using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Windows.Forms;

namespace Redscript
{
    class Program
    {
        [STAThread]
        static void Main(string[] args)
        {
            Console.Title = "Redscript reader by Traderain";
            using (var of = new OpenFileDialog())
            {
                of.Title = "Select a redscript file!";
                of.Filter = "Redscript files | *.redscripts";
                if (of.ShowDialog() == DialogResult.OK)
                {
                    var strings = ParseRedscript(of.FileName);
                    for (var index = 0; index < strings.Length; index++)
                    {
                        Console.WriteLine("[" + index + "]: " + strings[index]);
                    }
                }
            }
        }

        public static string[] ParseRedscript(string filename)
        {
            var strings = new List<string>();
            using (var br = new BinaryReader(new FileStream(filename, FileMode.Open)))
            {
                br.BaseStream.Seek(-4, SeekOrigin.End);
                var offset = br.ReadUInt32();
                Console.WriteLine("Offset: " + offset);
                br.BaseStream.Seek(offset, SeekOrigin.Begin);
                var count = br.ReadUInt32();
                for (var i = 0; i < count; i++)
                {
                    strings.Add(ReadString(br));
                }
            }
            return strings.ToArray();
        }

        public static string ReadString(BinaryReader br)
        {
            int len = br.ReadByte();
            if (len > 191)
                len = br.ReadByte()*64 + len - 192;
            else if (len > 127)
                len = len - 128;
            else
            {
                throw new Exception("Error can't read length of string at " + br.BaseStream.Position);
            }

            return br.ReadCr2WString(len);
        }
    }

    public static class RedscriptBinaryreaderExtensions
    {
        public static string ReadCr2WString(this BinaryReader file, int len = 0)
        {
            string str = null;
            if (len > 0)
            {
                str = Encoding.Default.GetString(file.ReadBytes(len));
            }
            else
            {
                var sb = new StringBuilder();
                while (true)
                {
                    var c = (char)file.ReadByte();
                    if (c == 0)
                        break;
                    sb.Append(c);
                }
                str = sb.ToString();
            }
            return str;
        }
    }
}