using System;
using System.Linq;
using Microsoft.Extensions.DependencyInjection;
using Svrnty.CQRS.Events.Abstractions.Subscriptions;

namespace Svrnty.CQRS.Events.PostgreSQL.Subscriptions;

/// <summary>
/// Service collection extensions for PostgreSQL subscription storage.
/// </summary>
public static class ServiceCollectionExtensions
{
    /// <summary>
    /// Add PostgreSQL subscription store to the service collection.
    /// Replaces any existing ISubscriptionStore registration.
    /// </summary>
    public static IServiceCollection AddPostgresSubscriptionStore(this IServiceCollection services)
    {
        // Remove existing IPersistentSubscriptionStore registration (e.g., in-memory)
        var descriptor = services.FirstOrDefault(d => d.ServiceType == typeof(IPersistentSubscriptionStore));
        if (descriptor != null)
        {
            services.Remove(descriptor);
        }

        // Register PostgreSQL implementation
        services.AddSingleton<IPersistentSubscriptionStore, PostgresSubscriptionStore>();

        return services;
    }
}