/*
 * (c) Copyright Ascensio System SIA 2010-2024
 *
 * This program is a free software product. You can redistribute it and/or
 * modify it under the terms of the GNU Affero General Public License (AGPL)
 * version 3 as published by the Free Software Foundation. In accordance with
 * Section 7(a) of the GNU AGPL its Section 15 shall be amended to the effect
 * that Ascensio System SIA expressly excludes the warranty of non-infringement
 * of any third-party rights.
 *
 * This program is distributed WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR  PURPOSE. For
 * details, see the GNU AGPL at: http://www.gnu.org/licenses/agpl-3.0.html
 *
 * You can contact Ascensio System SIA at 20A-6 Ernesta Birznieka-Upish
 * street, Riga, Latvia, EU, LV-1050.
 *
 * The  interactive user interfaces in modified source and object code versions
 * of the Program must display Appropriate Legal Notices, as required under
 * Section 5 of the GNU AGPL version 3.
 *
 * Pursuant to Section 7(b) of the License you must retain the original Product
 * logo when distributing the program. Pursuant to Section 7(e) we decline to
 * grant you any rights under trademark law for use of our trademarks.
 *
 * All the Product's GUI elements, including illustrations and icon sets, as
 * well as technical writing content are licensed under the terms of the
 * Creative Commons Attribution-ShareAlike 4.0 International. See the License
 * terms at http://creativecommons.org/licenses/by-sa/4.0/legalcode
 *
 */

'use strict';

const sockjs = require('sockjs');
const nodehun = require('nodehun');
const logger = require('./../../Common/sources/logger');
const utils = require('./../../Common/sources/utils');
const fs = require('fs');
const co = require('co');
const cfgSockjs = require('config').get('services.CoAuthoring.sockjs');
const languages = require('./languages');
const allLanguages = languages.allLanguages;
const path = require('path');
const arrExistDictionaries = {};
const pathDictionaries = require('config').get('SpellChecker.server.dictDir');
const arrDictionaries = {};

function spell(type, word, id) {
  return new Promise(function (resolve, reject) {
    let dict = null;
    if (arrDictionaries[id]) {
      dict = arrDictionaries[id];
    } else {
      if (arrExistDictionaries[id]) {
        let pathTmp = path.join(pathDictionaries, allLanguages[id], allLanguages[id] + '.');

        dict = arrDictionaries[id] = new nodehun(pathTmp + 'aff', pathTmp + 'dic');
      }
    }

    if (dict) {
      if ('spell' === type) {
        // use setImmediate because https://github.com/nodejs/node/issues/5691
        dict.spell(word).then(isCorrect => {
          return setImmediate(resolve, isCorrect);
        });
      } else if ('suggest' === type) {
        dict.suggest(word).then(suggestions => {
          return setImmediate(resolve, suggestions);
        });
      }
    } else {
      return setImmediate(resolve, true);
    }
  });
}

exports.install = function (server, callbackFunction) {
  'use strict';

  utils.listFolders(pathDictionaries, true).then(values => {
    return co(function* () {
      let lang;
      for (let i = 0; i < values.length; ++i) {
        lang = languages.sToId(path.basename(values[i]));
        if (-1 !== lang) {
          arrExistDictionaries[lang] = 1;
        }
      }
      yield spell('spell', 'color', 0x0409);
      callbackFunction();
    });
  });

  const sockjs_echo = sockjs.createServer(cfgSockjs);

  sockjs_echo.on('connection', function (conn) {
    if (!conn) {
      logger.error('null == conn');
      return;
    }
    conn.on('data', function (message) {
      try {
        let data = JSON.parse(message);
        switch (data.type) {
          case 'spellCheck':
            spellCheck(conn, data.spellCheckData);
            break;
        }
      } catch (e) {
        logger.error('error receiving response: %s', e);
      }
    });
    conn.on('error', function () {
      logger.error('On error');
    });
    conn.on('close', function () {
      logger.info('Connection closed or timed out');
    });

    sendData(conn, {type: 'init', languages: Object.keys(arrExistDictionaries)});
  });

  function sendData(conn, data) {
    conn.write(JSON.stringify(data));
  }

  function spellCheck(conn, data) {
    return co(function* () {
      let promises = [];
      for (let i = 0, length = data.usrWords.length; i < length; ++i) {
        promises.push(spell(data.type, data.usrWords[i], data.usrLang[i]));
      }
      yield Promise.all(promises).then(values => {
        data['spell' === data.type ? 'usrCorrect' : 'usrSuggest'] = values;
      });
      sendData(conn, {type: 'spellCheck', spellCheckData: data});
    });
  }

  sockjs_echo.installHandlers(server, {
    prefix: '/doc/[0-9-.a-zA-Z_=]*/c',
    log: function (severity, message) {
      //TODO: handle severity
      logger.info(message);
    }
  });
};
exports.spellSuggest = function (type, word, lang, callbackFunction) {
  return co(function* () {
    callbackFunction(yield spell(type, word, lang));
  });
};