using System;
using Svrnty.CQRS.Events.Abstractions.Streaming;
using Svrnty.CQRS.Events.RabbitMQ.Delivery;
using Svrnty.CQRS.Events.RabbitMQ.Configuration;
using Svrnty.CQRS.Events.Abstractions.Delivery;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection.Extensions;
using Svrnty.CQRS.Events.Abstractions;

namespace Svrnty.CQRS.Events.RabbitMQ;

/// <summary>
/// Extension methods for registering RabbitMQ event delivery services.
/// </summary>
public static class ServiceCollectionExtensions
{
    /// <summary>
    /// Registers RabbitMQ as an external event delivery provider.
    /// </summary>
    /// <param name="services">The service collection.</param>
    /// <param name="configure">Configuration action for RabbitMQ options.</param>
    /// <returns>The service collection for method chaining.</returns>
    /// <example>
    /// <code>
    /// services.AddRabbitMQEventDelivery(options =>
    /// {
    ///     options.ConnectionString = "amqp://guest:guest@localhost:5672/";
    ///     options.ExchangePrefix = "myapp";
    ///     options.DefaultExchangeType = "topic";
    ///     options.EnablePublisherConfirms = true;
    /// });
    /// </code>
    /// </example>
    public static IServiceCollection AddRabbitMQEventDelivery(
        this IServiceCollection services,
        Action<RabbitMQConfiguration> configure)
    {
        if (services == null)
            throw new ArgumentNullException(nameof(services));
        if (configure == null)
            throw new ArgumentNullException(nameof(configure));

        // Configure options
        services.Configure(configure);

        // Register RabbitMQEventDeliveryProvider as both IEventDeliveryProvider and IExternalEventDeliveryProvider
        services.TryAddSingleton<RabbitMQEventDeliveryProvider>();
        services.AddSingleton<IEventDeliveryProvider>(sp => sp.GetRequiredService<RabbitMQEventDeliveryProvider>());
        services.AddSingleton<IExternalEventDeliveryProvider>(sp => sp.GetRequiredService<RabbitMQEventDeliveryProvider>());

        // Register as hosted service to ensure Start/StopAsync are called
        services.AddHostedService<RabbitMQEventDeliveryHostedService>();

        return services;
    }

    /// <summary>
    /// Registers RabbitMQ as an external event delivery provider with connection string.
    /// </summary>
    /// <param name="services">The service collection.</param>
    /// <param name="connectionString">RabbitMQ connection string (amqp://...).</param>
    /// <param name="configure">Optional additional configuration.</param>
    /// <returns>The service collection for method chaining.</returns>
    /// <example>
    /// <code>
    /// services.AddRabbitMQEventDelivery("amqp://guest:guest@localhost:5672/");
    /// </code>
    /// </example>
    public static IServiceCollection AddRabbitMQEventDelivery(
        this IServiceCollection services,
        string connectionString,
        Action<RabbitMQConfiguration>? configure = null)
    {
        if (services == null)
            throw new ArgumentNullException(nameof(services));
        if (string.IsNullOrWhiteSpace(connectionString))
            throw new ArgumentException("Connection string cannot be null or whitespace.", nameof(connectionString));

        return services.AddRabbitMQEventDelivery(options =>
        {
            options.ConnectionString = connectionString;
            configure?.Invoke(options);
        });
    }
}