/*
 *	subtitleeditor -- a tool to create or edit subtitle
 *
 *	http://home.gna.org/subtitleeditor/
 *	https://gna.org/projects/subtitleeditor/
 *
 *	Copyright @ 2005-2009, kitone
 *
 *	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 "patternmanager.h"
#include <utility.h>
#include <cfg.h>

/*
 * Read and create all patterns as type from the install directory 
 * and the user profile directory.
 * 
 * type: 'common-error', 'hearing-impaired'
 */
PatternManager::PatternManager(const Glib::ustring &type)
{
	se_debug_message(SE_DEBUG_PLUGINS, "pattern manager for '%s'", type.c_str());
	m_type = type;

	Glib::ustring path = SE_DEV_VALUE(SE_PLUGIN_PATH_PATTERN, SE_PLUGIN_PATH_DEV);
	load_path(path);
	// Read the user patterns in '$config/plugins/textcorrection'
	load_path(get_config_dir("plugins/textcorrection"));
}

/*
 * Delete patterns.
 */
PatternManager::~PatternManager()
{
	se_debug(SE_DEBUG_PLUGINS);

	std::list<Pattern*>::iterator it;
	for(it = m_patterns.begin(); it != m_patterns.end(); ++it)
		delete *it;
	m_patterns.clear();
}

/*
 * Load patterns in the directory.
 */
void PatternManager::load_path(const Glib::ustring &path)
{
	if(Glib::file_test(path, Glib::FILE_TEST_EXISTS | Glib::FILE_TEST_IS_DIR) == false)
	{
		se_debug_message(SE_DEBUG_PLUGINS, "could not open the path %s", path.c_str());
		return;
	}

	try
	{
		se_debug_message(SE_DEBUG_PLUGINS, "path '%s'", path.c_str());
		// Only the pattern type
		Glib::RefPtr<Glib::Regex> re = Glib::Regex::create(
				Glib::ustring::compose("^(.*)\\.%1\\.se-pattern$", m_type));

		Glib::Dir dir(path);
		std::vector<Glib::ustring> files(dir.begin(), dir.end());
		for(unsigned int i=0; i< files.size(); ++i)
		{
			if(re->match(files[i]))
			{
				load_pattern(path, files[i]);
			}
		}
	}
	catch(const Glib::Error &ex)
	{
		std::cerr << ex.what() << std::endl;
	}
	catch(const std::exception &ex)
	{
		std::cerr << ex.what() << std::endl;
	}
}

/*
 * Load a pattern from a file.
 */
void PatternManager::load_pattern(const Glib::ustring &path, const Glib::ustring &filename)
{
	try
	{
		Glib::ustring fullname = Glib::build_filename(path, filename);

		se_debug_message(SE_DEBUG_PLUGINS, "filename '%s'", fullname.c_str());
		// name of file :
		// Script[-language-[COUNTRY]].PatternType.pattern
		Glib::RefPtr<Glib::Regex> re = Glib::Regex::create("^(.*)\\..*\\.se-pattern$");
		if(re->match(filename) == false)
			return;
		// Get codes
		Glib::ustring codes;
		std::vector<Glib::ustring> group = re->split(filename);
		codes = group[1];
		// Read the pattern
		xmlpp::DomParser parser;
		parser.set_substitute_entities();
		parser.parse_file(fullname.c_str());
		// patterns (root)
		const xmlpp::Element* xml_patterns = dynamic_cast<const xmlpp::Element*>(parser.get_document()->get_root_node());
		if(xml_patterns->get_name() != "patterns")
		{
			se_debug_message(SE_DEBUG_PLUGINS, "The file '%s' is not a pattern file", fullname.c_str());
			// throw InvalidFile
			return;
		}
		// read patterns
		xmlpp::Node::NodeList xml_pattern_list = xml_patterns->get_children("pattern");
		for(xmlpp::Node::NodeList::const_iterator it=xml_pattern_list.begin(); it!=xml_pattern_list.end(); ++it)
		{
			const xmlpp::Element * xml_pattern = dynamic_cast<const xmlpp::Element*>(*it);
			// read and add the patterns to the list
			Pattern *pattern = read_pattern(xml_pattern);
			if(pattern)
			{
				pattern->m_codes = codes;
				m_patterns.push_back(pattern);
			}
		}
	}
	catch(const std::exception &ex)
	{
		se_debug_message(SE_DEBUG_PLUGINS, "Could not read the pattern '%s' : %s", filename.c_str(), ex.what());
		std::cerr << ex.what() << std::endl;
	}
}

/*
 * Convert string flags to Glib::RegexCompileFlags
 */
Glib::RegexCompileFlags parse_flags(const Glib::ustring &string)
{
	Glib::RegexCompileFlags flags = static_cast<Glib::RegexCompileFlags>(0);

	if(string.find("CASELESS") != Glib::ustring::npos)
		flags |= Glib::REGEX_CASELESS;
	else if(string.find("MULTILINE") != Glib::ustring::npos)
		flags |= Glib::REGEX_MULTILINE;
	else if(string.find("DOTALL") != Glib::ustring::npos)
		flags |= Glib::REGEX_DOTALL;
	// FIXME UNICODE ?
	return flags;
}

/*
 * Read, create and return a pattern from xml element.
 */
Pattern* PatternManager::read_pattern(const xmlpp::Element *xml_pattern)
{
	Pattern *pattern = new Pattern;
	// get description
	pattern->m_name = xml_pattern->get_attribute_value("name"); 
	pattern->m_label = _(pattern->m_name.c_str()); // Localized name 
	pattern->m_description = xml_pattern->get_attribute_value("description");
	pattern->m_classes = xml_pattern->get_attribute_value("classes");
	pattern->m_policy = xml_pattern->get_attribute_value("policy");
	pattern->m_enabled = get_active(pattern->m_name);
	// get rules
	xmlpp::Node::NodeList xml_rule_list = xml_pattern->get_children("rule");
	for(xmlpp::Node::NodeList::const_iterator it = xml_rule_list.begin(); it!=xml_rule_list.end(); ++it)
	{
		const xmlpp::Element *xml_rule = dynamic_cast<const xmlpp::Element*>(*it);

		Glib::ustring regex = xml_rule->get_attribute_value("regex");
		Glib::ustring flags = xml_rule->get_attribute_value("flags");
		Glib::ustring replacement = xml_rule->get_attribute_value("replacement");
		Glib::ustring repeat = xml_rule->get_attribute_value("repeat");

		try
		{
			Pattern::Rule *rule = new Pattern::Rule;
			rule->m_regex = Glib::Regex::create(regex, parse_flags(flags));
			rule->m_replacement = replacement;
			rule->m_repeat = (repeat == "True") ? true : false;

			// Previous match rule
			xmlpp::Node::NodeList xml_previous_match = xml_rule->get_children("previousmatch");
			if(!xml_previous_match.empty())
			{
				const xmlpp::Element *pre = dynamic_cast<const xmlpp::Element*>(*xml_previous_match.begin()); 
				
				Glib::ustring preregex = pre->get_attribute_value("regex");
				Glib::ustring preflags = pre->get_attribute_value("flags");

				rule->m_previous_match = Glib::Regex::create(preregex, parse_flags(preflags));
			}

			pattern->m_rules.push_back(rule);
		}
		catch(Glib::Error &ex)
		{
			std::cerr << ex.what();
		}
	}

	return pattern;
}

/*
 * Return all codes needs to be used from args.
 * 'Zyyy', 'script', 'script-language' and 'script-language-country'.
 *
 * Zyyy is the first and it is always added.
 */
std::vector<Glib::ustring> PatternManager::get_codes(const Glib::ustring &script, const Glib::ustring &language, const Glib::ustring &country)
{
	std::vector<Glib::ustring> codes;
	codes.push_back("Zyyy");
	
	if(!script.empty())
	{
		codes.push_back(script);

		if(!language.empty())
		{
			codes.push_back( Glib::ustring::compose("%1-%2", script, language));

			if(!country.empty())
				codes.push_back( Glib::ustring::compose("%1-%2-%3", script, language, country));
		}
	}

	return codes;
}

/*
 * Return a list of patterns available from the codes.
 */
std::list<Pattern*> PatternManager::get_patterns(const Glib::ustring &script, const Glib::ustring &language, const Glib::ustring &country)
{
	se_debug_message(SE_DEBUG_PLUGINS, "Codes: %s-%s-%s", script.c_str(), language.c_str(), country.c_str());

	std::vector<Glib::ustring> codes = get_codes(script, language, country);

	std::list<Pattern*> patterns;

	for(unsigned int i=0; i< codes.size(); ++i)
	{
		for(std::list<Pattern*>::const_iterator it = m_patterns.begin(); it != m_patterns.end(); ++it)
		{
			if((*it)->m_codes == codes[i])
				patterns.push_back(*it);
		}
	}
	// the patterns need to be filtered to respect the Replace policy
	std::list<Pattern*> filtered = filter_patterns(patterns);
	
	if(se_debug_check_flags(SE_DEBUG_PLUGINS))
	{
		std::list<Pattern*>::iterator it;

		se_debug_message(SE_DEBUG_PLUGINS, "pattern list before filter (%d)", patterns.size());
		for(it = patterns.begin(); it != patterns.end(); ++it)
			se_debug_message(SE_DEBUG_PLUGINS, "[%s] [%s]", (*it)->m_codes.c_str(), (*it)->m_name.c_str());

		se_debug_message(SE_DEBUG_PLUGINS, "pattern list after filter (%d)", filtered.size());
		for(it = filtered.begin(); it != filtered.end(); ++it)
			se_debug_message(SE_DEBUG_PLUGINS, "[%s] [%s]", (*it)->m_codes.c_str(), (*it)->m_name.c_str());
	}
	
	return filtered;
}

/*
 * Return all scripts available. (Zyyy is skipped)
 */
std::vector<Glib::ustring> PatternManager::get_scripts()
{
	std::list<Glib::ustring> codes;

	Glib::RefPtr<Glib::Regex> re = Glib::Regex::create("^([A-Za-z]{4}).*$");
	std::list<Pattern*>::const_iterator it;
	for(it = m_patterns.begin(); it != m_patterns.end(); ++it)
	{
		if(!re->match((*it)->m_codes))
			continue;
		
		std::vector<Glib::ustring> group = re->split((*it)->m_codes);
		if(group[1] == "Zyyy")
			continue;

		codes.push_back(group[1]);
	}
	codes.unique();
	return std::vector<Glib::ustring>(codes.begin(), codes.end());
}

/*
 * Return all languages available for the script code.
 */
std::vector<Glib::ustring> PatternManager::get_languages(const Glib::ustring &script)
{
	std::list<Glib::ustring> codes;

	Glib::RefPtr<Glib::Regex> re = Glib::Regex::create(
			Glib::ustring::compose("^%1-([A-Za-z]{2}).*$", script));

	std::list<Pattern*>::const_iterator it;
	for(it = m_patterns.begin(); it != m_patterns.end(); ++it)
	{
		if(!re->match((*it)->m_codes))
			continue;
		
		std::vector<Glib::ustring> group = re->split((*it)->m_codes);

		codes.push_back(group[1]);
	}
	codes.unique();
	return std::vector<Glib::ustring>(codes.begin(), codes.end());
}

/*
 * Return all countries available for the script and language codes.
 */
std::vector<Glib::ustring> PatternManager::get_countries(const Glib::ustring &script, const Glib::ustring &language)
{
	std::list<Glib::ustring> codes;

	Glib::RefPtr<Glib::Regex> re = Glib::Regex::create(
			Glib::ustring::compose("^%1-%2-([A-Za-z]{2})$", script, language));

	std::list<Pattern*>::const_iterator it;
	for(it = m_patterns.begin(); it != m_patterns.end(); ++it)
	{
		if(!re->match((*it)->m_codes))
			continue;
		
		std::vector<Glib::ustring> group = re->split((*it)->m_codes);

		codes.push_back(group[1]);
	}
	codes.unique();
	return std::vector<Glib::ustring>(codes.begin(), codes.end());
}

/*
 * The patterns need to be filtered to respect the Replace policy
 * Maintain order of patterns with the same name
 */
std::list<Pattern*> PatternManager::filter_patterns(std::list<Pattern*> &pattern)
{
	std::list<Pattern*> filtered;
	std::list<Pattern*>::iterator p, f, last_idx;
	
	for( p = pattern.begin(); p != pattern.end(); ++p)
	{
		bool replace = ((*p)->m_policy == "Replace");

		last_idx = filtered.end();
		for(f=filtered.begin(); f!=filtered.end(); ++f)
		{
			if((*f)->m_name == (*p)->m_name)
			{
				last_idx = f;
				if(replace)
					*f = NULL;
			}
		}
		
		if(last_idx == filtered.end())
			filtered.push_back(*p);
		else
			filtered.insert(++last_idx, *p);

		// Remove NULL
		f = filtered.begin();
		while(f != filtered.end() )
		{
			if(*f == NULL)
				f = filtered.erase(f);
			else
				++f;
		}
	}
	return filtered;
}

/*
 * Enable or disable the patterns from his name. 
 * The configuration is update with the new state.
 *
 * It's managed in this class because a multiple pattern can be have a same name.
 */
void PatternManager::set_active(const Glib::ustring &name, bool state)
{
	if(name.empty())
	{
		std::cerr << "* set_active failed. name is empty." << std::endl;
		return;
	}

	Config::getInstance().set_value_string("patterns", name, state ? "enable" : "disable");

	for(std::list<Pattern*>::iterator it = m_patterns.begin(); it != m_patterns.end(); ++it)
	{
		if((*it)->m_name == name)
			(*it)->m_enabled = state;
	}
}

/*
 * Return the state of the pattern from his name.
 */
bool PatternManager::get_active(const Glib::ustring &name)
{
	if(name.empty())
	{
		std::cerr << "* get_active failed. name is empty." << std::endl;
		return false;
	}

	Config &cfg = Config::getInstance();

	if(cfg.has_key("patterns", name) == false)
	{
		cfg.set_value_string("patterns", name, "enable");
		return true;
	}
	Glib::ustring value = cfg.get_value_string("patterns", name);
	return (value == "enable") ? true : false;
}