using Akka.Actor;
using Akka.Hosting;
using Microsoft.AspNetCore.SignalR;
using Microsoft.Extensions.DependencyInjection;

namespace ZB.MOM.WW.OtOpcUa.AdminUI.Hubs;

public static class HubServiceCollectionExtensions
{
    public const string FleetStatusSignalRBridgeName = "fleet-status-signalr-bridge";
    public const string AlertSignalRBridgeName = "alert-signalr-bridge";
    public const string ScriptLogSignalRBridgeName = "script-log-signalr-bridge";
    public const string DriverStatusSignalRBridgeName = "driver-status-signalr-bridge";

    /// <summary>
    ///     Registers the in-process live-push services the AdminUI's Blazor Server panels read
    ///     directly (instead of self-connecting a SignalR <c>HubConnection</c>, which fails behind a
    ///     reverse proxy — see <see cref="IInProcessBroadcaster{T}"/>):
    ///     <list type="bullet">
    ///       <item><see cref="IDriverStatusSnapshotStore"/> — last-value snapshot per driver.</item>
    ///       <item><see cref="IInProcessBroadcaster{T}"/> — append-stream fan-out (alarm
    ///       transitions, script-log lines). Registered as an open generic so each closed type
    ///       resolves to its own singleton shared by the bridge actor and the consuming component.</item>
    ///     </list>
    /// </summary>
    /// <param name="services">The service collection.</param>
    public static IServiceCollection AddOtOpcUaDriverStatusServices(this IServiceCollection services)
    {
        services.AddSingleton<IDriverStatusSnapshotStore, InMemoryDriverStatusSnapshotStore>();
        services.AddSingleton(typeof(IInProcessBroadcaster<>), typeof(InProcessBroadcaster<>));
        return services;
    }

    /// <summary>
    /// Spawns the SignalR bridge actors that forward DPS messages to browser-facing SignalR
    /// hubs: <c>fleet-status</c> → <see cref="FleetStatusHub"/>, <c>alerts</c> →
    /// <see cref="AlertHub"/>, <c>script-logs</c> → <see cref="ScriptLogHub"/>.
    ///
    /// Call inside the admin-role configurator on the shared <see cref="AkkaConfigurationBuilder"/>:
    /// <code>
    /// if (hasAdmin)
    /// {
    ///     ab.WithOtOpcUaControlPlaneSingletons();
    ///     ab.WithOtOpcUaSignalRBridges();
    /// }
    /// </code>
    /// </summary>
    /// <param name="builder">The Akka configuration builder.</param>
    public static AkkaConfigurationBuilder WithOtOpcUaSignalRBridges(this AkkaConfigurationBuilder builder)
    {
        builder.WithActors((system, registry, resolver) =>
        {
            var fleetHub = resolver.GetService<IHubContext<FleetStatusHub>>();
            var fleetBridge = system.ActorOf(FleetStatusSignalRBridge.Props(fleetHub), FleetStatusSignalRBridgeName);
            registry.Register<FleetStatusSignalRBridgeKey>(fleetBridge);

            var alertHub = resolver.GetService<IHubContext<AlertHub>>();
            var alertBroadcaster = resolver.GetService<IInProcessBroadcaster<Commons.Messages.Alerts.AlarmTransitionEvent>>();
            var alertBridge = system.ActorOf(AlertSignalRBridge.Props(alertHub, alertBroadcaster), AlertSignalRBridgeName);
            registry.Register<AlertSignalRBridgeKey>(alertBridge);

            var scriptLogHub = resolver.GetService<IHubContext<ScriptLogHub>>();
            var scriptLogBroadcaster = resolver.GetService<IInProcessBroadcaster<Commons.Messages.Logging.ScriptLogEntry>>();
            var scriptLogBridge = system.ActorOf(ScriptLogSignalRBridge.Props(scriptLogHub, scriptLogBroadcaster), ScriptLogSignalRBridgeName);
            registry.Register<ScriptLogSignalRBridgeKey>(scriptLogBridge);

            var driverStatusHub = resolver.GetService<IHubContext<DriverStatusHub>>();
            var driverStatusStore = resolver.GetService<IDriverStatusSnapshotStore>();
            var driverStatusBridge = system.ActorOf(DriverStatusSignalRBridge.Props(driverStatusHub, driverStatusStore), DriverStatusSignalRBridgeName);
            registry.Register<DriverStatusSignalRBridgeKey>(driverStatusBridge);
        });
        return builder;
    }
}

/// <summary>Marker keys for <see cref="ActorRegistry"/> lookup of the SignalR bridge actors.</summary>
public sealed class FleetStatusSignalRBridgeKey { }
public sealed class AlertSignalRBridgeKey { }
public sealed class ScriptLogSignalRBridgeKey { }
public sealed class DriverStatusSignalRBridgeKey { }