/*
 *  Kchmviewer - a CHM and EPUB file viewer with broad language support
 *  Copyright (C) 2004-2014 George Yunaev, gyunaev@ulduzsoft.com
 *
 *  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 3 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, see <http://www.gnu.org/licenses/>.
 */

#include <QTextCodec>

#include "helper_entitydecoder.h"


HelperEntityDecoder::HelperEntityDecoder(QTextCodec *encoder)
{
	changeEncoding( encoder );

}

static inline QString encodeWithCodec( QTextCodec *encoder, const QByteArray& str )
{
	return (encoder ? encoder->toUnicode( str.constData () ) : str);
}

void HelperEntityDecoder::changeEncoding(QTextCodec *encoder)
{
	// Set up m_entityDecodeMap characters according to current textCodec
	m_entityDecodeMap.clear();

	m_entityDecodeMap[QStringLiteral("AElig")]	= encodeWithCodec( encoder, "\306"); // capital AE diphthong (ligature)
	m_entityDecodeMap[QStringLiteral("Aacute")]	= encodeWithCodec( encoder, "\301"); // capital A, acute accent
	m_entityDecodeMap[QStringLiteral("Acirc")]	= encodeWithCodec( encoder, "\302"); // capital A, circumflex accent
	m_entityDecodeMap[QStringLiteral("Agrave")]	= encodeWithCodec( encoder, "\300"); // capital A, grave accent
	m_entityDecodeMap[QStringLiteral("Aring")]	= encodeWithCodec( encoder, "\305"); // capital A, ring
	m_entityDecodeMap[QStringLiteral("Atilde")]	= encodeWithCodec( encoder, "\303"); // capital A, tilde
	m_entityDecodeMap[QStringLiteral("Auml")]	= encodeWithCodec( encoder, "\304"); // capital A, dieresis or umlaut mark
	m_entityDecodeMap[QStringLiteral("Ccedil")]	= encodeWithCodec( encoder, "\307"); // capital C, cedilla
	m_entityDecodeMap[QStringLiteral("Dstrok")]	= encodeWithCodec( encoder, "\320"); // whatever
	m_entityDecodeMap[QStringLiteral("ETH")]	= encodeWithCodec( encoder, "\320"); // capital Eth, Icelandic
	m_entityDecodeMap[QStringLiteral("Eacute")]	= encodeWithCodec( encoder, "\311"); // capital E, acute accent
	m_entityDecodeMap[QStringLiteral("Ecirc")]	= encodeWithCodec( encoder, "\312"); // capital E, circumflex accent
	m_entityDecodeMap[QStringLiteral("Egrave")]	= encodeWithCodec( encoder, "\310"); // capital E, grave accent
	m_entityDecodeMap[QStringLiteral("Euml")]	= encodeWithCodec( encoder, "\313"); // capital E, dieresis or umlaut mark
	m_entityDecodeMap[QStringLiteral("Iacute")]	= encodeWithCodec( encoder, "\315"); // capital I, acute accent
	m_entityDecodeMap[QStringLiteral("Icirc")]	= encodeWithCodec( encoder, "\316"); // capital I, circumflex accent
	m_entityDecodeMap[QStringLiteral("Igrave")]	= encodeWithCodec( encoder, "\314"); // capital I, grave accent
	m_entityDecodeMap[QStringLiteral("Iuml")]	= encodeWithCodec( encoder, "\317"); // capital I, dieresis or umlaut mark
	m_entityDecodeMap[QStringLiteral("Ntilde")]	= encodeWithCodec( encoder, "\321"); // capital N, tilde
	m_entityDecodeMap[QStringLiteral("Oacute")]	= encodeWithCodec( encoder, "\323"); // capital O, acute accent
	m_entityDecodeMap[QStringLiteral("Ocirc")]	= encodeWithCodec( encoder, "\324"); // capital O, circumflex accent
	m_entityDecodeMap[QStringLiteral("Ograve")]	= encodeWithCodec( encoder, "\322"); // capital O, grave accent
	m_entityDecodeMap[QStringLiteral("Oslash")]	= encodeWithCodec( encoder, "\330"); // capital O, slash
	m_entityDecodeMap[QStringLiteral("Otilde")]	= encodeWithCodec( encoder, "\325"); // capital O, tilde
	m_entityDecodeMap[QStringLiteral("Ouml")]	= encodeWithCodec( encoder, "\326"); // capital O, dieresis or umlaut mark
	m_entityDecodeMap[QStringLiteral("THORN")]	= encodeWithCodec( encoder, "\336"); // capital THORN, Icelandic
	m_entityDecodeMap[QStringLiteral("Uacute")]	= encodeWithCodec( encoder, "\332"); // capital U, acute accent
	m_entityDecodeMap[QStringLiteral("Ucirc")]	= encodeWithCodec( encoder, "\333"); // capital U, circumflex accent
	m_entityDecodeMap[QStringLiteral("Ugrave")]	= encodeWithCodec( encoder, "\331"); // capital U, grave accent
	m_entityDecodeMap[QStringLiteral("Uuml")]	= encodeWithCodec( encoder, "\334"); // capital U, dieresis or umlaut mark
	m_entityDecodeMap[QStringLiteral("Yacute")]	= encodeWithCodec( encoder, "\335"); // capital Y, acute accent
	m_entityDecodeMap[QStringLiteral("OElig")]	= encodeWithCodec( encoder, "\338"); // capital Y, acute accent
	m_entityDecodeMap[QStringLiteral("oelig")]	= encodeWithCodec( encoder, "\339"); // capital Y, acute accent

	m_entityDecodeMap[QStringLiteral("aacute")]	= encodeWithCodec( encoder, "\341"); // small a, acute accent
	m_entityDecodeMap[QStringLiteral("acirc")]	= encodeWithCodec( encoder, "\342"); // small a, circumflex accent
	m_entityDecodeMap[QStringLiteral("aelig")]	= encodeWithCodec( encoder, "\346"); // small ae diphthong (ligature)
	m_entityDecodeMap[QStringLiteral("agrave")]	= encodeWithCodec( encoder, "\340"); // small a, grave accent
	m_entityDecodeMap[QStringLiteral("aring")]	= encodeWithCodec( encoder, "\345"); // small a, ring
	m_entityDecodeMap[QStringLiteral("atilde")]	= encodeWithCodec( encoder, "\343"); // small a, tilde
	m_entityDecodeMap[QStringLiteral("auml")]	= encodeWithCodec( encoder, "\344"); // small a, dieresis or umlaut mark
	m_entityDecodeMap[QStringLiteral("ccedil")]	= encodeWithCodec( encoder, "\347"); // small c, cedilla
	m_entityDecodeMap[QStringLiteral("eacute")]	= encodeWithCodec( encoder, "\351"); // small e, acute accent
	m_entityDecodeMap[QStringLiteral("ecirc")]	= encodeWithCodec( encoder, "\352"); // small e, circumflex accent
	m_entityDecodeMap[QStringLiteral("Scaron")]	= encodeWithCodec( encoder, "\352"); // small e, circumflex accent
	m_entityDecodeMap[QStringLiteral("egrave")]	= encodeWithCodec( encoder, "\350"); // small e, grave accent
	m_entityDecodeMap[QStringLiteral("eth")]	= encodeWithCodec( encoder, "\360"); // small eth, Icelandic
	m_entityDecodeMap[QStringLiteral("euml")]	= encodeWithCodec( encoder, "\353"); // small e, dieresis or umlaut mark
	m_entityDecodeMap[QStringLiteral("iacute")]	= encodeWithCodec( encoder, "\355"); // small i, acute accent
	m_entityDecodeMap[QStringLiteral("icirc")]	= encodeWithCodec( encoder, "\356"); // small i, circumflex accent
	m_entityDecodeMap[QStringLiteral("igrave")]	= encodeWithCodec( encoder, "\354"); // small i, grave accent
	m_entityDecodeMap[QStringLiteral("iuml")]	= encodeWithCodec( encoder, "\357"); // small i, dieresis or umlaut mark
	m_entityDecodeMap[QStringLiteral("ntilde")]	= encodeWithCodec( encoder, "\361"); // small n, tilde
	m_entityDecodeMap[QStringLiteral("oacute")]	= encodeWithCodec( encoder, "\363"); // small o, acute accent
	m_entityDecodeMap[QStringLiteral("ocirc")]	= encodeWithCodec( encoder, "\364"); // small o, circumflex accent
	m_entityDecodeMap[QStringLiteral("ograve")]	= encodeWithCodec( encoder, "\362"); // small o, grave accent
	m_entityDecodeMap[QStringLiteral("oslash")]	= encodeWithCodec( encoder, "\370"); // small o, slash
	m_entityDecodeMap[QStringLiteral("otilde")]	= encodeWithCodec( encoder, "\365"); // small o, tilde
	m_entityDecodeMap[QStringLiteral("ouml")]	= encodeWithCodec( encoder, "\366"); // small o, dieresis or umlaut mark
	m_entityDecodeMap[QStringLiteral("szlig")]	= encodeWithCodec( encoder, "\337"); // small sharp s, German (sz ligature)
	m_entityDecodeMap[QStringLiteral("thorn")]	= encodeWithCodec( encoder, "\376"); // small thorn, Icelandic
	m_entityDecodeMap[QStringLiteral("uacute")]	= encodeWithCodec( encoder, "\372"); // small u, acute accent
	m_entityDecodeMap[QStringLiteral("ucirc")]	= encodeWithCodec( encoder, "\373"); // small u, circumflex accent
	m_entityDecodeMap[QStringLiteral("ugrave")]	= encodeWithCodec( encoder, "\371"); // small u, grave accent
	m_entityDecodeMap[QStringLiteral("uuml")]	= encodeWithCodec( encoder, "\374"); // small u, dieresis or umlaut mark
	m_entityDecodeMap[QStringLiteral("yacute")]	= encodeWithCodec( encoder, "\375"); // small y, acute accent
	m_entityDecodeMap[QStringLiteral("yuml")]	= encodeWithCodec( encoder, "\377"); // small y, dieresis or umlaut mark

	m_entityDecodeMap[QStringLiteral("iexcl")]	= encodeWithCodec( encoder, "\241");
	m_entityDecodeMap[QStringLiteral("cent")]	= encodeWithCodec( encoder, "\242");
	m_entityDecodeMap[QStringLiteral("pound")]	= encodeWithCodec( encoder, "\243");
	m_entityDecodeMap[QStringLiteral("curren")]	= encodeWithCodec( encoder, "\244");
	m_entityDecodeMap[QStringLiteral("yen")]	= encodeWithCodec( encoder, "\245");
	m_entityDecodeMap[QStringLiteral("brvbar")]	= encodeWithCodec( encoder, "\246");
	m_entityDecodeMap[QStringLiteral("sect")]	= encodeWithCodec( encoder, "\247");
	m_entityDecodeMap[QStringLiteral("uml")]	= encodeWithCodec( encoder, "\250");
	m_entityDecodeMap[QStringLiteral("ordf")]	= encodeWithCodec( encoder, "\252");
	m_entityDecodeMap[QStringLiteral("laquo")]	= encodeWithCodec( encoder, "\253");
	m_entityDecodeMap[QStringLiteral("not")]	= encodeWithCodec( encoder, "\254");
	m_entityDecodeMap[QStringLiteral("shy")]	= encodeWithCodec( encoder, "\255");
	m_entityDecodeMap[QStringLiteral("macr")]	= encodeWithCodec( encoder, "\257");
	m_entityDecodeMap[QStringLiteral("deg")]	= encodeWithCodec( encoder, "\260");
	m_entityDecodeMap[QStringLiteral("plusmn")]	= encodeWithCodec( encoder, "\261");
	m_entityDecodeMap[QStringLiteral("sup1")]	= encodeWithCodec( encoder, "\271");
	m_entityDecodeMap[QStringLiteral("sup2")]	= encodeWithCodec( encoder, "\262");
	m_entityDecodeMap[QStringLiteral("sup3")]	= encodeWithCodec( encoder, "\263");
	m_entityDecodeMap[QStringLiteral("acute")]	= encodeWithCodec( encoder, "\264");
	m_entityDecodeMap[QStringLiteral("micro")]	= encodeWithCodec( encoder, "\265");
	m_entityDecodeMap[QStringLiteral("para")]	= encodeWithCodec( encoder, "\266");
	m_entityDecodeMap[QStringLiteral("middot")]	= encodeWithCodec( encoder, "\267");
	m_entityDecodeMap[QStringLiteral("cedil")]	= encodeWithCodec( encoder, "\270");
	m_entityDecodeMap[QStringLiteral("ordm")]	= encodeWithCodec( encoder, "\272");
	m_entityDecodeMap[QStringLiteral("raquo")]	= encodeWithCodec( encoder, "\273");
	m_entityDecodeMap[QStringLiteral("frac14")]	= encodeWithCodec( encoder, "\274");
	m_entityDecodeMap[QStringLiteral("frac12")]	= encodeWithCodec( encoder, "\275");
	m_entityDecodeMap[QStringLiteral("frac34")]	= encodeWithCodec( encoder, "\276");
	m_entityDecodeMap[QStringLiteral("iquest")]	= encodeWithCodec( encoder, "\277");
	m_entityDecodeMap[QStringLiteral("times")]	= encodeWithCodec( encoder, "\327");
	m_entityDecodeMap[QStringLiteral("divide")]	= encodeWithCodec( encoder, "\367");

	m_entityDecodeMap[QStringLiteral("copy")]	= encodeWithCodec( encoder, "\251"); // copyright sign
	m_entityDecodeMap[QStringLiteral("reg")]	= encodeWithCodec( encoder, "\256"); // registered sign
	m_entityDecodeMap[QStringLiteral("nbsp")]	= encodeWithCodec( encoder, "\240"); // non breaking space

	m_entityDecodeMap[QStringLiteral("fnof")]	= QChar((unsigned short) 402);

	m_entityDecodeMap[QStringLiteral("Delta")]	= QChar((unsigned short) 916);
	m_entityDecodeMap[QStringLiteral("Pi")]	= QChar((unsigned short) 928);
	m_entityDecodeMap[QStringLiteral("Sigma")]	= QChar((unsigned short) 931);

	m_entityDecodeMap[QStringLiteral("beta")]	= QChar((unsigned short) 946);
	m_entityDecodeMap[QStringLiteral("gamma")]	= QChar((unsigned short) 947);
	m_entityDecodeMap[QStringLiteral("delta")]	= QChar((unsigned short) 948);
	m_entityDecodeMap[QStringLiteral("eta")]	= QChar((unsigned short) 951);
	m_entityDecodeMap[QStringLiteral("theta")]	= QChar((unsigned short) 952);
	m_entityDecodeMap[QStringLiteral("lambda")]	= QChar((unsigned short) 955);
	m_entityDecodeMap[QStringLiteral("mu")]	= QChar((unsigned short) 956);
	m_entityDecodeMap[QStringLiteral("nu")]	= QChar((unsigned short) 957);
	m_entityDecodeMap[QStringLiteral("pi")]	= QChar((unsigned short) 960);
	m_entityDecodeMap[QStringLiteral("rho")]	= QChar((unsigned short) 961);

	m_entityDecodeMap[QStringLiteral("lsquo")]	= QChar((unsigned short) 8216);
	m_entityDecodeMap[QStringLiteral("rsquo")]	= QChar((unsigned short) 8217);
	m_entityDecodeMap[QStringLiteral("rdquo")]	= QChar((unsigned short) 8221);
	m_entityDecodeMap[QStringLiteral("bdquo")]	= QChar((unsigned short) 8222);
	m_entityDecodeMap[QStringLiteral("trade")]  = QChar((unsigned short) 8482);
	m_entityDecodeMap[QStringLiteral("ldquo")]  = QChar((unsigned short) 8220);
	m_entityDecodeMap[QStringLiteral("ndash")]  = QChar((unsigned short) 8211);
	m_entityDecodeMap[QStringLiteral("mdash")]  = QChar((unsigned short) 8212);
	m_entityDecodeMap[QStringLiteral("bull")]  = QChar((unsigned short) 8226);
	m_entityDecodeMap[QStringLiteral("hellip")]  = QChar((unsigned short) 8230);
	m_entityDecodeMap[QStringLiteral("emsp")]  = QChar((unsigned short) 8195);
	m_entityDecodeMap[QStringLiteral("rarr")]  = QChar((unsigned short) 8594);
	m_entityDecodeMap[QStringLiteral("rArr")]  = QChar((unsigned short) 8658);
	m_entityDecodeMap[QStringLiteral("crarr")]  = QChar((unsigned short) 8629);
	m_entityDecodeMap[QStringLiteral("le")]  = QChar((unsigned short) 8804);
	m_entityDecodeMap[QStringLiteral("ge")]  = QChar((unsigned short) 8805);
	m_entityDecodeMap[QStringLiteral("lte")]  = QChar((unsigned short) 8804); // wrong, but used somewhere
	m_entityDecodeMap[QStringLiteral("gte")]  = QChar((unsigned short) 8805); // wrong, but used somewhere
	m_entityDecodeMap[QStringLiteral("dagger")]  = QChar((unsigned short) 8224);
	m_entityDecodeMap[QStringLiteral("Dagger")]  = QChar((unsigned short) 8225);
	m_entityDecodeMap[QStringLiteral("euro")]  = QChar((unsigned short) 8364);
	m_entityDecodeMap[QStringLiteral("asymp")]  = QChar((unsigned short) 8776);
	m_entityDecodeMap[QStringLiteral("isin")]  = QChar((unsigned short) 8712);
	m_entityDecodeMap[QStringLiteral("notin")]  = QChar((unsigned short) 8713);
	m_entityDecodeMap[QStringLiteral("prod")]  = QChar((unsigned short) 8719);
	m_entityDecodeMap[QStringLiteral("ne")]  = QChar((unsigned short) 8800);

	m_entityDecodeMap[QStringLiteral("amp")]	= QStringLiteral("&");	// ampersand
	m_entityDecodeMap[QStringLiteral("gt")] = QStringLiteral(">");	// greater than
	m_entityDecodeMap[QStringLiteral("lt")] = QStringLiteral("<"); 	// less than
	m_entityDecodeMap[QStringLiteral("quot")] = QStringLiteral("\""); // double quote
	m_entityDecodeMap[QStringLiteral("apos")] = QStringLiteral("'"); 	// single quote
	m_entityDecodeMap[QStringLiteral("frasl")]  = QStringLiteral("/");
	m_entityDecodeMap[QStringLiteral("minus")]  = QStringLiteral("-");
	m_entityDecodeMap[QStringLiteral("oplus")] = QStringLiteral("+");
	m_entityDecodeMap[QStringLiteral("Prime")] = QStringLiteral("\"");
}


QString HelperEntityDecoder::decode( const QString &entity ) const
{
	// If entity is an ASCII code like &#12349; - just decode it
	if ( entity.isEmpty() )
	{
		return QLatin1String("");
	}
	else if ( entity[0] == '#' )
	{
		bool valid;
		unsigned int ascode = entity.midRef(1).toUInt( &valid );

		if ( !valid )
		{
			qWarning ( "HelperEntityDecoder::decode: could not decode HTML entity '%s'", qPrintable( entity ) );
			return QString();
		}

		return (QString) (QChar( ascode ));
	}
	else
	{
		QMap<QString, QString>::const_iterator it = m_entityDecodeMap.find( entity );

		if ( it == m_entityDecodeMap.end() )
		{
			qWarning ("HelperEntityDecoder::decode: could not decode HTML entity '%s'", qPrintable( entity ));
			return QLatin1String("");
		}

		return *it;
	}
}