#include <config.h>

#include "lyxrow_funcs.h"
#include "lyxtext.h"
#include "paragraph.h"
#include "lyxlayout.h"

#include <boost/next_prior.hpp>
#include <algorithm>

using lyx::pos_type;
using std::max;
using std::min;


bool isParEnd(LyXText const & lt, RowList::iterator rit)
{
	RowList::iterator next_row = boost::next(rit);

	return next_row == lt.rows().end() ||
		next_row->par() != rit->par();
}


pos_type lastPos(LyXText const & lt, RowList::iterator rit)
{
	if (rit->par()->empty())
		return 0;

	if (isParEnd(lt, rit)) {
		return rit->par()->size() - 1;
	} else {
		return boost::next(rit)->pos() - 1;
	}
}


namespace {

bool nextRowIsAllInset(Row const & row, pos_type last)
{
	ParagraphList::iterator pit = row.par();

	if (last + 1 >= pit->size())
		return false;

	if (!pit->isInset(last + 1))
		return false;

	Inset const * i = pit->getInset(last + 1);
	return i->needFullRow() || i->display();
}

} // anon namespace


pos_type lastPrintablePos(LyXText const & lt, RowList::iterator rit)
{
	pos_type const last = lastPos(lt, rit);

	// if this row is an end of par, just act like lastPos()
	if (isParEnd(lt, rit))
		return last;

	bool const nextrownotinset = !nextRowIsAllInset(*rit, last);

	if (nextrownotinset && rit->par()->isSeparator(last))
		return last - 1;

	return last;
}


int numberOfSeparators(LyXText const & lt, RowList::iterator rit)
{
        pos_type const last = lastPrintablePos(lt, rit);
	ParagraphList::iterator pit = rit->par();

        int n = 0;

        pos_type p = max(rit->pos(), pit->beginningOfBody());
        for (; p < last; ++p) {
                if (pit->isSeparator(p)) {
                        ++n;
                }
        }
        return n;
}


// This is called _once_ from LyXText and should at least be moved into
// an anonymous namespace there. (Lgb)
int numberOfHfills(LyXText const & lt, RowList::iterator rit)
{
	pos_type const last = lastPos(lt, rit);
	pos_type first = rit->pos();
	ParagraphList::iterator pit = rit->par();

	// hfill *DO* count at the beginning of paragraphs!
	if (first) {
		while (first < last && pit->isHfill(first)) {
			++first;
		}
	}

	first = max(first, pit->beginningOfBody());

	int n = 0;

	// last, because the end is ignored!
	for (pos_type p = first; p < last; ++p) {
		if (pit->isHfill(p))
			++n;
	}
	return n;
}


// This is called _once_ from LyXText and should at least be moved into
// an anonymous namespace there. (Lgb)
int numberOfLabelHfills(LyXText const & lt, RowList::iterator rit)
{
	pos_type last = lastPos(lt, rit);
	pos_type first = rit->pos();
	ParagraphList::iterator pit = rit->par();

	// hfill *DO* count at the beginning of paragraphs!
	if (first) {
		while (first < last && pit->isHfill(first))
			++first;
	}

	last = min(last, pit->beginningOfBody());
	int n = 0;

	// last, because the end is ignored!
	for (pos_type p = first; p < last; ++p) {
		if (pit->isHfill(p))
			++n;
	}
	return n;
}


bool hfillExpansion(LyXText const & lt, RowList::iterator rit, pos_type pos)
{
	ParagraphList::iterator pit = rit->par();

	if (!pit->isHfill(pos))
		return false;

	// at the end of a row it does not count
	// unless another hfill exists on the line
	if (pos >= lastPos(lt, rit)) {
		pos_type i = rit->pos();
		while (i < pos && !pit->isHfill(i)) {
			++i;
		}
		if (i == pos) {
			return false;
		}
	}

	// at the beginning of a row it does not count, if it is not
	// the first row of a paragaph
	if (rit->isParStart())
		return true;

	// in some labels it does not count
	if (pit->layout()->margintype != MARGIN_MANUAL
	    && pos < pit->beginningOfBody())
		return false;

	// if there is anything between the first char of the row and
	// the specified position that is not a newline and not a hfill,
	// the hfill will count, otherwise not
	pos_type i = rit->pos();
	while (i < pos && (pit->isNewline(i) || pit->isHfill(i)))
		++i;

	return i != pos;
}