namespace SQLInsight.Core.Data;

/// <summary>
/// Globally enabled trace flags (<c>DBCC TRACESTATUS(-1)</c>).
/// </summary>
public sealed record TraceFlagSnapshot(DateTimeOffset CapturedAt, IReadOnlyList<int> GlobalTraceFlags)
{
    public bool IsEnabled(int flag) => GlobalTraceFlags.Contains(flag);
}

/// <summary>
/// Pages SQL Server has recorded as damaged (<c>msdb.dbo.suspect_pages</c>, 823/824/825 errors).
/// </summary>
public sealed record SuspectPageSnapshot(DateTimeOffset CapturedAt, IReadOnlyList<SuspectPage> Pages);

/// <param name="EventType">1: 823/824 error, 2: bad checksum, 3: torn page, 4: restored, 5: repaired, 7: deallocated.</param>
public sealed record SuspectPage(string DatabaseName, int FileId, long PageId, int EventType, int ErrorCount, DateTime LastUpdate)
{
    /// <summary>Event types 4, 5 and 7 mean the page has been fixed.</summary>
    public bool IsUnresolved => EventType is 1 or 2 or 3;
}

/// <summary>
/// Plan cache composition (<c>sys.dm_exec_cached_plans</c>).
/// </summary>
public sealed record PlanCacheSnapshot
{
    public required DateTimeOffset CapturedAt { get; init; }
    public required long TotalPlans { get; init; }
    public required double TotalMb { get; init; }

    /// <summary>Ad hoc plans used exactly once. A high share means plan cache bloat.</summary>
    public required long SingleUseAdhocPlans { get; init; }

    public required double SingleUseAdhocMb { get; init; }
}