using Microsoft.Practices.ServiceLocation;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;

/// <summary>
/// Contains <see cref="IServiceLocator"/> extension methods.
/// </summary>
public static class IServiceLocatorExtensions
{
    /// <summary>
    /// Gets all registered instances.
    /// </summary>
    /// <param name="locator">The service locator.</param>
    /// <returns></returns>
    public static List<Object> GetAllInstances(this IServiceLocator locator)
    {
        var dictionaries = locator.GetType().GetField("_instancesRegistry", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(locator) as Dictionary<Type, Dictionary<string, object>>;
        var instances = dictionaries.SelectMany(x => x.Value).Select(x => x.Value).ToList();
        return instances;
    }

    /// <summary>
    /// Gets all instances by the specified base type T.
    /// </summary>
    /// <typeparam name="T">Base type</typeparam>
    /// <param name="locator">The service locator.</param>
    /// <returns></returns>
    public static List<T> GetAllInstancesByBase<T>(this IServiceLocator locator)
    {
        return locator.GetAllInstances().Where(x => x != null && typeof(T).IsAssignableFrom(x.GetType())).Select(x => (T)x).ToList();
    }
}