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/*
  openedlist.cpp
*/

#include <qregexp.h>

#include "atom.h"
#include "openedlist.h"

QT_BEGIN_NAMESPACE

static const char roman[] = "m\2d\5c\2l\5x\2v\5i";

OpenedList::OpenedList( Style style )
    : sty( style ), ini( 1 ), nex( 0 )
{
}

OpenedList::OpenedList( const Location& location, const QString& hint )
    : sty( Bullet ), ini( 1 )
{
    QRegExp hintSyntax( "(\\W*)([0-9]+|[A-Z]+|[a-z]+)(\\W*)" );

    if ( hintSyntax.exactMatch(hint) ) {
        bool ok;
        int asNumeric = hint.toInt( &ok );
        int asRoman = fromRoman( hintSyntax.cap(2) );
        int asAlpha = fromAlpha( hintSyntax.cap(2) );

        if ( ok ) {
            sty = Numeric;
            ini = asNumeric;
        } else if ( asRoman > 0 && asRoman != 100 && asRoman != 500 ) {
            sty = ( hint == hint.toLower() ) ? LowerRoman : UpperRoman;
            ini = asRoman;
        } else {
            sty = ( hint == hint.toLower() ) ? LowerAlpha : UpperAlpha;
            ini = asAlpha;
        }
        pref = hintSyntax.cap( 1 );
        suff = hintSyntax.cap( 3 );
    } else if ( !hint.isEmpty() ) {
        location.warning( tr("Unrecognized list style '%1'").arg(hint) );
    }
    nex = ini - 1;
}

QString OpenedList::styleString() const
{
    switch ( style() ) {
    case Bullet:
    default:
        return ATOM_LIST_BULLET;
    case Tag:
        return ATOM_LIST_TAG;
    case Value:
        return ATOM_LIST_VALUE;
    case Numeric:
        return ATOM_LIST_NUMERIC;
    case UpperAlpha:
        return ATOM_LIST_UPPERALPHA;
    case LowerAlpha:
        return ATOM_LIST_LOWERALPHA;
    case UpperRoman:
        return ATOM_LIST_UPPERROMAN;
    case LowerRoman:
        return ATOM_LIST_LOWERROMAN;
    }
}

QString OpenedList::numberString() const
{
    return QString::number( number() );
    /*
    switch ( style() ) {
    case Numeric:
 return QString::number( number() );
    case UpperAlpha:
 return toAlpha( number() ).toUpper();
    case LowerAlpha:
 return toAlpha( number() );
    case UpperRoman:
 return toRoman( number() ).toUpper();
    case LowerRoman:
 return toRoman( number() );
    case Bullet:
    default:
 return "*";
    }*/
}

QString OpenedList::toAlpha( int n )
{
    QString str;

    while ( n > 0 ) {
        n--;
        str.prepend( (n % 26) + 'a' );
        n /= 26;
    }
    return str;
}

int OpenedList::fromAlpha( const QString& str )
{
    int n = 0;
    int u;

    for ( int i = 0; i < (int) str.length(); i++ ) {
        u = str[i].toLower().unicode();
        if ( u >= 'a' && u <= 'z' ) {
            n *= 26;
            n += u - 'a' + 1;
        } else {
            return 0;
        }
    }
    return n;
}

QString OpenedList::toRoman( int n )
{
    /*
      See p. 30 of Donald E. Knuth's "TeX: The Program".
    */
    QString str;
    int j = 0;
    int k;
    int u;
    int v = 1000;

    for ( ;; ) {
        while ( n >= v ) {
            str += roman[j];
            n -= v;
        }

        if ( n <= 0 )
            break;

        k = j + 2;
        u = v / roman[k - 1];
        if ( roman[k - 1] == 2 ) {
            k += 2;
            u /= 5;
        }
        if ( n + u >= v ) {
            str += roman[k];
            n += u;
        } else {
            j += 2;
            v /= roman[j - 1];
        }
    }
    return str;
}

int OpenedList::fromRoman( const QString& str )
{
    int n = 0;
    int j;
    int u;
    int v = 0;

    for ( int i = str.length() - 1; i >= 0; i-- ) {
        j = 0;
        u = 1000;
        while ( roman[j] != 'i' && roman[j] != str[i].toLower() ) {
            j += 2;
            u /= roman[j - 1];
        }
        if ( u < v ) {
            n -= u;
        } else {
            n += u;
        }
        v = u;
    }

    if ( str.toLower() == toRoman(n) ) {
        return n;
    } else {
        return 0;
    }
}

QT_END_NAMESPACE