using CliFx.Attributes;
using CliFx.Infrastructure;
using ZB.MOM.WW.OtOpcUa.Core.Abstractions;

namespace ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.Cli.Commands;

/// <summary>
///     PR 5.1 / #316 — stream TC3 EventLogger alarms to the terminal until Ctrl+C.
///     Mirrors the OPC UA Client CLI <c>alarms</c> verb shape: subscribe + print every
///     incoming <see cref="AlarmEventArgs"/> with timestamp, source, severity, and
///     message text. Requires <c>EnableAlarms=true</c> on the driver — set via the
///     base options builder when the verb is selected.
/// </summary>
[Command("alarms", Description =
    "Subscribe to TC3 EventLogger alarms via the driver's IAlarmSource bridge and " +
    "stream events to stdout until Ctrl+C.")]
public sealed class AlarmsCommand : TwinCATCommandBase
{
    [CommandOption("source", Description =
        "Optional alarm source filter (matched case-insensitively against the event's " +
        "Source field). Repeat the flag to match multiple sources; omit to subscribe to " +
        "every event the EventLogger surfaces.")]
    public IReadOnlyList<string> Sources { get; init; } = Array.Empty<string>();

    public override async ValueTask ExecuteAsync(IConsole console)
    {
        ConfigureLogging();
        var ct = console.RegisterCancellationHandler();

        // Empty Tags + EnableAlarms=true builds a driver that opens only the alarm path.
        // TwinCATDriverOptions is a regular class with init-only properties — rebuild
        // the instance instead of using a record-style `with` clone.
        var baseOptions = BuildOptions([]);
        var options = new TwinCATDriverOptions
        {
            Devices = baseOptions.Devices,
            Tags = baseOptions.Tags,
            Probe = baseOptions.Probe,
            Timeout = baseOptions.Timeout,
            UseNativeNotifications = baseOptions.UseNativeNotifications,
            EnableControllerBrowse = baseOptions.EnableControllerBrowse,
            MaxArrayExpansion = baseOptions.MaxArrayExpansion,
            EnableAlarms = true,
        };

        await using var driver = new TwinCATDriver(options, DriverInstanceId);
        IAlarmSubscriptionHandle? handle = null;
        try
        {
            await driver.InitializeAsync("{}", ct);

            driver.OnAlarmEvent += (_, e) =>
            {
                var line =
                    $"[{e.SourceTimestampUtc:HH:mm:ss.fff}] " +
                    $"{e.SourceNodeId} " +
                    $"sev={e.Severity} " +
                    $"type={e.AlarmType} " +
                    $"cond={e.ConditionId} " +
                    $"\"{e.Message}\"";
                console.Output.WriteLine(line);
            };

            handle = await driver.SubscribeAlarmsAsync(Sources, ct);

            var filterDesc = Sources.Count == 0
                ? "all sources"
                : $"sources [{string.Join(", ", Sources)}]";
            await console.Output.WriteLineAsync(
                $"Subscribed to TC3 EventLogger alarms on {AmsNetId}:{AmsPort} ({filterDesc}). Ctrl+C to stop.");
            await console.Output.WriteLineAsync(
                "Note: Beckhoff doesn't ship a managed TcEventLogger wrapper; the driver " +
                "uses a best-effort decode of AMS port 110 notifications. Some fields may " +
                "surface as 'Unknown' until a binary-protocol decoder lands.");
            try
            {
                await Task.Delay(System.Threading.Timeout.InfiniteTimeSpan, ct);
            }
            catch (OperationCanceledException)
            {
                // Expected on Ctrl+C.
            }
        }
        finally
        {
            if (handle is not null)
            {
                try { await driver.UnsubscribeAlarmsAsync(handle, CancellationToken.None); }
                catch { /* teardown best-effort */ }
            }
            await driver.ShutdownAsync(CancellationToken.None);
        }
    }
}