using System.Globalization;
using System.Reflection;

namespace CatalogLite;

internal static class ExpirationGuard
{
    private const string GeneratedMetadataKey = "CatalogLiteGeneratedExpirationDate";
    private const string MetadataKey = "CatalogLiteExpirationDate";

    public static bool IsExpired(out DateOnly? expirationDate)
    {
        expirationDate = TryReadExpirationDate();
        return expirationDate is null || DateOnly.FromDateTime(DateTime.Now) > expirationDate.Value;
    }

    private static DateOnly? TryReadExpirationDate()
    {
        if (TryParseDate(BuildExpiration.ExpirationDate, out var generatedDate))
        {
            return generatedDate;
        }

        var metadata = typeof(Program).Assembly.GetCustomAttributes<AssemblyMetadataAttribute>();
        var metadataValue = metadata.FirstOrDefault(attribute => string.Equals(attribute.Key, GeneratedMetadataKey, StringComparison.Ordinal))?.Value
            ?? metadata.FirstOrDefault(attribute => string.Equals(attribute.Key, MetadataKey, StringComparison.Ordinal))?.Value;

        return TryParseDate(metadataValue, out var metadataDate)
            ? metadataDate
            : null;
    }

    private static bool TryParseDate(string? value, out DateOnly date)
    {
        var trimmedValue = value?.Trim();
        return DateOnly.TryParseExact(trimmedValue, "yyyy-MM-dd", CultureInfo.InvariantCulture, DateTimeStyles.None, out date)
            || DateOnly.TryParse(trimmedValue, CultureInfo.CurrentCulture, DateTimeStyles.None, out date);
    }
}