phronCare/Core/Services/ExchangeRateService.cs

using Core.Interfaces;
using Domain.Entities;
using Models.Interfaces;
using System.Net.Http.Json;
using System.Text.Json.Serialization;

public class ExchangeRateRepository : IExchangeRateDom
{
    private readonly IPhOHExchangeRateHistory _repository;
    private readonly HttpClient _http;

    public ExchangeRateRepository(IPhOHExchangeRateHistory repository, HttpClient http)
    {
        _repository = repository;
        _http = http;
    }

    public async Task<EExchangeRateHistory> GetYesterdayRateAsync()
    {
        // 1) Calcular “ayer” en ART
        var argentinaNow = DateTime.UtcNow.AddHours(-3);
        var yesterday = DateOnly.FromDateTime(argentinaNow.Date.AddDays(-1));

        // 2) Intentar rescatar del histórico
        var existing = await _repository.GetByDateAsync(yesterday);
        if (existing is not null)
            return existing;

        // 3) Si no está, llamar al API BCRA pedimos desde hace 7 días hasta ayer para saltar feriados/fines de semana
        var from = yesterday.AddDays(-7).ToString("yyyy-MM-dd");
        var to = yesterday.ToString("yyyy-MM-dd");
        var url = $"estadisticascambiarias/v1.0/Cotizaciones/USD?fechadesde={from}&fechahasta={to}";

        var series = await _http.GetFromJsonAsync<SeriesResponse>(url)
                     ?? throw new InvalidOperationException("No se obtuvo JSON válido del BCRA");

        if (series.Results == null || !series.Results.Any())
            throw new InvalidOperationException("No hay datos de cotización en el período solicitado");

        // 4) El primer elemento es el más reciente (ayer o último día hábil)
        var day = series.Results.First();
        var detail = day.Details.First(d => d.CodigoMoneda == "USD");
        var rate = detail.TipoCotizacion;

        // 5) Construir dominio y persistir
        var entity = new EExchangeRateHistory
        {
            Ratedate = yesterday,
            Purchaserate = rate,
            Salerate = rate,
            Source = "BCRA",
            Createdat = DateTime.UtcNow
        };

        return await _repository.AddAsync(entity);
    }
    public Task<EExchangeRateHistory?> GetByDateAsync(DateOnly date)
    {
        // Simplemente delega al repositorio
        return _repository.GetByDateAsync(date);
    }
}

// Core/Services/Dto.cs

public class SeriesResponse
{
    public int Status { get; set; }
    public Metadata Metadata { get; set; } = null!;
    public List<RateDay> Results { get; set; } = new();
}

public class Metadata
{
    public Resultset Resultset { get; set; } = null!;
}

public class Resultset
{
    public int Count { get; set; }
    public int Offset { get; set; }
    public int Limit { get; set; }
}

public class RateDay
{
    public DateTime Fecha { get; set; }
    [JsonPropertyName("detalle")]
    public List<RateDetail> Details { get; set; } = new();
}

public class RateDetail
{
    public string CodigoMoneda { get; set; } = null!;
    public decimal TipoCotizacion { get; set; }
    // otros campos opcionales: descripcion, tipoPase, etc.
}