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

namespace Application.Features.Admin.Payment.Danal.Confirm.Search;

public sealed class Handler(IAppDbContext db) : IQueryHandler<Query, Response>
{
    public async Task<Response> Handle(Query request, CancellationToken ct)
    {
        var query = db.DanalConfirm.AsNoTracking().Include(x => x.Member).AsQueryable();

        // 키워드 검색
        if (!string.IsNullOrWhiteSpace(request.Keyword))
        {
            query = request.Search switch
            {
                1 => query.Where(x => x.TransactionID.Contains(request.Keyword)),
                2 => query.Where(x => x.OrderID.Contains(request.Keyword)),
                3 => query.Where(x => x.Member != null && x.Member.ID.ToString().Contains(request.Keyword)),
                4 => query.Where(x => x.Member != null && x.Member.Name != null && x.Member.Name.Contains(request.Keyword)),
                5 => query.Where(x => x.Member != null && x.Member.SID.Contains(request.Keyword)),
                _ => query
            };
        }

        // 기간 필터
        if (!string.IsNullOrWhiteSpace(request.StartAt) && DateTime.TryParse(request.StartAt, out var startAt))
        {
            query = query.Where(x => x.CreatedAt >= startAt);
        }

        if (!string.IsNullOrWhiteSpace(request.EndAt) && DateTime.TryParse(request.EndAt, out var endAt))
        {
            query = query.Where(x => x.CreatedAt <= endAt);
        }

        // 탭별 건수 (PayMethod 필터 전)
        var counts = await query.GroupBy(c => 1).Select(c => new Response.MethodCounts
        {
            Card = c.Count(x => x.Method == PaymentMethod.Card),
            VirtualAccount = c.Count(x => x.Method == PaymentMethod.VirtualAccount),
            Mobile = c.Count(x => x.Method == PaymentMethod.Mobile),
            Transfer = c.Count(x => x.Method == PaymentMethod.Transfer)
        }).FirstOrDefaultAsync(ct) ?? new Response.MethodCounts();

        if (request.PayMethod.HasValue)
        {
            query = query.Where(x => x.Method == request.PayMethod.Value);
        }

        var total = await query.CountAsync(ct);
        var skip = (request.Page - 1) * request.PerPage;

        var list = await query
            .OrderByDescending(x => x.ID)
            .Skip(skip)
            .Take(request.PerPage)
            .Select(x => new
            {
                x.ID,
                x.MemberID,
                MemberEmail = x.Member != null ? x.Member.Email : string.Empty,
                MemberName = x.Member != null ? x.Member.Name : null,
                x.Method,
                x.TransactionID,
                x.OrderID,
                x.Amount,
                x.TotalAmount,
                x.ResponseCode,
                x.ResponseMessage,
                x.PaymentOrderID,
                x.CreatedAt
            })
            .ToListAsync(ct);

        // 같은 PaymentOrderID로 DanalCancel 있는지 조회 (성공한 취소만)
        var orderIDs = list.Select(x => x.PaymentOrderID).Distinct().ToArray();

        var cancels = await db.DanalCancel.AsNoTracking()
            .Where(c => orderIDs.Contains(c.PaymentOrderID) && c.ResponseCode == "0000")
            .Select(c => new { c.PaymentOrderID, c.CancelType, c.CancelledAmount })
            .ToListAsync(ct);

        var cancelByOrder = cancels.GroupBy(c => c.PaymentOrderID).ToDictionary(
            g => g.Key,
            g => g.First()
        );

        var rows = list.Select((x, idx) =>
        {
            cancelByOrder.TryGetValue(x.PaymentOrderID, out var cancel);

            return new Response.Row
            {
                Num = total - skip - idx,
                ID = x.ID,
                MemberID = x.MemberID,
                MemberEmail = x.MemberEmail,
                MemberName = x.MemberName,
                Method = x.Method,
                TransactionID = x.TransactionID,
                OrderID = x.OrderID,
                Amount = x.Amount,
                TotalAmount = x.TotalAmount,
                ResponseCode = x.ResponseCode,
                ResponseMessage = x.ResponseMessage,
                CancelType = cancel?.CancelType,
                CancelledAmount = cancel?.CancelledAmount,
                CreatedAt = x.CreatedAt
            };
        }).ToList();

        return new Response
        {
            Total = total,
            Counts = counts,
            List = rows
        };
    }
}