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

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

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

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

        var statusCounts = new Response.StatusCounts(
            All: counts.Sum(x => x.Count),
            Pending: CountOf(GameSettlementStatus.Pending),
            Settled: CountOf(GameSettlementStatus.Settled)
        );

        // 필터 적용
        var query = db.GameSettlement.AsNoTracking()
            .Include(s => s.Game)
            .AsQueryable();

        if (request.GameID is > 0)
        {
            query = query.Where(s => s.GameID == request.GameID);
        }

        if (request.Year is > 0)
        {
            query = query.Where(s => s.Year == request.Year);
        }

        if (request.Month is > 0)
        {
            query = query.Where(s => s.Month == request.Month);
        }

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

        var total = await query.CountAsync(ct);

        // 합계 (필터 적용 후)
        var summary = await query
            .GroupBy(s => 1)
            .Select(g => new { Sum = g.Sum(s => (long)s.TotalRevenueAmount), Orders = g.Sum(s => s.OrderCount) })
            .FirstOrDefaultAsync(ct);

        var list = await query
            .OrderByDescending(s => s.Year)
            .ThenByDescending(s => s.Month)
            .ThenBy(s => s.GameID)
            .Skip((request.Page - 1) * request.PerPage)
            .Take(request.PerPage)
            .Select(s => new
            {
                s.ID,
                s.GameID,
                GameName = s.Game!.KorName,
                GamePublisher = s.Game.Publisher,
                s.Year,
                s.Month,
                s.TotalRevenueAmount,
                s.OrderCount,
                s.Status,
                s.CreatedAt,
                s.SettledAt,
                s.SettledByAdminUserId,
                s.SettledByAdminEmail,
                s.AdminMemo
            })
            .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.GameID,
                c.GameName,
                c.GamePublisher,
                c.Year,
                c.Month,
                c.TotalRevenueAmount,
                c.OrderCount,
                c.Status,
                c.CreatedAt,
                c.SettledAt,
                c.SettledByAdminUserId,
                c.SettledByAdminEmail,
                c.AdminMemo
            ))],
            Counts: statusCounts,
            Totals: new Response.Summary(
                TotalRevenue: summary?.Sum ?? 0,
                TotalOrders: summary?.Orders ?? 0
            )
        );
    }
}