ANTOOZA-BACKEND/Infrastructure/StockData/StooqHttp.cs

using Microsoft.Extensions.Logging;

namespace Infrastructure.StockData;

/// <summary>Stooq(stooq.com) 무인증 CSV 시세 호출 공통 — 인증 헤더 없음 + 간단 3회 재시도 (2s/4s 백오프).</summary>
internal static class StooqHttp
{
    public const string ClientName = "Stooq";

    private const int MaxAttempts = 3;

    public static async Task<string> GetStringWithRetryAsync(HttpClient client, string url, ILogger logger, CancellationToken ct)
    {
        for (var attempt = 1; ; attempt++)
        {
            try
            {
                using var response = await client.GetAsync(url, ct);
                response.EnsureSuccessStatusCode();
                return await response.Content.ReadAsStringAsync(ct);
            }
            catch (Exception ex) when (ex is not OperationCanceledException && attempt < MaxAttempts)
            {
                logger.LogWarning(ex, "[Stooq] HTTP 실패 — 재시도 {Attempt}/{Max}", attempt, MaxAttempts);
                await Task.Delay(TimeSpan.FromSeconds(2 * attempt), ct);
            }
        }
    }
}