using LY.App.Extensions.DI;
using System.Reflection;

namespace LY.App.Extensions
{
    public static class AutoDIExtensions
    {
        /// <summary>
        /// 
        /// </summary>
        /// <param name="serviceCollection"></param>
        /// <returns></returns>
        public static IServiceCollection ServicesAutoInjectionExtension(this IServiceCollection serviceCollection)
        {
            var directory = AppDomain.CurrentDomain.BaseDirectory;
            var types = Directory.GetFiles(directory, "*.dll", SearchOption.TopDirectoryOnly)
                .Where(s => !s.ToLower().Contains("sql"))
                .Select(Assembly.LoadFrom)
                .SelectMany(a => a.GetTypes());
            Injection(serviceCollection, types);
            return serviceCollection;
        }
        /// <summary>
        /// 服务自动注入
        /// </summary>
        /// <param name="serviceCollection">需要自动注入服务的服务集合</param>
        /// <param name="selector">应用于每个Assembly的筛选函数</param>
        /// <exception cref="ArgumentOutOfRangeException">指定的注入类型不在可注入的范围内</exception>
        /// <exception cref="NoImplementationInterfaceException">指定注入的类型未实现任何服务</exception>
        /// <exception cref="ArgumentException">输入的参数错误：1、注入的类型未实现指定的服务。2、指定的服务不是Interface类型</exception>
        /// <returns>自动注入服务后的服务集合</returns>
        public static IServiceCollection ServicesAutoInjection(this IServiceCollection serviceCollection, Func<Assembly, bool> selector)
        {
            var directory = AppDomain.CurrentDomain.BaseDirectory;
            var types = Directory.GetFiles(directory, "*.dll", SearchOption.TopDirectoryOnly)
                .Select(Assembly.LoadFrom)
                .Where(selector)
                .SelectMany(a => a.GetTypes());

            Injection(serviceCollection, types);

            return serviceCollection;
        }
        // 注入逻辑
        private static void Injection(IServiceCollection serviceCollection, IEnumerable<Type> types)
        {
            foreach (var type in types)
            {
                var attribute = type.GetCustomAttribute<ServiceInjectionAttribute>();
                if (attribute == null) continue;
                switch (attribute.InjectionType)
                {
                    case InjectionType.Transient:
                        serviceCollection.AddTransient(type);
                        break;
                    case InjectionType.Scoped:
                        serviceCollection.AddScoped(type);
                        break;
                    case InjectionType.Singleton:
                        serviceCollection.AddSingleton(type);
                        break;
                    default:
                        throw new ArgumentOutOfRangeException();
                }
            }

        }
    }
}