using System;
using System.Globalization;

namespace StellaOps.Provcache;

public sealed partial class ProvcacheOptions
{
    /// <summary>
    /// Compute time window epoch from a timestamp based on the configured bucket size.
    /// </summary>
    /// <param name="timestamp">The timestamp to compute the epoch for.</param>
    /// <returns>The epoch identifier string.</returns>
    public string ComputeTimeWindow(DateTimeOffset timestamp)
    {
        var bucketTicks = TimeWindowBucket.Ticks;
        var epoch = timestamp.UtcTicks / bucketTicks * bucketTicks;
        return new DateTimeOffset(epoch, TimeSpan.Zero).ToString("yyyy-MM-ddTHH:mm:ssZ", CultureInfo.InvariantCulture);
    }
}