apewer-dotnet/Apewer/Web/ApiServiceDescriptor.cs

#if Middleware

using System;
using System.Collections.Generic;
using System.Text;

namespace Apewer.Web
{

    /// <summary>API 服务描述。</summary>
    public sealed class ApiServiceDescriptor : IToJson
    {

        /// <summary>订阅器的生命周期。</summary>
        public ApiServiceLifetime Lifetime { get; private set; }

        /// <summary>服务的类型。</summary>
        public Type ServiceType { get; private set; }

        /// <summary>实现服务的类型。</summary>
        public Type ImplementationType { get; private set; }

        public object ImplementationInstance
        {
            get;
        }

        public Func<IServiceProvider, object> ImplementationFactory
        {
            get;
        }

        /// <summary>创建订阅器的实例。</summary>
        /// <param name="invoker">API 调用器。</param>
        /// <param name="lifetime">订阅器的生命周期。</param>
        /// <param name="service">服务的类型。</param>
        /// <param name="implementation">实现服务的类型。</param>
        /// <exception cref="ArgumentNullException" />
        /// <exception cref="ArgumentException" />
        internal ApiServiceDescriptor(ApiServiceLifetime lifetime, Type service, Type implementation)
        {
            if (invoker == null) throw new ArgumentNullException(nameof(invoker));
            if (service == null) throw new ArgumentNullException(nameof(service));
            if (implementation == null) throw new ArgumentNullException(nameof(implementation));

            if (!service.IsAssignableFrom(implementation)) throw new ArgumentException($"类型 {implementation.Name} 未实现服务。");
            if (!implementation.IsClass) throw new ArgumentException($"实现服务的类型 {implementation.Name} 不是引用类型。");
            if (implementation.IsAbstract) throw new ArgumentException($"实现服务的类型 {implementation.Name} 是抽象类型，无法实例化。");

            Lifetime = lifetime;
            ServiceType = service;
            ImplementationType = implementation;
        }

        /// <summary>创建订阅器的实例。</summary>
        /// <param name="invoker">API 调用器。</param>
        /// <param name="lifetime">订阅器的生命周期。</param>
        /// <param name="service">服务的类型。</param>
        /// <param name="implementation">实现服务的方法。</param>
        /// <exception cref="ArgumentNullException" />
        /// <exception cref="ArgumentException" />
        internal ApiServiceDescriptor(ApiServiceLifetime lifetime, Type service, Func<Type,  implementation)
        {
            if (invoker == null) throw new ArgumentNullException(nameof(invoker));
            if (service == null) throw new ArgumentNullException(nameof(service));
            if (implementation == null) throw new ArgumentNullException(nameof(implementation));

            if (!service.IsAssignableFrom(implementation)) throw new ArgumentException($"类型 {implementation.Name} 未实现服务。");
            if (!implementation.IsClass) throw new ArgumentException($"实现服务的类型 {implementation.Name} 不是引用类型。");
            if (implementation.IsAbstract) throw new ArgumentException($"实现服务的类型 {implementation.Name} 是抽象类型，无法实例化。");

            Invoker = invoker;
            Lifetime = lifetime;
            ServiceType = service;
            ImplementationType = implementation;
        }

        /// <summary>生成 JSON 实例。</summary>
        public Json ToJson()
        {
            var json = new Json();
            json["Lifetime"] = Lifetime.ToString();
            json["Service"] = ServiceType.FullName;
            json["Implementation"] = Implementation.FullName;
            return json;
        }

    }

}

#endif