using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Ionic.Zip;
using System.IO;

namespace Aiwaz.Common
{
    public class FileSystem : IDisposable
    {
        private ZipFile zipFile;
        public FileSystem()
        {
            if (File.Exists("data.pak"))
            {
                zipFile = ZipFile.Read("data.pak");
            }
        }

        ~FileSystem()
        {
            this.Dispose();
        }

        public Stream Open(string argFileName)
        {
            if (File.Exists(argFileName))
            {
                Stream fileStream = new FileStream(argFileName, FileMode.Open);
                if (fileStream != null)
                    return fileStream;
            }

            if (zipFile != null)
            {
                var file = zipFile[argFileName];
                if (file != null)
                {
                    Stream outputStream = new MemoryStream();
                    file.Extract(outputStream);
                    return outputStream;
                }
            }

            throw new FileNotFoundException(argFileName);
        }

        #region IDisposable Members

        public void Dispose()
        {
            if (zipFile != null)
            {
                zipFile.Dispose();
            }
        }

        #endregion
    }

    public static class BinaryReaderExtensions
    {
        public static string ReadNullTerminatedString(this BinaryReader reader)
        {
            string result = string.Empty;
            char readChar = '\0';
            do
            {
                readChar = reader.ReadChar();
                if (readChar != '\0')
                    result += readChar;
            }
            while (readChar != '\0');
            return result;
        }
    }   

}