// This file contains most of the magic that extracts "context
// information" from the unstructered layout-oriented stuff in an
// MathArray.


#include "math_charinset.h"
#include "math_deliminset.h"
#include "math_exfuncinset.h"
#include "math_funcinset.h"
#include "math_matrixinset.h"
#include "math_mathmlstream.h"
#include "math_scriptinset.h"
#include "math_stringinset.h"
#include "debug.h"


std::ostream & operator<<(ostream & os, MathArray const & ar)
{
	NormalStream ws(os);	
	ws << ar;
	return os;
}


MathScriptInset const * asScript(MathArray::const_iterator it)
{
	if (it->nucleus()->asScriptInset())
		return 0;
	++it;
	if (!it->nucleus())
		return 0;
	return it->nucleus()->asScriptInset();
}



// returns sequence of char with same code starting at it up to end
// it might be less, though...
string charSequence(MathArray::const_iterator it, MathArray::const_iterator end)
{
	string s;
	MathCharInset const * p = it->nucleus()->asCharInset();
	if (p) {
		for (MathTextCodes c = p->code(); it != end; ++it) {
			if (!it->nucleus())
				break;
			p = it->nucleus()->asCharInset();
			if (!p || p->code() != c)
				break;
			s += p->getChar();
		}
	}
	return s;
}


void glueChars(MathArray & dat)
{
	MathArray ar;
	MathArray::const_iterator it = dat.begin();
	while (it != dat.end()) {
		if (it->nucleus() && it->nucleus()->asCharInset()) {
			string s = charSequence(it, dat.end());
			MathTextCodes c = it->nucleus()->asCharInset()->code();
			ar.push_back(MathAtom(new MathStringInset(s, c)));
			it += s.size();
		} else {
			ar.push_back(*it);
			++it;
		}
	}
	ar.swap(dat);
}


bool needAsterisk(MathAtom const &, MathAtom const &)
{
	return false;
}


void guessAsterisks(MathArray & dat)
{
	if (dat.size() <= 1)
		return;
	MathArray ar;
	ar.push_back(*dat.begin());
	MathArray::const_iterator it = dat.begin();
	MathArray::const_iterator jt = it + 1;
	for (; jt != dat.end(); ++it, ++jt) {
		if (needAsterisk(*it, *jt))
			ar.push_back(MathAtom(new MathCharInset('*')));
		ar.push_back(*it);
	}
	ar.push_back(*dat.end());
	ar.swap(dat);
}


MathInset * singleItem(MathArray & ar)
{
	lyxerr << "ar.size: " << ar.size() << "\n";
	//lyxerr << "ar.begin: " << ar.begin() << "\n";
	//lyxerr << "ar.nuc: " << ar.begin()->nucleus() << "\n";
	lyxerr << "ar.nuc: " << *ar.begin()->nucleus() << "\n";
	return ar.size() == 1 ? ar.begin()->nucleus() : 0;
}


void extractMatrices(MathArray & ar)
{
	for (MathArray::iterator it = ar.begin(); it != ar.end(); ++it) {
		if (!it->nucleus())
			continue;	
		MathDelimInset * del = it->nucleus()->asDelimInset();
		if (!del)
			continue;
		MathInset * arr = singleItem(del->cell(0));
		if (!arr || !arr->asArrayInset())
			continue;
		*it = MathAtom(new MathMatrixInset(*(arr->asArrayInset())));
	}
} 


void extractDelims(MathArray & ar) {
	// use indices rather than iterators for the loop  because we are going
	// to modify the array.
	for (MathArray::size_type i = 0; i < ar.size(); ++i) {
		MathArray::iterator it = ar.begin() + i;
		if (!it->nucleus())
			continue;	
		if ((*it)->getChar() != '(')
			continue;

		// search last closing paranthesis
		MathArray::iterator et = ar.end();
		for (MathArray::iterator jt = it + 1; jt != ar.end(); ++jt)
			if ((*jt)->getChar() == ')')
				et = jt;
		if (et == ar.end())
			continue;

		// create a proper deliminset
		MathAtom at(new MathDelimInset("(", ")"));
		at->cell(0) = MathArray(it + 1, et);

		// replace the original stuff by the new inset
		ar.erase(it + 1, et + 1);
		*it = at;
	}
} 


// assume 'extractDelims' ran before
void extractFunctions(MathArray & ar)
{
	// we need at least two items...
	if (ar.size() <= 1)
		return;

	for (MathArray::size_type i = 0; i < ar.size() - 1; ++i) {
		MathArray::iterator it = ar.begin() + i;

		// is this a function name?
		if (!it->nucleus())
			continue;	
		MathFuncInset * func = (*it)->asFuncInset();
		if (!func)
			continue;

		// do we have an exponent?
		// simply skippping the postion does the right thing:
		// 'sin' '^2' 'x' -> 'sin(x)' '^2'
		MathArray::iterator jt = it + 1;
		if (MathScriptInset * script = (*jt)->asScriptInset()) {
			// allow superscripts only
			if (script->hasDown())
				continue;
			++jt;
			if (jt == ar.end())
				continue;
		}

		// jt points now to the "argument". Since we had run "extractDelims"
		// before, this could be a single argument only. Get hold of this.
		MathArray arg;
		MathDelimInset * del = (*jt)->asDelimInset();
		if (del && del->isParanthesis()) 
			arg = del->cell(0);
		else
			arg.push_back(*jt);

		// replace the function name by a real function inset
		(*it).reset(new MathExFuncInset(func->name(), arg));
		
		// remove the source of the argument from the array
		ar.erase(jt);
	}
} 


void extractStructure(MathArray & ar)
{
	glueChars(ar);
	extractMatrices(ar);
	extractDelims(ar);
	extractFunctions(ar);
}


void write(MathArray const & dat, WriteStream & wi)
{
	MathArray ar = dat;
	glueChars(ar);
	for (MathArray::const_iterator it = ar.begin(); it != ar.end(); ++it) {
		MathInset const * p = it->nucleus();
		if (it + 1 != ar.end()) {
			if (MathScriptInset const * q = asScript(it)) {
				q->write(p, wi);
				++it;
				continue;
			} 
		}
		p->write(wi);
	}
}


void normalize(MathArray const & dat, NormalStream & os)
{
	MathArray ar = dat;
	glueChars(ar);
	for (MathArray::const_iterator it = ar.begin(); it != ar.end(); ++it) {
		MathInset const * p = it->nucleus();
		if (it + 1 != ar.end()) {
			if (MathScriptInset const * q = asScript(it)) {
				q->normalize(p, os);
				++it;	
				continue;
			}
		}
		p->normalize(os);
	}
}


void octavize(MathArray const & dat, OctaveStream & os)
{
	MathArray ar = dat;
	extractStructure(ar);
	for (MathArray::const_iterator it = ar.begin(); it != ar.end(); ++it) {
		MathInset const * p = it->nucleus();
		if (it + 1 != ar.end()) {
			if (MathScriptInset const * q = asScript(it)) {
				q->octavize(p, os);
				++it;	
				continue;
			}
		}
		p->octavize(os);
	}
}


void maplize(MathArray const & dat, MapleStream & os)
{
	MathArray ar = dat;
	extractStructure(ar);
	for (MathArray::const_iterator it = ar.begin(); it != ar.end(); ++it) {
		MathInset const * p = it->nucleus();
		if (it + 1 != ar.end()) {
			if (MathScriptInset const * q = asScript(it)) {
				q->maplize(p, os);
				++it;	
				continue;
			}
		}
		p->maplize(os);
	}
}


void mathmlize(MathArray const & dat, MathMLStream & os)
{
	MathArray ar = dat;
	extractStructure(ar);
	if (ar.size() == 0)
		os << "<mrow/>";
	else if (ar.size() == 1)
		os << ar.begin()->nucleus();
	else {
		os << MTag("mrow");
		for (MathArray::const_iterator it = ar.begin(); it != ar.end(); ++it) {
			MathInset const * p = it->nucleus();
			if (it + 1 != ar.end()) {
				if (MathScriptInset const * q = asScript(it)) {
					q->mathmlize(p, os);
					++it;	
					continue;
				}
			}
			p->mathmlize(os);
		}
		os << ETag("mrow");
	}
}