using Dpz.Core.Entity.Base;
using Dpz.Core.MessageQueue.Abstractions;
using Dpz.Core.MessageQueue.Configuration;
using Dpz.Core.MessageQueue.Models;
using Dpz.Core.MessageQueue.RabbitMQ;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;

namespace Dpz.Core.MessageQueue.Extensions;

/// <summary>
/// 消息队列服务扩展方法
/// </summary>
public static class MessageQueueServiceExtensions
{
    /// <summary>
    /// 添加RabbitMQ服务
    /// </summary>
    /// <param name="services">服务集合</param>
    /// <param name="configuration">配置</param>
    /// <param name="configSection">配置节名称，默认为"RabbitMQ"</param>
    /// <returns></returns>
    public static IServiceCollection AddRabbitMQ(
        this IServiceCollection services,
        IConfiguration configuration,
        string configSection = RabbitMQOptions.SectionName
    )
    {
        // 注册配置
        var section = configuration.GetSection(configSection);
        services.Configure<RabbitMQOptions>(section);

        // 注册连接工厂（单例）
        services.AddSingleton<IRabbitMQConnectionFactory, RabbitMQConnectionFactory>();

        // 注册路由约定（单例）
        services.AddSingleton<IMessageRoutingConvention, DefaultMessageRoutingConvention>();

        // 注册发布者（单例）
        services.AddSingleton(typeof(IMessagePublisher<>), typeof(RabbitMQPublisher<>));

        // 注册 Outbox 空实现（默认不启用，可通过 AddMessageOutbox() 替换为 MongoDB 实现）
        services.AddSingleton<IMessageOutboxStore, NullMessageOutboxStore>();
        services.AddSingleton<IMessageOutboxRetryPublisher, NullMessageOutboxRetryPublisher>();

        return services;
    }

    /// <summary>
    /// 添加消息消费者
    /// 每个消息类型配置一个消费者和处理器
    /// </summary>
    /// <typeparam name="TMessage">消息类型</typeparam>
    /// <typeparam name="THandler">处理器类型</typeparam>
    /// <param name="services">服务集合</param>
    /// <returns></returns>
    public static IServiceCollection AddMessageConsumer<TMessage, THandler>(
        this IServiceCollection services
    )
        where TMessage : MessageBase
        where THandler : class, IMessageHandler<TMessage>
    {
        // 注册处理器（Scoped，每次处理消息创建新实例）
        services.AddScoped<IMessageHandler<TMessage>, THandler>();

        // 注册消费者后台服务
        services.AddHostedService<RabbitMQConsumerBackgroundService<TMessage>>();

        return services;
    }

    /// <summary>
    /// 添加消息消费者（支持返回结果）
    /// 每个消息类型配置一个消费者和处理器
    /// </summary>
    /// <typeparam name="TMessage">消息类型</typeparam>
    /// <typeparam name="THandler">处理器类型</typeparam>
    /// <typeparam name="TResult">返回结果类型</typeparam>
    /// <param name="services">服务集合</param>
    /// <returns></returns>
    public static IServiceCollection AddMessageConsumer<TMessage, THandler, TResult>(
        this IServiceCollection services
    )
        where TMessage : MessageBase
        where TResult : MessageHandlerResult
        where THandler : class, IMessageHandler<TMessage, TResult>
    {
        // 注册处理器（Scoped，每次处理消息创建新实例）
        services.AddScoped<IMessageHandler<TMessage, TResult>, THandler>();

        // 注册消费者后台服务（支持返回结果）
        services.AddHostedService<RabbitMQConsumerBackgroundServiceWithResult<TMessage, TResult>>();

        return services;
    }

    /// <summary>
    /// 添加自定义路由约定
    /// </summary>
    /// <typeparam name="TConvention">自定义路由约定类型</typeparam>
    /// <param name="services">服务集合</param>
    /// <returns></returns>
    public static IServiceCollection AddCustomRoutingConvention<TConvention>(
        this IServiceCollection services
    )
        where TConvention : class, IMessageRoutingConvention
    {
        services.AddSingleton<IMessageRoutingConvention, TConvention>();
        return services;
    }

    /// <summary>
    /// 添加批次追踪服务
    /// （多实例部署时需要配置分布式缓存如Redis）
    /// </summary>
    /// <param name="services">服务集合</param>
    /// <returns></returns>
    public static IServiceCollection AddBatchTracking(this IServiceCollection services)
    {
        services.AddSingleton<IBatchTracker, DistributedBatchTracker>();
        return services;
    }

    /// <summary>
    /// 添加 Outbox 后台补发服务。
    /// </summary>
    /// <param name="services">服务集合。</param>
    /// <returns>注册后的服务集合。</returns>
    public static IServiceCollection AddMessageOutboxRetryWorker(this IServiceCollection services)
    {
        services.AddSingleton<IMessageOutboxRetryService, MessageOutboxRetryService>();
        services.AddHostedService<MessageOutboxRetryBackgroundService>();
        return services;
    }
}