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

namespace Application.Features.Admin.Payment.Toss.Cancel.Search;

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

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

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

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

        // 탭별 건수 (State 필터 전)
        var counts = await query.GroupBy(c => 1).Select(c => new Response.StateCounts
        {
            Success = c.Count(x => x.ResponseCode == "SUCCESS"),
            Failed = c.Count(x => x.ResponseCode != null && x.ResponseCode != "SUCCESS"),
            Pending = c.Count(x => x.ResponseCode == null)
        }).FirstOrDefaultAsync(ct) ?? new Response.StateCounts();

        if (request.State.HasValue)
        {
            query = request.State.Value switch
            {
                1 => query.Where(c => c.ResponseCode == "SUCCESS"),
                2 => query.Where(c => c.ResponseCode != null && c.ResponseCode != "SUCCESS"),
                3 => query.Where(c => c.ResponseCode == null),
                _ => query
            };
        }

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

        var list = await query
            .OrderByDescending(c => c.ID)
            .Skip(skip)
            .Take(request.PerPage)
            .Select(c => new
            {
                c.ID,
                c.MemberID,
                MemberEmail = c.Member != null ? c.Member.Email : string.Empty,
                MemberName = c.Member != null ? c.Member.Name : null,
                c.PaymentKey,
                c.OrderID,
                c.CancelAmount,
                c.CancelReason,
                c.CancelRequester,
                c.Status,
                c.ResponseCode,
                c.ResponseMessage,
                c.CreatedAt
            })
            .ToListAsync(ct);

        var rows = list.Select((c, idx) => new Response.Row
        {
            Num = total - skip - idx,
            ID = c.ID,
            MemberID = c.MemberID,
            MemberEmail = c.MemberEmail,
            MemberName = c.MemberName,
            PaymentKey = c.PaymentKey,
            OrderID = c.OrderID,
            CancelAmount = c.CancelAmount,
            CancelReason = c.CancelReason,
            CancelRequester = c.CancelRequester,
            Status = c.Status,
            ResponseCode = c.ResponseCode,
            ResponseMessage = c.ResponseMessage,
            CreatedAt = c.CreatedAt
        }).ToList();

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