using System.Globalization;

namespace StellaOps.Scanner.Core.Utility;

public static class ScannerTimestamps
{
    private const long TicksPerMicrosecond = TimeSpan.TicksPerMillisecond / 1000;

    public static DateTimeOffset Normalize(DateTimeOffset value)
    {
        var utc = value.ToUniversalTime();
        var ticks = utc.Ticks - (utc.Ticks % TicksPerMicrosecond);
        return new DateTimeOffset(ticks, TimeSpan.Zero);
    }

    public static DateTimeOffset UtcNow(TimeProvider? provider = null)
        => Normalize((provider ?? TimeProvider.System).GetUtcNow());

    public static string ToIso8601(DateTimeOffset value)
        => Normalize(value).ToString("yyyy-MM-dd'T'HH:mm:ss.ffffff'Z'", CultureInfo.InvariantCulture);

    public static bool TryParseIso8601(string? value, out DateTimeOffset timestamp)
    {
        if (string.IsNullOrWhiteSpace(value))
        {
            timestamp = default;
            return false;
        }

        if (DateTimeOffset.TryParse(
                value,
                CultureInfo.InvariantCulture,
                DateTimeStyles.AssumeUniversal | DateTimeStyles.AdjustToUniversal,
                out var parsed))
        {
            timestamp = Normalize(parsed);
            return true;
        }

        timestamp = default;
        return false;
    }
}