using System;

namespace StellaOps.Provcache;

/// <summary>
/// Cache metrics for monitoring and observability.
/// </summary>
public sealed record ProvcacheMetrics
{
    /// <summary>
    /// Total cache requests since startup.
    /// </summary>
    public long TotalRequests { get; init; }

    /// <summary>
    /// Total cache hits since startup.
    /// </summary>
    public long TotalHits { get; init; }

    /// <summary>
    /// Total cache misses since startup.
    /// </summary>
    public long TotalMisses { get; init; }

    /// <summary>
    /// Cache hit rate (0.0 - 1.0).
    /// </summary>
    public double HitRate => TotalRequests == 0 ? 0.0 : (double)TotalHits / TotalRequests;

    /// <summary>
    /// Average lookup latency in milliseconds.
    /// </summary>
    public double AvgLatencyMs { get; init; }

    /// <summary>
    /// P99 lookup latency in milliseconds.
    /// </summary>
    public double P99LatencyMs { get; init; }

    /// <summary>
    /// Current number of entries in cache.
    /// </summary>
    public long CurrentEntryCount { get; init; }

    /// <summary>
    /// Total invalidations since startup.
    /// </summary>
    public long TotalInvalidations { get; init; }

    /// <summary>
    /// Valkey cache health status.
    /// </summary>
    public bool ValkeyCacheHealthy { get; init; }

    /// <summary>
    /// Postgres repository health status.
    /// </summary>
    public bool PostgresRepositoryHealthy { get; init; }

    /// <summary>
    /// Timestamp when metrics were collected.
    /// </summary>
    public DateTimeOffset CollectedAt { get; init; }
}