMinRunPos, int nEndRunPos, bool bRTL );

    bool    IsEmpty() const     { return maRuns.empty(); }
    void    ResetPos()          { mnRunIndex = 0; }
    void    NextRun()           { mnRunIndex += 2; }
    bool    GetRun( int* nMinRunPos, int* nEndRunPos, bool* bRTL ) const;
    bool    GetNextPos( int* nCharPos, bool* bRTL );
    bool    PosIsInRun( int nCharPos ) const;
    bool    PosIsInAnyRun( int nCharPos ) const;
};

class ImplLayoutArgs
{
public:
    // string related inputs
    LanguageTag         maLanguageTag;
    SalLayoutFlags      mnFlags;
    const OUString&     mrStr;
    int                 mnMinCharPos;
    int                 mnEndCharPos;

    // performance hack
    vcl::TextLayoutCache const* m_pTextLayoutCache;

    // positioning related inputs
    const DeviceCoordinate* mpDXArray;     // in pixel units
    DeviceCoordinate    mnLayoutWidth;      // in pixel units
    int                 mnOrientation;      // in 0-3600 system

    // data for bidi and glyph+script fallback
    ImplLayoutRuns      maRuns;
    ImplLayoutRuns      maFallbackRuns;

public:
                ImplLayoutArgs( const OUString& rStr,
                                int nMinCharPos, int nEndCharPos, SalLayoutFlags nFlags,
                                const LanguageTag& rLanguageTag,
                                vcl::TextLayoutCache const* pLayoutCache);

    void        SetLayoutWidth( DeviceCoordinate nWidth )       { mnLayoutWidth = nWidth; }
    void        SetDXArray( const DeviceCoordinate* pDXArray )  { mpDXArray = pDXArray; }
    void        SetOrientation( int nOrientation )  { mnOrientation = nOrientation; }

    void        ResetPos()
                    { maRuns.ResetPos(); }
    bool        GetNextPos( int* nCharPos, bool* bRTL )
                    { return maRuns.GetNextPos( nCharPos, bRTL ); }
    bool        GetNextRun( int* nMinRunPos, int* nEndRunPos, bool* bRTL );
    void        NeedFallback( int nCharPos, bool bRTL )
                    { maFallbackRuns.AddPos( nCharPos, bRTL ); }
    void        NeedFallback( int nMinRunPos, int nEndRunPos, bool bRTL )
                    { maFallbackRuns.AddRun( nMinRunPos, nEndRunPos, bRTL ); }
    // methods used by BiDi and glyph fallback
    bool        NeedFallback() const
                    { return !maFallbackRuns.IsEmpty(); }
    bool        PrepareFallback();

protected:
    void        AddRun( int nMinCharPos, int nEndCharPos, bool bRTL );
};

// For nice SAL_INFO logging of ImplLayoutArgs values
std::ostream &operator <<(std::ostream& s, ImplLayoutArgs &rArgs);

// helper functions often used with ImplLayoutArgs
int GetVerticalFlags( sal_UCS4 );

// all positions/widths are in font units
// one exception: drawposition is in pixel units

// Unfortunately there is little documentation to help implementors of
// new classes derived from SalLayout ("layout engines"), and the code
// and data structures are far from obvious.

// For instance, I *think* the important virtual functions in the
// layout engines are called in this order:

// * InitFont()
// * LayoutText()
// * AdjustLayout(), any number of times (but presumably
// usually not at all or just once)
// * Optionally, DrawText()

// Functions that just return information like GetTexWidth() and
// FillDXArray() are called after LayoutText() and before DrawText().

// Another important questions is which parts of an ImplLayoutArgs can
// be changed by callers between LayoutText() and AdjustLayout()
// calls. It probably makes sense only if one assumes that the "string
// related inputs" part are not changed after LayoutText().

// But why use the same ImplLayoutArgs structure as parameter for both
// LayoutText() and AdjustLayout() in the first place? And why
// duplicate some of the fields in both SalLayout and ImplLayoutArgs
// (mnMinCharPos, mnEndCharPos, mnLayoutFlags==mnFlags,
// mnOrientation)? Lost in history...

class VCL_PLUGIN_PUBLIC SalLayout
{
public:
    // used by upper layers
    Point&          DrawBase()                              { return maDrawBase; }
    const Point&    DrawBase() const                        { return maDrawBase; }
    Point&          DrawOffset()                            { return maDrawOffset; }
    const Point&    DrawOffset() const                      { return maDrawOffset; }
    Point           GetDrawPosition( const Point& rRelative = Point(0,0) ) const;

    virtual bool    LayoutText( ImplLayoutArgs& ) = 0;  // first step of layouting
    virtual void    AdjustLayout( ImplLayoutArgs& );    // adjusting after fallback etc.
    virtual void    InitFont() const {}
    virtual void    DrawText( SalGraphics& ) const = 0;
    virtual bool    DrawTextSpecial( SalGraphics& /* rGraphics */, sal_uInt32 /* flags */ ) const { return false; }
#define DRAWTEXT_F_OUTLINE ((sal_uInt32)(1<<0))

    int             GetUnitsPerPixel() const                { return mnUnitsPerPixel; }
    int             GetOrientation() const                  { return mnOrientation; }

    // methods using string indexing
    virtual sal_Int32 GetTextBreak(DeviceCoordinate nMaxWidth, DeviceCoordinate nCharExtra=0, int nFactor=1) const = 0;
    virtual DeviceCoordinate FillDXArray( DeviceCoordinate* pDXArray ) const = 0;
    virtual DeviceCoordinate GetTextWidth() const { return FillDXArray( nullptr ); }
    virtual void    GetCaretPositions( int nArraySize, long* pCaretXArray ) const = 0;
    virtual bool    IsKashidaPosValid ( int /*nCharPos*/ ) const { return true; } // i60594

    // methods using glyph indexing
    virtual int     GetNextGlyphs( int nLen, sal_GlyphId* pGlyphIdAry, Point& rPos, int&,
                                   DeviceCoordinate* pGlyphAdvAry = nullptr, int* pCharPosAry = nullptr,
                                   const PhysicalFontFace** pFallbackFonts = nullptr ) const = 0;
    virtual bool    GetOutline( SalGraphics&, basegfx::B2DPolyPolygonVector& ) const;
    virtual bool    GetBoundRect( SalGraphics&, Rectangle& ) const;

    static bool     IsSpacingGlyph( sal_GlyphId );

    // reference counting
    void            Release() const;

    // used by glyph+font+script fallback
    virtual void    MoveGlyph( int nStart, long nNewXPos ) = 0;
    virtual void    DropGlyph( int nStart ) = 0;
    virtual void    Simplify( bool bIsBase ) = 0;
    virtual void    DisableGlyphInjection( bool /*bDisable*/ ) {}

    virtual std::shared_ptr<vcl::TextLayoutCache>
        CreateTextLayoutCache(OUString const&) const;

protected:
    // used by layout engines
                    SalLayout();
    virtual         ~SalLayout();

    // used by layout layers
    void            SetUnitsPerPixel( int n )               { mnUnitsPerPixel = n; }
    void            SetOrientation( int nOrientation )      // in 0-3600 system
                    { mnOrientation = nOrientation; }

    static int      CalcAsianKerning( sal_UCS4, bool bLeft, bool bVertical );

private:
                    SalLayout( const SalLayout& ) = delete;
                    SalLayout& operator=( const SalLayout& ) = delete;

protected:
    int             mnMinCharPos;
    int             mnEndCharPos;
    SalLayoutFlags  mnLayoutFlags;

    int             mnUnitsPerPixel;
    int             mnOrientation;

    mutable int     mnRefCount;
    mutable Point   maDrawOffset;
    Point           maDrawBase;
};

class VCL_PLUGIN_PUBLIC MultiSalLayout : public SalLayout
{
public:
    virtual void    DrawText( SalGraphics& ) const override;
    virtual sal_Int32 GetTextBreak(DeviceCoordinate nMaxWidth, DeviceCoordinate nCharExtra, int nFactor) const override;
    virtual DeviceCoordinate FillDXArray( DeviceCoordinate* pDXArray ) const override;
    virtual void    GetCaretPositions( int nArraySize, long* pCaretXArray ) const override;
    virtual int     GetNextGlyphs( int nLen, sal_GlyphId* pGlyphIdxAry, Point& rPos,
                                   int&, DeviceCoordinate* pGlyphAdvAry, int* pCharPosAry,
                                   const PhysicalFontFace** pFallbackFonts ) const override;
    virtual bool    GetOutline( SalGraphics&, basegfx::B2DPolyPolygonVector& ) const override;

    // used only by OutputDevice::ImplLayout, TODO: make friend
    explicit        MultiSalLayout( SalLayout& rBaseLayout,
                                    const PhysicalFontFace* pBaseFont = nullptr );
    void            AddFallback( SalLayout& rFallbackLayout,
                                 ImplLayoutRuns&, const PhysicalFontFace* pFallbackFont );
    virtual bool    LayoutText( ImplLayoutArgs& ) override;
    virtual void    AdjustLayout( ImplLayoutArgs& ) override;
    virtual void    InitFont() const override;

    void SetIncomplete(bool bIncomplete);

protected:
    virtual         ~MultiSalLayout();

private:
    // dummy implementations
    virtual void    MoveGlyph( int, long ) override {}
    virtual void    DropGlyph( int ) override {}
    virtual void    Simplify( bool ) override {}

                    MultiSalLayout( const MultiSalLayout& ) = delete;
                    MultiSalLayout& operator=( const MultiSalLayout& ) = delete;

private:
    SalLayout*      mpLayouts[ MAX_FALLBACK ];
    const PhysicalFontFace* mpFallbackFonts[ MAX_FALLBACK ];
    ImplLayoutRuns  maFallbackRuns[ MAX_FALLBACK ];
    int             mnLevel;
    bool            mbIncomplete;
};

struct GlyphItem
{
    int     mnFlags;
    int     mnCharPos;      // index in string

    int     mnOrigWidth;    // original glyph width
    int     mnNewWidth;     // width after adjustments
    int     mnXOffset;

    sal_GlyphId maGlyphId;
    Point   maLinearPos;    // absolute position of non rotated string

public:
            GlyphItem()
                : mnFlags(0)
                , mnCharPos(0)
                , mnOrigWidth(0)
                , mnNewWidth(0)
                , mnXOffset(0)
                , maGlyphId(0)
            {}

            GlyphItem( int nCharPos, sal_GlyphId aGlyphId, const Point& rLinearPos,
                long nFlags, int nOrigWidth )
            :   mnFlags(nFlags), mnCharPos(nCharPos),
                mnOrigWidth(nOrigWidth), mnNewWidth(nOrigWidth),
                mnXOffset(0),
                maGlyphId(aGlyphId), maLinearPos(rLinearPos)
            {}

            GlyphItem( int nCharPos, sal_GlyphId aGlyphId, const Point& rLinearPos,
                long nFlags, int nOrigWidth, int nXOffset )
            :   mnFlags(nFlags), mnCharPos(nCharPos),
                mnOrigWidth(nOrigWidth), mnNewWidth(nOrigWidth),
                mnXOffset(nXOffset),
                maGlyphId(aGlyphId), maLinearPos(rLinearPos)
            {}

    enum{ FALLBACK_MASK=0xFF, IS_IN_CLUSTER=0x100, IS_RTL_GLYPH=0x200, IS_DIACRITIC=0x400 };

    bool    IsClusterStart() const  { return ((mnFlags & IS_IN_CLUSTER) == 0); }
    bool    IsRTLGlyph() const      { return ((mnFlags & IS_RTL_GLYPH) != 0); }
    bool    IsDiacritic() const     { return ((mnFlags & IS_DIACRITIC) != 0); }
};

typedef std::list<GlyphItem> GlyphList;

class VCL_PLUGIN_PUBLIC GenericSalLayout : public SalLayout
{
public:
    // used by layout engines
    void            AppendGlyph( const GlyphItem& );
    void            Reserve(int size) { m_GlyphItems.reserve(size + 1); }
    virtual void    AdjustLayout( ImplLayoutArgs& ) override;
    void    ApplyDXArray( ImplLayoutArgs& );
    void    Justify( DeviceCoordinate nNewWidth );
    void            KashidaJustify( long nIndex, int nWidth );
    void            ApplyAsianKerning(const OUString& rStr);
    void            SortGlyphItems();

    // used by upper layers
    virtual DeviceCoordinate GetTextWidth() const override;
    virtual DeviceCoordinate FillDXArray( DeviceCoordinate* pDXArray ) const override;
    virtual sal_Int32 GetTextBreak(DeviceCoordinate nMaxWidth, DeviceCoordinate nCharExtra, int nFactor) const override;
    virtual void    GetCaretPositions( int nArraySize, long* pCaretXArray ) const override;

    // used by display layers
    virtual int     GetNextGlyphs( int nLen, sal_GlyphId* pGlyphIdxAry, Point& rPos, int&,
                                   DeviceCoordinate* pGlyphAdvAry = nullptr, int* pCharPosAry = nullptr,
                                   const PhysicalFontFace** pFallbackFonts = nullptr ) const override;

protected:
                    GenericSalLayout();
    virtual         ~GenericSalLayout();

    // for glyph+font+script fallback
    virtual void    MoveGlyph( int nStart, long nNewXPos ) override;
    virtual void    DropGlyph( int nStart ) override;
    virtual void    Simplify( bool bIsBase ) override;

    bool            GetCharWidths( DeviceCoordinate* pCharWidths ) const;

    std::vector<GlyphItem>     m_GlyphItems;

private:
    mutable Point   maBasePoint;

                    GenericSalLayout( const GenericSalLayout& ) = delete;
                    GenericSalLayout& operator=( const GenericSalLayout& ) = delete;
};

#undef SalGraphics

#endif // INCLUDED_VCL_INC_SALLAYOUT_HXX

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