// subtitleeditor -- a tool to create or edit subtitle
//
// https://subtitleeditor.github.io/subtitleeditor/
// https://github.com/subtitleeditor/subtitleeditor/
//
// Copyright @ 2005-2018, 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 <cfg.h>
#include <utility.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_dbg_msg(SE_DBG_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_dbg(SE_DBG_PLUGINS);

   for (auto p : m_patterns) {
      delete p;
   }
   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_dbg_msg(SE_DBG_PLUGINS, "could not open the path %s", path.c_str());
      return;
   }

   try {
      se_dbg_msg(SE_DBG_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 (const auto& file : files) {
         if (re->match(file)) {
            load_pattern(path, file);
         }
      }
   } 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_dbg_msg(SE_DBG_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_dbg_msg(SE_DBG_PLUGINS, "The file '%s' is not a pattern file", fullname.c_str());
         // throw InvalidFile
         return;
      }
      // read patterns
      auto xml_pattern_list = xml_patterns->get_children("pattern");
      for (const auto& node : xml_pattern_list) {
         const auto xml_pattern = dynamic_cast<const xmlpp::Element*>(node);
         // 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_dbg_msg(SE_DBG_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
   auto xml_rule_list = xml_pattern->get_children("rule");

   for (const auto& node : xml_rule_list) {
      auto xml_rule = dynamic_cast<const xmlpp::Element*>(node);

      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
         auto xml_previous_match = xml_rule->get_children("previousmatch");
         if (!xml_previous_match.empty()) {
            auto 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_dbg_msg(SE_DBG_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 (auto const& code : codes) {
      for (auto const& pattern : m_patterns) {
         if (pattern->m_codes == code)
            patterns.push_back(pattern);
      }
   }
   // the patterns need to be filtered to respect the Replace policy
   std::list<Pattern*> filtered = filter_patterns(patterns);

   if (se_dbg_check_flags(SE_DBG_PLUGINS)) {
      se_dbg_msg(SE_DBG_PLUGINS, "pattern list before filter (%d)", patterns.size());
      for (const auto& p : patterns) {
         se_dbg_msg(SE_DBG_PLUGINS, "[%s] [%s]", p->m_codes.c_str(), p->m_name.c_str());
      }

      se_dbg_msg(SE_DBG_PLUGINS, "pattern list after filter (%d)", filtered.size());
      for (const auto& p : filtered) {
         se_dbg_msg(SE_DBG_PLUGINS, "[%s] [%s]", p->m_codes.c_str(), p->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}).*$");
   for (const auto& p : m_patterns) {
      if (!re->match(p->m_codes))
         continue;

      std::vector<Glib::ustring> group = re->split(p->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));

   for (const auto& p : m_patterns) {
      if (!re->match(p->m_codes))
         continue;

      std::vector<Glib::ustring> group = re->split(p->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));

   for (const auto& p : m_patterns) {
      if (!re->match(p->m_codes))
         continue;

      std::vector<Glib::ustring> group = re->split(p->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;
   }

   cfg::set_string("patterns", name, state ? "enable" : "disable");

   for (auto p : m_patterns) {
      if (p->m_name == name)
         p->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;
   }

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