/*
 * synergy -- mouse and keyboard sharing utility
 * Copyright (C) 2012-2016 Symless Ltd.
 * Copyright (C) 2002 Chris Schoeneman
 *
 * This package is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * found in the file LICENSE that should have accompanied this file.
 *
 * This package 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/>.
 */
#if WINAPI_XWINDOWS
#include <algorithm>
#include <fstream>
#include <sstream>

#include "ISO639Table.h"
#include "SynergyXkbKeyboard.h"
#include "X11LayoutsParser.h"
#include "base/Log.h"
#include "pugixml.hpp"

namespace {

void splitLine(std::vector<String> &parts, const String &line, char delimiter) {
  std::stringstream stream(line);
  while (stream.good()) {
    String part;
    getline(stream, part, delimiter);
    parts.push_back(part);
  }
}

} // namespace

bool X11LayoutsParser::readXMLConfigItemElem(
    const pugi::xml_node *root, std::vector<Lang> &langList) {
  auto configItemElem = root->child("configItem");
  if (!configItemElem) {
    LOG((CLOG_WARN "failed to read \"configItem\" in xml file"));
    return false;
  }

  langList.emplace_back();
  auto nameElem = configItemElem.child("name");
  if (nameElem) {
    langList.back().name = nameElem.text().as_string();
  }

  auto languageListElem = configItemElem.child("languageList");
  if (languageListElem) {
    for (pugi::xml_node isoElem : languageListElem.children("iso639Id")) {
      langList.back().layoutBaseISO639_2.emplace_back(
          isoElem.text().as_string());
    }
  }

  return true;
}

std::vector<X11LayoutsParser::Lang>
X11LayoutsParser::getAllLanguageData(const String &pathToEvdevFile) {
  std::vector<Lang> allCodes;
  pugi::xml_document doc;
  if (!doc.load_file(pathToEvdevFile.c_str())) {
    LOG((CLOG_WARN "failed to open %s", pathToEvdevFile.c_str()));
    return allCodes;
  }

  auto xkbConfigElem = doc.child("xkbConfigRegistry");
  if (!xkbConfigElem) {
    LOG(
        (CLOG_WARN "failed to read xkbConfigRegistry in %s",
         pathToEvdevFile.c_str()));
    return allCodes;
  }

  auto layoutListElem = xkbConfigElem.child("layoutList");
  if (!layoutListElem) {
    LOG((CLOG_WARN "failed to read layoutList in %s", pathToEvdevFile.c_str()));
    return allCodes;
  }

  for (pugi::xml_node layoutElem : layoutListElem.children("layout")) {
    if (!readXMLConfigItemElem(&layoutElem, allCodes)) {
      continue;
    }

    auto variantListElem = layoutElem.child("variantList");
    if (variantListElem) {
      for (pugi::xml_node variantElem : variantListElem.children("variant")) {
        readXMLConfigItemElem(&variantElem, allCodes.back().variants);
      }
    }
  }

  return allCodes;
}

void X11LayoutsParser::appendVectorUniq(
    const std::vector<String> &source, std::vector<String> &dst) {
  for (const auto &elem : source) {
    if (std::find_if(dst.begin(), dst.end(), [elem](const String &s) {
          return s == elem;
        }) == dst.end()) {
      dst.push_back(elem);
    }
  }
};

void X11LayoutsParser::convertLayoutToISO639_2(
    const String &pathToEvdevFile, bool needToReloadEvdev,
    const std::vector<String> &layoutNames,
    const std::vector<String> &layoutVariantNames,
    std::vector<String> &iso639_2Codes) {
  if (layoutNames.size() != layoutVariantNames.size()) {
    LOG((CLOG_WARN
         "error in language layout or language layout variants list"));
    return;
  }

  static std::vector<X11LayoutsParser::Lang> allLang;
  if (allLang.empty() || needToReloadEvdev) {
    allLang = getAllLanguageData(pathToEvdevFile);
  }
  for (size_t i = 0; i < layoutNames.size(); i++) {
    const auto &layoutName = layoutNames[i];
    auto langIter = std::find_if(
        allLang.begin(), allLang.end(),
        [&layoutName](const Lang &l) { return l.name == layoutName; });
    if (langIter == allLang.end()) {
      LOG((CLOG_WARN "language \"%s\" is unknown", layoutNames[i].c_str()));
      continue;
    }

    const std::vector<String> *toCopy = nullptr;
    if (layoutVariantNames[i].empty()) {
      toCopy = &langIter->layoutBaseISO639_2;
    } else {
      const auto &variantName = layoutVariantNames[i];
      auto langVariantIter = std::find_if(
          langIter->variants.begin(), langIter->variants.end(),
          [&variantName](const Lang &l) { return l.name == variantName; });
      if (langVariantIter == langIter->variants.end()) {
        LOG(
            (CLOG_WARN "variant \"%s\" of language \"%s\" is unknown",
             layoutVariantNames[i].c_str(), layoutNames[i].c_str()));
        continue;
      }

      if (langVariantIter->layoutBaseISO639_2.empty()) {
        toCopy = &langIter->layoutBaseISO639_2;
      } else {
        toCopy = &langVariantIter->layoutBaseISO639_2;
      }
    }

    if (toCopy) {
      appendVectorUniq(*toCopy, iso639_2Codes);
    }
  }
}

std::vector<String>
X11LayoutsParser::getX11LanguageList(const String &pathToEvdevFile) {
  std::vector<String> layoutNames;
  std::vector<String> layoutVariantNames;

  synergy::linux::SynergyXkbKeyboard keyboard;
  splitLine(layoutNames, keyboard.getLayout(), ',');
  splitLine(layoutVariantNames, keyboard.getVariant(), ',');

  std::vector<String> iso639_2Codes;
  iso639_2Codes.reserve(layoutNames.size());
  convertLayoutToISO639_2(
      pathToEvdevFile, true, layoutNames, layoutVariantNames, iso639_2Codes);
  return convertISO639_2ToISO639_1(iso639_2Codes);
}

String X11LayoutsParser::convertLayotToISO(
    const String &pathToEvdevFile, const String &layoutLangCode,
    bool needToReloadFiles) {
  std::vector<String> iso639_2Codes;
  convertLayoutToISO639_2(
      pathToEvdevFile, needToReloadFiles, {layoutLangCode}, {""},
      iso639_2Codes);
  if (iso639_2Codes.empty()) {
    LOG(
        (CLOG_WARN "failed to convert layout lang code: \"%s\"",
         layoutLangCode.c_str()));
    return "";
  }

  auto iso639_1Codes = convertISO639_2ToISO639_1(iso639_2Codes);
  if (iso639_1Codes.empty()) {
    LOG((CLOG_WARN "failed to convert ISO639/2 lang code to ISO639/1"));
    return "";
  }

  return *iso639_1Codes.begin();
}

std::vector<String> X11LayoutsParser::convertISO639_2ToISO639_1(
    const std::vector<String> &iso639_2Codes) {
  std::vector<String> result;
  for (const auto &isoCode : iso639_2Codes) {
    const auto &tableIter = std::find_if(
        ISO_Table.begin(), ISO_Table.end(),
        [&isoCode](const std::pair<String, String> &c) {
          return c.first == isoCode;
        });
    if (tableIter == ISO_Table.end()) {
      LOG(
          (CLOG_WARN "the ISO 639-2 code \"%s\" is missed in table",
           isoCode.c_str()));
      continue;
    }

    appendVectorUniq({tableIter->second}, result);
  }

  return result;
}

#endif // WINAPI_XWINDOWS
