using System;
using System.Collections;

using BLToolkit.Reflection;

namespace BLToolkit.Mapping
{
    public class EnumeratorMapper : IMapDataSourceList
    {
        public EnumeratorMapper(IEnumerator enumerator)
        {
            _enumerator = enumerator;
        }

        private readonly IEnumerator _enumerator;
        private          Type        _objectType;

        #region IMapDataSourceList Members

        public virtual void InitMapping(InitContext initContext)
        {
            _enumerator.Reset();
        }

        public virtual bool SetNextDataSource(InitContext initContext)
        {
            if (initContext == null) throw new ArgumentNullException("initContext");

            if (_enumerator.MoveNext() == false)
                return false;

            object sourceObject = _enumerator.Current;

            if (_objectType != sourceObject.GetType())
            {
                _objectType = sourceObject.GetType();
                initContext.DataSource = initContext.MappingSchema.GetObjectMapper(_objectType);
            }

            initContext.SourceObject = sourceObject;

            return true;
        }

        public virtual void EndMapping(InitContext initContext)
        {
        }

        #endregion
    }
}