using System.Linq.Expressions;

namespace YLErp.Modules.TradeModule.QueryModule
{
    public class BatchGetTradeRelationDataService<T> where T : DBModelBase
    {
        public List<T> GetListByWhere(Expression<Func<T, bool>> expression, DbSet<T> dataSet, int batchSize = 500)
        {
            var result = new List<T>();
            var newExpression = expression;
            while (true)
            {
                var list = dataSet.AsNoTracking().Where(newExpression).OrderBy(p => p.id).Take(batchSize).ToList();
                if (list != null && list.Count > 0)
                {
                    result.AddRange(list);
                }
                if (list == null || list.Count < batchSize)
                {
                    break;
                }
                var maxId = list.Max(p => p.id);
                newExpression = expression.And(p => p.id > maxId);
            }
            return result;
        }

    }
}