namespace MxGateway.Server.Configuration;

/// <summary>
///     Per-gateway alarm-subsystem configuration. Drives the auto-subscribe
///     hook in <see cref="Sessions.SessionManager"/>: when
///     <see cref="Enabled"/> is true and a session reaches Ready, the
///     manager issues a <c>SubscribeAlarmsCommand</c> to the worker with
///     the configured <see cref="SubscriptionExpression"/>.
/// </summary>
/// <remarks>
///     Defaults preserve current behaviour (alarms disabled). Operators
///     opt in by setting <c>MxGateway:Alarms:Enabled = true</c> and
///     supplying a canonical
///     <c>\\&lt;machine&gt;\Galaxy!&lt;area&gt;</c> subscription
///     expression. The literal "Galaxy" provider is correct regardless of
///     the configured Galaxy database name (the wnwrap consumer doesn't
///     accept the database name as the provider).
/// </remarks>
public sealed class AlarmsOptions
{
    /// <summary>Gate the auto-subscribe hook on session open. Default false.</summary>
    public bool Enabled { get; init; }

    /// <summary>
    ///     AVEVA alarm-subscription expression. When empty and
    ///     <see cref="Enabled"/> is true, the gateway falls back to
    ///     <c>\\$(MachineName)\Galaxy!$(DefaultArea)</c> if
    ///     <see cref="DefaultArea"/> is set; otherwise the session open
    ///     fails with a configuration diagnostic.
    /// </summary>
    public string SubscriptionExpression { get; init; } = string.Empty;

    /// <summary>
    ///     Optional area name used to compose a default subscription when
    ///     <see cref="SubscriptionExpression"/> is empty. Combined with
    ///     <c>Environment.MachineName</c> as
    ///     <c>\\&lt;MachineName&gt;\Galaxy!&lt;DefaultArea&gt;</c>.
    /// </summary>
    public string DefaultArea { get; init; } = string.Empty;

    /// <summary>
    ///     If true, an auto-subscribe failure faults the session. If false
    ///     (default), the failure is logged and the session remains Ready —
    ///     alarm-side commands return "not subscribed" but data subscriptions
    ///     work normally.
    /// </summary>
    public bool RequireSubscribeOnOpen { get; init; }
}