/**
 * \file ControlSpellchecker.C
 * This file is part of LyX, the document processor.
 * Licence details can be found in the file COPYING.
 *
 * \author Edwin Leuven
 *
 * Full author contact details are available in file CREDITS.
 */

#include <config.h>

#include "ControlSpellchecker.h"
#include "ViewBase.h"

#include "buffer.h"
#include "bufferparams.h"
#include "BufferView.h"
#include "cursor.h"
#include "CutAndPaste.h"
#include "debug.h"
#include "gettext.h"
#include "language.h"
#include "lyxrc.h"
#include "paragraph.h"

#include "ispell.h"
#ifdef USE_PSPELL
# include "pspell.h"
#else
#ifdef USE_ASPELL
# include "aspell_local.h"
#endif
#endif

#include "support/tostr.h"

#include "frontends/Alert.h"


using lyx::support::bformat;

using std::advance;
using std::distance;
using std::endl;
using std::string;


ControlSpellchecker::ControlSpellchecker(LyXView & lv, Dialogs & d)
	: ControlDialogBD(lv, d),
	  oldval_(0), newvalue_(0), count_(0)
{}


ControlSpellchecker::~ControlSpellchecker()
{}


void ControlSpellchecker::setParams()
{
	lyxerr[Debug::GUI] << "spell setParams" << endl;
	startSession();
}


void ControlSpellchecker::clearParams()
{
	lyxerr[Debug::GUI] << "spell clearParams" << endl;
	endSession();
}


namespace {


SpellBase * getSpeller(BufferParams const & bp)
{
	string lang = (lyxrc.isp_use_alt_lang)
	              ? lyxrc.isp_alt_lang
		      : bp.language->code();

#ifdef USE_ASPELL
	if (lyxrc.use_spell_lib)
		return new ASpell(bp, lang);
#endif
#ifdef USE_PSPELL
	if (lyxrc.use_spell_lib)
		return new PSpell(bp, lang);
#endif

	lang = (lyxrc.isp_use_alt_lang) ?
		lyxrc.isp_alt_lang : bp.language->lang();

	return new ISpell(bp, lang);
}

}


void ControlSpellchecker::startSession()
{
	lyxerr[Debug::GUI] << "spell startSession" << endl;

	if (speller_.get()) {
		lyxerr[Debug::GUI] << "startSession: speller exists" << endl;
		speller_.reset(0);
		return;
	}

	speller_.reset(getSpeller(buffer()->params()));

	// reset values to initial
	oldval_ = 0;
	newvalue_ = 0;
	count_ = 0;
	emergency_exit_ = false;

	// start off the check
	if (speller_->error().empty()) {
		check();
		return;
	}

	emergency_exit_ = true;
	string message = speller_->error();
	if (message.empty())
		message = _("The spell-checker could not be started.\n"
			 "Maybe it is mis-configured.");

	Alert::error(_("The spell-checker has failed"), message);
	speller_.reset(0);
}


void ControlSpellchecker::endSession()
{
	lyxerr[Debug::GUI] << "spell endSession" << endl;

	emergency_exit_ = true;

	if (!speller_.get()) {
		lyxerr[Debug::GUI] << "endSession with no speller" << endl;
		return;
	}

	speller_.reset(0);
}


namespace {

bool isLetter(DocumentIterator const & cur)
{
	return !cur.empty()
		&& cur.paragraph().isLetter(cur.pos())
		&& !isDeletedText(cur.paragraph(), cur.pos());
		//&& (!cur.nextInset() || cur.nextInset()->allowSpellCheck());
}


WordLangTuple nextWord(DocumentIterator & cur, ptrdiff_t & progress,
	BufferParams & bp)
{
	// skip until we have real text (will jump paragraphs)
	for (; cur.size() && !isLetter(cur); cur.forwardChar());
		++progress;

	// hit end
	if (cur.empty())
		return WordLangTuple(string(), string());

	string lang_code = cur.paragraph().
		getFontSettings(bp, cur.pos()).language()->code();
	string str;
	// and find the end of the word (insets like optional hyphens
	// and ligature break are part of a word)
	for (; cur.size() && isLetter(cur); cur.forwardChar(), ++progress) {
		if (!cur.paragraph().isInset(cur.pos()))
			str += cur.paragraph().getChar(cur.pos());
	}

	return WordLangTuple(str, lang_code);
}

} // namespace anon



void ControlSpellchecker::check()
{
	lyxerr[Debug::GUI] << "spell check a word" << endl;

	SpellBase::Result res = SpellBase::OK;

	DocumentIterator cur = bufferview()->cursor();

	// a rough estimate should be sufficient:
	//DocumentIterator::difference_type start = distance(beg, cur);
	//DocumentIterator::difference_type const total = start + distance(cur, end);

	ptrdiff_t start = 0, total = 0;
	DocumentIterator it = DocumentIterator(buffer()->inset());
	for (start = 0; it != cur; it.forwardPos())
		++start; 	

	for (total = start; it.size(); it.forwardPos())
		++total; 	

	for (; cur.size() && isLetter(cur); cur.forwardPos())
		++start;

	while (res == SpellBase::OK || res == SpellBase::IGNORE) {
		word_ = nextWord(cur, start, buffer()->params());

		// end of document
		if (word_.word().empty())
			break;

		++count_;

		// Update slider if and only if value has changed
		float progress = total ? float(start)/total : 1;
		newvalue_ = int(100.0 * progress);
		if (newvalue_!= oldval_) {
			lyxerr[Debug::GUI] << "Updating spell progress." << endl;
			oldval_ = newvalue_;
			// set progress bar
			view().partialUpdate(SPELL_PROGRESSED);
		}

		// speller might be dead ...
		if (!checkAlive())
			return;

		res = speller_->check(word_);

		// ... or it might just be reporting an error
		if (!checkAlive())
			return;
	}

	lyxerr[Debug::GUI] << "Found word \"" << word_.word() << "\"" << endl;

	if (word_.word().empty()) {
		showSummary();
		endSession();
		return;
	}

	int const size = word_.word().size();
#if 0
	advance(cur, -size);
	bufferview()->putSelectionAt(cur, size, false);
	advance(cur, size);
#else
	bufferview()->putSelectionAt(cur, size, true);
#endif

	// set suggestions
	if (res != SpellBase::OK && res != SpellBase::IGNORE) {
		lyxerr[Debug::GUI] << "Found a word needing checking." << endl;
		view().partialUpdate(SPELL_FOUND_WORD);
	}
}


bool ControlSpellchecker::checkAlive()
{
	if (speller_->alive() && speller_->error().empty())
		return true;

	string message = speller_->error();
	if (message.empty())
		message = _("The spell-checker has died for some reason.\n"
			 "Maybe it has been killed.");

	view().hide();
	speller_.reset(0);

	Alert::error(_("The spell-checker has failed"), message);
	return false;
}


void ControlSpellchecker::showSummary()
{
	if (!checkAlive() || count_ == 0) {
		view().hide();
		return;
	}

	string message;
	if (count_ != 1)
		message = bformat(_("%1$s words checked."), tostr(count_));
	else
		message = _("One word checked.");

	view().hide();
	Alert::information(_("Spell-checking is complete"), message);
}


void ControlSpellchecker::replace(string const & replacement)
{
	lyx::cap::replaceWord(bufferview()->cursor(), replacement);
	bufferview()->buffer()->markDirty();
	bufferview()->update();
	// fix up the count
	--count_;
	check();
}


void ControlSpellchecker::replaceAll(string const & replacement)
{
	// TODO: add to list
	replace(replacement);
}


void ControlSpellchecker::insert()
{
	speller_->insert(word_);
	check();
}


string const ControlSpellchecker::getSuggestion() const
{
	return speller_->nextMiss();
}


string const ControlSpellchecker::getWord() const
{
	return word_.word();
}


void ControlSpellchecker::ignoreAll()
{
	speller_->accept(word_);
	check();
}