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

namespace Application.Features.Admin.Store.Shipment.Search;

public sealed class Handler(IAppDbContext db) : IQueryHandler<Query, Response>
{
    public async Task<Response> Handle(Query request, CancellationToken ct)
    {
        // navtab 카운트 (필터 무관 전체)
        var counts = await db.Shipment.AsNoTracking()
            .GroupBy(s => s.Status)
            .Select(g => new { Status = g.Key, Count = g.Count() })
            .ToListAsync(ct);

        int CountOf(ShipmentStatus s) => counts.FirstOrDefault(x => x.Status == s)?.Count ?? 0;

        var statusCounts = new Response.StatusCounts(
            All: counts.Sum(x => x.Count),
            Preparing: CountOf(ShipmentStatus.Preparing),
            Pickup: CountOf(ShipmentStatus.Pickup),
            InTransit: CountOf(ShipmentStatus.InTransit),
            Delivered: CountOf(ShipmentStatus.Delivered),
            Failed: CountOf(ShipmentStatus.Failed)
        );

        var query = db.Shipment.AsNoTracking()
            .Include(s => s.Order).ThenInclude(o => o!.Member)
            .AsQueryable();

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

        if (!string.IsNullOrWhiteSpace(request.Keyword))
        {
            var kw = request.Keyword.Trim();

            query = request.Search switch
            {
                1 => query.Where(s => s.Order!.OrderNumber.Contains(kw)),
                2 => query.Where(s => s.Order!.Member!.Email.Contains(kw)),
                3 => query.Where(s => s.TrackingNumber != null && s.TrackingNumber.Contains(kw)),
                _ => query.Where(s =>
                    s.Order!.OrderNumber.Contains(kw)
                    || (s.TrackingNumber != null && s.TrackingNumber.Contains(kw)))
            };
        }

        if (DateTime.TryParse(request.StartAt, out var startAt))
        {
            query = query.Where(s => s.CreatedAt >= startAt);
        }

        if (DateTime.TryParse(request.EndAt, out var endAt))
        {
            query = query.Where(s => s.CreatedAt <= endAt);
        }

        var total = await query.CountAsync(ct);

        var list = await query
            .OrderByDescending(s => s.ID)
            .Skip((request.Page - 1) * request.PerPage)
            .Take(request.PerPage)
            .Select(s => new Response.Row(
                0,
                s.ID,
                s.OrderID,
                s.Order!.OrderNumber,
                s.Order.Member!.Email,
                s.Status,
                s.Carrier,
                s.TrackingNumber,
                s.CreatedAt,
                s.ShippedAt,
                s.DeliveredAt
            ))
            .ToListAsync(ct);

        var startNum = total - ((request.Page - 1) * request.PerPage);

        return new Response(
            total,
            [.. list.Select((c, i) => c with { Num = startNum - i })],
            statusCounts
        );
    }
}