Unity basic lang system

using UnityEngine;
using UnityEditor;
using System.IO;
using System.Collections.Generic;

namespace ModelisaTools
{
    [InitializeOnLoad]
    public static class Lang
    {
        private static int currentLanguage;
        private static List<string> languages;
        private static List<List<string>> words;

        static Lang ()
        {
            currentLanguage = 0;
            languages = new List<string> ();
            words = new List<List<string>> ();

            if (Directory.Exists (Application.dataPath + "/ModelisaTools/Lang"))
            {
                string[] files = Directory.GetFiles (Application.dataPath + "/ModelisaTools/Lang");
                if (files.Length > 0)
                {
                    string langs = "";
                    for (int i = 0; i < files.Length; i++)
                    {
                        ReadFile (files[i]);
                        languages.Add (Path.GetFileName (files[i]).Substring (0, 2));
                        langs += languages[i];
                        if (i < files.Length - 1) langs += ", ";
                    }
                    DebugConsole.Log ("Lang initialized : " + langs);
                }
                else
                {
                    DebugConsole.Log ("Lang initialization failed : no files found.");
                }
            }
            else
            {
                DebugConsole.Log ("ModelisaTools : Lang directory not found !");
            }
        }

        private static void ReadFile (string path)
        {
            List<string> langWords = new List<string> ();
            string[] data = File.ReadAllText (path).Split ('$');

            for (int i = 0; i < data.Length; i++)
            {
                data[i] = data[i].Trim (" \n\t".ToCharArray ());
                if (!string.IsNullOrEmpty (data[i]) && !data[i].StartsWith ("//"))
                {
                    langWords.Add (data[i]);
                }
            }

            words.Add (langWords);
        }

        public static string Trad (string str)
        {
            string trad = "";

            if (languages[currentLanguage] == "EN")
            {
                trad = str;
            }
            else
            {
                if (words[languages.IndexOf ("EN")].Contains (str))
                {
                    trad = words[currentLanguage][words[languages.IndexOf ("EN")].IndexOf (str)];
                }
                else {
                    trad = "TRAD ERROR : " + str;
                }
            }

            return trad;
        }

        public static void DrawLangButton (Rect rect)
        {
            if (GUI.Button (rect, languages[currentLanguage]))
            {
                currentLanguage = (currentLanguage + 1) % languages.Count;
            }
        }
    }
}