/*
 * DAWN OF LIGHT - The first free open source DAoC server emulator
 * 
 * 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 2
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 */

using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Reflection;
using System.Text;
using System.Text.RegularExpressions;
using log4net;

namespace DOL.GS
{
    /// <summary>
    /// LanguageMgr take care about all support of multi-language on server
    /// </summary>
    public class LanguageMgr
    {
        #region Variables
        private static readonly ILog log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

        private static SortedList<String, SortedList<String, String>> m_languageArray;

        private static char m_dirSep = Path.DirectorySeparatorChar;

        private static string m_lngDir = "Language";

        private static string m_lngRegex = @"[(.*)] = [(.*)]";
        #endregion

        /// <summary>
        /// Initializes the LanguageMgr
        /// </summary>
        /// <returns>True if initialization succeeded</returns>
        public static bool Initialize()
        {
            m_languageArray = new SortedList<String, SortedList<String, String>>(StringComparer.CurrentCultureIgnoreCase);

            try
            {
                string path = "." + m_dirSep + m_lngDir + m_dirSep;
                ParseDirectory(path, "*.lng");
            }
            catch (Exception e)
            {
                if (log.IsErrorEnabled)
                    log.Error("Language file exception", e);

                return false;
            }

            return true;
        }

        /// <summary>
        /// Retrieves a stored key/value pair, and returns a default string if the specified key doesn't exist
        /// </summary>
        /// <param name="language">The language to look at</param>
        /// <param name="key">The key for the string</param>
        /// <param name="defaultString">The default string to return</param>
        /// <returns>The value associated with the key, or the default string</returns>
        public static string GetString(string language, string key, string defaultString)
        {
            SortedList<String, String> langDict = m_languageArray[language.ToLower()];
            if (langDict == null) return defaultString;

            return (langDict[key] == null ? defaultString : langDict[key]);
        }

        /// <summary>
        /// Parses a directory for all source files
        /// </summary>
        /// <param name="path">The root directory to start the search in</param>
        /// <param name="filter">A filter representing the types of files to search for</param>
        private static void ParseDirectory(string path, string filter)
        {
            if (!Directory.Exists(path))
            {
                Directory.CreateDirectory(path);
            }

            string[] dirs = Directory.GetDirectories(path);
            foreach (string dir in dirs)
            {
                ParseDirectory(dir, filter);
            }

            string[] files = Directory.GetFiles(path, filter);
            foreach (string file in files)
            {
                ParseLanguageFile(file);
            }
        }

        /// <summary>
        /// Parses a language file and stores all key/value pairs found
        /// </summary>
        /// <param name="file">The file name of the language file to parse</param>
        private static void ParseLanguageFile(string file)
        {
            if (!File.Exists(file))
            {
                throw new Exception("Invalid file: " + file);
            }

            using (StreamReader filereader = File.OpenText(file))
            {
                // Figure out the language of the file.
                FileInfo lngFileInfo = new FileInfo(file);
                string languageType = lngFileInfo.Name.Remove(lngFileInfo.Name.Length - 4);

                SortedList<String, String> languageDict = new SortedList<String, String>(StringComparer.CurrentCultureIgnoreCase);

                string line;
                while ((line = filereader.ReadLine()) != null)
                {
                    // Try and match a key/value pair.
                    Regex entryRegex = new Regex(m_lngRegex);
                    Match entryMatcher = entryRegex.Match(line);

                    if (entryMatcher.Groups.Count == 2)
                    {
                        // We have a match, store it.
                        languageDict.Add(entryMatcher.Groups[0].Value, entryMatcher.Groups[1].Value);
                    }
                }

                m_languageArray.Add(languageType.ToLower(), languageDict);
            }
        }
    }
}