englisch

2026-04-17 07:08:04 +02:00
parent ca91af9682
commit 0d3bd47f7a
34 changed files with 17503 additions and 160 deletions
@@ -0,0 +1,121 @@
+using Microsoft.EntityFrameworkCore;
+using TrafagSalesExporter.Data;
+
+namespace TrafagSalesExporter.Services;
+
+public class CurrencyExchangeRateService : ICurrencyExchangeRateService
+{
+    private static readonly Dictionary<string, string> BuiltInCurrencyAliases = new(StringComparer.OrdinalIgnoreCase)
+    {
+        ["$"] = "USD",
+        ["US$"] = "USD",
+        ["USD"] = "USD",
+        ["€"] = "EUR",
+        ["EUR"] = "EUR",
+        ["CHF"] = "CHF",
+        ["SFR"] = "CHF",
+        ["INR"] = "INR",
+        ["RS"] = "INR",
+        ["GBP"] = "GBP",
+        ["CAD"] = "CAD"
+    };
+
+    private readonly IDbContextFactory<AppDbContext> _dbFactory;
+
+    public CurrencyExchangeRateService(IDbContextFactory<AppDbContext> dbFactory)
+    {
+        _dbFactory = dbFactory;
+    }
+
+    public decimal? ResolveRate(string fromCurrency, string toCurrency, DateTime? effectiveDate)
+    {
+        var normalizedFrom = NormalizeCurrencyCode(fromCurrency);
+        var normalizedTo = NormalizeCurrencyCode(toCurrency);
+        if (string.IsNullOrWhiteSpace(normalizedFrom) || string.IsNullOrWhiteSpace(normalizedTo))
+            return null;
+
+        if (string.Equals(normalizedFrom, normalizedTo, StringComparison.OrdinalIgnoreCase))
+            return 1m;
+
+        var date = (effectiveDate ?? DateTime.UtcNow).Date;
+
+        using var db = _dbFactory.CreateDbContext();
+        var directRate = db.CurrencyExchangeRates
+            .AsNoTracking()
+            .Where(x => x.IsActive
+                && x.FromCurrency.ToUpper() == normalizedFrom
+                && x.ToCurrency.ToUpper() == normalizedTo
+                && x.ValidFrom.Date <= date
+                && (!x.ValidTo.HasValue || x.ValidTo.Value.Date >= date))
+            .OrderByDescending(x => x.ValidFrom)
+            .FirstOrDefault();
+
+        if (directRate is not null)
+            return directRate.Rate;
+
+        var inverseRate = db.CurrencyExchangeRates
+            .AsNoTracking()
+            .Where(x => x.IsActive
+                && x.FromCurrency.ToUpper() == normalizedTo
+                && x.ToCurrency.ToUpper() == normalizedFrom
+                && x.ValidFrom.Date <= date
+                && (!x.ValidTo.HasValue || x.ValidTo.Value.Date >= date))
+            .OrderByDescending(x => x.ValidFrom)
+            .FirstOrDefault();
+
+        if (inverseRate is not null && inverseRate.Rate != 0m)
+            return 1m / inverseRate.Rate;
+
+        var fromToEur = ResolveDirectOrInverseRate(db, normalizedFrom, "EUR", date);
+        var eurToTarget = ResolveDirectOrInverseRate(db, "EUR", normalizedTo, date);
+        if (fromToEur.HasValue && eurToTarget.HasValue)
+            return fromToEur.Value * eurToTarget.Value;
+
+        return null;
+    }
+
+    public string NormalizeCurrencyCode(string? currencyCode)
+    {
+        var normalized = currencyCode?.Trim() ?? string.Empty;
+        if (string.IsNullOrWhiteSpace(normalized))
+            return string.Empty;
+
+        return BuiltInCurrencyAliases.TryGetValue(normalized, out var mapped)
+            ? mapped
+            : normalized.ToUpperInvariant();
+    }
+
+    private static decimal? ResolveDirectOrInverseRate(AppDbContext db, string fromCurrency, string toCurrency, DateTime date)
+    {
+        if (string.Equals(fromCurrency, toCurrency, StringComparison.OrdinalIgnoreCase))
+            return 1m;
+
+        var directRate = db.CurrencyExchangeRates
+            .AsNoTracking()
+            .Where(x => x.IsActive
+                && x.FromCurrency.ToUpper() == fromCurrency
+                && x.ToCurrency.ToUpper() == toCurrency
+                && x.ValidFrom.Date <= date
+                && (!x.ValidTo.HasValue || x.ValidTo.Value.Date >= date))
+            .OrderByDescending(x => x.ValidFrom)
+            .FirstOrDefault();
+
+        if (directRate is not null)
+            return directRate.Rate;
+
+        var inverseRate = db.CurrencyExchangeRates
+            .AsNoTracking()
+            .Where(x => x.IsActive
+                && x.FromCurrency.ToUpper() == toCurrency
+                && x.ToCurrency.ToUpper() == fromCurrency
+                && x.ValidFrom.Date <= date
+                && (!x.ValidTo.HasValue || x.ValidTo.Value.Date >= date))
+            .OrderByDescending(x => x.ValidFrom)
+            .FirstOrDefault();
+
+        if (inverseRate is not null && inverseRate.Rate != 0m)
+            return 1m / inverseRate.Rate;
+
+        return null;
+    }
+}