using System.IO;

namespace Com.Xagasoft.Gats
{
    public abstract class GatsObject
    {
        public abstract void Read( Stream s, char type );
        public abstract void Write( Stream s );

        public static GatsObject Read( Stream s )
        {
            int b = s.ReadByte();
            if( b == -1 )
                throw new GatsException( GatsException.Type.PrematureEnd );
            char type = (char)b;
            GatsObject ret = null;
            switch( type )
            {
                case 'i':
                    ret = new GatsInteger();
                    break;

                case 's':
                    ret = new GatsString();
                    break;

                case '0':
                case '1':
                    ret = new GatsBoolean();
                    break;

                case 'l':
                    ret = new GatsList();
                    break;

                case 'd':
                    ret = new GatsDictionary();
                    break;

                case 'f':
                case 'F':
                    ret = new GatsFloat();
                    break;

                case 'n':
                    ret = new GatsNull();
                    break;

                case 'e':
                    return null;

                default:
                    throw new GatsException( GatsException.Type.InvalidType );
	    	}

    		ret.Read( s, type );

            return ret;
        }
    }
}