using System.Collections.Generic;
using System.IO;
using Bloomberg.Message.Entities;
using Bloomberg.Message.Utils;

namespace Bloomberg.Message.Reader
{
    public class AttributeReader
    {
        public List<DataAttribute> Read(Stream currentStream)
        {
            var dataAttributesList = new List<DataAttribute>();
            ReaderHelper.ValidateMarker(MessageConstants.AttributeStartMarker, ReaderHelper.ReadUInt(currentStream), "AttributeStartMarker");

            uint length;
            while (true)
            {
                length = ReaderHelper.ReadUInt(currentStream);
                // Verify if we've reach the end
                if (length == MessageConstants.AttributeEndMarker)
                    break;

                string name = "";
                string value = "";

                // Name
                if (length > 0)
                {
                    name =  ReaderHelper.ReadString(currentStream, length);
                }

                // Value
                length = ReaderHelper.ReadUInt(currentStream);
                if (length > 0)
                {
                    value = ReaderHelper.ReadString(currentStream, length);
                }

                dataAttributesList.Add(new DataAttribute {Name = name, Value = value});
            }

            ReaderHelper.ValidateMarker(MessageConstants.AttributeEndMarker, length, "AttributeEndMarker");
            return dataAttributesList;
        }
    }
}