using Application.Abstractions.Data;
using Application.Abstractions.Messaging;
using Domain.Entities.Store.ValueObject;
using Microsoft.EntityFrameworkCore;

namespace Application.Features.Api.Store.Orders.List;

internal sealed class Handler(IAppDbContext db) : IQueryHandler<Query, Response>
{
    public async Task<Response> Handle(Query request, CancellationToken ct)
    {
        var query = db.Order.AsNoTracking()
            .Include(o => o.Channel)
            .Include(o => o.Items)
            .ThenInclude(i => i.Product)
            .Where(o => o.MemberID == request.MemberID);

        if (request.Status.HasValue)
        {
            query = query.Where(o => o.Status == request.Status.Value);
        }
        else
        {
            // Pending(미결제) 은 사용자 뷰에서 제외
            query = query.Where(o => o.Status != OrderStatus.Pending);
        }

        // 기간 필터: Year 명시 → 해당 연도 / 미명시 → 최근 6개월 (CreatedAt UTC 기준)
        if (request.Year.HasValue)
        {
            var start = new DateTime(request.Year.Value, 1, 1, 0, 0, 0, DateTimeKind.Utc);
            var end = start.AddYears(1);
            query = query.Where(o => o.CreatedAt >= start && o.CreatedAt < end);
        }
        else
        {
            var sixMonthsAgo = DateTime.UtcNow.AddMonths(-6);
            query = query.Where(o => o.CreatedAt >= sixMonthsAgo);
        }

        // 상품명 검색 — 주문 라인 중 1개라도 매칭되면 주문 노출
        if (!string.IsNullOrWhiteSpace(request.Keyword))
        {
            var kw = request.Keyword.Trim();
            query = query.Where(o => o.Items.Any(i => i.Product!.Name.Contains(kw)));
        }

        var total = await query.CountAsync(ct);

        var list = await query
            .OrderByDescending(o => o.ID)
            .Skip((request.Page - 1) * request.PerPage)
            .Take(request.PerPage)
            .Select(o => new
            {
                o.ID,
                o.OrderNumber,
                o.TotalAmount,
                o.Status,
                o.ChannelID,
                ChannelName = o.Channel != null ? o.Channel.Name : null,
                HasPhysical = o.Items.Any(i => i.Product!.Type == ProductType.Physical),
                HasDigital = o.Items.Any(i => i.Product!.Type == ProductType.Digital),
                o.CreatedAt,
                o.PaidAt,
                ItemCount = o.Items.Count,
                FirstItemName = o.Items.OrderBy(i => i.ID).Select(i => i.Product!.Name).FirstOrDefault() ?? "",
                FirstItemThumbnail = o.Items.OrderBy(i => i.ID).Select(i => i.Product!.Thumbnail).FirstOrDefault(),
                ShipmentStatus = db.Shipment.Where(s => s.OrderID == o.ID).Select(s => (ShipmentStatus?)s.Status).FirstOrDefault(),
                HasActiveRefundRequest = db.OrderRefund.Any(r => r.OrderID == o.ID && r.Status == RefundStatus.Requested)
            })
            .ToListAsync(ct);

        return new Response(
            total,
            [.. list.Select(c => new Response.Row(
                c.ID,
                c.OrderNumber,
                c.TotalAmount,
                c.Status,
                c.ChannelID,
                c.ChannelName,
                c.HasPhysical,
                c.HasDigital,
                c.CreatedAt,
                c.PaidAt,
                c.ItemCount,
                c.FirstItemName,
                c.FirstItemThumbnail,
                c.ShipmentStatus,
                c.HasActiveRefundRequest
            ))]
        );
    }
}