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

namespace Application.Features.Api.Stocks.GetCbExercises;

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 input = request.CodeOrIsin?.Trim();
        if (string.IsNullOrEmpty(input))
        {
            return Result.Failure<Response>(Error.Problem("Stock.CodeRequired", "종목 코드가 필요합니다."));
        }

        // 단축코드(6자리)면 Stock 조인으로 ISIN 확보, 아니면 입력을 ISIN 으로 간주.
        var isin = await db.Stock.AsNoTracking().Where(c => c.Code == input && c.ISIN != null).Select(c => c.ISIN!).FirstOrDefaultAsync(ct) ?? input;

        var page = request.Page < 1 ? 1 : request.Page;
        var perPage = request.PerPage is 0 or > MaxPerPage ? (ushort)30 : request.PerPage;

        // 행사주식(기본) 또는 채권 기준 조회
        var query = request.ByBond
            ? db.ConvertibleExercise.AsNoTracking().Where(c => c.BondIsin == isin)
            : db.ConvertibleExercise.AsNoTracking().Where(c => c.XrcStkIsin == isin);

        var total = await query.CountAsync(ct);

        var list = await query
            .OrderByDescending(c => c.RgtStdDt)
            .ThenBy(c => c.BondIsin)
            .Skip((page - 1) * perPage)
            .Take(perPage)
            .Select(c => new Response.Row
            {
                BondIsin = c.BondIsin,
                BondName = c.BondKorSecnNm,
                BondKind = c.BondKindNm,
                ExerciseStockIsin = c.XrcStkIsin,
                ExerciseStockName = c.StkKorSecnNm,
                RgtStdDt = c.RgtStdDt,
                ExercisePrice = c.XrcPrice,
                ExerciseQty = c.XrcQty,
                ExerciseAmt = c.XrcAmt,
                ListDt = c.ListDt
            })
            .ToListAsync(ct);

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