using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Launcher_Editor
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine(FFXIVLoginStringDecodeBinary("C:\\Program Files (x86)\\SquareEnix\\FINAL FANTASY XIV\\ffxivlogin.exe"));
        }

        public static string FFXIVLoginStringDecodeBinary(string path)
        {
            Console.OutputEncoding = System.Text.Encoding.UTF8;
            byte[] data = File.ReadAllBytes(path);
            //int offset = 0x5405a;
            //int offset = 0x5425d;
            int offset = 0x53ea0;
            while (true)
            {
                string result = "";
                uint key = (uint)data[offset + 0] << 8 | data[offset + 1];
                uint key2 = data[offset + 2];
                key = RotateRight(key, 1) & 0xFFFF;
                key -= 0x22AF;
                key &= 0xFFFF;
                key2 = key2 ^ key;
                key = RotateRight(key, 1) & 0xFFFF;
                key -= 0x22AF;
                key &= 0xFFFF;
                uint finalKey = key;
                key = data[offset + 3];
                uint count = (key2 & 0xFF) << 8;
                key = key ^ finalKey;
                key &= 0xFF;
                count |= key;

                int count2 = 0;
                while (count != 0)
                {
                    uint encrypted = data[offset + 4 + count2];
                    finalKey = RotateRight(finalKey, 1) & 0xFFFF;
                    finalKey -= 0x22AF;
                    finalKey &= 0xFFFF;
                    encrypted = encrypted ^ (finalKey & 0xFF);

                    result += (char)encrypted;
                    count--;
                    count2++;
                }

                offset += 4 + count2;
            }
        }

        public static string FFXIVLoginStringDecode(byte[] data)
        {
            string result = "";
            uint key = (uint)data[0] << 8 | data[1];
            uint key2 = data[2];
            key = RotateRight(key, 1) & 0xFFFF;
            key -= 0x22AF;
            key2 = key2 ^ key;
            key = RotateRight(key, 1) & 0xFFFF;
            key -= 0x22AF;
            uint finalKey = key;
            key = data[3];
            uint count = (key2 & 0xFF) << 8;
            key = key ^ finalKey;
            key &= 0xFF;
            count |= key;

            int count2 = 0;
            while (count != 0)
            {
                uint encrypted = data[4 + count2];
                finalKey = RotateRight(finalKey, 1) & 0xFFFF;
                finalKey -= 0x22AF;
                encrypted = encrypted ^ (finalKey & 0xFF);
                result += (char)encrypted;
                count--;
                count2++;
            }

            return result;
        }

        public static byte[] FFXIVLoginStringEncode(uint key, string text)
        {
            key = key & 0xFFFF;

            uint count = 0;
            byte[] asciiBytes = Encoding.ASCII.GetBytes(text);
            byte[] result = new byte[4 + text.Length];
            for (count = 0; count < text.Length; count++)
            {
                result[result.Length - count - 1] = (byte)(asciiBytes[asciiBytes.Length - count - 1] ^ (key & 0xFF));
                key += 0x22AF;
                key &= 0xFFFF;
                key = RotateLeft(key, 1) & 0xFFFF;
            }

            count = count ^ key;
            result[3] = (byte)(count & 0xFF);

            key += 0x22AF & 0xFFFF;
            key = RotateLeft(key, 1) & 0xFFFF;

            result[2] = (byte)(key & 0xFF);

            key += 0x22AF & 0xFFFF;
            key = RotateLeft(key, 1) & 0xFFFF;


            result[1] = (byte)(key & 0xFF);
            result[0] = (byte)((key >> 8) & 0xFF);

            return result;
        }

        public static uint RotateLeft(uint value, int bits)
        {
            return (value << bits) | (value >> (16 - bits));
        }

        public static uint RotateRight(uint value, int bits)
        {
            return (value >> bits) | (value << (16 - bits));
        }

    }
}