ANTOOZA-BACKEND/Application/Features/Api/Paper/GetTrackRecord/Handler.cs

using Application.Abstractions.Data;
using Application.Abstractions.Messaging;
using Microsoft.EntityFrameworkCore;

namespace Application.Features.Api.Paper.GetTrackRecord;

/// <summary>
/// 프로필 모의투자 성적 (익명 허용) — SID→회원→계좌→최신 스냅샷. 계좌/스냅샷 없으면 HasAccount=false (d4 M3 리더보드 백엔드 구현).
/// 승률은 전체 매도 기준(RealizedPnL>0 / RealizedPnL!=null).
/// </summary>
internal sealed class Handler(IAppDbContext db) : IQueryHandler<Query, Response>
{
    private static readonly Response Empty = new(false, 0, 0, 0, 0, null);

    public async Task<Response> Handle(Query request, CancellationToken ct)
    {
        if (string.IsNullOrWhiteSpace(request.Sid))
        {
            return Empty;
        }

        var memberID = await db.Member.AsNoTracking().Where(c => c.SID == request.Sid).Select(c => (int?)c.ID).FirstOrDefaultAsync(ct);

        if (memberID is null)
        {
            return Empty;
        }

        var accountID = await db.PaperAccount.AsNoTracking().Where(c => c.MemberID == memberID.Value).Select(c => (int?)c.ID).FirstOrDefaultAsync(ct);

        if (accountID is null)
        {
            return Empty;
        }

        var latest = await db.PaperDailySnapshot.AsNoTracking()
            .Where(c => c.AccountID == accountID.Value)
            .OrderByDescending(c => c.TradeDate)
            .Select(c => new { c.CumReturnBp, c.MddBp, c.FillCountCum, c.TradeDate })
            .FirstOrDefaultAsync(ct);

        if (latest is null)
        {
            return Empty;
        }

        var totalSells = await db.PaperFill.AsNoTracking().CountAsync(c => c.RealizedPnL != null && c.Order.AccountID == accountID.Value, ct);
        var winningSells = await db.PaperFill.AsNoTracking().CountAsync(c => c.RealizedPnL > 0 && c.Order.AccountID == accountID.Value, ct);

        var winRateBp = totalSells > 0 ? (int)Math.Round(winningSells / (double)totalSells * 10000, MidpointRounding.AwayFromZero) : 0;

        return new Response(true, latest.CumReturnBp, latest.MddBp, winRateBp, latest.FillCountCum, latest.TradeDate);
    }
}