/***************************************************************************
    copyright            : (C) 2005 by Inge Wallin
    email                : inge@lysator.liu.se
 ***************************************************************************/
/***************************************************************************
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/

#include "moleculeparser.h"

#include <ctype.h>

#include <kstandarddirs.h>
#include <kdebug.h>
#include <QFile>

// ================================================================
//                    class ElementCountMap



ElementCountMap::ElementCountMap()
{
	m_map.clear();
}


ElementCountMap::~ElementCountMap()
{
}


ElementCount *
ElementCountMap::search(Element *_element)
{
	foreach( ElementCount* c, m_map ){
		if ( c->element() == _element )
			return c;
	}

	return 0;
}


void
ElementCountMap::add(ElementCountMap &_map)
{
	foreach( ElementCount* c, _map.m_map ){
		add( c->m_element, c->m_count );
	}
	
}

QList<Element*> 
ElementCountMap::elements()
{
	QList<Element*> list;

	foreach( ElementCount* c, m_map ){
		Element* e = c->m_element;
		if ( !list.contains( e ) )
			list << e;
	}

	return list;
}


void
ElementCountMap::add(Element *_element, int _count)
{
	ElementCount  *elemCount;

	elemCount = search(_element);
	if (elemCount)
		elemCount->m_count += _count;
	else
		m_map.append(new ElementCount(_element, _count));
}


void
ElementCountMap::multiply(int _factor)
{
  foreach (ElementCount * count, m_map) {
      count->multiply(_factor);
  }
}


// ================================================================
//                    class MoleculeParser


MoleculeParser::MoleculeParser( const QList<Element*>& list)
    : Parser()
{
	m_elementList = list;
	m_aliasList = new QSet<QString>;
}


MoleculeParser::MoleculeParser(const QString& _str)
    : Parser(_str)
{
	m_aliasList = new QSet<QString>;
}


MoleculeParser::~MoleculeParser()
{
}


// ----------------------------------------------------------------
//                            public methods


// Try to parse the molecule and get the weight of it.
//
// This method also acts as the main loop.

bool
MoleculeParser::weight(const QString&         _shortMoleculeString, 
					   double          *_resultMass,
					   ElementCountMap *_resultMap)
{
	if ( _shortMoleculeString.isEmpty() )
		return false;
	// Clear the list of aliases and start filling it again.
	
	m_aliasList -> clear();
	QString _moleculeString;
	// Clear the result variables and set m_error to false
	_resultMap->clear();
	m_error = false;
	*_resultMass = 0.0;
	
	// Expand the molecule string
	// Example : MeOH -> (CH3)OH
	kDebug() << _shortMoleculeString << "is going to be expanded";
	_moleculeString = expandFormula(_shortMoleculeString);
	kDebug() << _moleculeString << "is the expanded string";
	
	// Now set the expanded string
	// Initialize the parsing process, and parse te molecule.
	start(_moleculeString);
	parseSubmolecule(_resultMass, _resultMap);

	if (nextToken() != -1)
		return false;

	if ( m_error )//there was an error in the input...
		return false;
		
	return true;
}

QSet<QString>
MoleculeParser::aliasList()
{
	return *m_aliasList;
}
// ----------------------------------------------------------------
//            helper methods for the public methods


// Parse a submolecule.  This is a list of terms.
//

bool
MoleculeParser::parseSubmolecule(double          *_resultMass,
								 ElementCountMap *_resultMap)
{
    double           subMass = 0.0;
    ElementCountMap  subMap;

    *_resultMass = 0.0;
	_resultMap->clear();
    while (parseTerm(&subMass, &subMap)) {
		//kDebug() << "Parsed a term, weight = " << subresult;

		// Add the mass and composition of the submolecule to the total.
		*_resultMass += subMass;
		_resultMap->add(subMap);
    }

    return true;
}


// Parse a term within the molecule, i.e. a single atom or a
// submolecule within parenthesis followed by an optional number.
// Examples: Bk, Mn2, (COOH)2
//
// Return true if correct, otherwise return false.  

// If correct, the mass of the term is returned in *_resultMass, and
// the flattened composition of the molecule in *_resultMap.
//

bool
MoleculeParser::parseTerm(double          *_resultMass,
						  ElementCountMap *_resultMap)
{
    *_resultMass = 0.0;
	_resultMap->clear();
 
    if (nextToken() == ELEMENT_TOKEN) {
		//kDebug() << "Parsed an element: " << m_elementVal->symbol();
		*_resultMass = m_elementVal->dataAsVariant( ChemicalDataObject::mass ).toDouble();
		_resultMap->add(m_elementVal, 1);

		getNextToken();
    }

    else if (nextToken() == '(') {
		// A submolecule.

		getNextToken();
		parseSubmolecule(_resultMass, _resultMap);

		// Must end in a ")".
		if (nextToken() == ')') {
			//kDebug() << "Parsed a submolecule. weight = " << *_result;
			getNextToken();
		}
		else
			return false;
    }
    else 
		// Neither an element nor a list within ().
		return false;

    // Optional number.
    if (nextToken() == INT_TOKEN) {
		//kDebug() << "Parsed a number: " << intVal();

    	*_resultMass *= intVal();
		_resultMap->multiply(intVal());

		getNextToken();
    }

    kDebug() << "Weight of term = " << *_resultMass;
    return true;
}


// ----------------------------------------------------------------
//                           protected methods


// Extend Parser::getNextToken with elements.

int
MoleculeParser::getNextToken()
{
    QString  name;

#if 0
    kDebug() << "getNextToken(): Next character = "
	      << nextChar() << endl;
#endif

    // Check if the token is an element name.
    if ('A' <= nextChar() && nextChar() <= 'Z') {
		name = char(nextChar());
		getNextChar();

		if ('a' <= nextChar() && nextChar() <= 'z') {
			    name.append(char(nextChar()));
			    getNextChar();
		}

			// Look up the element from the name..
		m_elementVal = lookupElement(name);
		if (m_elementVal)
		{
		    m_nextToken = ELEMENT_TOKEN;
		}
		else
		    m_nextToken = -1;
    }
    else
		return Parser::getNextToken();

    return m_nextToken;
}


// ----------------------------------------------------------------
//                          private methods


Element *
MoleculeParser::lookupElement( const QString& _name )
{
    kDebug() << "looking up " << _name;

	foreach( Element* e, m_elementList ){
		if ( e->dataAsVariant(ChemicalDataObject::symbol) == _name ) {
			kDebug() << "Found element " << _name;
			return e;
		}
	}

	//if there is an error make m_error true.
	m_error = true;

	kDebug() << "no such element!: " << _name;

	return NULL;
}

QString
MoleculeParser::expandFormula( const QString& _shortString)
{
	QString _fullString;		// The expanded string that will be returned
	QString::const_iterator i;		// iterator
	QString temp;	 			// A temporary string that will contain a single element/group
	QString expandedTerm;		// expansion of a particular term.
	
	// Go through all letters in the string.
	for(i = _shortString.constBegin(); i != _shortString.constEnd(); )
	{
		temp = "";
		
		// If a capital letter was found
		if((*i).category() == QChar::Letter_Uppercase) {
			temp += (*i);
			i++;
			
			// A small letter following a capital letter
			if(i != _shortString.end() && (*i).category() == QChar::Letter_Lowercase) {
				temp += (*i);
				i++;
			}
			
			// If element is found, append it
			if (lookupElement(temp)) {
				_fullString += temp;
			}
			
			// If an expansion was made, return the expansion
			else if (!((expandedTerm = expandTerm(temp)).isEmpty())) {
				kDebug() << "expanded" << temp << "to" << expandedTerm;
				_fullString += "("+expandedTerm+")";
			}
			// invalid term, append it. ( Validation is done later anyway. )
			else {
				_fullString += temp;
			}
			
		}
		
		// Return parenthesis as and when found
		else if (*i == '(') {
			_fullString += '(';
			i++;
		}
		else if (*i == ')') {
			_fullString += ')';
			i++;
		}
		
		// If # is found, we have a short-form eg #EDTA#
		else if (*i == '#') {
			i ++;		// go to the next character
			// Get the term between # and #
			while (*i != '#' && i != _shortString.constEnd() )
			{
				temp += *i;
				i ++;
			}
			// If the string ended, just add the part that comes after #
			if ( i == _shortString.constEnd()) {
				_fullString += temp;
				break;
			}
			// else expand the term between # and #
			else if (!temp.isEmpty())
			{
				// if alias is not found, just add without expanding the term
				if((expandedTerm = expandTerm(temp)).isEmpty())
					_fullString += temp;
				// else add the expanded term
				else
					_fullString += expandedTerm;
			}
			i ++;
		}
		// If number was found, return it
		else if ((*i).category() == QChar::Number_DecimalDigit) {
			_fullString += *i;
			i++;
		}
		else { // invalid character, return it, validation is done again later
			_fullString += *i;
			i++;
			kDebug() << *i << "invalid character!";
		}		
	}
	
	// Reset all "element not found" errors.
	m_error = false;
	return _fullString;
}

QString
MoleculeParser::expandTerm (const QString& _group)
{

	QString shortForm, fullForm;	// short form (symbol) and full form (expansion)
	QString temp;					// A temporary QString used in Regular expressions
	
	// Search in User defined aliases.
	QString fileName = KStandardDirs::locate( "data", "libkdeedu/data/symbols2.csv");
	QFile file(fileName);
	
	// Check file validity
    if (!(!file.open(QIODevice::ReadOnly | QIODevice::Text)))
    {
	    kDebug() << fileName << " opened";
    	QTextStream in(&file);
    	
    	// Get all shortForms and fullForms in the file.
    	while (!in.atEnd()) {
    	    QString line = in.readLine();
			shortForm = line.section(',', 0, 0);
			shortForm.remove(QChar('\"'));
			fullForm  = line.section(',', 1, 1);
			fullForm.remove(QChar('\"'));
			
			// If short term is found, return fullForm
			if (shortForm == _group)
			{
				*m_aliasList << (_group + " : " + fullForm);
				return (fullForm);
			}
    	}
    }
    else
    {
    	kDebug() << fileName << " could not be opened!";
    }
    
	// Find the system defined aliases	
	// Open the file
	fileName = KStandardDirs::locate( "data", "libkdeedu/data/symbols.csv");
	QFile file2(fileName);
	
	// Check file validity
    if (!(!file2.open(QIODevice::ReadOnly | QIODevice::Text)))
    {
	    kDebug() << fileName << " opened";
    	QTextStream in(&file2);
    	
    	// Get all shortForms and fullForms in the file.
    	while (!in.atEnd()) {
    	    QString line = in.readLine();
			shortForm = line.section(',', 0, 0);
			shortForm.remove(QChar('\"'));
			fullForm  = line.section(',', 1, 1);
			fullForm.remove(QChar('\"'));
			
			if (shortForm == _group)
			{
				*m_aliasList << (_group + " : " + fullForm);				
				return (fullForm);
			}
    	}
    }
    else
    {
    	kDebug() << fileName << " could not be opened!";
    }
    
    // Sample expansions, work even when file is not found, testing purposes
	if (_group == "Me")
		return ("CH3");
	else if (_group == "Et")
		return ("C2H5");

	// If not found return an empty string.
	else
		return ("");
}