using ErsatzTV;
using ErsatzTV.Controllers.Api;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Mvc.ApplicationParts;
using Microsoft.AspNetCore.OpenApi;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.FileProviders;
using Microsoft.Extensions.Hosting;
using Microsoft.OpenApi;
using NSubstitute;
using NUnit.Framework;

namespace ErsatzTV.Tests.Support;

/// <summary>
///     Builds the "v1" OpenAPI document in-process from the real <see cref="Startup.ConfigureServices" />
///     registrations, so contract tests validate the document the running app would actually serve —
///     including every registered document/operation/schema transformer — rather than a stale committed
///     <c>wwwroot/openapi/v1.json</c> that is regenerated out-of-band. Mirrors the DI-only bootstrap that
///     <c>ApiControllerSecurityTests</c> uses to inspect <c>MvcOptions</c>.
/// </summary>
public static class GeneratedOpenApiDocument
{
    public static async Task<OpenApiDocument> BuildV1Async()
    {
        var settings = new Dictionary<string, string?>
        {
            ["provider"] = "sqlite",
            ["ConnectionStrings:Data"] = "Data Source=:memory:"
        };

        IConfiguration configuration = new ConfigurationBuilder().AddInMemoryCollection(settings).Build();

        var environment = Substitute.For<IWebHostEnvironment>();
        environment.ApplicationName.Returns("ErsatzTV");
        environment.EnvironmentName.Returns("Development");
        environment.ContentRootPath.Returns(TestContext.CurrentContext.TestDirectory);
        environment.WebRootPath.Returns(TestContext.CurrentContext.TestDirectory);
        environment.ContentRootFileProvider.Returns(new NullFileProvider());
        environment.WebRootFileProvider.Returns(new NullFileProvider());

        var services = new ServiceCollection();

        // The host normally provides these; supply them so the OpenAPI document service and the
        // API-key provider (an operation-transformer dependency) can be constructed.
        services.AddSingleton(configuration);
        services.AddLogging();
        services.AddSingleton(environment);
        services.AddSingleton<IHostEnvironment>(environment);

        new Startup(configuration, environment).ConfigureServices(services);

        // In the running app ErsatzTV is the entry assembly and its controllers are discovered
        // automatically; under the test runner it is not, so register it as an application part.
        ApplicationPartManager? partManager = services
            .FirstOrDefault(d => d.ServiceType == typeof(ApplicationPartManager))?.ImplementationInstance
            as ApplicationPartManager;
        if (partManager is not null &&
            !partManager.ApplicationParts.OfType<AssemblyPart>()
                .Any(p => p.Assembly == typeof(CollectionController).Assembly))
        {
            partManager.ApplicationParts.Add(new AssemblyPart(typeof(CollectionController).Assembly));
        }

        await using ServiceProvider provider = services.BuildServiceProvider();
        IOpenApiDocumentProvider documentProvider = provider.GetRequiredKeyedService<IOpenApiDocumentProvider>("v1");
        return await documentProvider.GetOpenApiDocumentAsync();
    }
}