using System;
using Svrnty.CQRS.Events.Abstractions.Replay;

namespace Svrnty.CQRS.Events.Abstractions.Replay;

/// <summary>
/// Progress information for replay operations.
/// </summary>
public record ReplayProgress
{
    /// <summary>
    /// Current offset being processed.
    /// </summary>
    public required long CurrentOffset { get; init; }

    /// <summary>
    /// Total number of events processed so far.
    /// </summary>
    public required long EventsProcessed { get; init; }

    /// <summary>
    /// Estimated total events to replay (if known).
    /// </summary>
    public long? EstimatedTotal { get; init; }

    /// <summary>
    /// Current timestamp of event being processed.
    /// </summary>
    public DateTimeOffset? CurrentTimestamp { get; init; }

    /// <summary>
    /// Elapsed time since replay started.
    /// </summary>
    public required TimeSpan Elapsed { get; init; }

    /// <summary>
    /// Events per second processing rate.
    /// </summary>
    public double EventsPerSecond => EventsProcessed / Math.Max(Elapsed.TotalSeconds, 0.001);

    /// <summary>
    /// Progress percentage (0-100) if total is known.
    /// </summary>
    public double? ProgressPercentage => EstimatedTotal.HasValue && EstimatedTotal.Value > 0
        ? (EventsProcessed / (double)EstimatedTotal.Value) * 100
        : null;
}