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

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

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

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

        var statusCounts = new Response.StatusCounts(
            All: counts.Sum(x => x.Count),
            Paid: CountOf(OrderStatus.Paid),
            Preparing: CountOf(OrderStatus.Preparing),
            Shipped: CountOf(OrderStatus.Shipped),
            Delivered: CountOf(OrderStatus.Delivered),
            Cancelled: CountOf(OrderStatus.Cancelled),
            Refunded: CountOf(OrderStatus.Refunded),
            Exchanged: CountOf(OrderStatus.Exchanged)
        );

        // 필터 적용
        var query = db.Order.AsNoTracking().AsQueryable();

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

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

            query = request.Search switch
            {
                1 => query.Where(c => c.OrderNumber.Contains(kw)),
                2 => query.Where(c => c.Member!.Email.Contains(kw)),
                _ => query.Where(c => c.OrderNumber.Contains(kw) || c.Member!.Email.Contains(kw))
            };
        }

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

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

        var total = await query.CountAsync(ct);

        var list = await query
            .OrderByDescending(c => c.ID)
            .Skip((request.Page - 1) * request.PerPage)
            .Take(request.PerPage)
            .Select(c => new
            {
                c.ID,
                c.OrderNumber,
                c.MemberID,
                MemberEmail = c.Member!.Email,
                c.ChannelID,
                ChannelName = c.Channel != null ? c.Channel.Name : null,
                c.TotalAmount,
                c.PlatformFeeAmount,
                c.GameRevenueAmount,
                c.ChannelRewardAmount,
                c.Status,
                c.CreatedAt,
                c.PaidAt
            })
            .ToListAsync(ct);

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

        return new Response(
            Total: total,
            List: [.. list.Select((c, i) => new Response.Row(
                Num: startNum - i,
                c.ID,
                c.OrderNumber,
                c.MemberID,
                c.MemberEmail,
                c.ChannelID,
                c.ChannelName,
                c.TotalAmount,
                c.PlatformFeeAmount,
                c.GameRevenueAmount,
                c.ChannelRewardAmount,
                c.Status,
                c.CreatedAt,
                c.PaidAt
            ))],
            Counts: statusCounts
        );
    }
}