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

namespace Application.Features.Api.Stocks.GetLockupCalendar;

internal sealed class Handler(IAppDbContext db) : IQueryHandler<Query, Result<Response>>
{
    private const ushort MaxPerPage = 200;

    public async Task<Result<Response>> Handle(Query request, CancellationToken ct)
    {
        var page = request.Page < 1 ? 1 : request.Page;
        var perPage = request.PerPage is 0 or > MaxPerPage ? (ushort)30 : request.PerPage;

        var query = db.LockupEvent.AsNoTracking();

        // ReturnDt(락업 해제) 또는 SafedpDt(예수)가 기간 안에 걸리는 이벤트. from/to 미지정 시 전체.
        if (request.From.HasValue)
        {
            var from = request.From.Value;
            query = query.Where(c => c.SafedpDt >= from || (c.ReturnDt != null && c.ReturnDt >= from));
        }

        if (request.To.HasValue)
        {
            var to = request.To.Value;
            query = query.Where(c => c.SafedpDt <= to || (c.ReturnDt != null && c.ReturnDt <= to));
        }

        var total = await query.CountAsync(ct);

        // 정렬 기준: 반환일 있으면 반환일, 없으면 예수일 (락업 해제 캘린더 관점) 내림차순
        var list = await query
            .OrderByDescending(c => c.ReturnDt ?? c.SafedpDt)
            .ThenByDescending(c => c.SafedpDt)
            .Skip((page - 1) * perPage)
            .Take(perPage)
            .Select(c => new Response.Row
            {
                IssucoCustno = c.IssucoCustno,
                ShortCode = c.ShotnIsin,
                Name = c.KorSecnNm,
                OccrSeq = c.OccrSeq,
                SafedpDt = c.SafedpDt,
                SafedpQty = c.SafedpQty,
                ReasonCode = c.DutySafedpRacd,
                ReturnDt = c.ReturnDt,
                ReturnQty = c.ReturnQty,
                TotalStkCnt = c.TotalStkCnt
            })
            .ToListAsync(ct);

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