using Microsoft.Extensions.DependencyInjection;
using MultiTerm.Core.Factories;
using MultiTerm.Core.ViewModel;

namespace MultiTerm.Core.Helpers;

public static class ServiceExtensions
{
    /// <summary>
    /// Service Extension to add all implementations of <see cref="ITerminalViewModel"/> to Dependency Injection.
    /// Also adds <see cref="TerminalViewModelFactory"/> to Dependency injection, which allows instanciation of <see cref="ITerminalViewModel"/> during runtime.
    /// </summary>
    /// <param name="services">existing services collection</param>
    public static void AddTerminalViewModelFactory(this IServiceCollection services)
    {
        // add all implementations to the services collection
        services.AddTransient<ITerminalViewModel, SendReceiveViewModel>();
        // TODO extend

        // add a function to the services collection, which is used by the TerminalViewModelFactory
        // to get a list of all registered implementations of ITerminalViewModel
        services.AddSingleton<Func<IEnumerable<ITerminalViewModel>>>(x => () => x.GetService<IEnumerable<ITerminalViewModel>>()!);

        // add the factory itself to the services collection
        services.AddSingleton<ITerminalViewModelFactory, TerminalViewModelFactory>();
    }
}