using System.Globalization;
using Microsoft.EntityFrameworkCore;
using YLErp.BLL;
using YLErp.Modules.AppModule;

namespace YLErp.Modules.ReportModule
{
    /// <summary>
    /// 为结算确认书邮件准备交易编号和平仓总额模板变量。
    /// </summary>
    public static class SettlementMailTemplateHelper
    {
        /// <summary>
        /// 根据当前客户的确认书反查对应交易和平仓记录。
        /// 文档编号可能在不同文档类型中重复，因此必须同时匹配编号和类型。
        /// </summary>
        public static List<Datas> GetSettlementRows(YLContext dbContext, IEnumerable<trade_contract_document> documents, int clientId)
        {
            var documentKeys = documents
                .Where(document => !string.IsNullOrWhiteSpace(document.Code))
                .Select(document => BuildDocumentKey(document.Code, document.Type))
                .Distinct()
                .ToHashSet();

            if (documentKeys.Count == 0)
            {
                return new List<Datas>();
            }

            var contractCodes = documents.Select(document => document.Code).Distinct().ToList();
            var rows = (from relation in dbContext.trade_contract_r
                        join tradeCash in dbContext.trade_cash on relation.TradeCashId equals tradeCash.id
                        join tradeData in dbContext.trade on tradeCash.TradeId equals tradeData.id
                        where contractCodes.Contains(relation.ContractCode)
                              && relation.IsValid
                              && !tradeCash.IsDeleted
                              && tradeData.ClientId == clientId
                        select new
                        {
                            relation.ContractCode,
                            relation.Type,
                            Trade = tradeData,
                            TradeCash = tradeCash
                        }).AsNoTracking().ToList();

            return rows
                // 数据库先按编号缩小范围，再在内存中用“编号+类型”精确匹配附件。
                .Where(row => documentKeys.Contains(BuildDocumentKey(row.ContractCode, row.Type)))
                .Select(row => new Datas
                {
                    trade = row.Trade,
                    tradecash = row.TradeCash
                }).ToList();
        }

        /// <summary>
        /// 将批量加载的数据限制到当前结算日，避免跨日发送时变量汇总串日。
        /// </summary>
        public static List<Datas> ForValueDate(IEnumerable<Datas> rows, DateTime valueDate)
        {
            return (rows ?? Enumerable.Empty<Datas>())
                .Where(row => row?.tradecash != null && row.tradecash.ValueDate.Date == valueDate.Date)
                .ToList();
        }

        /// <summary>
        /// 将去重后的交易编号及客户视角平仓总额写入邮件模板参数。
        /// </summary>
        public static void PopulateSettlementFields(MailInfoRequestModel request, IEnumerable<Datas> rows)
        {
            ArgumentNullException.ThrowIfNull(request);

            // 同一平仓记录可能因关联多份文档重复出现，按 trade_cash.id 去重以避免重复计入金额。
            var distinctRows = (rows ?? Enumerable.Empty<Datas>())
                .Where(row => row?.trade != null && row.tradecash != null)
                .GroupBy(row => row.tradecash.id)
                .Select(group => group.First())
                .ToList();

            request.TradeNumber = string.Join(",", distinctRows
                .Select(row => row.trade.TradeNumber)
                .Where(number => !string.IsNullOrWhiteSpace(number))
                .Distinct()
                .OrderBy(number => number));

            if (distinctRows.Count == 0)
            {
                request.UnwindTotalAmount = string.Empty;
                return;
            }

            // trade_cash.Amount 为交易员视角，邮件展示需取反转换为客户视角。
            var customerAmount = -distinctRows.Sum(row => row.tradecash.Amount);
            if (customerAmount == 0)
            {
                // 消除浮点求和可能产生的 -0.00。
                customerAmount = 0;
            }
            request.UnwindTotalAmount = customerAmount.ToString("F2", CultureInfo.InvariantCulture);
        }

        private static string BuildDocumentKey(string code, string type)
        {
            return $"{code}\u001f{type}";
        }
    }
}