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

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

namespace Application.Features.Api.Paper.GetOrders;

internal sealed class Handler(IAppDbContext db) : IQueryHandler<Query, Response>
{
    public async Task<Response> Handle(Query request, CancellationToken ct)
    {
        var accountID = await db.PaperAccount.AsNoTracking().Where(c => c.MemberID == request.MemberID).Select(c => (int?)c.ID).FirstOrDefaultAsync(ct);

        if (accountID is null)
        {
            return new Response(0, []);
        }

        var query = db.PaperOrder.AsNoTracking().Where(c => c.AccountID == accountID.Value);

        if (request.Status.HasValue)
        {
            query = query.Where(c => c.Status == request.Status.Value);
        }

        var total = await query.CountAsync(ct);

        var orders = await query
            .OrderByDescending(c => c.ID)
            .Skip((request.Page - 1) * request.PerPage)
            .Take(request.PerPage)
            .Select(c => new
            {
                c.ID,
                c.StockCode,
                c.Side,
                c.FillRule,
                c.Quantity,
                c.ReservedAmount,
                c.TargetDate,
                c.CancelableUntil,
                c.Status,
                c.RejectReason,
                c.CreatedAt,
                Fill = db.PaperFill.Where(f => f.OrderID == c.ID).Select(f => new Response.FillInfo(
                    f.Price,
                    f.Quantity,
                    f.Fee,
                    f.Tax,
                    f.Amount,
                    f.RealizedPnL,
                    f.PriceDate,
                    f.FilledAt
                )).FirstOrDefault()
            })
            .ToListAsync(ct);

        var codes = orders.Select(c => c.StockCode).Distinct().ToList();
        var names = await db.Stock.AsNoTracking()
            .Where(c => codes.Contains(c.Code))
            .Select(c => new { c.Code, c.Name })
            .ToDictionaryAsync(c => c.Code, c => c.Name, ct);

        var list = orders.Select(c => new Response.Row(
            c.ID,
            c.StockCode,
            names.GetValueOrDefault(c.StockCode, c.StockCode),
            c.Side,
            c.FillRule,
            c.Quantity,
            c.ReservedAmount,
            c.TargetDate,
            c.CancelableUntil,
            c.Status,
            c.RejectReason,
            c.CreatedAt,
            c.Fill
        )).ToList();

        return new Response(total, list);
    }
}