using System;
using System.Linq;
using Autofac;
using Autofac.Builder;
using Autofac.Core;
using Autofac.Features.Scanning;

namespace HiddenNamespace
{
    public static class RegistrationExtensions
    {
        /// <summary>
        /// Specifies that a type from a scanned assembly is registered using the default interface.
        /// Following the convention of Type, IType. The default interface for ProductRepository will be
        /// IProductRepository
        /// </summary>
        /// <typeparam name="TLimit">Registration limit type.</typeparam>
        /// <typeparam name="TScanningActivatorData">Activator data type.</typeparam>
        /// <param name="registration">Registration to set service mapping on.</param>
        /// <returns>Registration builder allowing the registration to be configured.</returns>
        public static IRegistrationBuilder<TLimit, TScanningActivatorData, DynamicRegistrationStyle>
            AsDefaultInterface<TLimit, TScanningActivatorData>(this IRegistrationBuilder<TLimit, TScanningActivatorData, DynamicRegistrationStyle> registration)
            where TScanningActivatorData : ScanningActivatorData
        {
            if (registration == null) throw new ArgumentNullException("registration");

            return registration.As(t => t.GetInterfaces()
                .Where(i => i != typeof(IDisposable))
                .Where(i => i.IsDefaultInterfaceFor(t))
                .Select(i => new TypedService(i))
                // ReSharper disable RedundantEnumerableCastCall
                .Cast<Service>());
            // ReSharper restore RedundantEnumerableCastCall
        }

        /// <summary>
        /// Specifies that a is registered using the default interface.
        /// Following the convention of Type, IType. The default interface for ProductRepository will be
        /// IProductRepository
        /// </summary>
        /// <typeparam name="TLimit">Registration limit type.</typeparam>
        /// <typeparam name="TScanningActivatorData">Activator data type.</typeparam>
        /// <param name="registration">Registration to set service mapping on.</param>
        /// <returns>Registration builder allowing the registration to be configured.</returns>
        public static IRegistrationBuilder<TLimit, TScanningActivatorData, SingleRegistrationStyle>
            AsImplementedInterfaces<TLimit, TScanningActivatorData>(this IRegistrationBuilder<TLimit, TScanningActivatorData, SingleRegistrationStyle> registration)
        {
            if (registration == null) throw new ArgumentNullException("registration");
            return registration.As(typeof(TLimit).GetInterfaces()
                .Where(i=>i.IsDefaultInterfaceFor(typeof(TLimit)))
                .Select(i => new TypedService(i))
                .Cast<Service>()
                .ToArray());
        }

        public static bool IsDefaultInterfaceFor(this Type interfaceType, Type type)
        {
            return interfaceType.Name == "I" + type.Name;
        }
    }
}