namespace SQLInsight.Core.Data;

/// <summary>
/// Deadlocks captured by the <c>system_health</c> Extended Events session since the previous collection.
/// </summary>
public sealed record DeadlockSnapshot
{
    public required DateTimeOffset CapturedAt { get; init; }

    /// <summary>Deadlocks newer than the previous collection.</summary>
    public required IReadOnlyList<DeadlockEvent> NewDeadlocks { get; init; }

    /// <summary>Newest event time seen so far; the next collection starts after it.</summary>
    public DateTimeOffset? LastEventTime { get; init; }

    /// <summary>Where reading stopped in the event file, so the next read does not rescan all files.</summary>
    public string? LastFileName { get; init; }

    public long? LastFileOffset { get; init; }
}

public sealed record DeadlockEvent
{
    public required DateTimeOffset Time { get; init; }
    public required IReadOnlyList<DeadlockProcess> Processes { get; init; }

    /// <summary>The raw deadlock graph (XDL), for download and viewing in SSMS.</summary>
    public required string GraphXml { get; init; }

    /// <summary>
    /// Every participant is SQLInsight Pro itself (monitoring or its own repository), e.g. when the repository lives on
    /// a monitored instance. Not the customer's problem, so not reported. A deadlock with any other session is kept.
    /// </summary>
    public bool IsOwn => Processes.Count > 0
        && Processes.All(p => p.ClientApp?.StartsWith(OwnApplicationName, StringComparison.Ordinal) == true);

    /// <summary>Application Name prefix on all of SQLInsight Pro's connections ("SQLInsight Pro", "SQLInsight Pro (repository)").</summary>
    public const string OwnApplicationName = "SQLInsight Pro";
}

public sealed record DeadlockProcess
{
    public required string Id { get; init; }
    public bool IsVictim { get; init; }
    public int? SessionId { get; init; }
    public string? DatabaseName { get; init; }
    public string? LoginName { get; init; }
    public string? HostName { get; init; }
    public string? ClientApp { get; init; }
    public string? IsolationLevel { get; init; }
    public string? WaitResource { get; init; }
    public string? LockMode { get; init; }
    public string? InputBuffer { get; init; }
}