using System;
using Svrnty.CQRS.Events.Abstractions.Notifications;
using Svrnty.CQRS.Events.Abstractions.EventStore;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.Extensions.Logging;
using Svrnty.CQRS.Events.Abstractions;
using Svrnty.CQRS.Events.Abstractions.Subscriptions;

namespace Svrnty.CQRS.Events.Grpc;

/// <summary>
/// gRPC implementation of IEventNotifier that pushes events to active gRPC streams for Phase 8 persistent subscriptions.
/// </summary>
public sealed class GrpcEventNotifier : IEventNotifier
{
    private readonly IPersistentSubscriptionStore _subscriptionStore;
    private readonly ILogger<GrpcEventNotifier> _logger;

    public GrpcEventNotifier(
        IPersistentSubscriptionStore subscriptionStore,
        ILogger<GrpcEventNotifier> logger)
    {
        _subscriptionStore = subscriptionStore ?? throw new ArgumentNullException(nameof(subscriptionStore));
        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
    }

    public async Task NotifyAsync(ICorrelatedEvent @event, long sequence, CancellationToken cancellationToken = default)
    {
        try
        {
            // Use the static method from EventServiceImpl to notify active gRPC subscribers
            await EventServiceImpl.NotifySubscribersAsync(
                @event.CorrelationId,
                @event,
                sequence,
                _subscriptionStore);

            _logger.LogDebug(
                "Notified gRPC subscribers about event {EventType} {EventId} (sequence {Sequence})",
                @event.GetType().Name,
                @event.EventId,
                sequence);
        }
        catch (Exception ex)
        {
            _logger.LogError(
                ex,
                "Error notifying gRPC subscribers about event {EventType} {EventId}",
                @event.GetType().Name,
                @event.EventId);
        }
    }
}