using System;
using System.Data;
using System.Data.SqlTypes;
using Microsoft.SqlServer.Server;
using System.IO;

namespace UDA
{
    [Serializable]
    [SqlUserDefinedAggregate(Microsoft.SqlServer.Server.Format.UserDefined, IsInvariantToNulls=true, IsInvariantToDuplicates=true, MaxByteSize=-1)]
    public class GroupConcatSimple:IBinarySerialize
    {
        SqlString line;
        SqlString accvalues;

        public void Init()
        {
            line = new SqlString("");
            accvalues = new SqlString("");
        }

        public void Accumulate(SqlString value, SqlString delim) {
            if (!value.IsNull)
                line = String.Concat(line.Value, value.Value, delim.IsNull ? "," : delim.Value);

            accvalues = String.Concat(accvalues.Value, value.IsNull ? "NONE" : value.Value, "/");
        }

        public void Merge(GroupConcatSimple instance) {
            if (instance.line != null) String.Concat(line, instance.line);
        }

        public SqlString Terminate() {
            if (line.IsNull) return SqlString.Null;
            return new SqlString(line.Value + "\n" + accvalues.Value);
        }



        public void Read(BinaryReader r)
        {
            line = new SqlString(r.ReadString());
            accvalues = new SqlString(r.ReadString());
        }

        public void Write(BinaryWriter w)
        {
            w.Write(line.Value);
            w.Write(accvalues.Value);
        }
    }
}