using System.Net.Http.Json;
using Microsoft.AspNetCore.Mvc.Testing;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Omika.Core.Contracts.Mobile.Languages;

namespace Omika.Tests.Api;

/// <summary>
/// Tests HTTP de l'API dédiée de téléchargement des modèles de langue (ONNX).
/// Accès anonyme : vérifie le manifeste, le streaming de fichier et les 404.
/// </summary>
public class LanguageEndpointsTests : IDisposable
{
    private const string ManifestJson = """
        {
          "packs": [
            {
              "code": "es",
              "libelle": "Espagnol",
              "version": "1.0.0",
              "fichiers": [
                { "sens": "versFrancais", "nomFichier": "encoder.onnx", "tailleOctets": 16, "sha256": "abc" }
              ]
            }
          ]
        }
        """;

    private readonly string _root;
    private readonly WebApplicationFactory<Omika.Langues.Api.Program> _factory;

    public LanguageEndpointsTests()
    {
        _root = CreateRoot();
        Populate(_root);
        _factory = CreateFactory(_root);
    }

    public void Dispose()
    {
        _factory.Dispose();
        Directory.Delete(_root, true);
    }

    [Fact]
    public async Task Langues_Manifest_RetournePacksEtUrls()
    {
        var client = _factory.CreateClient();

        var response = await client.GetAsync("/api/langues");

        Assert.Equal(200, (int)response.StatusCode);
        var manifest = await response.Content.ReadFromJsonAsync<LanguageManifestResponse>();
        Assert.NotNull(manifest);
        var pack = Assert.Single(manifest.Packs);
        Assert.Equal("es", pack.Code);
        Assert.Equal("Espagnol", pack.Libelle);
        var fichier = Assert.Single(pack.Fichiers);
        Assert.Equal("/api/langues/es/versFrancais/encoder.onnx", fichier.Url);
    }

    [Fact]
    public async Task Langues_Fichier_RetourneContenu()
    {
        var client = _factory.CreateClient();

        var response = await client.GetAsync("/api/langues/es/versFrancais/encoder.onnx");

        Assert.Equal(200, (int)response.StatusCode);
        string content = await response.Content.ReadAsStringAsync();
        Assert.Equal("fake-model-bytes", content);
    }

    [Fact]
    public async Task Langues_Fichier_Introuvable_Retourne404()
    {
        var client = _factory.CreateClient();

        var response = await client.GetAsync("/api/langues/es/versFrancais/absent.onnx");

        Assert.Equal(404, (int)response.StatusCode);
    }

    [Fact]
    public async Task Langues_ManifestAbsent_Retourne404()
    {
        string emptyRoot = CreateRoot();
        using var emptyFactory = CreateFactory(emptyRoot);
        try
        {
            var client = emptyFactory.CreateClient();

            var response = await client.GetAsync("/api/langues");

            Assert.Equal(404, (int)response.StatusCode);
        }
        finally
        {
            Directory.Delete(emptyRoot, true);
        }
    }

    // ===== Helpers =====

    private static string CreateRoot()
    {
        string root = Path.Combine(Path.GetTempPath(), "omika-langues-" + Guid.NewGuid().ToString("N"));
        Directory.CreateDirectory(root);
        return root;
    }

    private static void Populate(string root)
    {
        Directory.CreateDirectory(Path.Combine(root, "es", "versFrancais"));
        File.WriteAllText(Path.Combine(root, "manifest.json"), ManifestJson);
        File.WriteAllText(Path.Combine(root, "es", "versFrancais", "encoder.onnx"), "fake-model-bytes");
    }

    private static WebApplicationFactory<Omika.Langues.Api.Program> CreateFactory(string root)
        => new WebApplicationFactory<Omika.Langues.Api.Program>()
            .WithWebHostBuilder(builder =>
            {
                builder.ConfigureServices(services =>
                {
                    var config = new ConfigurationBuilder()
                        .AddInMemoryCollection(new Dictionary<string, string?>
                        {
                            ["Langues:RootPath"] = root,
                            ["Langues:ManifestFileName"] = "manifest.json"
                        })
                        .Build();
                    services.AddSingleton<IConfiguration>(config);
                });
            });
}