using CsvHelper;
using CsvHelper.Configuration;
using System.Globalization;
using System.Text;
using YieldChain.Helpers;
using YLErp.Model;

namespace YLErp.Modules.VolatilityModule
{
    /// <summary>
    /// 品种波动率调整服务
    /// </summary>
    public class VarietyVolAdjustService : YLBaseService
    {
        public VarietyVolAdjustService(OptUserInfo userInfo) : base(userInfo)
        {
        }

        public IEnumerable<VarietyVolAdjustModel> GetList()
        {
            var query = from n in DbContext.variety
                            //where n.UnderlyingInstrumentType == "CommodityFutures"
                        orderby n.VarietyCode
                        select new VarietyVolAdjustModel
                        {
                            VarietyId = n.id,
                            VarietyCode = n.VarietyCode,
                            Volitality = n.VolatilityAdjust
                        };
            return query.ToArray();
        }

        public int SaveData(VarietyVolAdjustModel model)
        {
            if (model is null)
            {
                throw new ArgumentNullException(nameof(model));
            }

            var dbData = DbContext.variety.Find(model.VarietyId);
            if (dbData == null)
            {
                throw new ServiceException("保存失败:品种数据不存在");
            }
            dbData.VolatilityAdjust = model.Volitality;
            return DbContext.SaveChanges();
        }

        public ImportResultModel ImportCsvDatas(Stream stream)
        {
            var result = new ImportResultModel();

            IEnumerable<ImportModel> importModels;

            var csvConfig = new CsvConfiguration(CultureInfo.InvariantCulture)
            {
                //规避空数据行
                ShouldSkipRecord = n => n.Row.Parser.Record == null || n.Row.Parser.Record.All(m => string.IsNullOrWhiteSpace(m))
            };

            //当前编码支持ansi和utf with bom
            using (var sr = new StreamReader(stream, Encoding.Default))
            using (var csv = new CsvReader(sr, csvConfig))
            {
                csv.Context.TypeConverterCache.AddConverter<string>(Helpers.CsvTypeConverts.StringConverter.Required);
                csv.Context.TypeConverterCache.AddConverter<double>(Helpers.CsvTypeConverts.DoubleConverter.Required);
                csv.Context.RegisterClassMap<ImportModel.ImportMap>();
                importModels = csv.GetRecords<ImportModel>().ToArray();
            }

            if (!importModels.Any())
            {
                throw new ServiceException("没有可导入的数据");
            }

            result.TotalCount = importModels.Count();

            var dic = DbContext.variety.ToDictionary(n => n.VarietyCode, StringComparer.OrdinalIgnoreCase);

            foreach (var item in importModels)
            {
                if (dic.TryGetValue(item.code, out var variety))
                {
                    result.SuccessCount++;
                    variety.VolatilityAdjust = item.vol;
                }
                else
                {
                    result.Errors.Add(item.code + ": 品种数据不存在");
                }
            }

            DbContext.SaveChanges();

            return result;
        }

        /// <summary>
        /// 获取导入模板
        /// </summary>
        public static string GetCsvTemplate()
        {
            return new ImportModel.ImportMap().GenTemplate();
        }

        class ImportModel
        {
            public string code { get; set; }

            public double vol { get; set; }

            public class ImportMap : ClassMap<ImportModel>
            {
                public ImportMap()
                {
                    Map(m => m.code).Name("品种代码").TypeConverter(Helpers.CsvTypeConverts.StringConverter.Required);
                    Map(m => m.vol).Name("历史波动率").TypeConverter(Helpers.CsvTypeConverts.DoubleConverter.Required);
                }

                public string GenTemplate()
                {
                    var sb = new StringBuilder(512);

                    foreach (var map in MemberMaps)
                    {
                        sb.AppendCSVCell(map.Data.Names.First()).Append(',');
                    }

                    if (sb.Length > 0)
                    {
                        sb.Remove(sb.Length - 1, 1);
                    }

                    return sb.ToString();
                }
            }
        }
    }
}