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

namespace Application.Features.Admin.Donation.List.Search;

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

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

        // 날짜 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);
        }

        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.Amount,
                x.Message,
                x.SendName,
                x.IsTest,
                x.CreatedAt,
                x.SponsorMemberID,
                x.ReceiverMemberID,
                SponsorID = x.Sponsor != null ? x.Sponsor.ID : 0,
                SponsorEmail = x.Sponsor != null ? x.Sponsor.Email : string.Empty,
                SponsorName = x.Sponsor != null ? x.Sponsor.Name : null,
                SponsorSID = x.Sponsor != null ? x.Sponsor.SID : null,
                ReceiverID = x.Receiver != null ? x.Receiver.ID : 0,
                ReceiverEmail = x.Receiver != null ? x.Receiver.Email : string.Empty,
                ReceiverName = x.Receiver != null ? x.Receiver.Name : null,
                ReceiverSID = x.Receiver != null ? x.Receiver.SID : null
            })
            .ToListAsync(ct);

        // 관련 회원의 지갑 잔액 일괄 조회 (행별 N+1 방지)
        var memberIDs = list.Select(x => x.SponsorMemberID).Concat(list.Select(x => x.ReceiverMemberID)).Distinct().ToArray();

        var wallets = await db.Wallet
            .AsNoTracking()
            .Where(w => memberIDs.Contains(w.MemberID))
            .Include(w => w.Balances)
            .ToListAsync(ct);

        var balanceByMember = wallets.ToDictionary(
            w => w.MemberID,
            w => new
            {
                Total = (long)w.Balances.Where(b => b.Type != WalletBalanceType.Locked).Sum(b => b.Amount.Value),
                Donation = (long)(w.Balances.FirstOrDefault(b => b.Type == WalletBalanceType.Donation)?.Amount.Value ?? 0)
            });

        var rows = list.Select((x, idx) => new Response.Row
        {
            Num = total - skip - idx,
            ID = x.ID,
            Amount = x.Amount,
            Message = x.Message,
            SendName = x.SendName,
            IsTest = x.IsTest,
            Sponsor = new Response.MemberInfo
            {
                ID = x.SponsorID,
                Email = x.SponsorEmail,
                Name = x.SponsorName,
                SID = x.SponsorSID
            },
            Receiver = new Response.MemberInfo
            {
                ID = x.ReceiverID,
                Email = x.ReceiverEmail,
                Name = x.ReceiverName,
                SID = x.ReceiverSID
            },
            SponsorBalance = balanceByMember.TryGetValue(x.SponsorMemberID, out var sb) ? sb.Total : 0L,
            ReceiverDonationBalance = balanceByMember.TryGetValue(x.ReceiverMemberID, out var rb) ? rb.Donation : 0L,
            CreatedAt = x.CreatedAt
        }).ToList();

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