/*
    Copyright (c) 2008-2022 Jan W. Krieger (<jan@jkrieger.de>)



    This software is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License (LGPL) as published by
    the Free Software Foundation, either version 2.1 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 Lesser General Public License (LGPL) for more details.

    You should have received a copy of the GNU Lesser General Public License (LGPL)
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/



#include "jkqtmathtext/nodes/jkqtmathtexttextnode.h"
#include "jkqtmathtext/jkqtmathtexttools.h"
#include "jkqtmathtext/nodes/jkqtmathtextnode.h"
#include "jkqtmathtext/jkqtmathtext.h"
#include "jkqtcommon/jkqtpcodestructuring.h"
#include "jkqtcommon/jkqtpstringtools.h"
#include <cmath>
#include <QFontMetricsF>
#include <QDebug>
#include <QFontDatabase>
#include <QFontInfo>
#include <QApplication>
#include <QFont>





JKQTMathTextTextBaseNode::JKQTMathTextTextBaseNode(JKQTMathText *parent, const QString &text_):
    JKQTMathTextNode(parent),
    text(text_)
{

}

JKQTMathTextTextBaseNode::~JKQTMathTextTextBaseNode()
{

}

QString JKQTMathTextTextBaseNode::getText() const
{
    return text;
}




QString JKQTMathTextTextBaseNode::textTransform(const QString &text, const JKQTMathTextEnvironment &/*currentEv*/) const
{
    return  text;
}


bool JKQTMathTextTextBaseNode::toHtml(QString &html, JKQTMathTextEnvironment currentEv, JKQTMathTextEnvironment defaultEv) {
    html=html
            +currentEv.toHtmlStart(defaultEv, parentMathText)
            +textTransform(text, currentEv).toHtmlEscaped()
            +currentEv.toHtmlAfter(defaultEv, parentMathText);
    return true;
}



QHash<QChar, uint32_t> JKQTMathTextTextNode::blackboardUnicodeTable=QHash<QChar, uint32_t>();

void JKQTMathTextTextNode::fillStaticTables() {
    if (blackboardUnicodeTable.size()>0) return;

    blackboardUnicodeTable['C']=0x2102;
    blackboardUnicodeTable['H']=0x210D;
    blackboardUnicodeTable['N']=0x2115;
    blackboardUnicodeTable['P']=0x2119;
    blackboardUnicodeTable['Q']=0x211A;
    blackboardUnicodeTable['R']=0x211D;
    blackboardUnicodeTable['Z']=0x2124;

    for (const QChar ch: QString("ABDEFGIJKLMOSTUVWXYZ")) {
        blackboardUnicodeTable[ch]=0x1D538+(ch.unicode()-QChar('A').unicode());
    }
    for (const QChar ch: QString("abcdefghijklmnopqrstuvwxyz")) {
        blackboardUnicodeTable[ch]=0x1D552+(ch.unicode()-QChar('a').unicode());
    }
    for (const QChar ch: QString("0123456789")) {
        blackboardUnicodeTable[ch]=0x1D7D8+(ch.unicode()-QChar('0').unicode());
    }
}

JKQTMathTextTextNode::JKQTMathTextTextNode(JKQTMathText* _parent, const QString& textIn, bool addWhitespace, bool stripInnerWhitepace):
    JKQTMathTextTextBaseNode(_parent, "")
{
    fillStaticTables();
    QString textTransformed=textIn;

    if (stripInnerWhitepace) {
        textTransformed="";
        for (int i=0; i<textIn.size(); i++) {
            if (!textIn[i].isSpace()) textTransformed+=textIn[i];
        }
    }

    text=textTransformed;
    // strip all whitespace from left
    while (text.size()>1 && text[0].isSpace()) {
        text=text.right(text.size()-1);
    }
    if (addWhitespace && (text.size()>0) && (!text[text.size()-1].isSpace())) text=text+" ";
    //qDebug()<<"JKQTMathTextTextNode( text="<<text<<" addWhitespace="<<addWhitespace<<")   [=> this->text="<<this->text<<"]";
}

JKQTMathTextTextNode::~JKQTMathTextTextNode() = default;

void JKQTMathTextTextNode::getSizeInternal(QPainter& painter, JKQTMathTextEnvironment currentEv, double& width, double& baselineHeight, double& overallHeight, double& strikeoutPos, const JKQTMathTextNodeSize* /*prevNodeSize*/) {
    QStringList textpart;
    QList<FontMode> fontMode;
    QList<double> textpartXPos;
    getSizeInternalAndData(painter, currentEv, width, baselineHeight, overallHeight, strikeoutPos,textpart, fontMode, textpartXPos);
}

void JKQTMathTextTextNode::getSizeInternalAndData(QPainter &painter, JKQTMathTextEnvironment currentEv, double &width, double &baselineHeight, double &overallHeight, double &strikeoutPos, QStringList &textpart, QList<FontMode> &fontMode, QList<double> &textpartXPos)
{
    textpart.clear();
    fontMode.clear();
    const QString txt=textTransform(text, currentEv);
    splitTextForLayout(painter, currentEv, txt, textpart, fontMode);

    const QFont f=currentEv.getFont(parentMathText);
    const QFont fUpright=JKQTMathTextGetNonItalic(f);
    const QFont fFallbackSym=currentEv.exchangedFontFor(MTEFallbackSymbols).getFont(parentMathText);
    const QFont fRoman=currentEv.exchangedFontForRoman().getFont(parentMathText);
    const QFontMetricsF fmUpright(fUpright, painter.device());
    const QFontMetricsF fm(f, painter.device());
    const QFontMetricsF fmFallbackSym(fFallbackSym, painter.device());
    const QFontMetricsF fmRoman(fRoman, painter.device());
#if (QT_VERSION>=QT_VERSION_CHECK(5, 15, 0))
    const double sp=fm.horizontalAdvance(' ');
#else
    const double sp=fm.width(' ');
#endif
    width=0;
    double ascent=0;
    double descent=0;
    for (int i=0; i<textpart.size(); i++) {
        QRectF br, tbr;
        switch(fontMode[i]) {
            case FMasDefined:
            case FMasDefinedOutline:
                br=fm.boundingRect(textpart[i]);
                tbr=JKQTMathTextGetTightBoundingRect(f, textpart[i], painter.device());
                break;
            case FMasDefinedForceUpright:
                br=fmUpright.boundingRect(textpart[i]);
                tbr=JKQTMathTextGetTightBoundingRect(fUpright, textpart[i], painter.device());
                break;
            case FMroman:
                br=fmRoman.boundingRect(textpart[i]);
                tbr=JKQTMathTextGetTightBoundingRect(fRoman, textpart[i], painter.device());
                break;
            case FMfallbackSymbol:
                br=fmFallbackSym.boundingRect(textpart[i]);
                tbr=JKQTMathTextGetTightBoundingRect(fFallbackSym, textpart[i], painter.device());
                break;
        }
        textpartXPos.append(width);
        width+=br.width();
        if (textpart[i].size()>0 && textpart[i].at(textpart[i].size()-1).isSpace()) {
            // this correction is necessary, because it seems that QFontMetricsF::boundingRect() ignores trailing spaces
            width+=sp;
        }
        const double thisAscent=-tbr.top();
        const double thisDescent=tbr.bottom();
        ascent=qMax(ascent, thisAscent);
        descent=qMax(descent, thisDescent);
    }
    overallHeight=(ascent+descent); //fm.height();
    baselineHeight=ascent;
    strikeoutPos=fm.strikeOutPos();
}

void JKQTMathTextTextNode::splitTextForLayout(QPainter &painter, JKQTMathTextEnvironment currentEv, const QString &txt, QStringList &textpart, QList<FontMode> &fontMode) const
{
    auto isForcedUprightChar=[](const QChar& c) {
        return c.isDigit()
                || c=='(' || c=='[' || c=='|' || c==']' || c==')' || c=='<' || c=='>'|| c=='{' || c=='}' || c=='|'
                || c==QChar(0x2329) || c==QChar(0x232A) || c==QChar(0x2308) || c==QChar(0x2309) || c==QChar(0x230A) || c==QChar(0x230B);
    };

    //const QFont f=currentEv.getFont(parentMathText);
    //const QFont fUpright=JKQTMathTextGetNonItalic(f);
    const QFont fFallbackSym=currentEv.exchangedFontFor(MTEFallbackSymbols).getFont(parentMathText);
    const QFont fRoman=currentEv.exchangedFontForRoman().getFont(parentMathText);
    //const QFontMetricsF fm(f, painter.device());
    //const QFontMetricsF fmUpright(fUpright, painter.device());
    const QFontMetricsF fmFallbackSym(fFallbackSym, painter.device());
    const QFontMetricsF fmRoman(fRoman, painter.device());
    const JKQTMathTextBlackboradDrawingMode bbMode=parentMathText->getFontBlackboradMode();

    textpart.clear();
    fontMode.clear();
    QString currentSection="";
    FontMode currentSectionFontMode=FMasDefined;
    int i=0;
    while (i<txt.size()) {
        const QChar c=txt[i];
        QString cs=c;
        FontMode CFontMode=FMasDefined;
        const bool CisForcedUprightChar=isForcedUprightChar(c);
        const bool CisForcedUprightCharExt=CisForcedUprightChar||(c=='.')||(c==',');
        if (currentEv.insideMath && currentEv.insideMathForceDigitsUpright && (currentEv.font==MTEroman || currentEv.font==MTEmathRoman)) {
            if (currentSection.size()==0) {
                if (CisForcedUprightChar) {
                    CFontMode=FMasDefinedForceUpright;
                }
            } else {
                if (CisForcedUprightCharExt) {
                    CFontMode=FMasDefinedForceUpright;
                }
            }
        } else if (currentEv.font==MTEblackboard) {
            if (bbMode==MTBBDMfontDirectly) {
                CFontMode=FMasDefined;
            } else if (bbMode==MTBBDMsimulate) {
                CFontMode=FMasDefinedOutline;
            } else if (bbMode==MTBBDMunicodeCharactersOrSimulate || bbMode==MTBBDMunicodeCharactersOrFontDirectly) {
                if (blackboardUnicodeTable.contains(c) && fmRoman.inFontUcs4(blackboardUnicodeTable[c])) {
                    cs=jkqtp_UnicodeToUTF8Q(blackboardUnicodeTable[c]);
                    CFontMode=FMroman;
                } else if (blackboardUnicodeTable.contains(c) && fmFallbackSym.inFontUcs4(blackboardUnicodeTable[c])) {
                    cs=jkqtp_UnicodeToUTF8Q(blackboardUnicodeTable[c]);
                    CFontMode=FMfallbackSymbol;
                } else {
                    if (bbMode==MTBBDMunicodeCharactersOrSimulate) {
                        CFontMode=FMasDefinedOutline;
                    } else if (bbMode==MTBBDMunicodeCharactersOrFontDirectly) {
                        CFontMode=FMasDefined;
                    }
                }
            }
        }

        if (currentSection.size()==0) {
            // start new section
            currentSectionFontMode=CFontMode;
            currentSection+=cs;
        } else {
            // existing section
            if (CFontMode==currentSectionFontMode) {
                // continue current section
                currentSection+=cs;
            } else {
                // start new section
                textpart.append(currentSection);
                fontMode.append(currentSectionFontMode);
                currentSection=cs;
                currentSectionFontMode=CFontMode;
            }
        }

        i++;
    }
    if (currentSection.size()>0) {
        textpart.append(currentSection);
        fontMode.append(currentSectionFontMode);
    }
}

double JKQTMathTextTextNode::draw(QPainter& painter, double x, double y, JKQTMathTextEnvironment currentEv, const JKQTMathTextNodeSize* /*prevNodeSize*/) {
    doDrawBoxes(painter, x, y, currentEv);
    double width=0;
    double baselineHeight=0;
    double overallHeight=0;
    double sp=0;
    QStringList textpart;
    QList<double> textpartXPos;
    QList<FontMode> fontMode;
    getSizeInternalAndData(painter, currentEv, width, baselineHeight, overallHeight, sp, textpart, fontMode, textpartXPos);


    const QFont f=currentEv.getFont(parentMathText);
    const QFont fUpright=JKQTMathTextGetNonItalic(f);
    const QFont fFallbackSym=currentEv.exchangedFontFor(MTEFallbackSymbols).getFont(parentMathText);
    const QFont fRoman=currentEv.exchangedFontForRoman().getFont(parentMathText);
    const QFontMetricsF fm(f, painter.device());
    const QFontMetricsF fmUpright(fUpright, painter.device());
    const QFontMetricsF fmFallbackSym(fFallbackSym, painter.device());
    const QFontMetricsF fmRoman(fRoman, painter.device());

    painter.save(); auto __finalpaint=JKQTPFinally([&painter]() {painter.restore();});
    painter.setFont(f);
    painter.setPen(currentEv.color);

    //qDebug()<<"JKQTMathTextTextNode: text="<<text<<" font="<<f;


    for (int i=0; i<textpart.size(); i++) {
        switch(fontMode[i]) {
            case FMasDefined:
                painter.setFont(f);
                painter.drawText(QPointF(x+textpartXPos[i], y), textpart[i]);
                break;
            case FMasDefinedOutline:
                JKQTMathTextDrawStringSimBlackboard(painter, f, currentEv.color, x+textpartXPos[i], y, textpart[i]);
                break;
            case FMasDefinedForceUpright:
                painter.setFont(fUpright);
                painter.drawText(QPointF(x+textpartXPos[i], y), textpart[i]);
                break;
            case FMroman:
                painter.setFont(fRoman);
                painter.drawText(QPointF(x+textpartXPos[i], y), textpart[i]);
                break;
            case FMfallbackSymbol:
                painter.setFont(fFallbackSym);
                painter.drawText(QPointF(x+textpartXPos[i], y), textpart[i]);
                break;
        }
    }

    return x+width;
}



QString JKQTMathTextTextNode::getTypeName() const
{
    return QLatin1String("JKQTMathTextTextNode(")+text+")";
}

void JKQTMathTextTextNode::removeTrailingWhitespace()
{
    while (text.size()>0 && text[text.size()-1].isSpace()) text=text.left(text.size()-1);
}

void JKQTMathTextTextNode::removeLeadingWhitespace()
{
    while (text.size()>0 && text[0].isSpace()) text=text.right(text.size()-1);
}

QString JKQTMathTextTextNode::textTransform(const QString &text, const JKQTMathTextEnvironment &currentEv) const
{
    QString txt=text;
    auto fnt=parentMathText->getFontData(currentEv.font, currentEv.insideMath);
    const QFontMetricsF fm(currentEv.getFont(parentMathText));
    if (fnt.second==MTFELatin1 || fnt.second==MTFEUnicode) {
        if (currentEv.insideMath) {
            txt="";
            for (int i=0; i<text.size(); i++) {
                QChar c=text[i];
                switch(c.unicode()) {
                    case '-':
                    if (fm.inFont(QChar(0x2212))) {
                        txt+=QString(QString(" ")+QChar(0x2212));
                    } else {
                        txt+=QString(QString(" -"));
                    }
                    break;
                    case '+': txt+=QString(QString(" +")); break;
                    case '<': txt+=QString(QString(" <")); break;
                    case '>': txt+=QString(QString(" >")); break;
                    case '=': txt+=QString(QString(" =")); break;
                    case ';': txt+=QString(QString("; ")); break;
                    case ',': txt+=QString(QString(", ")); break;
                    default: txt+=c; break;
                }
            }
            txt=txt.replace("  ", " ");
        }
    }

    return txt;
}








JKQTMathTextVerbatimNode::JKQTMathTextVerbatimNode(JKQTMathText *_parent, const QString& _text, bool visibleWhitespace_, JKQTMathTextHorizontalAlignment _alignment, double _linespacingFactor, JKQTMathTextVerticalOrientation _verticalOrientation):
    JKQTMathTextTextBaseNode(_parent, _text),
    alignment(_alignment),
    lineSpacingFactor(_linespacingFactor),
    verticalOrientation(_verticalOrientation),
    visibleWhitespace(visibleWhitespace_)
{

}

QString JKQTMathTextVerbatimNode::getTypeName() const
{
    return QLatin1String("JKQTMathTextVerbatimNode");
}

JKQTMathTextHorizontalAlignment JKQTMathTextVerbatimNode::getAlignment() const
{
    return alignment;
}

JKQTMathTextVerticalOrientation JKQTMathTextVerbatimNode::getVerticalOrientation() const
{
    return verticalOrientation;
}

double JKQTMathTextVerbatimNode::getLineSpacingFactor() const
{
    return lineSpacingFactor;
}

bool JKQTMathTextVerbatimNode::getVisibleWhitespace() const
{
    return visibleWhitespace;
}

double JKQTMathTextVerbatimNode::draw(QPainter &painter, double x, double y, JKQTMathTextEnvironment currentEv, const JKQTMathTextNodeSize *prevNodeSize)
{
    doDrawBoxes(painter, x, y, currentEv);
    transformEnvironment(currentEv);
    const LayoutInfo l=calcLayout(painter, currentEv);
    QFont f=currentEv.getFont(parentMathText);
    f.setStyleStrategy(QFont::PreferDefault);
    f.setFixedPitch(true);
    painter.save(); auto __finalpaint=JKQTPFinally([&painter]() {painter.restore();});
    painter.setFont(f);
    for (int i=0; i<l.lines.size(); i++) {
        painter.drawText(QPointF(x+l.X.at(i).x(), y+l.X.at(i).y()), l.lines.at(i));
    }
    return x+l.width;
}

bool JKQTMathTextVerbatimNode::toHtml(QString &html, JKQTMathTextEnvironment currentEv, JKQTMathTextEnvironment defaultEv)
{
    transformEnvironment(currentEv);
    const bool isMultiLine=text.count('\n')>0;
    html+=currentEv.toHtmlStart(defaultEv, parentMathText);
    if (isMultiLine) {
        if (alignment==MTHALeft) {
            html+="<div align=\"left\">";
        } else if (alignment==MTHACentered) {
            html+="<div align=\"center\">";
        } else if (alignment==MTHARight) {
            html+="<div align=\"right\">";
        }
    }
    html+="<pre>";
    html+=textTransform(text, currentEv).toHtmlEscaped();
    html+="</pre>";
    if (isMultiLine) html+="</div>";
    html+=currentEv.toHtmlAfter(defaultEv, parentMathText);
    return true;
}

void JKQTMathTextVerbatimNode::getSizeInternal(QPainter &painter, JKQTMathTextEnvironment currentEv, double &width, double &baselineHeight, double &overallHeight, double &strikeoutPos, const JKQTMathTextNodeSize *prevNodeSize)
{
    transformEnvironment(currentEv);
    const  LayoutInfo l=calcLayout(painter, currentEv);
    width=l.width;
    overallHeight=l.overallHeight;
    baselineHeight=l.baselineHeight;
    strikeoutPos=l.strikeoutPos;
}

void JKQTMathTextVerbatimNode::transformEnvironment(JKQTMathTextEnvironment &currentEv) const
{
    currentEv.font=MTEtypewriter;
}

JKQTMathTextVerbatimNode::LayoutInfo JKQTMathTextVerbatimNode::calcLayout(QPainter &painter, const JKQTMathTextEnvironment& currentEv) const
{
    LayoutInfo l;
    QFont f=currentEv.getFont(parentMathText);
    f.setStyleStrategy(QFont::PreferDefault);
    f.setFixedPitch(true);
    const QFontMetricsF fm(f);
    const double linespacing=fm.lineSpacing()*lineSpacingFactor;
    const double fleading=fm.leading();
    const double synLeading=fm.lineWidth();
    const double lineLeading=((fabs(fleading)>1e-6)?fleading:synLeading)*lineSpacingFactor;

    if (text.size()<=0) {
        return l;
    }
    l.lines=textTransform(text, currentEv).split('\n');

    // from now on we have at least one child node!!!

    QList<double> widths, heights, ascents, descents, strikeouts;
    double heightSum=0;
    QList<double> ysFromFirstLine; // y-position of each line, where the first line is always at y=0 (i.e. ysFromFirstLine[0]==0)
    double y=0;
    for (int i=0; i<l.lines.size(); i++) {

        if (i==0) {
            heightSum=fm.ascent();
        } else if (i>0) {
            const double deltaLine=qMax(linespacing, descents.last()+lineLeading+fm.ascent());
            heightSum=heightSum+deltaLine;
            y=y+deltaLine;
        }
        widths<<fm.boundingRect(l.lines[i]).width();
        l.width=qMax(l.width, widths.last());
        heights<<fm.height();
        ascents<<fm.ascent();
        descents<<fm.descent();
        strikeouts<<fm.strikeOutPos();
        ysFromFirstLine<<y;
    }
    heightSum+=descents.last();

    l.overallHeight=heightSum;
    double y0=0;
    if (verticalOrientation==MTVOTop) {
        l.baselineHeight=0;
        l.strikeoutPos=0;
        y0=ascents.first();
    } else if (verticalOrientation==MTVOFirstLine) {
        l.baselineHeight=ascents.first();
        l.strikeoutPos=strikeouts.first();
        y0=0;
    } else if (verticalOrientation==MTVOCentered) {
        l.baselineHeight=heightSum/2.0;
        l.strikeoutPos=heightSum/4.0;
        y0=-heightSum/2.0+ascents.first();
    } else if (verticalOrientation==MTVOLastLine) {
        l.baselineHeight=heightSum-descents.last();
        l.strikeoutPos=strikeouts.last();
        y0=-(heightSum-ascents.first()-descents.last());
    } else if (verticalOrientation==MTVOBottom) {
        l.baselineHeight=heightSum;
        l.strikeoutPos=0;
        y0=-(heightSum-ascents.first());
    }
    for (int i=0; i<l.lines.size(); i++) {
        double x=0;
        if (alignment==MTHARight) x=l.width-widths[i];
        else if (alignment==MTHACentered) x=(l.width-widths[i])/2.0;
        l.X<<QPointF(x,ysFromFirstLine[i]+y0);
    }
    return l;
}

QString JKQTMathTextVerbatimNode::textTransform(const QString &text, const JKQTMathTextEnvironment &currentEv) const
{
    QFont f=currentEv.getFont(parentMathText);
    f.setStyleStrategy(QFont::PreferDefault);
    const QFontMetricsF fm(f);

    QString spRep=QChar(0xB7);
    if (!fm.inFont(spRep[0])) {
        spRep=QChar(0x2423);
    }
    QString tabRep=QString(4,QChar(0x2192));
    if (!fm.inFont(tabRep[0])) {
        spRep=QString(4,QChar(0xAC));
    }

    QString res=JKQTMathTextTextBaseNode::textTransform(text, currentEv);
    if (res.startsWith('\n')) res=res.right(res.size()-1);
    if (res.endsWith('\n')) res=res.left(res.size()-1);
    if (visibleWhitespace) {
        res.replace(' ', spRep);
        res.replace('\t', tabRep);
        return res;
    }
    return res;
}


JKQTMathTextVerbatimNode::LayoutInfo::LayoutInfo():
    JKQTMathTextNodeSize(), lines(), X()
{

}