// Copyright (c) The Geekeey Authors
// SPDX-License-Identifier: EUPL-1.2

using System.Collections;

using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Options;

namespace Geekeey.Request.Dispatcher.Tests;

internal sealed class SearchHandlerInAssemblyTests
{
	[Test]
	public async Task I_can_search_handlers_in_an_assembly()
	{
		var assembly = Roslyn.Compile(options => options.AddFromEmbeddedSource("SearchTopLevelHandler.cs"));

		var services = new ServiceCollection();
		services.AddRequestDispatcher(builder => builder
			.SearchHandlerInAssembly(assembly));
		await using var provider = services.BuildServiceProvider();
		var options = provider.GetRequiredService<IOptions<RequestDispatcherOptions>>().Value;
		var requestType = assembly.GetType("Sample.Ping", throwOnError: true)!;
		var handlerType = assembly.GetType("Sample.PingHandler", throwOnError: true)!;
		var handlerInterface = typeof(IScalarRequestHandler<,>).MakeGenericType(requestType, typeof(string));
		var handlers = GetRequestHandlers(options, handlerInterface, provider).ToArray();

		using var scope = Assert.Multiple();
		await Assert.That(handlers).Count().IsEqualTo(1);
		await Assert.That(handlers.Single()!.GetType()).IsEqualTo(handlerType);
	}

	[Test]
	public async Task I_can_search_handlers_in_an_assembly_with_a_lifetime()
	{
		var assembly = Roslyn.Compile(options => options.AddFromEmbeddedSource("SearchTopLevelHandler.cs"));

		var services = new ServiceCollection();
		services.AddRequestDispatcher(builder => builder
			.SearchHandlerInAssembly(assembly, ServiceLifetime.Singleton));
		var handlerType = assembly.GetType("Sample.PingHandler", throwOnError: true)!;
		var descriptor = services.SingleOrDefault(service => service.ServiceType == handlerType);

		using var scope = Assert.Multiple();
		await Assert.That(descriptor).IsNotNull();
		await Assert.That(descriptor!.Lifetime).IsEqualTo(ServiceLifetime.Singleton);
	}

	[Test]
	public async Task I_can_get_an_exception_when_nested_handlers_are_present()
	{
		var assembly = Roslyn.Compile(options => options.AddFromEmbeddedSource("SearchNestedHandler.cs"));

		var services = new ServiceCollection();
		var builder = services.AddRequestDispatcher();

		await Assert.That(() => builder.SearchHandlerInAssembly(assembly))
			.Throws<InvalidOperationException>().And.HasMessageContaining("Sample.Container+PingHandler");
	}

	private static IEnumerable<object?> GetRequestHandlers(RequestDispatcherOptions options, Type handlerInterface,
		IServiceProvider provider)
	{
		return ((IEnumerable)typeof(RequestDispatcherOptions)
				.GetMethod(nameof(RequestDispatcherOptions.GetRequestHandlers))!
				.MakeGenericMethod(handlerInterface)
				.Invoke(options, [provider])!)
			.Cast<object?>();
	}
}