ANTOOZA-BACKEND/Infrastructure/StockData/KrxStockParser.cs

using System.Globalization;
using System.Text.Json;
using Domain.Entities.Stocks.ValueObject;

namespace Infrastructure.StockData;

/// <summary>
/// KRX OpenAPI(data-dbg.krx.co.kr) 주식(종목) 응답 파서 — 순수 C# (System.Text.Json). "D1 KRX 주식(종목) 데이터 수집".
/// 응답 골격: { "OutBlock_1": [ { ...string values }, ... ] }. 모든 값은 문자열, 천단위 콤마 포함 가능, 결측치는 "" 또는 "-".
/// 일별매매(stk_bydd_trd/ksq_bydd_trd): ISU_CD 가 6자리 단축코드. FLUC_RT(%)는 소수 % 그대로 저장한다
/// (StockDailyPrice.ChangeRate / Stock.LastChangeRate 이 decimal % 이므로 DataGoKrStockParser 와 동일 스케일 유지 — Bp 변환 안 함).
/// 종목기본정보(stk_isu_base_info/ksq_isu_base_info): ISU_SRT_CD 가 6자리 단축코드, ISU_CD 가 표준코드(KR7…) ISIN.
/// </summary>
public static class KrxStockParser
{
    /// <summary>종목기본정보 1행 (마스터 upsert 원천). ISU_ABBRV → Name, ISU_ENG_NM → EnglishName, LIST_DD → ListedDate.</summary>
    public sealed record MasterItem(
        string Code,
        string? Isin,
        string Name,
        string? EnglishName,
        StockMarket Market,
        string? SectorName,
        DateOnly ListedDate
    );

    /// <summary>일별매매 1행 (등락률은 소수 % 그대로 — Bp 아님)</summary>
    public sealed record DailyPriceItem(
        string Code,
        DateOnly TradingDate,
        int Open,
        int High,
        int Low,
        int Close,
        long Volume,
        long TradingValue,
        int ChangeAmount,
        decimal ChangeRate,
        long? MarketCap,
        long? ListedShares
    );

    /// <summary>일별매매(stk_bydd_trd/ksq_bydd_trd) 파싱. market 은 호출 엔드포인트로 결정 (응답 MKT_NM 은 무시하고 인자 신뢰).</summary>
    public static IReadOnlyList<DailyPriceItem> ParseDailyPrices(string json, StockMarket market)
    {
        using var doc = JsonDocument.Parse(json);
        var rows = new List<DailyPriceItem>();

        if (!doc.RootElement.TryGetProperty("OutBlock_1", out var block) || block.ValueKind != JsonValueKind.Array)
        {
            return rows;
        }

        foreach (var item in block.EnumerateArray())
        {
            var code = NormalizeCode(GetString(item, "ISU_CD"));
            var tradingDate = ParseDate(GetString(item, "BAS_DD"));

            if (code is null || tradingDate is null)
            {
                continue;
            }

            rows.Add(new DailyPriceItem(
                code,
                tradingDate.Value,
                ParseInt(GetString(item, "TDD_OPNPRC")),
                ParseInt(GetString(item, "TDD_HGPRC")),
                ParseInt(GetString(item, "TDD_LWPRC")),
                ParseInt(GetString(item, "TDD_CLSPRC")),
                ParseLong(GetString(item, "ACC_TRDVOL")),
                ParseLong(GetString(item, "ACC_TRDVAL")),
                ParseInt(GetString(item, "CMPPREVDD_PRC")),
                ParseDecimal(GetString(item, "FLUC_RT")),
                ParseNullableLong(GetString(item, "MKTCAP")),
                ParseNullableLong(GetString(item, "LIST_SHRS"))
            ));
        }

        return rows;
    }

    /// <summary>종목기본정보(stk_isu_base_info/ksq_isu_base_info) 파싱. market 은 호출 엔드포인트로 결정.</summary>
    public static IReadOnlyList<MasterItem> ParseMasterInfo(string json, StockMarket market)
    {
        using var doc = JsonDocument.Parse(json);
        var rows = new List<MasterItem>();

        if (!doc.RootElement.TryGetProperty("OutBlock_1", out var block) || block.ValueKind != JsonValueKind.Array)
        {
            return rows;
        }

        foreach (var item in block.EnumerateArray())
        {
            var code = NormalizeCode(GetString(item, "ISU_SRT_CD"));
            var name = GetString(item, "ISU_ABBRV");
            var listedDate = ParseDate(GetString(item, "LIST_DD"));

            if (code is null || name.Length == 0 || listedDate is null)
            {
                continue;
            }

            var isin = GetString(item, "ISU_CD");
            var englishName = GetString(item, "ISU_ENG_NM");
            var sectorName = GetString(item, "SECT_TP_NM");

            rows.Add(new MasterItem(
                code,
                isin.Length == 12 ? isin : null,
                name,
                englishName.Length == 0 ? null : englishName,
                market,
                sectorName.Length == 0 ? null : sectorName,
                listedDate.Value
            ));
        }

        return rows;
    }

    private static string GetString(JsonElement element, string name)
    {
        if (!element.TryGetProperty(name, out var value))
        {
            return string.Empty;
        }

        return value.ValueKind switch
        {
            JsonValueKind.String => value.GetString()?.Trim() ?? string.Empty,
            JsonValueKind.Number => value.GetRawText(),
            _ => string.Empty
        };
    }

    /// <summary>단축코드 정규화 — 'A' 프리픽스 등 6자리 초과분은 뒤 6자리만 취하고, 6자리 숫자만 유효</summary>
    private static string? NormalizeCode(string raw)
    {
        if (raw.Length > 6)
        {
            raw = raw[^6..];
        }

        if (raw is not { Length: 6 } || raw.Any(c => !char.IsAsciiDigit(c)))
        {
            return null;
        }

        return raw;
    }

    private static DateOnly? ParseDate(string raw)
    {
        return DateOnly.TryParseExact(raw, "yyyyMMdd", CultureInfo.InvariantCulture, DateTimeStyles.None, out var date) ? date : null;
    }

    private static int ParseInt(string raw)
    {
        return int.TryParse(raw, NumberStyles.Integer | NumberStyles.AllowThousands, CultureInfo.InvariantCulture, out var value) ? value : 0;
    }

    private static long ParseLong(string raw)
    {
        return long.TryParse(raw, NumberStyles.Integer | NumberStyles.AllowThousands, CultureInfo.InvariantCulture, out var value) ? value : 0L;
    }

    private static long? ParseNullableLong(string raw)
    {
        return long.TryParse(raw, NumberStyles.Integer | NumberStyles.AllowThousands, CultureInfo.InvariantCulture, out var value) ? value : null;
    }

    /// <summary>등락률(%) 문자열 → decimal % 그대로. "" 나 "-" 등 파싱 실패는 0 (DataGoKrStockParser.fltRt 와 동일 스케일).</summary>
    private static decimal ParseDecimal(string raw)
    {
        return decimal.TryParse(raw, NumberStyles.Float | NumberStyles.AllowThousands, CultureInfo.InvariantCulture, out var value) ? value : 0m;
    }
}