/*
 * This program source code file is part of KiCad, a free EDA CAD application.
 *
 * Copyright The KiCad Developers, see AUTHORS.txt for contributors.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, you may find one here:
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 * or you may search the http://www.gnu.org website for the version 2 license,
 * or you may write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */

#include "pin_layout_cache.h"

#include <geometry/direction45.h>
#include <pgm_base.h>
#include <settings/settings_manager.h>
#include <sch_symbol.h>
#include <eeschema_settings.h>
#include <schematic_settings.h>

#include <geometry/shape_utils.h>


namespace
{

// small margin in internal units between the pin text and the pin line
const int PIN_TEXT_MARGIN = 4;

struct EXTENTS_CACHE
{
    KIFONT::FONT* m_Font = nullptr;
    int           m_FontSize = 0;
    VECTOR2I      m_Extents;
};

/// Utility for getting the size of the 'external' pin decorators (as a radius)
// i.e. the negation circle, the polarity 'slopes' and the nonlogic
// marker
int externalPinDecoSize( const SCHEMATIC_SETTINGS* aSettings, const SCH_PIN& aPin )
{
    if( aSettings && aSettings->m_PinSymbolSize )
        return aSettings->m_PinSymbolSize;

    return aPin.GetNumberTextSize() / 2;
}


int internalPinDecoSize( const SCHEMATIC_SETTINGS* aSettings, const SCH_PIN& aPin )
{
    if( aSettings && aSettings->m_PinSymbolSize > 0 )
        return aSettings->m_PinSymbolSize;

    return aPin.GetNameTextSize() != 0 ? aPin.GetNameTextSize() / 2 : aPin.GetNumberTextSize() / 2;
}

} // namespace


PIN_LAYOUT_CACHE::PIN_LAYOUT_CACHE( const SCH_PIN& aPin ) :
        m_pin( aPin ), m_schSettings( nullptr ), m_dirtyFlags( DIRTY_FLAGS::ALL )
{
    // Resolve the schematic (can be null, e.g. in previews)
    const SCHEMATIC* schematic = aPin.Schematic();

    if( schematic )
    {
        m_schSettings = &schematic->Settings();
    }
}


void PIN_LAYOUT_CACHE::MarkDirty( int aDirtyFlags )
{
    m_dirtyFlags |= aDirtyFlags;
}


void PIN_LAYOUT_CACHE::SetRenderParameters( int aNameThickness, int aNumberThickness,
                                            bool aShowElectricalType, bool aShowAltIcons )
{
    if( aNameThickness != m_nameThickness )
    {
        MarkDirty( DIRTY_FLAGS::NAME );
        m_nameThickness = aNameThickness;
    }

    if( aNumberThickness != m_numberThickness )
    {
        MarkDirty( DIRTY_FLAGS::NUMBER );
        m_numberThickness = aNumberThickness;
    }

    if( aShowElectricalType != m_showElectricalType )
    {
        MarkDirty( DIRTY_FLAGS::ELEC_TYPE );
        m_showElectricalType = aShowElectricalType;
    }

    // Not (yet?) cached
    m_showAltIcons = aShowAltIcons;
}


void PIN_LAYOUT_CACHE::recomputeExtentsCache( bool aDefinitelyDirty, KIFONT::FONT* aFont, int aSize,
                                              const wxString&        aText,
                                              const KIFONT::METRICS& aFontMetrics,
                                              TEXT_EXTENTS_CACHE&    aCache )
{
    // Even if not definitely dirty, verify no font changes
    if( !aDefinitelyDirty && aCache.m_Font == aFont && aCache.m_FontSize == aSize )
    {
        return;
    }

    aCache.m_Font = aFont;
    aCache.m_FontSize = aSize;

    VECTOR2D fontSize( aSize, aSize );
    int      penWidth = GetPenSizeForNormal( aSize );

    aCache.m_Extents =
            aFont->StringBoundaryLimits( aText, fontSize, penWidth, false, false, aFontMetrics );
}


void PIN_LAYOUT_CACHE::recomputeCaches()
{
    SETTINGS_MANAGER&      mgr = Pgm().GetSettingsManager();
    EESCHEMA_SETTINGS*     cfg = mgr.GetAppSettings<EESCHEMA_SETTINGS>( "eeschema" );
    KIFONT::FONT*          font = KIFONT::FONT::GetFont( cfg->m_Appearance.default_font );
    const KIFONT::METRICS& metrics = m_pin.GetFontMetrics();

    // Due to the fact a shadow text in position INSIDE or OUTSIDE is drawn left or right aligned,
    // it needs an offset = shadowWidth/2 to be drawn at the same place as normal text
    // texts drawn as GR_TEXT_H_ALIGN_CENTER do not need a specific offset.
    // this offset is shadowWidth/2 but for some reason we need to slightly modify this offset
    // for a better look (better alignment of shadow shape), for KiCad font only
    if( !font->IsOutline() )
        m_shadowOffsetAdjust = 1.2f; // Value chosen after tests
    else
        m_shadowOffsetAdjust = 1.0f;

    {
        const bool     dirty = isDirty( DIRTY_FLAGS::NUMBER );
        const wxString number = m_pin.GetShownNumber();
        recomputeExtentsCache( dirty, font, m_pin.GetNumberTextSize(), number, metrics,
                               m_numExtentsCache );
    }

    {
        const bool     dirty = isDirty( DIRTY_FLAGS::NAME );
        const wxString name = m_pin.GetShownName();
        recomputeExtentsCache( dirty, font, m_pin.GetNameTextSize(), name, metrics,
                               m_nameExtentsCache );
    }

    {
        double fontSize = std::max( m_pin.GetNameTextSize() * 3 / 4, schIUScale.mmToIU( 0.7 ) );
        recomputeExtentsCache( isDirty( DIRTY_FLAGS::ELEC_TYPE ), font, fontSize,
                               m_pin.GetElectricalTypeName(), metrics, m_typeExtentsCache );
    }

    setClean( DIRTY_FLAGS::NUMBER | DIRTY_FLAGS::NAME | DIRTY_FLAGS::ELEC_TYPE );
}


void PIN_LAYOUT_CACHE::transformBoxForPin( BOX2I& aBox ) const
{
    // Now, calculate boundary box corners position for the actual pin orientation
    switch( m_pin.PinDrawOrient( DefaultTransform ) )
    {
    case PIN_ORIENTATION::PIN_UP:
    {
        // Pin is rotated and texts positions are mirrored
        VECTOR2I c1{ aBox.GetLeft(), aBox.GetTop() };
        VECTOR2I c2{ aBox.GetRight(), aBox.GetBottom() };

        RotatePoint( c1, VECTOR2I( 0, 0 ), ANGLE_90 );
        RotatePoint( c2, VECTOR2I( 0, 0 ), ANGLE_90 );

        aBox = BOX2I::ByCorners( c1, c2 );
        break;
    }
    case PIN_ORIENTATION::PIN_DOWN:
    {
        VECTOR2I c1{ aBox.GetLeft(), aBox.GetTop() };
        VECTOR2I c2{ aBox.GetRight(), aBox.GetBottom() };

        RotatePoint( c1, VECTOR2I( 0, 0 ), -ANGLE_90 );
        RotatePoint( c2, VECTOR2I( 0, 0 ), -ANGLE_90 );

        c1.x = -c1.x;
        c2.x = -c2.x;

        aBox = BOX2I::ByCorners( c1, c2 );
        break;
    }
    case PIN_ORIENTATION::PIN_LEFT:
        // Flip it around
        aBox.Move( { -aBox.GetCenter().x * 2, 0 } );
        break;

    default:
    case PIN_ORIENTATION::PIN_RIGHT:
        // Already in this form
        break;
    }

    aBox.Move( m_pin.GetPosition() );
}


void PIN_LAYOUT_CACHE::transformTextForPin( TEXT_INFO& aInfo ) const
{
    // Now, calculate boundary box corners position for the actual pin orientation
    switch( m_pin.PinDrawOrient( DefaultTransform ) )
    {
    case PIN_ORIENTATION::PIN_LEFT:
    {
        aInfo.m_HAlign = GetFlippedAlignment( aInfo.m_HAlign );
        aInfo.m_TextPosition.x = -aInfo.m_TextPosition.x;
        break;
    }
    case PIN_ORIENTATION::PIN_UP:
    {
        aInfo.m_Angle = ANGLE_VERTICAL;
        aInfo.m_TextPosition = { aInfo.m_TextPosition.y, -aInfo.m_TextPosition.x };
        break;
    }
    case PIN_ORIENTATION::PIN_DOWN:
    {
        aInfo.m_Angle = ANGLE_VERTICAL;
        aInfo.m_TextPosition = { aInfo.m_TextPosition.y, aInfo.m_TextPosition.x };
        aInfo.m_HAlign = GetFlippedAlignment( aInfo.m_HAlign );
        break;
    }
    default:
    case PIN_ORIENTATION::PIN_RIGHT:
        // Already in this form
        break;
    }

    aInfo.m_TextPosition += m_pin.GetPosition();
}


BOX2I PIN_LAYOUT_CACHE::GetPinBoundingBox( bool aIncludeLabelsOnInvisiblePins,
                                           bool aIncludeNameAndNumber, bool aIncludeElectricalType )
{
    if( const SCH_SYMBOL* symbol = dynamic_cast<const SCH_SYMBOL*>( m_pin.GetParentSymbol() ) )
    {
        SCH_PIN* const libPin = m_pin.GetLibPin();
        wxCHECK( libPin, BOX2I() );

        BOX2I r = libPin->GetBoundingBox( aIncludeLabelsOnInvisiblePins, aIncludeNameAndNumber,
                                          aIncludeElectricalType );

        r = symbol->GetTransform().TransformCoordinate( r );
        r.Offset( symbol->GetPosition() );
        r.Normalize();

        return r;
    }

    bool     includeName = aIncludeNameAndNumber && !m_pin.GetShownName().IsEmpty();
    bool     includeNumber = aIncludeNameAndNumber && !m_pin.GetShownNumber().IsEmpty();
    bool     includeType = aIncludeElectricalType;

    if( !aIncludeLabelsOnInvisiblePins && !m_pin.IsVisible() )
    {
        includeName = false;
        includeNumber = false;
        includeType = false;
    }

    if( const SYMBOL* parentSymbol = m_pin.GetParentSymbol() )
    {
        if( !parentSymbol->GetShowPinNames() )
            includeName = false;

        if( !parentSymbol->GetShowPinNumbers() )
            includeNumber = false;
    }

    recomputeCaches();

    const int pinLength = m_pin.GetLength();

    // Creating and merging all the boxes is pretty quick, if cached we'd have
    // to track many variables here, which is possible, but unlikely to be worth it.
    BOX2I bbox;

    // Untransformed pin box
    {
        BOX2I pinBox = BOX2I::ByCorners( { 0, 0 }, { pinLength, 0 } );
        pinBox.Inflate( m_pin.GetPenWidth() / 2 );
        bbox.Merge( pinBox );
    }

    if( OPT_BOX2I decoBox = getUntransformedDecorationBox() )
    {
        bbox.Merge( *decoBox );
    }

    if( includeName )
    {
        if( OPT_BOX2I nameBox = getUntransformedPinNameBox() )
        {
            bbox.Merge( *nameBox );
        }

        if( OPT_BOX2I altIconBox = getUntransformedAltIconBox() )
        {
            bbox.Merge( *altIconBox );
        }
    }

    if( includeNumber )
    {
        if( OPT_BOX2I numBox = getUntransformedPinNumberBox() )
        {
            bbox.Merge( *numBox );
        }
    }

    if( includeType )
    {
        if( OPT_BOX2I typeBox = getUntransformedPinTypeBox() )
        {
            bbox.Merge( *typeBox );
        }
    }

    transformBoxForPin( bbox );

    if( m_pin.IsDangling() )
    {
        // Not much point caching this, but we could
        const CIRCLE c = GetDanglingIndicator();

        BOX2I cBox = BOX2I::ByCenter( c.Center, { c.Radius * 2, c.Radius * 2 } );
        // TODO: need some way to find the thickness...?
        // cBox.Inflate( ??? );

        bbox.Merge( cBox );
    }

    bbox.Normalize();
    bbox.Inflate( ( m_pin.GetPenWidth() / 2 ) + 1 );

    return bbox;
}


CIRCLE PIN_LAYOUT_CACHE::GetDanglingIndicator() const
{
    return CIRCLE{
        m_pin.GetPosition(),
        TARGET_PIN_RADIUS,
    };
}


int PIN_LAYOUT_CACHE::getPinTextOffset() const
{
    const float offsetRatio =
            m_schSettings ? m_schSettings->m_TextOffsetRatio : DEFAULT_TEXT_OFFSET_RATIO;
    return schIUScale.MilsToIU( KiROUND( 24 * offsetRatio ) );
}


OPT_BOX2I PIN_LAYOUT_CACHE::getUntransformedPinNameBox() const
{
    int pinNameOffset = 0;
    if( const SYMBOL* parentSymbol = m_pin.GetParentSymbol() )
    {
        if( parentSymbol->GetShowPinNames() )
            pinNameOffset = parentSymbol->GetPinNameOffset();
    }

    // We're considering the PIN_RIGHT scenario
    //      TEXT
    //   X-------|  TEXT
    //      TEXT
    //
    // We'll rotate it later.

    OPT_BOX2I box;
    const int pinLength = m_pin.GetLength();

    if( pinNameOffset > 0 )
    {
        // This means name inside the pin
        box = BOX2I::ByCenter( { pinLength, 0 }, m_nameExtentsCache.m_Extents );

        // Bump over to be left aligned just inside the pin
        box->Move( { m_nameExtentsCache.m_Extents.x / 2 + pinNameOffset, 0 } );
    }
    else
    {
        // The pin name is always over the pin
        box = BOX2I::ByCenter( { pinLength / 2, 0 }, m_nameExtentsCache.m_Extents );

        // Bump it up
        box->Move( { 0, -m_nameExtentsCache.m_Extents.y / 2 - getPinTextOffset() } );
    }

    return box;
}


OPT_BOX2I PIN_LAYOUT_CACHE::getUntransformedPinNumberBox() const
{
    int pinNameOffset = 0;

    if( const SYMBOL* parentSymbol = m_pin.GetParentSymbol() )
    {
        if( parentSymbol->GetShowPinNames() )
            pinNameOffset = parentSymbol->GetPinNameOffset();
    }

    const int pinLength = m_pin.GetLength();

    // The pin name is always over the pin
    OPT_BOX2I box = BOX2I::ByCenter( { pinLength / 2, 0 }, m_numExtentsCache.m_Extents );

    int textPos = -m_numExtentsCache.m_Extents.y / 2 - getPinTextOffset();

    // The number goes below, if there is a name outside
    if( pinNameOffset == 0 && !m_pin.GetShownName().empty()
        && m_pin.GetParentSymbol()->GetShowPinNames() )
        textPos *= -1;

    // Bump it up (or down)
    box->Move( { 0, textPos } );

    return box;
}


OPT_BOX2I PIN_LAYOUT_CACHE::getUntransformedPinTypeBox() const
{
    if( !m_showElectricalType )
        return std::nullopt;

    BOX2I box{
        { -m_typeExtentsCache.m_Extents.x, -m_typeExtentsCache.m_Extents.y / 2 },
        m_typeExtentsCache.m_Extents,
    };

    // Jog left
    box.Move( { -schIUScale.MilsToIU( PIN_TEXT_MARGIN ) - TARGET_PIN_RADIUS, 0 } );

    return box;
}


OPT_BOX2I PIN_LAYOUT_CACHE::getUntransformedAltIconBox() const
{
    const OPT_BOX2I nameBox = getUntransformedPinNameBox();

    if( !nameBox || m_pin.GetAlternates().empty() || !m_showAltIcons )
        return std::nullopt;

    const int iconSize = std::min( m_pin.GetNameTextSize(), schIUScale.mmToIU( 1.5 ) );

    VECTOR2I c{ 0, ( nameBox->GetTop() + nameBox->GetBottom() ) / 2 };
    if( m_pin.GetParentSymbol()->GetPinNameOffset() > 0 )
    {
        // name inside, so icon more inside
        c.x = nameBox->GetRight() + iconSize * 0.75;
    }
    else
    {
        c.x = nameBox->GetLeft() - iconSize * 0.75;
    }

    return BOX2I::ByCenter( c, { iconSize, iconSize } );
}


OPT_BOX2I PIN_LAYOUT_CACHE::getUntransformedDecorationBox() const
{
    const GRAPHIC_PINSHAPE shape = m_pin.GetShape();
    const int              decoSize = externalPinDecoSize( m_schSettings, m_pin );
    const int              intDecoSize = internalPinDecoSize( m_schSettings, m_pin );

    const auto makeInvertBox = [&]()
    {
        return BOX2I::ByCenter( { -decoSize, 0 }, { decoSize * 2, decoSize * 2 } );
    };

    const auto makeLowBox = [&]()
    {
        return BOX2I::ByCorners( { -decoSize * 2, -decoSize * 2 }, { 0, 0 } );
    };

    const auto makeClockBox = [&]()
    {
        return BOX2I::ByCorners( { 0, -intDecoSize }, { intDecoSize, intDecoSize } );
    };

    OPT_BOX2I box;

    switch( shape )
    {
    case GRAPHIC_PINSHAPE::INVERTED:
    {
        box = makeInvertBox();
        break;
    }
    case GRAPHIC_PINSHAPE::CLOCK:
    {
        box = makeClockBox();
        break;
    }
    case GRAPHIC_PINSHAPE::INVERTED_CLOCK:
    {
        box = makeInvertBox();
        box->Merge( makeClockBox() );
        break;
    }
    case GRAPHIC_PINSHAPE::INPUT_LOW:
    {
        box = makeLowBox();
        break;
    }
    case GRAPHIC_PINSHAPE::FALLING_EDGE_CLOCK:
    case GRAPHIC_PINSHAPE::CLOCK_LOW:
    {
        box = makeLowBox();
        box->Merge( makeClockBox() );
        break;
    }
    case GRAPHIC_PINSHAPE::NONLOGIC:
    {
        box = BOX2I::ByCenter( { 0, 0 }, { decoSize * 2, decoSize * 2 } );
        break;
    }
    case GRAPHIC_PINSHAPE::LINE:
    default:
    {
        // No decoration
        break;
    }
    }

    if( box )
    {
        // Put the box at the root of the pin
        box->Move( { m_pin.GetLength(), 0 } );
        box->Inflate( m_pin.GetPenWidth() / 2 );
    }

    return box;
}


OPT_BOX2I PIN_LAYOUT_CACHE::GetPinNameBBox()
{
    recomputeCaches();
    OPT_BOX2I box = getUntransformedPinNameBox();

    if( box )
        transformBoxForPin( *box );

    return box;
}


OPT_BOX2I PIN_LAYOUT_CACHE::GetPinNumberBBox()
{
    recomputeCaches();
    OPT_BOX2I box = getUntransformedPinNumberBox();

    if( box )
        transformBoxForPin( *box );

    return box;
}


OPT_BOX2I PIN_LAYOUT_CACHE::GetAltIconBBox()
{
    OPT_BOX2I box = getUntransformedAltIconBox();

    if( box )
        transformBoxForPin( *box );

    return box;
}


std::optional<PIN_LAYOUT_CACHE::TEXT_INFO> PIN_LAYOUT_CACHE::GetPinNameInfo( int aShadowWidth )
{
    recomputeCaches();
    wxString name = m_pin.GetShownName();

    // TODO - work out exactly what we need to do to cache this
    // (or if it's worth the memory/complexity)
    // But it's not hugely expensive to recompute, and that's what's always been
    // done to now
    //
    // Because pins are very likely to share a lot of characteristics, a global
    // cache might make more sense than a per-pin cache.

    if( name.IsEmpty() || !m_pin.GetParentSymbol()->GetShowPinNames() )
        return std::nullopt;

    std::optional<TEXT_INFO> info = TEXT_INFO();
    info->m_Text = std::move( name );
    info->m_TextSize = m_pin.GetNameTextSize();
    info->m_Thickness = m_nameThickness;
    info->m_Angle = ANGLE_HORIZONTAL;

    if( m_pin.GetParentSymbol()->GetPinNameOffset() > 0 )
    {
        // This means name inside the pin
        VECTOR2I  pos = { m_pin.GetLength() + m_pin.GetParentSymbol()->GetPinNameOffset(), 0 };
        const int thickOffset =
                info->m_Thickness - KiROUND( aShadowWidth * m_shadowOffsetAdjust ) / 2;

        info->m_TextPosition = pos + VECTOR2I{ thickOffset, 0 };
        info->m_HAlign = GR_TEXT_H_ALIGN_LEFT;
        info->m_VAlign = GR_TEXT_V_ALIGN_CENTER;
    }
    else
    {
        // The pin name is always over the pin
        VECTOR2I pos = { m_pin.GetLength() / 2, -getPinTextOffset() - info->m_Thickness / 2 };

        info->m_TextPosition = pos;
        info->m_HAlign = GR_TEXT_H_ALIGN_CENTER;
        info->m_VAlign = GR_TEXT_V_ALIGN_BOTTOM;
    }

    transformTextForPin( *info );
    return info;
}


std::optional<PIN_LAYOUT_CACHE::TEXT_INFO> PIN_LAYOUT_CACHE::GetPinNumberInfo( int aShadowWidth )
{
    recomputeCaches();

    wxString number = m_pin.GetShownNumber();
    if( number.IsEmpty() || !m_pin.GetParentSymbol()->GetShowPinNumbers() )
        return std::nullopt;

    std::optional<TEXT_INFO> info;

    info = TEXT_INFO();
    info->m_Text = std::move( number );
    info->m_TextSize = m_pin.GetNumberTextSize();
    info->m_Thickness = m_numberThickness;
    info->m_Angle = ANGLE_HORIZONTAL;
    info->m_TextPosition = { m_pin.GetLength() / 2, 0 };
    info->m_HAlign = GR_TEXT_H_ALIGN_CENTER;

    // The pin number is above the pin if there's no name, or the name is inside
    const bool numAbove =
            m_pin.GetParentSymbol()->GetPinNameOffset() > 0
            || ( m_pin.GetShownName().empty() || !m_pin.GetParentSymbol()->GetShowPinNames() );

    if( numAbove )
    {
        info->m_TextPosition.y -= getPinTextOffset() + info->m_Thickness / 2;
        info->m_VAlign = GR_TEXT_V_ALIGN_BOTTOM;
    }
    else
    {
        info->m_TextPosition.y += getPinTextOffset() + info->m_Thickness / 2;
        info->m_VAlign = GR_TEXT_V_ALIGN_TOP;
    }

    transformTextForPin( *info );
    return info;
}


std::optional<PIN_LAYOUT_CACHE::TEXT_INFO>
PIN_LAYOUT_CACHE::GetPinElectricalTypeInfo( int aShadowWidth )
{
    recomputeCaches();

    if( !m_showElectricalType )
        return std::nullopt;

    std::optional<TEXT_INFO> info = TEXT_INFO();
    info->m_Text = m_pin.GetElectricalTypeName();
    info->m_TextSize = std::max( m_pin.GetNameTextSize() * 3 / 4, schIUScale.mmToIU( 0.7 ) );
    info->m_Angle = ANGLE_HORIZONTAL;
    info->m_Thickness = info->m_TextSize / 8;
    info->m_TextPosition = { -getPinTextOffset() - info->m_Thickness / 2
                                     + KiROUND( aShadowWidth * m_shadowOffsetAdjust ) / 2,
                             0 };
    info->m_HAlign = GR_TEXT_H_ALIGN_RIGHT;
    info->m_VAlign = GR_TEXT_V_ALIGN_CENTER;

    info->m_TextPosition.x -= TARGET_PIN_RADIUS;

    if( m_pin.IsDangling() )
    {
        info->m_TextPosition.x -= TARGET_PIN_RADIUS / 2;
    }

    transformTextForPin( *info );
    return info;
}