using System.ComponentModel.DataAnnotations;

namespace Domain.Entities.Stocks;

/// <summary>
/// SEIBro 파생결합증권 기초자산 행사정보 (getAssetXrcInfo) — 행사기준비율·행사가격 (Wave 5). 자연키 UNIQUE (Isin, AssetSeq, XrcStdSeq).
/// rolling per-ISIN(DerivMaster 있는 것). AssetSeq 로 DerivAsset 연계, 행사기준일련번호(XrcStdSeq)별 기준비율/행사가격 다수 행.
/// ⚠️ 응답에 ISIN 이 없어(요청 파라미터로만 받음) 배치가 요청 ISIN 을 스탬핑한다.
/// </summary>
public class DerivAssetExercise
{
    [Key]
    public int ID { get; private set; }

    /// <summary>종목코드 (ISIN, 스탬핑)</summary>
    public string Isin { get; private set; } = default!;

    /// <summary>자산일련번호 (ASSET_SEQ) — getAssetInfo 연계</summary>
    public int AssetSeq { get; private set; }

    /// <summary>행사기준일련번호 (XRC_STD_SEQ)</summary>
    public int XrcStdSeq { get; private set; }

    /// <summary>행사기준비율 % (XRC_STD_RATIO) — 기준가 대비</summary>
    public decimal? XrcStdRatio { get; private set; }

    /// <summary>행사가격 (XRC_PRICE)</summary>
    public decimal? XrcPrice { get; private set; }

    public DateTime UpdatedAt { get; private set; } = DateTime.UtcNow;

    private DerivAssetExercise() { }

    public static DerivAssetExercise Create(string isin, int assetSeq, int xrcStdSeq, decimal? xrcStdRatio, decimal? xrcPrice)
    {
        if (string.IsNullOrWhiteSpace(isin))
        {
            throw new ArgumentException("isin required", nameof(isin));
        }

        return new DerivAssetExercise
        {
            Isin = isin.Trim(),
            AssetSeq = assetSeq,
            XrcStdSeq = xrcStdSeq,
            XrcStdRatio = xrcStdRatio,
            XrcPrice = xrcPrice
        };
    }

    /// <summary>재수집 반영 — 변경 필드가 있을 때만 UpdatedAt 갱신 (자연키 Isin/AssetSeq/XrcStdSeq 은 불변)</summary>
    public void Update(decimal? xrcStdRatio, decimal? xrcPrice)
    {
        var changed = false;

        changed |= Set(xrcStdRatio, XrcStdRatio, v => XrcStdRatio = v);
        changed |= Set(xrcPrice, XrcPrice, v => XrcPrice = v);

        if (changed)
        {
            UpdatedAt = DateTime.UtcNow;
        }
    }

    private static bool Set<T>(T incoming, T current, Action<T> assign)
    {
        if (EqualityComparer<T>.Default.Equals(incoming, current))
        {
            return false;
        }

        assign(incoming);
        return true;
    }
}